Technical Field
[0001]
The present disclosure relates to a current limiting circuit, a DC power
10 supply connector, and a DC power source device.
Background Art
[0002]
In either DC power feeding or AC power feeding, an arc discharge occurs at
15 power off. In the case of AC, since there is an instant at which the voltage becomes
zero at every predetermined time (for example, every 10 milliseconds), the arc
discharge stops spontaneously at least within the above-described predetermined
time (for example, within 10 milliseconds). In DC power feeding, however, the arc
discharge does not stop spontaneously since there is no instant at which the voltage
20 becomes zero.
25
30
[0003]
Therefore, technologies for the purpose of suppressing occurrence of an arc
discharge at power off in the case of DC power feeding have been disclosed (see
Patent Literature I, Patent Literature 2 and the like).
Patent Literature
[0004]
Patent Literature 1 :
Patent Literature 2:
Citation List
JP 2003-203721A
JP 2014-522088T
Technical Problem
[0005]
2/53
Disclosure oflnvention
SP362655WOOO
Occurrence of an arc discharge should certainly be suppressed at power off
5 in the case of DC power feeding, while it is unpreferable that a configuration for
suppressing occurrence of an arc discharge be increased in scale. It is also
unpreferable that the addition of the configuration for suppressing occurrence of an
arc discharge reduces power supply efficiency during DC power feeding. It is
therefore desirable to suppress occurrence of an arc discharge at DC power off with a
10 small-scale configuration without reducing power efficiency during DC power
supply.
[0006]
Therefore, the present disclosure proposes a current limiting circuit, a DC
power supply connector, and a DC power source device being novel and improved
15 that can suppress occurrence of an arc discharge at DC power off with a small-scale
configuration without reducing power efficiency during DC power supply.
20
Solution to Problem
[0007]
According to the present disclosure, there is provided a current limiting
circuit configured to: before release of a touch between a second contact provided at
a position where a terminal on a power receiving side in which a current flows at
supply of DC power in an electrode that supplies the DC power touches before
touching a first contact provided for the electrode at supply of the DC power and the
25 terminal, decrease the current flowing into the terminal through the second contact;
30
and avoid flowing a current in a case where the terminal is touching the first contact,
and decrease the current flowing into the terminal through the second contact only in
a case where the terminal is touching the second contact.
[0008]
In addition, according to the present disclosure, there is provided a DC
power supply connector at least including: a positive-electrode-side electrode and a
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negative-electrode-side electrode configured to supply DC power. At least any of
the positive-electrode-side electrode and the negative-electrode-side electrode
includes a first contact, a second contact provided at a position where a terminal on a
power receiving side in which a DC current flows at supply of the DC power touches
5 before touching the first contact, and a current limiting circuit configured to decrease
the current flowing into the terminal through the second contact before release of a
touch between the terminal and the second contact. The current limiting circuit
does not flow a current in a case where the terminal is touching the first contact, and
the current limiting circuit decreases the current flowing into the terminal through the
10 second contact only in a case where the terminal is touching the second contact.
[0009]
In addition, according to the present disclosure, there is provided a DC
power source device at least including: a DC power source configured to supply DC
power; and a positive-electrode-side electrode and a negative-electrode-side
15 electrode configured to supply the DC power from the DC power source. At least
any of the positive-electrode-side electrode and the negative-electrode-side electrode
includes a first contact, a second contact provided at a position where a terminal on a
power receiving side in which a DC current flows at supply of the DC power touches
before touching the first contact, and a current limiting circuit configured to decrease
20 the current flowing into the terminal through the second contact before release of a
touch between the terminal and the second contact. The current limiting circuit
does not flow a current in a case where the terminal is touching the first contact, and
the current limiting circuit decreases the current flowing into the terminal through the
second contact only in a case where the terminal is touching the second contact.
25
Advantageous Effects of Invention
[0010]
According to the present disclosure as described above, there can be
provided a current limiting circuit, a DC power supply connector, and a DC power
30 source device being novel and improved that can suppress occurrence of an arc
discharge at DC power off with a small-scale configuration without reducing power
efficiency during DC power supply.
[00 11]
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SP362655WOOO
Note that the effects described above are not necessarily limitative. With
or in the place of the above effects, there may be achieved any one of the effects
5 described in this specification or other effects that may be grasped from this
specification.
Brief Description of Drawings
[0012]
[FIG. 1] FIG. 1 is an explanatory diagram showing an exemplary configuration of a
10 DC power supply system according to an embodiment of the present disclosure.
[FIG. 2] FIG. 2 is an explanatory diagram showing an exemplary configuration of a
DC power source device 100.
[FIG. 3] FIG. 3 is an explanatory diagram showing a specific exemplary
configuration of the DC power source device 100.
15 [FIG. 4] FIG. 4 is an explanatory diagram showing a state where a plug 11 has been
inserted in a plug receiver 20.
[FIG. 5] FIG. 5 is an explanatory diagram showing a state where the plug 11 is being
removed from the plug receiver 20.
[FIG. 6] FIG. 6 is an explanatory diagram schematically showing a state where the
20 plug 11 has been inserted in the DC power source device 100.
[FIG. 7] FIG. 7 is an explanatory diagram showing voltage changes of an end-to-end
voltage V1 of a current limiting circuit 30 and voltage changes of a voltage V2
applied to a load 10 in relation to the place where the plug 11 is inserted.
[FIG. 8] FIG. 8 is an explanatory diagram showing a variation of the DC power
25 source device 100.
[FIG. 9] FIG. 9 is an explanatory diagram showing a variation of the DC power
source device 100.
[FIG. 10] FIG. 10 is an explanatory diagram showing an exemplary configuration in a
case where a plurality of plug receivers 20 exist in the DC power source device I 00.
30 [FIG. II] FIG. 11 is an explanatory diagram showing an exemplary configuration in a
case of connecting two DC power source devices 1 OOa and 1 OOb.
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[FIG. 12] FIG. 12 is an explanatory diagram showing an exemplary configuration of
the DC power source device I 00 according to an embodiment of the present
disclosure.
[FIG. 13] FIG. 13 is an explanatory diagram showing an exemplary configuration of
5 the DC power source device 100 according to an embodiment of the present
disclosure.
[FIG. 14] FIG. 14 is an explanatory diagram showing an exemplary configuration of
the DC power source device 100 according to an embodiment of the present
disclosure.
10 [FIG. 15] FIG. 15 is an explanatory diagram showing an exemplary configuration of
the DC power source device I 00 according to an embodiment of the present
disclosure.
[FIG. 16] FIG. 16 is an explanatory diagram showing an exemplary configuration of
the DC power source device I 00 according to an embodiment of the present
15 disclosure.
[FIG. 17] FIG. 17 is an explanatory diagram showing an exemplary configuration of
the DC power source device I 00 according to an embodiment of the present
disclosure.
[FIG. 18] FIG. 18 is an explanatory diagram showing exemplary transitions of
20 currents and voltages in the exemplary configuration of the DC power source device
I 00 shown in FIG. 17.
[FIG. 19] FIG. 19 is an explanatory diagram showing an exemplary configuration of
the DC power source device 100 according to an embodiment of the present
disclosure.
25 [FIG. 20] FIG. 20 is an explanatory diagram showing an exemplary configuration of
the DC power source device I 00 according to an embodiment of the present
disclosure.
[FIG. 21] FIG. 21 is an explanatory diagram showing an exemplary configuration of
the DC power source device 100 according to an embodiment of the present
30 disclosure.
[FIG. 22] FIG. 22 is an explanatory diagram showing voltage changes of the end-toSP362655WOOO
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end voltage Vl of the current limiting circuit 30 and voltage changes of the voltage
V2 applied to the load 10 in relation to the place where the plug 11 is inserted.
[FIG. 23] FIG. 23 is an explanatory diagram showing an exemplary functional
configuration of an electric driven member provided with the current limiting circuit
5 30 according to an embodiment of the present disclosure.
Mode(s) for Carrying Out the Invention
[0013]
Hereinafter, (a) preferred embodiment(s) of the present disclosure will be
10 described in detail with reference to the appended drawings. In this specification
and the appended drawings, structural elements that have substantially the same
function and structure are denoted with the same reference numerals, and repeated
explanation of these structural elements is omitted.
15
[0014]
Note that description will be provided in the following order.
1. Embodiment of the present disclosure
1.1. Background
1.2. Exemplary configuration
2. Conclusion
20 [0015]
<1. Embodiment of the present disclosure>
[ 1.1. Background]
Before describing an embodiment of the present disclosure in detail, the
background of the embodiment of the present disclosure will be described first.
25 [0016]
In either DC power feeding or AC power feeding, a spark or an arc
discharge due to a potential difference between electrodes occurs at power off when a
voltage and a current reach certain predetermined values or higher. In the case of
AC, since there is an instant at which the voltage becomes zero at every
30 predetermined time (for example, every 10 milliseconds), the arc discharge stops
spontaneously at least within the above-described predetermined time (for example,
within 10 milliseconds).
[0017]
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SP362655WOOO
In DC power feeding, however, the arc discharge does not stop
spontaneously since there is no instant at which the voltage becomes zero unlike AC
5 power feeding. The arc discharge may cause degradation of contacts, such as metal
fusing or welding, and may reduce reliability of power feeding.
[0018]
Therefore, technologies for the purpose of suppressing occurrence of an arc
discharge at power off in the case of DC power feeding have been disclosed. For
10 example, an avoidance technology by connecting a snubber circuit, in which a
capacitor and a resistor are used, between oscillating contact elements has been
conventionally proposed.
[0019]
In order to prevent an arc discharge using the snubber circuit in the case of
15 DC power feeding, however, sufficient effects will not be obtained unless a largecapacity
capacitor and a small resistor are used. For obtaining sufficient effects, the
snubber circuit will be increased in size. Moreover, in the case of preventing an arc
discharge using the snubber circuit, a short-circuit current due to charges charged in
the large-capacity capacitor will be increased if an attempt is made to make
20 reconnection to a DC power source after DC power off, so that contacts will be
welded.
[0020]
Furthermore, m a case of performing DC power feeding by
inserting/removing an insertion plug in/from a plug receiver, there is also a
25 technology for providing the insertion plug with a mechanical switch to prevent
occurrence of an arc discharge, and operating the mechanical switch when removing
the insertion plug from the plug receiver, thereby preventing occurrence of an arc
discharge. However, this technology raises the need to force a user to perform a
complicated operation of operating the mechanical switch at removal of the insertion
30 plug.
[0021]
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There is also a method of mechanically removing an arc discharge. In
order to mechanically remove an arc discharge, however, a structure is required
which increases the speed of detaching contacts or detaches arcs by a magnetic
circuit, resulting in size increase of a circuit for removing an arc discharge.
5 [0022]
10
15
20
The technologies for the purpose of suppressing occurrence of an arc
discharge at power off in the case of DC power feeding are found additionally in the
above-mentioned Patent Literature 1, Patent Literature 2 and the like.
[0023]
The above-mentioned Patent Literature I discloses a technology for
providing a switching element on a path along which a current flows during DC
power feeding, and turning off the switching element at removal of the insertion plug
trom the plug receiver, thereby suppressing occurrence of an arc discharge.
[0024]
According to the technology disclosed in the Patent Literature 1, however,
power is consumed in the switching element during DC power feeding and the
switching element generates heat during DC power feeding since a current flows
through the switching element during DC power feeding.
[0025]
The above-mentioned Patent Literature 2 also discloses a technology for
providing an arc absorbing circuit including switching elements on a path along
which a current flows during DC power feeding, and turning off the switching
elements at removal of the insertion plug from the plug receiver, thereby suppressing
occurrence of an arc discharge.
25 [0026]
According to the technology disclosed in the Patent Literature 2, however,
two switching elements as the arc absorbing circuit and a timer for turning off the
switching element are provided, which requires a circuit for temporarily storing arc
power and discharging the stored power, resulting in size increase of the circuit.
30 [0027]
In consideration of the above-described background, the discloser of the
SP362655WOOO
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present application has therefore conducted intense study on a technology capable of
suppressing occurrence of an arc discharge with a small-scale configuration at DC
power off without reducing power efficiency during DC power supply. As a result,
the discloser of the present application has devised a technology capable of
5 suppressing occurrence of an arc discharge with a small-scale configuration at DC
power off without reducing power efficiency during DC power supply by providing a
positive-electrode-side electrode with two contacts and, when switching contacts
with a power-receiving-side electrode, suppressing a voltage generated between the
electrodes at DC power off, as will be described below.
10 [0028]
The background of the embodiment of the .present disclosure has been
described above. Next, an embodiment of the present disclosure will be described
in detail.
[0029]
15 [1.2. Exemplary configuration]
First, an exemplary configuration of a DC power supply system according
to an embodiment of the present disclosure will be described. FIG. I is an
explanatory diagram showing an exemplary configuration of a DC power supply
system according to an embodiment of the present disclosure. Hereinbelow, the
20 exemplary configuration of the DC power supply system according to an
embodiment of the present disclosure will be described using FIG. I.
[0030]
FIG. I shows an exemplary configuration of a DC power supply system I
including a DC power source device 100 that feeds DC power and a load 10 that
25 receives DC power from the DC power source device 100. The DC power source
device 100 is a power source device that feeds DC power, and for example, may be a
device that includes a storage battery in the inside to feed DC power to the load 10,
or may be a device that feeds power generated by sunlight, wind power, geothermal
heat, biomass, or another type of natural energy to the load 10 as DC power.
30 [0031]
When the load 10 receives feeding of DC power from the DC power source
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device 100, a plug 11 is inserted in the plug receiver 20. Then, when stopping
feeding of DC power from the DC power source device I 00, the plug 11 is removed
from the plug receiver 20. Failure in considering suppression of an arc discharge
leads to damage or the like to the plug II or the plug receiver 20 as described above
5 when the plug II is removed from the plug receiver 20.
[0032]
Therefore, in the present embodiment, the DC power source device I 00
includes a current limiting circuit for suppressing a current flowing from the DC
power source device 100 to the load I 0 when the plug 11 is removed from the plug
10 receiver 20 in order to suppress an arc discharge when the plug 11 is removed from
the plug receiver 20.
[0033]
The DC power source device 100 is configured such that no current flows in
the current limiting circuit provided for the DC power source device 100 when the
15 plug 11 is completely inserted in the plug receiver 20 and while DC power is fed
from the DC power source device 100 to the load 10. Moreover, when the plug 11
is removed from the plug receiver 20, the current limiting circuit functions for the
current flowing from the DC power source device 100 to the load 1 0 to decrease
while flowing the current from the DC power source device I 00 to the load I 0
20 through the current limiting circuit.
[0034]
In the present embodiment, occurrence of an arc discharge can be
suppressed at DC power off without reducing power efficiency during DC power
supply by providing the DC power source device 100 with the current limiting circuit
25 as described above. Moreover, since the current limiting circuit according to the
present embodiment can be a small-scale circuit as will be described later,
occurrence of an arc discharge can be suppressed at DC power off without increasing
the circuit scale.
30
[0035]
FIG. 2 is an explanatory diagram showing an exemplary configuration of the
DC power source device I 00. As shown in FIG. 2, the DC power source device 100
SP362655WOOO
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includes a current limiting circuit 30. Moreover, the plug receiver 20 included in
the DC power source device I 00 has two contact elements 20a, 20b on a positive
electrode side and one contact element 20c on a negative electrode side, respectively.
[0036]
5 The current limiting circuit 30 is a circuit that functions for the current
flowing through the current from the DC power source device 100 to the load I 0 to
decrease to such a degree that an arc discharge does not occur when the plug I I is
completely removed from the plug receiver 20 while flowing the current from the
DC power source device I 00 to the load 10 through the current limiting circuit 30
10 when the plug I I is removed from the plug receiver 20. The current limiting circuit
30 is configured such that no current flows when the plug II is completely inserted
in the plug receiver 20 and while DC power is fed from the DC power source device
I 00 to the load I 0.
15
[0037]
FIG. 3 is an explanatory diagram showing a specific exemplary
configuration of the DC power source device I 00. As shown in FIG. 3, the DC
power source device 100 includes the current limiting circuit 30. Moreover, the
plug receiver 20 included in the DC power source device 100 has the two contact
elements 20a, 20b on the positive electrode side and the one contact element 20c on
20 the negative electrode side, respectively.
[0038]
The plug 11 of the load 10 includes a positive-electrode-side terminal 11a
and a negative-electrode-side terminal II b. FIG. 4 is an explanatory diagram
showing a state where the plug 11 has been inserted in the plug receiver 20. When
25 the plug II is inserted in the plug receiver 20, the positive-electrode-side terminal
!Ia is first connected to the contact element 20b, and after connection to the contact
element 20b, is connected to the contact element 20a as shown in FIG. 4.
[0039]
FIG. 5 is an explanatory diagram showing a state where the plug 11 is being
30 removed from the plug receiver 20. When the plug II is removed from the plug
receiver 20, the positive-electrode-side terminal 11 a in the state connected to the
SP362655WOOO
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contact element 20a is connected to the contact element 20b as shown in FIG 5 along
with the removal, and is thereafter completely removed from the plug receiver 20.
[0040]
In the current limiting circuit 30, no current flows in the state where the plug
5 11 has been completely inserted in the plug receiver 20 and the contact element 20a
and the contact element 20b are short-circuited by the positive-electrode-side
terminal lla, while a current flows in the state where the positive-electrode-side
terminal lla is connected to the contact element 20h. Therefore, since no current
flows in the current limiting circuit 30 in the state where the plug 11 has been
10 completely inserted in the plug receiver 20, the DC power source device l 00 can
feed DC power to the load l 0 without reducing power efficiency during DC power
supply.
[0041]
The current limiting circuit 30 includes a MOSFET Tl, a capacitor CJ, a
15 resistor R1, and a diode OJ. The current limiting circuit 30 functions as a voltage
integrating circuit.
[0042]
In the present embodiment, an n-type metal oxide semiconductor field effect
transistor (MOSFET) is used for the MOSFET T1, and is provided on a path along
20 which a current flows from the DC power source device l 00 to the load 10 in the
state where the positive-electrode-side terminallla of the plug 1 l is connected to the
contact element 20b of the plug receiver 20. The capacitor C l is provided between
a drain terminal and a gate terminal ofthe MOSFET Tl. Moreover, the resistor Rl
is provided between the gate terminal and a source terminal of the MOSFET TJ.
25 Furthermore, the capacitor Cl and the resistor R1 are connected in series.
[0043]
The function of the current limiting circuit 30 will be described also using
FIG. 6 and FIG. 7 together. FIG. 6 is an explanatory diagram schematically showing
laterally a state where the load l 0 including the plug 11 has been inserted in the plug
30 receiver 20 of the DC power source device 100. FIG. 6 shows a state where the
positive-electrode-side terminal 11 a is touching both of the contact element 20a and
5
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the contact element 20b. Moreover, FIG. 6 is an explanatory diagram showing
exemplary transitions of currents and voltage when removing from the plug II from
the plug receiver 20.
[0044]
As described above, in the state where the plug 11 has been completely
inserted in the plug receiver 20 and the positive-electrode-side terminal II a touches
both of the contact element 20a and the contact element 20b to short-circuit the
contact element 20a and the contact element 20b, no current flows in the current
limiting circuit 30. When the plug II is started being removed from the plug
10 receiver 20, the both ends of the current limiting circuit 30 are short-circuited by the
positive-electrode-side terminal II a, and thus, the MOSFET T1 is also in the off state.
[0045]
Thereafter, the plug 11 is further removed continuously from the plug
receiver 20, and when the positive-electrode-side terminal II a no longer touches the
15 contact element 20a at a position X I and only touches the contact element 20b,
current concentration occurs at a part of a touch point between the positive-electrodeside
terminal II a and the contact element 20a, and a voltage due to the current
concentration is generated between the contact element 20a and the contact element
20b.
20 [0046]
The voltage generated between the contact element 20a and the contact
element 20b induces the gate voltage of the MOSFET T1 via the capacitor C 1 to
bring the MOSFET Tl into the on state. When the MOSFET T1 is brought into the
on state, a current flows in a direction that the voltage between the contact element
25 20a and the contact element 20b drops.
[0047]
With the MOSFET Tl brought into the on state and the current flowing into
the direction that the voltage between the contact element 20a and the contact
element 20b drops, the potential difference between the positive-electrode-side
30 terminal lla and the contact element 20a is reduced. With the potential difference
between the positive-electrode-side terminal lla and the contact element 20a reduced,
SP362655WOOO
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separation of the positive-electrode-side terminal 11a from the contact element 20a
will not lead to occurrence of an arc discharge.
[0048]
The voltage between the drain terminal and the source terminal of the
5 MOSFET Tl falls within voltages along the transfer function in terms of the gate
voltage of the FET. When charging of the capacitor C 1 is advanced by the voltage
generated between the contact element 20a and the contact element 20b after the
positive-electrode-side terminal 11 a is separated from the contact element ~Oa, the
gate voltage of the MOSFET T1 drops, and the MOSFET T1 transitions to the off
10 state, so that the current no longer flows in the MOSFET Tl. Separation of the
positive-electrode-side terminal 11a from the contact element 20b after the MOSFET
T1 transitions to the off state will not lead to occurrence of an arc discharge since no
current flows in tbe MOSFET Tl.
15
[0049]
The diode Dl connected in parallel with the resistor R1 of the current
limiting circuit 30 is provided for discharging charges accumulated in the capacitor
C 1 within a short period of time without passing through the resistor R 1 in the case
where the positive-electrode-side terminal 1la touches both of the contact element
20a and the contact element 20b to short-circuit the contact element 20a and the
20 contact element 20b.
[0050]
With the diode Dl provided in parallel with the resistor Rl in the current
limiting circuit 30, the voltage integrating function of the current limiting circuit 30
can be recovered within a short period of time even if connection between the
25 contact element 20a and the contact element 20b, for example, causes a phenomenon
such as chattering. The resistor R1 supplies a voltage to the gate terminal of the
MOSFET Tl. The time for supplying the voltage is determined in relation to the
product of the capacitance of the capacitor Cl and the resistance value of the resistor
Rl.
30 [0051]
FIG. 7 shows voltage changes of an end-to-end voltage VI of the current
SP362655WOOO
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limiting circuit 30 and voltage changes of a voltage V2 applied to the load 10 in
relation to the place where the plug II is inserted. FIG. 7 also shows current
changes of a current il flowing to the contact element 20a side and a current i2
flowing to the contact element 20b side in relation to the place where the plug 11 is
5 inserted.
[0052]
At a position X I where the positive-electrode-side terminal II a is separated
from the contact element 20a, the end-to-end voltage VI of the current limiting
circuit 30 remains at a constant voltage, and as removal of the plug 11 progresses, the
10 end-to-end voltage VI rises gradually, while the voltage V2 applied to the load I 0
drops gradually.
[0053]
Moreover, at the position XI where the positive-electrode-side tenninal II a
is separated from the contact element 20a, the current i1 flowing to the contact
15 element 20a side drops suddenly to OA, while the current i2 flowing to the contact
element 20b side rises suddenly from OA. With the current i 1 dropping suddenly to
OA and the current i2 rising suddenly from OA, the current limiting circuit 30
suppresses occurrence of a potential difference between the positive-electrode-side
terminal!! a and the contact element 20a.
20 [0054]
Then, at a position X2 where the positive-electrode-side terminal 11 a is
separated from the contact element 20b, the drop in the voltage V2 applied to the
load I 0 and the current i2 has progressed, and there is no condition where current
concentration between the positive-electrode-side terminal II a and the contact
25 element 20b occurs. Therefore, separation of the positive-electrode-side terminal
II a from the wntact element 20b will not lead to occurrence of an arc discharge.
[0055]
Note that, in the above-described example, an n-type MOSFET is used for
the MOSFET Tl, and the current limiting circuit 30 having the voltage integrating
30 function is disposed on the positive electrode side, whilst the present disclosure is not
limited to such an example. A p-type MOSFET may be used, and the current
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limiting circuit 30 having the voltage integrating function may be disposed at the
negative electrode.
[0056]
Moreover, the above-described example has shown the case of DC power
5 feeding in the two-wire system with positive and negative electrodes, whilst the
current limiting circuit 30 having the voltage integrating function may also be
disposed in a case of DC power feeding in a three-wire system with a positive
electrode, neutral and a negative electrode. In the case of DC power feeding in the
three-wire system, occurrence of an arc discharge at removal of the plug can be
10 suppressed by disposing the current limiting circuits 30 at both electrodes of the
positive electrode and the negative electrode.
[0057]
The example in which start and stop of DC power feeding from the DC
power source device I 00 is performed by inserting and removing the plug II has
15 been described, whilst the present disclosure is not limited to such an example. FIG.
8 is an explanatory diagram showing a variation of the DC power source device 100.
Shown in FIG. 8 is an example in which start and stop of DC power feeding from the
DC power source device I 00 is performed by operating a switch 22 including
terminals 22a and 22b.
20 [0058]
The switch 22 shown in FIG. 8 is configured such that the terminals 22a and
22b touch both of the contact elements 2la and 21b when starting DC power feeding
from the DC power source device I 00, and when stopping DC power feeding from
the DC power source device I 00, the terminal 22b is first separated from the contact
25 element 21 b, and after the terminal 22b is separated from the contact element 21 b,
the terminal 22a is separated from the contact element 21a by an elastic force of a
spring or the like.
[0059]
Even in the case where start and stop of DC power feeding from the DC
30 power source device 100 is performed by the switch 22 as shown in FIG. 8,
occurrence of an arc discharge when turning off the switch 22 can be suppressed by
disposing the current limiting circuit 30.
[0060]
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SP362655WOOO
FIG. 9 is an explanatory diagram showing a variation of the DC power
source device 100. Shown in FIG. 9 is an example in which the DC power source
5 device 100 is provided with a DC relay 31 and start and stop of DC power feeding
from the DC power source device 100 is performed by the DC relay 31.
[0061]
In the case where start and stop of DC power feeding from the DC power
source device 100 is performed by the DC relay 31 as in FIG. 9, the MOSFET T1
10 may be turned on at an instant when the capacitor C 1 is charged with charges to flow
an excessive current to the load 10.
[0062]
Therefore, in order to avoid turning on the MOSFET Tl at an instant when
the capacitor Cl is charged with charges to flow an excessive current to the load 10,
15 the current generated by charges charged in the capacitor C 1 is bypassed via a make
contact of the DC relay 31 as shown in FIG. 9. By bypassing the current generated
by charges charged in the capacitor Cl via the make contact of the DC relay 31, a
flow of an excessive current to the load 1 0 can be suppressed.
20
[0063]
FIG. 10 is an explanatory diagram showing an exemplary configuration in a
case where a plurality of plug receivers 20 exist in the DC power source device 100.
Even in the case where the plurality of plug receivers 20 exist in the DC power
source device 100 as shown in FIG. 10, occurrence of an arc discharge at removal of
the plug ll from the plug receiver 20 can be suppressed by one current limiting
25 circuit 30.
[0064]
In the case of connecting DC power source devices that feed DC power to
each other, each of the DC power source devices can also suppress occurrence of an
arc discharge at removal of the plug 11 from the plug receiver 20 by providing each
30 of the DC power source devices with a current limiting circuit. For example, in
such a case of connecting DC power source devices each including a battery to each
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other and charging the battery of one of the DC power source devices with the other
DC power source device, each of the DC power source devices can suppress
occurrence of an arc discharge at removal of the plug II from the plug receiver 20 by
including the current limiting circuit.
5 [0065]
FIG. II is an explanatory diagram showing an exemplary configuration in a
case of connecting two DC power source devices 1 OOa and 1 OOb. The DC power
source device I OOa includes the contact elements 20a, 20b and 20c, and also includes
a positive-electrode-side terminal 11c and a negative-electrode-side terminal 11d of
10 the plug. The DC power source device 1 OOb includes contact elements 20d, 20e
and 20f, and also includes the positive-electrode-side terminal 11a and the negativeelectrode-
side terminal II b of the plug.
[0066]
For example, in the case of connecting the DC power source device 1 OOb to
15 the DC power source device I OOa to receive power supply from the DC power
source device I OOa, the positive-electrode-side terminal !Ia and the negativeelectrode-
side terminal 11 b of the plug are inserted in the DC power source device
I OOa. Then, when stopping power supply in the DC power source device I OOb
from the DC power source device I OOa, the positive-electrode-side terminal 11 a and
20 the negative-electrode-side terminall1b of the plug are removed from the DC power
source device I OOa, and at removal the current limiting circuit 30 functions to
suppress occurrence of an arc discharge between the positive-electrode-side terminal
lla and the contact elements 20a, 20b.
25
[0067]
Similarly, in the case of connecting the DC power source device 1 OOa to the
DC power source device 1 OOb to receive power supply from the DC power source
device I OOb, the positive-electrode-side terminal 11 c and the negative-electrode-side
terminal lid of the plug are inserted in the DC power source device lOOb. Then,
when stopping power supply in the DC power source device 1 OOa from the DC
30 power source device 1 OOb, the positive-electrode-side terminal 11 c and the negativeelectrode-
side terminal 11d of the plug are removed from the DC power source
SP362655WOOO
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device IOOb. When the positive-electrode-side terminal lie and the negativeelectrode-
side terminal II d of the plug are removed from the DC power source
device I OOb, the current limiting circuit 30 functions to suppress occurrence of an arc
discharge between the positive-electrode-side terminal lie and the contact elements
5 20d, 20e.
[0068]
Note that in the case of connecting the two DC power source devices I OOa
and I OOb, it is desirable to prevent current backflow by providing a diode D2 on the
drain electrode side of the MOSFET Tl of the current limiting circuit 30.
10 [0069]
In the case of connecting the DC power source devices I OOa and I OOb each
including a battery to each other as shown in FIG. II and charging the battery of one
of the DC power source devices with the other DC power source device, occurrence
of an arc discharge at removal of the terminals of the plug from the contact elements
15 can be suppressed with the DC power source devices I OOa and 1 OOb provided with
the current limiting circuit 30.
[0070]
The exemplary configuration for suppressing occurrence of an arc discharge
at removal of the plug II from the plug receiver 20 has been described so far ... Next,
20 an exemplary configuration for suppressing occurrence of a spark (thermal arc) at
insertion of the plug II in the plug receiver 20 will be described.
[0071]
FIG. 12 is an explanatory diagram showing an exemplary configuration of
the DC power source device I 00 according to an embodiment of the present
25 disclosure. The DC power source device I 00 shown in FIG. 12 includes a current
limiting circuit 40 for suppressing occurrence of a spark (thermal arc) occurring at
insertion of the plug 1 1 in the plug receiver 20.
[0072]
The current limiting circuit 40 is a circuit for adjusting a current to flow
30 gradually fi·om the DC power source device I 00 to the load I 0 at insertion of the
plug ll in the plug receiver 20, and includes the MOSFET Tl, resistors R2, R3, and
a capacitor C2.
[0073]
20/53
SP362655WOOO
When the plug 1 1 is inserted to a position X3 in FIG. 12, the resistors R2,
R3 and the capacitor C2 form a current integrating circuit. When the plug 11 is
5 inserted to a position X2 in FIG. 12 after the plug 11 is inserted to the position X3 in
FIG. 12, the current integrating circuit formed by the resistors R2, R3 and the
capacitor C2 allows the current to flow gradually from the DC power source device
100 to the load 10.
10
[0074]
Then, when the plug 11 is finally inserted to the position XI in FIG. 12, the
current flown by the current integrating circuit fonned by the resistors R2, R3 and
the capacitor C2 is reduced to reduce the gate voltage ofthe MOSFET Tl, so that the
MOSFET T1 is brought into the off state. With the MOSFET Tl brought into the
off state, a shunt current no longer flows in the current limiting circuit 40, and thus,
15 the DC power source device 100 shown in FIG. 12 can supply power efficiently from
the DC power source device 1 00 to the load 1 0.
[0075]
Therefore, the DC power source device I 00 shown in FIG. 12 can suppress
occurrence of a spark (thermal arc) when the plug II is inserted in the plug receiver
20 20 with the current limiting circuit 40 allowing the current to flow gradually from the
DC power source device 100 to the load 10 when the plug 1 I is inserted in the plug
receiver 20.
[0076]
Here, by combining the current limiting circuit 30 shown in FIG. 3 and the
25 like with the current limiting circuit 40 shown in FIG. 12, occurrence of a spark
(thermal arc) when the plug 11 is inserted in the plug receiver 20 and occurrence of
an arc discharge at removal of the plug 11 from the plug receiver 20 can be
suppressed together. An example of the case where the current limiting circuit 30
shown in FIG. 3 and the like and the current limiting circuit 40 shown in FIG. 12 are
30 combined will be described.
[0077]
SP362655WOOO
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FIG 13 is an explanatory diagram showing an exemplary configuration of
the DC power source device 100 according to an embodiment of the present
disclosure. The DC power source device 100 shown in FIG 13 includes a current
limiting circuit 50 for suppressing occurrence of a spark (thermal arc) when the plug
5 11 is inserted in the plug receiver 20 and occurrence of an arc discharge at removal
of the plug 11 from the plug receiver 20. Moreover, the plug receiver 20 shown in
FIG 13 is provided with two contact elements 20c and 20d on the negative electrode
side as well.
[0078]
10 The current limiting circuit 50 is a circuit in which the current limiting
circuit 30 shown in FIG 3 and the like and the current limiting circuit 40 shown in
FIG 12 are combined. That is, the current limiting circuit 50 is a circuit for
functioning in such a manner that a current flows gradually from the DC power
source device 100 to the load 10 at insertion of the plug 11 in the plug receiver 20,
15 and is also a circuit for functioning in such a manner that the current gradually
decreases from the DC power source device 100 to the load 10 at removal ofthe plug
11 from the plug receiver 20.
[0079]
The current limiting circuit 50 includes the MOSFET Tl, the resistors Rl,
20 R2, R3, the capacitors C1, C2, the diode Dl, and a switch SWl. The switch SWl is
a switch of such a structure that the gate terminal ofthe MOSFET Tl connects to the
resistor R2 at insertion of the plug 11 in the plug receiver 20 and the gate terminal of
the MOSFET Tl connects to the resistor R! at removal of the plug II from the plug
receiver 20.
25 [0080]
When insertion of the plug 11 in the plug receiver 20 is started, the switch
S W 1 performs a switching operation toward connecting the gate terminal of the
MOSFET Tl to the resistor R2 in accordance with a friction force or the like
according to insertion of the plug 11 in the plug receiver 20, and conversely, when
30 removal of the plug 11 from the plug receiver 20 is started, perfonns a switching
operation toward connecting the gate terminal of the MOSFET Tl to the resistor R 1
SP362655WOOO
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in accordance with a friction force or the like according to insertion of the plug II in
the plug receiver 20.
[0081]
With the switch SWI shown in FIG. 13 performing the switching operations
5 as described above, the current limiting circuit 50 functions in such a manner that the
current flows gradually from the DC power source device I 00 to the load I 0 at
insertion of the plug II in the plug receiver 20, and also functions in such a manner
that the current flows gradually from the DC power source device 100 to the load 10
at removal of the plug II from the plug receiver 20.
10 [0082]
Note that, as shown in FIG. 14, the current limiting circuit 50 may be
provided with a resistor R3 for protecting the MOSFET Tl on the gate terminal side,
and may be provided with a Zener diode Dzl also for protecting the MOSFET Tl
between the gate terminal and the source terminal of the MOSFET Tl.
15 [0083]
The example of the case where DC power feeding is performed by the touch
between two terminals and electrodes, that is, the case where the plug 11 of the load
I 0 has two terminals, has been described so far, whilst the present disclosure is not
. .limited to such an example. In a case where DC power feeding is performed by the
20 touch between three or more terminals and electrodes, occurrence of an arc discharge
or a spark (thermal arc) ·can also be suppressed similarly by a current limiting circuit.
That is, the plug of the load 10 and the electrodes of the DC power source device I 00
may have three or more terminals.
25
[0084]
FIG. 15 is an explanatory diagram showing an exemplary configuration of
the DC power source device I 00 according to an embodiment of the present
disclosure. Shown in FIG. 15 is an exemplary configuration of the DC power
source device I 00 that perfmms DC power feeding via three terminals. The DC
power source device 100 shown in FIG. 15 includes electrodes 120a, 120b and 120c
30 in which tetminals Ilia, Ill b and 111 c of the plug are insetied respectively.
[0085]
SP362655WOOO
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When inserting the terminals lila, lllb and lllc of the plug in the
electrodes 120a, 120b and 120c, the terminals lllb and lllc first touch the
electrodes 120b and 120c substantially simultaneously, and after the terminals Ill b
and llic touch the electrodes 120b and 120c substantially simultaneously, the
5 terminal lli a touches the electrode 120a.
[0086]
Then, when removing the terminals llia, Ill b and lilc of the plug from
the electrodes 120a, 120b and 120c, the terminal lila is first separated from the
electrode 120a, and after the terminal lila is separated from the electrode 120a, the
10 te1minals llib and 111c are separated from the electrodes 120b and 120c
substantially simultaneously. Then, with the terminal 111 a separated from the
electrode 120a, the current limiting circuit 30 starts functioning in such a manner that
the current decreases gradually from the DC power source device 100 to the load 10.
15
[0087]
FIG. 16 is an explanatory diagram showing an exemplary configuration of
the DC power source device 100 according to an embodiment of the present
disclosure. Shown in FIG. 16 is an exemplary configuration of the DC power
source device 100 that performs DC power feeding via four terminals. The DC
power source device 100 shown in FIG. 16 includes the electrodes 120a, 120b, 120c,
20 and 120d in which the terminals lila, lllb, 1\lc, and 1lld of the plug are inserted
respectively.
[0088]
When inserting the tenninals llla, 111 b, 111 c, and llld of the plug in the
electrodes 120a, 120b, 120c, and 120d, the terminals 111 b, Ill c and 1li d first touch
25 the electrodes 120b, 120c and 120d substantially simultaneously, and after the
terminals 111b, l.llc and lild touch the electrodes 120b, 120c and 120d
substantially simultaneously, the terminal Ilia touches the electrode 120a. With
the terminal lila touching the electrode 120a sent from the other terminals 111 b,
1llc and 111 d, the current limiting circuit 50 starts functioning in such a manner that
30 the current flows gradually from the DC power source device I 00 to the load I 0.
[0089]
SP362655WOOO
24/53
Then, when removing the terminals lila, lllb, lllc, and llld of the plug
from the electrodes 120a, 120b, 120c and 120d, the terminal lila is first separated
from the electrode 120a, and after the terminal Ill a is separated from the electrode
120a, the terminals 111 b, Ill c and Ill d are separated from the electrodes 120b, 120c
5 and 120d substantially simultaneously. Then, with the terminal lila separated from
the electrode 120a, the cun-ent limiting circuit 50 starts functioning in such a manner
that the cun-ent decreases gradually from the DC power source device I 00 to the load
10.
10
[0090]
As described above, in the case where DC power feeding is performed by
the touch between three or more terminals and electrodes, the DC power source
device 100 can also suppress occun-ence of an arc discharge or a spark (thermal arc)
by the cun-ent limiting circuit similarly to the case where DC power feeding is
performed by tbe touch between two terminals and electrodes.
15 [0091]
FIG. 17 is an explanatory diagram showing an exemplary configuration of
the DC power source device 100 according to an embodiment of the present
disclosure. Shown in FIG. 17 is an exemplary configuration of the DC power
source device 100 in which a single-pole double-throw switch SW2 is used when
20 disconnecting the load 10 from the DC power source device 100. The example
shown in FIG. 17 is characterized in that a b-contact of the single-pole double-throw
switch SW2 is connected to a node between the capacitor C 1 and the resistor R 1 of
the cun-ent limiting circuit 30. Even in the case of using the single-pole doublethrow
switch SW2 when disconnecting the load 10 from the DC power source device
25 100, occun-ence of an arc discharge or a spark (thermal arc) can be suppressed by the
cun-ent limiting circuit 30.
[0092]
FIG. 18 is an explanatory diagram showing exemplary transitions of cun-ents
and voltages in the exemplary configuration of the DC power source device 100
30 shown in FIG. 17.
[0093]
SP362655WOOO
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When a voltage is applied to the DC power source device I 00 in the power
off state where DC power feeding from the DC power source device I 00 to the load
I 0 is not performed, that is, in the state where the single-pole double-throw switch
SW2 is connected to the b-contact, the voltage V2 is applied to the capacitor C 1, and
5 a charging current flows. In a case where the capacitor C 1 has a capacitance of
approximately 0.1 rtF, a microcurrent directly flows in the load I 0, and the MOSFET
Tl remains in the off state. Therefore, a large current does not flow from the DC
power source device I 00 to the load I 0 since the MOSFET Tl is in the off state.
[0094]
10 When the single-pole double-throw switch SW2 is pressed at a point oftime
tl in FIG. 18 to connect a conducting plate to an a-contact, a voltage VO of the DC
power source device I 00 is completely applied to the load I 0. When the voltage
VO and the voltage VI of the load 10 reach an equivalent value, the current limiting
circuit 30 is brought into the short-circuit state. When the current limiting circuit 30
15 is brought into the short-circuit state, charges accumulated in the capacitor C 1 are
discharged rapidly via the diode Dl.
[0095]
When the single-pole double-throw switch SW2 is pressed at a point of time
t2 in FIG. 18 to release the connection between the conducting plate and the a-contact,
20 the voltage V2 which is the drain-source voltage of the MOSFET Tl starts to rise,
and a current i3 flows in the capacitor C I. The flow of the current i3 in the
capacitor Cl produces a voltage in the resistor Rl, and when a gate voltage Vg of the
MOSFET Tl rises to Vg-on, the MOSFET Tl is turned on. When the MOSFET Tl
is turned on, the charging voltage of the capacitor Cl rises gradually, while the
25 current i2 flowing from the DC power source device I 00 to the load 1 0 decreases.
[0096]
When the switching operation of the single-pole double-throw switch SW2
ends, the conducting plate of the single-pole double-throw switch SW2 and the bcontact
are connected at a point of time t3 in FIG. 18. The gate voltage V g of the
30 MOSFET Tl reaches OV, and the current i2 flowing from the DC power source
device 100 to the load I 0 is interrupted.
SP362655WOOO
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[0097]
By the above-described series of operations, the DC power source device
100 shown in FIG. 17 prevents the current limiting circuit 30 from operating when
the voltage VO of the DC power source device I 00 is applied to the load 10 as an
5 initial state. Moreover, when in the off operation of the single-pole double-throw
switch SW2, the DC power source device l 00 shown in FIG 17 can ensure a
distance that an arc discharge does not occur even if the conducting plate is separated
sufficiently from the contact a and is separated even to the contact b, and suspends
the operation of the current limiting circuit 30 to reduce unnecessary power
10 consumption, and reduces heat generation of the MOSFET Tl which is a switching
element.
[0098]
The above-described series of operations similarly apply to the exemplary
configuration shown in FIG. 9 in which the DC power source device 100 is provided
15 with the DC relay 31, and start and stop of DC power feeding from the DC power
source device 100 is performed by the DC relay 31.
[0099]
FIG. 19 is an explanatory diagram showing an exemplary configuration of
the DC power source device 100 according to an embodiment of the present
20 disclosure. Shown in FIG. 19 is an exemplary configuration of the DC power
source device 100 that performs DC power feeding via four terminals. The DC
power source device 100 shown in FIG. 19 includes the electrodes 120a, 120b, 120c
and 120d in which the terminals 111 a, 111 b, 1 11 c, and 11 1 d of the plug are inserted
respectively.
25 [0100]
When inserting the terminals 111 a, 111 b, 111 c, and 111d of the plug in the
electrodes 120a, 120b, 120c, and 120d, the terminals 11 1 b, 111 c and 111 d first touch
the electrodes 120b, 120c and 120d substantially simultaneously, and after the
te1minals 111b, lllc and llld touch the electrodes 120b, 120c and 120d
30 substantially simultaneously, the terminal 111a touches the electrode 120a.
[0101]
SP362655WOOO
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Then, when removing the tenninals Ill a, 111 b, lllc, and Ill d of the plug
from the electrodes 120a, 120b, 120c and 120d, the terminal Ill a is first separated
from the electrode 120a, and after the terminal lila is separated from the electrode
120a, the terminals 111 b, lllc and llld are separated from the electrodes 120b, 120c
5 and 120d substantially simultaneously. Then, with the terminal Ilia separated from
the electrode 120a, the current limiting circuit 30 starts functioning in such a manner
that the current decreases gradually from the DC power source device 100 to the load
10.
10
[0 1 02]
ln the example shown in FIG. 19, the terminals 111 a and lllc of the plug do
not touch the electrodes 120a and 120c simultaneously. The leading position and
the rear end position of the terminals are different between the terminals Ill a and
111 c of the plug, and moreover, the position of the electrodes 120a and 120c is also
located such that the terminals lila and lllc of the plug do not touch the electrodes
15 120a and 120c simultaneously.
[0 1 03]
By providing the terminals lila, lllb, lllc, and llld of the plug and the
electrodes 120a, 120b, 120c and 120d as shown in FIG. 19, occurrence of an arc
discharge or a spark (thermal arc) can also be suppressed by the current limiting
20 circuit 30.
[OJ 04]
FIG. 20 is an explanatory diagram showing an exemplary configuration of
the DC power source device I 00 according to an embodiment of the present
disclosure. Shown in FIG. 20 is an exemplary configuration of the DC power
25 source device I 00 in which a switch SW3 is used when disconnecting the load I 0
from the DC power source device 100. FIG. 20 shows a configuration in which a
conducting plate of the switch SW3 is switched between the contact a and the contact
b by a touch between the terminal !Ia of the plug and the switch SW3. Moreover,
the example shown in FIG. 20 is characterized in that the b-contact of the switch
30 SW3 is connected to a node between the capacitor Cl and the resistor Rl of the
current limiting circuit 30.
SP362655WOOO
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[0 1 05]
When inserting the plug in the DC power source device 100, the contact
element 20a and the contact element 20b touch the terminallla and the terminal llb,
respectively. Moreover, when inserting the plug in the DC power source device 100,
5 the touch between the contact element 20a and the terminal 11 a allows a
microcurrent to flow in the capacitor C1 via the b-contact of the switch SW3, and the
capacitor C 1 is charged.
[0 I 06]
Thereafter, the plug is further inserted in the DC power source device 100,
10 and the conducting plate of the switch SW3 is switched from the contact b to the
contact a by the touch with the terminal 11a. When the conducting plate of the
switch SW3 is switched to the contact a, DC power from the DC power source
device 100 is supplied to the load 10 via the contact a. Moreover, when the
conducting plate of the switch SW3 is switched to the contact a, charges accumulated
15 in the capacitor C1 are discharged rapidly via the diode Dl.
[0107]
When the plug is removed from the DC power source device 100, the
conducting plate of the switch SW3 is first switched from the contact a to the contact
b by releasing the touch with the tenninal 11 b. When the conducting plate of the
20 switch SW3 is disconnected from the contact a, the current limiting circuit 30
operates to bypass the current from the DC power source device 100 to the current
limiting circuit 30, thereby suppressing occurrence of an arc discharge.
[0 1 08]
Then, when the conducting plate of the switch SW3 is connected to the
25 contact b, the gate voltage of the MOSFET Tl. drops to bring the MOSFET Tl into
the off state. With the MOSFET T1 brought into the off state, the current flowing
from the DC power source device 100 to the load 10 becomes zero.
[OJ 09]
FIG. 21 is an explanatory diagram showing an exemplary configuration of
30 the DC power source device 100 according to an embodiment of the present
disclosure. Shown in FIG. 2 J is an exemplary configuration of the DC power
SP362655WOOO
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source device I 00 including the current limiting circuit 30 in which a thermistor I 50
is used instead of the resistor R I .
[0 II 0]
The thennistor I 50 is a negative temperature coefficient (NTC) thermistor
5 whose resistance value is inversely proportional to temperature. The current
limiting circuit 30 shown in FIG. 21 shortens the charging time for the capacitor Cl
using the effect that the thermistor 150 generates heat on its own by the current
flowing into the thermistor 150 which is an NTC thermistor and the resistance value
at room temperature suddenly decreases.
10 [0111]
The current limiting circuit 30 shown in FIG. 21 can shorten the charging
time for the capacitor C I, thereby shortening the operating time of the MOSFET Tl.
Moreover, the current limiting circuit 30 shown in FIG. 21 can shorten the charging
time for the capacitor C I utilizing the changes in resistance caused by self-heating of
15 the thermistor 150 which is an NTC thermistor, and can suppress the arc discharge
condition while reducing heat generation due to power consumption of the MOSFET
Tl irrespective of a difference in source voltage of DC power sources.
[0112]
FIG. 22 is an explanatory diagram showing an example ofvoltage changes
20 of the end-to-end voltage VJ of the current limiting circuit 30 and voltage changes of
the vohage V2 applied to the load I 0 in relation to the place where the plug II is
inserted in the power control device I 00 shown in FIG. 21. Moreover, FIG. 22 also
shows an example of current changes of the current il flowing to the contact element
20a side and the current i2 flowing to the contact element 20b side in relation to the
25 place where the plug II is inserted. Note that the voltages VI, V2 and the currents
i I, i2 in the graph of voltage changes shown in FIG. 7 are indicated in FIG. 22 by
broken lines as pressures VI', V2' and currents i I', i2', respectively.
[0113]
ln the current limiting circuit 30 shown in FIG. 21, the voltages VI, V2 and
30 the currents i I, i2 change as in the graph shown in FIG. 22 through the use of the
thermistor !50 which is an NTC thermistor. The current limiting circuit 30 shown
SP362655WOOO
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in FIG. 21 can shorten the operating time of the MOSFET T1 irrespective of a
difference in source voltage by shortening the charging time for the capacitor C 1 and
can suppress occurrence of an arc discharge while reducing heat generation due to
power consumption of the MOSFET Tl.
5 [0114]
FIG. 22 also shows transitions of consumption power P of the MOSFET Tl
in relation to the place where the plug ll is inserted. With the voltages V1, V2 and
the currents i1, i2 changing as in the graph shown in FIG. 22, the consumption power
P of the MOSFET Tl also changes from P' toP. That is, the current limiting circuit
10 30 shown in FIG. 21 can reduce the amount of power consumption of the MOSFET
T1 through the use of the thermistor 150 which is an NTC thermistor.
[0 115]
Note that although the NTC thermistor is used for the thermistor 150 shown
in FIG. 21, the effect of suppressing occurrence of an arc discharge while reducing
15 heat generation due to power consumption of the MOSFET T1 can also be expected
with a critical temperature resistor (CTR) thermistor in place of the NTC thermistor.
The CTR thermistor is a thermistor whose resistance decreases suddenly when a
certain temperature is exceeded, and the current limiting circuit 30 can also shorten
the charging time for the capacitor C I using the CTR thermistor in place of the NTC
20 thermistor whose resistance value is inversely proportional to temperature.
[0116]
Moreover, by combining a resistor or a positive temperature coefficient
(PTC) thennistor in parallel with the thermistor 150 shown in FIG. 21 which is an
NTC thermistor, variations in integration time depending on the operating
25 environment temperature of the current limiting circuit 30 can also be suppressed.
The PTC thermistor is a thermistor whose resistance rises suddenly when a certain
temperature is exceeded contrarily to the CTR thermistor. By combining the NTC
thennistor and the PTC thermistor in parallel, it is possible to prevent wide variations
from occurring in the resistance value of the thermistors as a whole combined in
30 parallel even if the operating environment temperature of the current limiting circuit
30 varies.
SP362655WOOO
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[0 117]
The current limiting circuit 30 shown in FIG. 21 can shorten the interruption
time of the MOSFET Tl since the integration time is not proportional to voltage
changes of the DC power source. Moreover, when performing DC interruption,
5 even if the voltage of the DC power source becomes twice, consumption power of
the MOSFET Tl will not increase in proportion to that voltage increase, and the DC
limiting circuit 30 shown in FIG. 21 can reduce heat dissipation of the MOSFETTl.
[0 118]
FIG. 23 is an explanatory diagram showing an exemplary functional
10 configuration of a movable body 200 including the current limiting circuit 30. For
example, the movable body 200 may be a movable body powered by gasoline, such
as a gasoline vehicle, or may be a movable body mainly powered by a chargeable
and dischargeable battery, such as an electric vehicle, a hybrid vehicle, or an electric
motorcycle. FIG. 23 shows an example of a case where the movable body 200 is
15 provided with a battery 210 and a drive unit 220 driven by power supplied from the
battery. The drive unit 220 may include, for example, equipment provided for a
vehicle, such as a wiper, a power window, a light, a car navigation system, and an air
conditioner, a device that drives the movable body 200, such as a motor, and the like.
[0119]
20 The movable body 200 shown in FIG. 23 is provided with the current
limiting circuit 30 on the way of a path along which DC power is supplied from the
battery 210 to the drive unit 220. With the current limiting circuit 30 provided on
the path along which DC power is supplied from the battery 210 to the drive unit 220,
the movable body 200 shown in FIG. 23 can suppress occurrence of an arc discharge
25 when temporarily attaching/detaching the battery 210, for example.
[0120]
Note that FIG. 23 shows an example of the movable body 200 provided with
only one current limiting circuit 30, whilst the present disclosure is not limited to
such an example. That is, a plurality of current limiting circuits 30 may be provided
30 on the way of the path along which DC power is supplied. Moreover, not only on
the way of the path along which DC power is supplied from the battery 210 to the
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drive unit 220, the current limiting circuit 30 may also be provided at another place,
for example, on the way of a path when charging the battery 210 with DC power.
With the current limiting circuit 30 provided on the way of the path when charging
the battery 210 with DC power, the movable body 200 can allow the battery 210 to
5 be charged with the DC power safely.
[0121]
<2. Conclusion>
According to an embodiment of the present disclosure as described above,
the DC power source device I 00 is provided which includes the current limiting
10 circuit 30 that can function in the direction that a current flowing from the DC power
source device 100 to the load 10 is gradually reduced when the plug 11 is removed
from the DC power source device 100 while DC power feeding is performed from
the DC power source device 100 to the load 10, and can suppress occurrence of an
arc discharge when the plug I1 is removed from the DC power source device 100.
15 [0122]
No current flows in the current limiting circuit 30 in the state where the plug
II has been completely inserted in the DC power source device I 00. The current
limiting circuit 30 will not consume power while DC power feeding is performed
from the DC power source device 100 to the load I 0 since no current flows in the
20 state where the plug II has been completely inserted in the DC power source device
100, and thus will not reduce power supply efficiency.
[0123]
Then, the current limiting circuit 30 accumulates charges in the capacitor C1
by the current produced by the potential difference generated between the drain and
25 the source of the MOSFET Tl when the plug I1 is removed from the DC power
source device 100, and raises the gate voltage of the MOSFET T1 in accordance with
the accumulation of charges in the capacitor Cl to turn on the MOSFET T1.
[OI24]
With the MOSFET T1 turned on by the accumulation of charges in the
30 capacitor C 1 to flow the current from the DC power source device 100 to the load 10
through the MOSFET Tl, the current limiting circuit 30 can inhibit occurrence of a
5
SP362655WOOO
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potential difference from a contact element which an electrode of the plug II has
been touching so far to suppress occurrence of an arc discharge when the plug II is
removed from the DC power source device 100.
[0125]
The plug II and the plug receiver 20 according to an embodiment of the
present disclosure may be applied to a male connector and a female connector of a
universal serial bns (USB), respectively. In a case where DC power is supplied
from the female connector to the male connector of the USB, occurrence of an arc
discharge when the male connector is removed from the female connector of the
10 USB can be suppressed with the DC limiting circuit 30 according to an embodiment
of the present disclosure provided in an apparatus including a USB port.
[0126]
The preferred embodiment(s) of the present disclosure has/have been
described above with reference to the accompanying drawings, whilst the present
15 disclosure is not limited to the above examples. A person skilled in the art may find
various alterations and modifications within the scope of the appended claims, and it
should be understood that they will naturally come under the technical scope of the
present disclosure.
[0127]
20 Further, the effects described in this specification are merely illustrative or
25
exemplified effects, and are not limitative. That is, with or in the place of the above
effects, the technology according to the present disclosure may achieve other effects
that are clear to those skilled in the art from the description of this specification.
[0 128]
Additionally, the present technology may also be configured as below.
(1)
A current limiting circuit configured to:
before release of a touch between a second contact provided at a position
where a terminal on a power receiving side in which a current flows at supply of DC
30 power in an electrode that supplies the DC power touches before touching a first
contact provided for the electrode at supply of the DC power and the terminal,
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decrease the current flowing into the terminal through the second contact; and
avoid flowing a current in a case where the terminal is touching the first
contact, and decrease the current flowing into the terminal through the second
contact only in a case where the tenninal is touching the second contact.
5 (2)
The current limiting circuit according to (1 ), configured to:
decrease a potential difference between a positive electrode and a negative
electrode of an apparatus that receives the DC power by gradually increasing a
potential difference between the first contact and the second contact to decrease the
10 current flowing between the second contact and the terminaL
(3)
The current limiting circuit according to (2), including:
a switching element configured to be brought into an on state at a time point
when the terminal is no longer connected to the first contact to decrease the current
15 flowing into the terminal through the second contact in a state where the terminal is
connected only to the second contact.
(4)
The current limiting circuit according to (3), including:
a capacitive element configured to start being charged at a time point when
20 the terminal is no longer connected to the first contact to raise a gate voltage of the
switching element in the state where the terminal is connected only to the second
contact.
25
(5)
The current limiting circuit according to ( 4 ), including:
a resistive element configured to set a time for applying a voltage to a gate
terminal of the switching element in conjunction with the capacitive element.
(6)
The current limiting circuit according to (5),
in which the resistive element is an element whose resistance value drops
30 with an increase in temperature.
(7)
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The current limiting circuit according to any of (I) to (6), configured to:
gradually increase the current flowing into the terminal through the second
contact when the terminal touches the second contact before touching the first
contact.
5 (8)
The current limiting circuit according to (7), including:
a switch configured to switch functions between a case where the terminal
touches the second contact before touching the first contact and a case where the
terminal touches the second contact after touching the first contact.
10 (9)
A DC power supply connector at least including:
a positive-electrode-side electrode and a negative-electrode-side electrode
configured to supply DC power,
in which at least any of the positive-electrode-side electrode and the
15 negative-electrode-side electrode includes
20
a first contact,
a second contact provided at a position where a term ina! on a
power receiving side in which a DC current flows at supply ofthe DC power touches
before touching the first contact, and
a current limiting circuit configured to decrease the current flowing
into the terminal through the second contact before release of a touch between the
terminal and the second contact, and
the current limiting circuit does not flow a current in a case where the
terminal is touching the first contact, and the current limiting circuit decreases the
25 current flowing into the terminal through the second contact only in a case where the
terminal is touching the second contact.
(10)
The DC power supply connector according to (9),
in which the current limiting circuit decreases a potential difference between
30 a positive electrode and a negative electrode of an apparatus that receives the DC
power by gradually increasing a potential difference between the first contact and the
5
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second contact to decrease the current flowing between the second contact and the
terminal.
(11)
The DC power supply connector according to (10),
in which the current limiting circuit includes a switching element configured
to be brought into an on state at a time point when the terminal is no longer
connected to the first contact to decrease the current flowing into the terminal
through the second contact in a state where the terminal is connected only to the
second contact.
10 ( 12)
The DC power supply connector according to (II),
in which the current limiting circuit includes a capacitive element
configured to start being charged at a time point when the terminal is no longer
connected to the first contact to raise a gate voltage of the switching element in the
15 state where the terminal is connected only to the second contact.
(13)
The DC power supply connector according to (12),
in which the current limiting circuit includes a resistive element configured
to set a time for applying a voltage to a gate terminal of the switching element in
20 conjunction with the capacitive element.
(14)
The current limiting connector according to (13),
in which the resistive element is an element whose resistance value drops
with an increase in temperature.
25 (15)
The DC power supply connector according to any of(9) to (14),
in which the current limiting circuit gradually increases the current flowing
into the terminal through the second contact when the terminal touches the second
contact before touching the first contact.
30 (16)
The current limiting connector according to (I 5),
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in which the current limiting circuit includes a switch configured to switch
functions between a case where the terminal touches the second contact before
touching the first contact and a case where the terminal touches the second contact
after touching the first contact
5 (17)
10
A DC power source device at least including:
a DC power source configured to supply DC power; and
a positive-electrode-side electrode and a negative-electrode-side electrode
configured to supply the DC power from the DC power source,
in which at least any of the positive-electrode-side electrode and the
negative-electrode-side electrode includes
a first contact,
a second contact provided at a position where a terminal on a
power receiving side in which a DC current flows at supply of the DC power touches
15 before touching the first contact, and
a current limiting circuit configured to decrease the current flowing
into the terminal through the second contact before release of a touch between the
terminal and the second contact, and
the current limiting circuit does not flow a cmTent in a case where the
20 terminal is touching the first contact, and the current limiting circuit decreases the
current flowing into the terminal through the second contact only in a case where the
terminal is touching the second contact.
25
(18)
The DC power source device according to (17),
in which the current limiting circuit decreases a potential difference between
a positive electrode and a negative electrode of an apparatus that receives the DC
power by gradually increasing a potential difference between the first contact and the
second contact to decrease the current flowing between the second contact and the
terminal.
30 (19)
The DC power source device according to (18), including:
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a switching element configured to be brought into an on state at a time point
when the terminal is no longer connected to the first contact to decrease the current
flowing into the terminal through the second contact in a state where the terminal is
connected only to the second contact
5 (20)
The DC power source device according to (19),
in which the current limiting circuit includes a capacitive element
configured to start being charged at a time point when the terminal is no longer
connected to the first contact to raise a gate voltage of the switching element in the
10 state where the terminal is connected only to the second contact.
(21)
The DC power source device according to (20),
in which the current limiting circuit includes a resistive element configured
to set a time for applying a voltage to a gate terminal of the switching element in
15 conjunction with the capacitive element
(22)
The DC power source device according to (21 ),
in which the resistive element is an element whose resistance value drops
with an. increase in temperature.
20 (23)
The DC power source device according to any of (17) to (22),
in which the current limiting circuit gradually increases the current flowing
into the tenninal through the second contact when the terminal touches the second
contact before touching the first contact.
25 (24)
The DC power source device according to (23),
in which the current limiting circuit includes a switch configured to switch
functions between a case where the tenninal touches the second contact before
touching the first contact and a case where the terminal touches the second contact
30 after touching the first contact.
(25)
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A current limiting circuit including:
a switching element configured to be brought into an on state at a time point
when a terminal that receives supply of DC power is no longer connected to a drainside
contact to, in a state where the terminal is connected only to a source-side
5 contact, decrease a current flowing into the terminal through the source-side contact;
10
a capacitive element configured to start being charged at a time point when
the terminal is no longer connected to the drain-side contact to raise a gate voltage of
the switching element in the state where the terminal is connected only to the sourceside
contact; and
a resistive element configured to set a time for applying a voltage to a gate
terminal of the switching element in conjunction with the capacitive element.
(26)
The current limiting circuit according to (25), configured to:
decrease a potential difference between a positive electrode and a negative
15 electrode of an apparatus that receives the DC power by gradually increasing a
potential difference between the drain-side contact and the source-side contact to
decrease the current flowing between the source-side contact and the terminal.
20
(27)
The current limiting circuit according to (25) or (26),
in which the resistive element is an element whose resistance value drops
with an increase in temperature.
(28)
The current limiting circuit according to any of (25) to (27), configured to:
gradually increase the current flowing into the terminal through the source-
25 side contact when the terminal touches the source-side contact before touching the
drain-side contact.
(29)
The current limiting circuit according to (28), including:
a switch configured to switch functions between a case where the terminal
30 touches the source-side contact before touching the drain-side contact and a case
where the terminal touches the source-side contact after touching the drain-side
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contact.
(30)
A movable body including the current limiting circuit according to any of
(I) to (8).
5 (31)
A power supply system including:
a battery configured to supply DC power;
a drive unit configured to be driven by the DC power supplied from the
battery; and
10 at least one current limiting circuit according to claim 1 that is provided
between the battery and the drive unit.
(32)
The power supply system according to (31 ),
in which the power supply system is provided for a movable body.
15 (33)
The power supply system according to (31) or (32),
in which the current limiting circuit decreases a potential difference between
a positive electrode and a negative electrode of an apparatus that receives the DC
power by gradually increasing a potential difference between the first contact and the
20 second contact to decrease the current flowing between the second contact and the
terminal.
(34)
The power supply system according to (33), including:
a switching element configured to be brought into an on state at a time point
25 when the terminal is no longer connected to the first contact to decrease the current
flowing into the terminal through the second contact in a state where the terminal is
connected only to the second contact.

CLAIMS
Claim I
A current limiting circuit configured to:
before release of a touch between a second contact provided at a position
5 where a terminal on a power receiving side in which a current flows at supply of DC
power in an electrode that supplies the DC power touches before touching a first
contact provided for the electrode at supply of the DC power and the terminal,
decrease the current flowing into the terminal through the second contact; and
avoid flowing a current in a case where the tenninal is touching the first
10 contact, and decrease the current flowing into the terminal through the second
contact only in a case where the terminal is touching the second contact.
Claim 2
The current limiting circuit according to claim I, configured to:
15 decrease a potential difference between a positive electrode and a negative
electrode of an apparatus that receives the DC power by gradually increasing a
potential difference between the first contact and the second contact to decrease the
current flowing between the second contact and the terminal.
20 Claim 3
The current limiting circuit according to claim 2, comprising:
a switching element configured to be brought into an on state at a time point
when the terminal is no longer connected to the first contact to decrease the current
flowing into the terminal through the second contact in a state where the term ina! is
25 connected only to the second contact.
Claim 4
The current limiting circuit according to claim 3, comprising:
a capacitive element configured to start being charged at a time point when
30 the terminal is no longer connected to the first contact to raise a gate voltage of the
switching element in the state where the terminal is connected only to the second
5
10
15
20
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contact.
Claim 5
The current limiting circuit according to claim 4, comprising:
a resistive element configured to set a time for applying a voltage to a gate
terminal of the switching element in conjunction with the capacitive element.
Claim 6
The current limiting circuit according to claim 5,
wherein the resistive element is an element whose resistance value drops
with an increase in temperature.
Claim 7
The current limiting circuit according to claim 1, configured to:
gradually increase the current flowing into the terminal through the second
contact when the terminal touches the second contact before touching the first
contact.
Claim 8
The current limiting circuit according to claim 7, comprising:
a switch configured to switch functions between a case where the terminal
touches the second contact before touching the first contact and a case where the
terminal touches the second contact after touching the first contact.
25 Claim 9
A DC power supply connector at least comprising:
a positive-electrode-side electrode and a negative-electrode-side electrode
configured to supply DC power,
wherein at least any of the positive-electrode-side electrode and the
30 negative-electrode-side electrode includes
a first contact,
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a second contact provided at a position where a tenninal on a
power receiving side in which a DC current flows at supply of the DC power touches
before touching the first contact, and
a current limiting circuit configured to decrease the current flowing
5 into the terminal through the second contact before release of a touch between the
tetminal and the second contact, and
the current limiting circuit does not flow a current in a case where the
terrninal is touching the first contact, and the current limiting circuit decreases the
current flowing into the terrninal through the second contact only in a case where the
10 terrninal is touching the second contact.
Claim 10
The DC power supply connector according to claim 9,
wherein the current limiting circuit decreases a potential difference between
15 a positive electrode and a negative electrode of an apparatus that receives the DC
power by gradually increasing a potential difference between the first contact and the
second contact to decrease the current flowing between the second contact and the
terrninal.
20 Claim II
The DC power supply connector according to claim 1 0,
wherein the current limiting circuit includes a switching element configured
to be brought into an on state at a time point when the terrninal is no longer
connected to the first contact to decrease the current flowing into the terminal
25 through the second contact in a state where the terrninal is connected only to the
second contact.
30
Claim 12
The DC power supply connector according to claim 11,
wherein the current limiting circuit includes a capacitive element configured
to start being charged at a time point when the terminal is no longer connected to the
5
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first contact to raise a gate voltage of the switching element in the state where the
terminal is connected only to the second contact.
Claim 13
The DC power supply connector according to claim 12,
wherein the current limiting circuit includes a resistive element configured
to set a time for applying a voltage to a gate terminal of the switching element in
conjunction with the capacitive element.
10 Claim 14
The current limiting connector according to claim 13,
wherein the resistive element is an element whose resistance value drops
with an increase in temperature.
15 Claim 15
20
The DC power supply connector according to claim 9,
wherein the current limiting circuit gradually increases the current flowing
into the terminal through the second contact when the terminal touches the second
contact before touching the first contact.
Claim 16
The current limiting connector according to claim 15,
wherein the current limiting circuit includes a switch configured to switch
functions between a case where the terminal touches the second contact before
25 touching the first contact and a case where the terminal touches the second contact
after touching the first contact.
Claim 17
A DC power source device at least comprising:.
30 a DC power source configured to supply DC power; and
a positive-electrode-side electrode and a negative-electrode-side electrode
5
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configured to supply the DC power from the DC power source,
wherein at least any of the positive-electrode-side electrode and the
negative-electrode-side electrode includes
a first contact,
a second contact provided at a position where a tenninal on a
power receiving side in which a DC current flows at supply of the DC power touches
before touching the first contact, and
a current limiting circuit configured to decrease the current flowing
into the terminal through the second contact before release of a touch between the
10 terminal and the second contact, and
15
the current limiting circuit does not flow a current in a case where the
terminal is touching the first contact, and the current limiting circuit decreases the
current flowing into the terminal through the second contact only in a case where the
terminal is touching the second contact.
Claim 18
The DC power source device according to claim 17,
wherein the current limiting circuit decreases a potential difference between
a positive electrode and a negative electrode of an apparatus that receives the DC
20 power by gradually increasing a potential difference between the first contact and the
second contact to decrease the current flowing between the second contact and the
terminal.
25
30
Claim 19
T11e DC power source device according to claim 18, comprising:
a switching element configured to be brought into an on state at a time point
when the terminal is no longer connected to the first contact to decrease the current
flowing into the terminal through the second contact in a state where the terminal is
connected only to the second contact.
Claim 20
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The DC power source device according to claim 19,
wherein the current limiting circuit includes a capacitive element configured
to start being charged at a time point when the terminal is no longer connected to the
first contact to raise a gate voltage of the switching element in the state where the
5 terminal is connected only to the second contact.
Claim 21
The DC power source device according to claim 20,
wherein the current limiting circuit includes a resistive element configured
10 to set a time for applying a voltage to a gate terminal of the switching element in
conjunction with the capacitive element.
15
20
25
30
Claim 22
The DC power source device according to claim 21,
wherein the resistive element is an element whose resistance value drops
with an increase in temperature.
Claim 23
The DC power source device according to claim 17,
wherein the current limiting circuit gradually increases the current flowing
into the terminal through the second contact when the terminal touches the second
contact before touching the first contact.
Claim 24
The DC power source device according to claim 23,
wherein the current limiting circuit includes a switch configured to switch
functions between a case where the terminal touches the second contact before
touching the first contact and a case where the terminal touches the second contact
after touching the first contact.
Claim 25
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A current limiting circuit comprising:
a switching element configured to be brought into an on state at a time point
when a terminal that receives supply of DC power is no longer connected to a drainside
contact to, in a state where the terminal is connected only to a source-side
5 contact, decrease a current flowing into the terminal through the source-side contact;
10
15
a capacitive element configured to start being charged at a time point when
the terminal is no longer connected to the drain-side contact to raise a gate voltage of
the switching element in the state where the terminal is connected only to the sourceside
contact; and
a resistive element configured to set a time for applying a voltage to a gate
terminal of the switching element in conjunction with the capacitive element.
Claim 26
The current limiting circuit according to claim 25, configured to:
decrease a potential difference between a positive electrode and a negative
electrode of an apparatus that receives the DC power by gradually increasing a
potential difference between the drain-side contact and the source-side contact to
decrease the current flowing between the source-side contact and the terminal.
20 Claim 27
The current limiting circuit according to claim 25,
wherein the resistive element is an element whose resistance value drops
with an increase in temperature.
25 Claim 28
30
The current limiting circuit according to claim 25, configured to:
gradually increase the current flowing into the terminal through the sourceside
contact when the tenninal touches the source-side contact before touching the
drain-side contact.
Claim 29
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The current limiting circuit according to claim 28, comprising:
a switch configured to switch functions between a case where the terminal
touches the source-side contact before touching the drain-side contact and a case
where the terminal touches the source-side contact after touching the drain-side
5 contact.
Claim 30
A movable body comprising the current limiting circuit according to claim 1.
10 Claim 31
A power supply system comprising:
a battery configured to supply DC power;
a drive unit configured to be driven by the DC power supplied from the
battery; and
15 at least one current limiting circuit according to claim 1 that is provided
between the battery and the drive unit.
Claim 32
The power supply system according to claim 31,
20 wherein the power supply system is provided for a movable body.
Claim 33
The power supply system according to claim 31,
wherein the current limiting circuit decreases a potential difference between
25 a positive electrode and a negative electrode of an apparatus that receives the DC
power by gradually increasing a potential difference between the first contact and the
second contact to decrease the current flowing between the second contact and the
terminal.
30 Claim 34
The power supply system according to claim 33, comprising:
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a switching element configured to be brought into an on state at a time point
when the terminal is no longer connected to the first contact to decrease the current
flowing into the terminal through the second contact in a state where the terminal is
connected only to the second contact.
Claim 35
The power supply system according to claim 34,
wherein the current limiting circuit includes a capacitive element configured
to start being charged at a time point when the terminal is no longer connected to the
10 first contact to raise a gate voltage of the switching element in the state where the
terminal is connected only to the second contact.
Claim 36
The power supply system according to claim 35,
15 wherein the current limiting circuit includes a resistive element configured
20
25
to set a time for applying a voltage to a gate terminal of the switching element in
conjunction with the capacitive element.
Claim 37
The power supply system according to claim 36,
wherein the resistive element is an element whose resistance value drops
with an increase in temperature.
Claim 38
The power supply system according to claim 31,
wherein the current limiting circuit gradually increases the current flowing
into the terminal through the second contact when the terminal. touches the second
contact before touching the first contact.
30 Claim 39
The power supply system according to claim 38,
5
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wherein the current limiting circuit includes a switch configured to switch
functions between a case where the terminal touches the second contact before
touching the first contact and a case where the terminal touches the secoud contact
after touching the first contact.