FIELD OF THE INVENTION
The present invention relates to a power supply system for telephone exchange and the
like and in particular to switching modules for such power supply systems of telephone
exchanges. Importantly, the switching modules of the power supply to telephone
exchanges of the invention is directed to avoid shut down of telephone exchanges due to
faults in supply and thereby give better service to the subscribers and also to save the
telephone exchange batteries from being damaged due to problem in power supply to the
unit.
BACKGROUND ART
Telephone exchanges are well known to be run based on DC supply voltages. Usually
such DC voltage is supplied to the exchange by a machine called power plant.
Conventionally every S.M.P.S.(switching mode power supply) type power plant has four
modules wherein two number modules are the running modules while the other two
modules are reserve modules. Such power plants in turn are supplied with AC single
phase for below 1K exchanges and three phases AC supply for 1K and above exchanges.
Output voltage from a power plant is usually 53.5 volts of DC + - 0.5 voltage. These
modules of power plants supply DC voltage to the exchange and also charge the two sets
of batteries, which are installed in parallel. Every set of battery has 24 cells, each cell
voltage is 2 volts i.e. every set is total 48 volts. Usually the exchange batteries are thus
charged to 53.5 volts (+) (-) 0.5 volts.
It would be apparent from the above as to the importance of power plants and its smooth
operation to function the telephone exchange and serve its subscribers. While such may
be the required importance/purpose of power plants in telephone exchanges, however, it
is experienced that very often such power plants become faulty due to variety of reasons
like fluctuation of AC voltage, lightning and other like causes. Therefore for such reasons
when such modules of power plants are in faulty condition it is obviously not possible to
supply DC voltage to the Exchange or to change the battery. In such situation the battery
is require to supply the DC voltage to the Exchange whereby the battery voltage is bound
to gradually decrease since the exchange load is on the battery.
Similarly, in case the A.C. supply to the power plant is not available for a long time the
exchange battery cannot be charged and leads to failure of the Exchange. Again in case of
phase failure it is again very serious because such problem can not be readily detected
and in such situation the modules of the power plant stop functioning and the exchange
battery gradually decreases to finally effect the operation of exchange.
Therefore in such fault situation, when the battery voltage goes down to about 44.4
volts, the telephone exchange usually shuts down. It is observed that in most such cases
power plant i.e. the SMPS modules are required to be restored by manual operation of
expert engineers after shut down of the telephone exchange.
This is observed in verity of telephone exchanges especially those, which are in towns,
villages and the like. It would be clearly apparently from the above that the off and on
shut down of the various telephone exchanges is very much prevalent which necessarily
go to affect the uninterrupted services that the subscribers usually look for in such
emergency services like telephone, power and the like. Moreover apart from the
subscribers discomfort the present day power plants for telephone exchanges are
extremely man dependent and therefore any fault in supply and like usually call for
physical intervention of the service personnel. This is necessarily associated with shut
down and breaks of service to the subscriber of exchangers. Thus in the absence of
effective online rectification of the supply in telephone exchanges due to fault
conditions, it is obvious that the telephone exchanges are exposed to conditions which
can caused permanent or at least temporary damage to the exchangers thereby causing
huge looses in terms of revenue earning reputation of the exchange as a regular and
good service provider.
OBJECT OF THE INVENTION
It is thus the basis object of the invention to provide for a system for power supply to
telephone exchange and the like whereby the telephone exchange/ service provider will
be able to provide better service by way of ensuring no shut down of exchange services.
Another object of the present invention is to provide for a system for power supply to
telephone exchange and the like which would avoid faulty off and on of running
modules of power plant due to associated faults like fluctuation in voltages, AC supply,
faults in running modules lighting etc.
Yet another object of the present invention is to provide for a system for power supply
to telephone exchange and the like involving switching modules adapted to save the
telephone exchange from being shut down and /or damage to the exchange batteries by
automatic operation of S.M.P.S modules of power plant even in situations including (i)
when the running modules of power plant is in fault conditions ; (ii) when Ac supply
voltage is not available for a long time and (iii) in case of any phase failure.
It is another object of the present invention to provide a switching module of power plant
of telephone exchange and the like which enable improvement in communication system
telephone throughout the country and out side.
Yet further object is directed to provide switching module of telephone exchanges and
like which would enable the telephone exchange service provider to save the battery
from being damages by way of preventing off and on shut down of the telephone
exchanges.
Another object of the provide for a system for power supply to telephone exchange and
the like which would enable operating of the exchanges free of shut down problems and
thereby facilitate generating of increased revenue by the service provider.
SUMMARY OF THE INVENTION
Thus according the basis aspect of the present invention there is provided a system for
power supply to telephone exchange comprising:
A power plant adapted to generate required D.C supply to a telephone exchange and to
charge the exchange batteries;
Said power plant comprising atleast four S.M.P.S. Modules wherein two constitute
running modules and the other two constitute reserve modules;
An A.C supply source operatively connected to said power plant;
Means to protect the telephone exchange from unwanted shut-down comprising atleast
one of (i) means to continue supply to the exchange when said running modules of
the power plant are faulty; (ii) means to continue supply to the exchange when the
A.C. supply voltage is not available for a long time; and (iii) means to continue supply
to the exchange when there is any phase failure in the supply line.
In accordance with an aspect of the present invention there is provided a system for
power supply to telephone exchange wherein said means to continue supply to the
exchange when said running modules of the power plant are faulty comprise:
means to monitor the fall in the exchange battery voltage in such situation:
a switching module adapted to put ON the said reserve modules when the exchange
battery voltages falls to a predetermined lower level.
In accordance with another aspect of the present invention there is provided a system for
power supply to telephone exchange wherein said means to continue supply to the
exchange when the A.C. supply voltage is not available for a long time comprises:
means to monitor the fall in the exchange battery voltage in such situation;
a switching module adapted to put ON an engine alternator to supply voltage to the
reserve modules which will charge the exchange battery and when the A.C. supply
voltage is again available to put OFF the engine alternator and the supply to the modules
is restored. It is noted that when the diesel supply to engine alternator will be below the
requirement, the engine alternator will be automatically stopped.
In accordance with yet another aspect of the present invention there is provided a system
for power supply to telephone exchange wherein said means to continue supply to the
exchange when there is any phase failure in the supply line comprise:
means to monitor the fall in the exchange battery voltage in such situation;
a switching module adapted a automatically put ON an engine alternator to supply
\'oltage to the reserve modules which will charge the exchange battery in case of any
phase failure and when the phase failure is rectified and A.C. supply voltage is again
available to automatically put OFF the engine alternator and restore the supply to the
modules.
In accordance with a preferred aspect of the present invention there is provided a system
for power supply to telephone exchange comprising:
a power plant adapted to generate required D.C. supply to a telephone exchange and to
charge the exchange batteries;
said power plant comprising atleast four S.M.P.S modules wherein two constitute
running modules and the other two constitute reserve modules;
an AC supply source operatively connected to said power plant;
means to protect the telephone exchange from unwanted shut down comprising
(i) means to monitor the fall in the exchange battery voltage in such situation;
(ii) a first switching modules adapted to put ON the said reserve modules when
the exchange battery voltages falls to a pre determined lower level due to the
running modules of the power plant being faulty;
(iii) a second switching module adapted to automatically put ON and engine
alternator to supply voltage to the reserve modules which will charge the
exchange battery when the AC supply voltage is not available for a long time
and when AC supply voltage is again available to automatically put OFF the
engine alternator and the supply to the modules is restored; and
(iv) a third switching modules adapted automatically put ON and engine alternator
to supph voltage to the reserve modules which will charge the exchange
battery in case of any phase failure and when phase failure is rectified and
AC supply voltage is again available to automatically put OFF the engine
alternator and restore the supply to the modules;
The above - disclosed system of the invention can comprise display means for
continuously displaying the monitored exchange battery voltage. Such display can be
1,1'D based display system.
It is also possible to include in the system available alarm means to indicate low
exchange battery voltage preferably , the alarm is adapted to be activated when the
exchange battery voltage is 48 volts.
In accordance with another preferred aspect the said switching modules are adapted tro
be activated when the decreasing battery voltage is about 47+/ -1 Volts.
Preferably, the operative connection for said first switching module comprises a display
card and a mother card based operative connection. The operative connection Ibr said
second switching module comprises a main control card based operative connection.
Likewise, the operative connection for said third switching modules comprises a
swathing card based operating connection.
In accordance with yet further aspect the switching module can comprise indicator
means to indicate ON and OFF conditions.
BRIEF DESCRIPTION OF THE ACCOMPANING FIGURES
The details of the invention, its object s and advantages are explained hereunder in
greater detail in relation to non-limiting exemplary embodiments of the system of the
invention as per the accompanying figure wherein:
FIGURE 1 is a schematic representation of the system of the invention involving the
switching modules 1 to 3
FIGURE 2 is an illustration of an embodiment of the switching module 1 involving a
display
card and a mother card operating connection.
I'lGURE 3 is an embodiment of the switching module 2 involving a main
control card
operating connection:
FIGURE 4 is an embodiment of the switching module 3 involving a switching card
operating
connection;
FIGURE 5 is an illustration of the mother card operative connection used in the
system of
invention;
FIGURE 6 is an illustration of the display card operative connection used in the
system of
invention;
FIGURE 7 is an illustration of the main control card operative connection used in the
system of invention;
FIGURE 8 is an iluastration of the switching card operative connection used in the
system
of invention;
FlCiURE 9A is in the illustration of external view of the switching module 1
used in the system.
FIGURE 9B is an illustration of external view of switching module 2 used in the
system
FIGURE 9C is an illustration of external view of the switching module 3 used in the
system of the invention.
FIGURE 10 is an interconnection diagram of A.C. and D.C. cable connection of
switching modules No. SM-l, SM-2 and SM-3.
Preference is first invited to accompanying Figure 1, which shows by way of a schematic
illustration the system of power supply to the telephone exchange in accordance of the
present invention. As illustrated in said Figure, the power plant (PP) is comprised of the
usual four SMPS modules comprising SMPS-1, SMPS-2, SMPS-3 and SMPS-4. As usual
the power plant is adapted to run the telephone exchange by supplying required DC
voltage. Importantly the running modules supply the DC voltage to the exchanges and
also charge the battery, which are, installed in parallel connection. Every set of battery
has 24 cells, each cell voltage is 2 volt i.e. every set provides for total 48 volts.
1 he power plant is thus supposed to supply 53 volt (+) (-) 0.5 volt and is basically the
heart oif every telephone exchange.
As discussed above the system of the present invention is directed to take care of
problems of running modules of power plants which become faulty off and on due to
various reason like fluctuation of AC voltage, lightening and the like. Therefore for such
reason when these modules are in faulty condition, naturally there can not be any stable
supply of DC voltage lo the exchange nor is such supply/source capable of charging the
batteries. In such situation the battery is required to supply DC voltage to the exchange
and the battery gradually decreases due to exchange load being on the battery. In such
case when the battery voltage drops to about 44.4 voltage the telephone exchange is shut
down. It is experienced that apart from problems of discontinuation to service the every
The system of the nivention as illustrated in accompanying Figure 1 is directed to lake
care of the aforediscussed problems of SMPS module based power plants supplying the
telephone exchanges.
In particular the system of the invention includes switching modules (SM-l,SM-2
and SM-3), which are adapted to save the telephone exchange from being
shut down by automatic operation of SMPS module of the power plant in
various fault situations.
Importantly the three switching modules are adapted to take care three different
problem situation viz. situation No.l when the running modules of the power plant is in
faulty condition, situation No. 2 when AC supply voltage will not be available for long
time and situation no. ?> when phase failure takes place.
The system and its operation/adaptability to take care of the above situation involving
the switching modules SM-1, SM-2,and SM-3 is explaineds hereunder in greater detil.
As would be evident from Figure 1 there are as is usual atleast 4 SMPS modules
SMPSM 1, SMPSM2. SMPSM 3 and SMPSM4 in the power plant as shown. Out of
these two modules are running conditions and the other two modules are kept in
reserve. The running modules are adapted to supply the DC voltage to the exchange as
well as change the exchange battery.
Usually if the running modules are in faulty condition it will be able to supply DC volt
to exchange and also not be charge the battery. In such situation the exchange battery
voltage will gradually decrease since the exchange load is on the battery. Thus in effect
when the exchange battery voltage is below 44.4. the exchange is shut down. However,
the switching module provided in the system of the invention ensure that when the
decreasing voltage is about 47 volt, the first switching module (SM-1) automatically
puts on the reserve modules of the power plant (PP) which charge the batteries and also
supply the exchange DC voltage. Thus by use of the switching module (SM-1) the
telephone exchange will be saved from shut down due to lowering of the supply voltage.
fhe working of the switching module (SM-2) also included in the system of the
invention is now explained hereunder:
When AC supply voltage is not available for a long time, which can happen during
critical time of day and night, naturally the power plant will not work and the battery
voltage decreases. 1 lowever, by means of the switching module (SM-2) when the
exchange battery voltage drops to about 47 volt, the engine alternator (EA) is
automatically started which thus enable the reserve module to again charge the
exchange battery to thereby save the exchange from shut down. Again when the AC
supply voltage is a\ailable then the engine alternator (EA) will be automatically
Slopped and the AC supply voltage will automatically supply the module.
In accordance with another aspect the system of the invention is adapted to ensure
avoiding problems during phase failure. It is a very serious problem, since it can not be
detected easily since the total AC supply voltage, is not in off condition. In such
situation usually modules power plant do not work and the exchange battery gets
gradually drained. 1 o prevent such situation usually module power plant do not work
and the exchange batter>- gets gradually drained. To prevent such situation as above the
engine alternator get automatically started and supply the voltage to the reserve module.
After restorations of phase engine alternator get automatically stopped and the .AC supply
voltage then restores supply to the module.
It would be clearly apparent from the above system of the invention how the same is
beneficial to the subscriber as well as to the provider of the service. Importantly since the
shut down is avoided the subscriber gets continued access to use the exchange while the
service provider can be benefited by the increase in revenue generation . Moreover the
system ensure improvement of the communication to telephone exchange.
Reference is now invited to Figure 3 which shows the switching module (SM-3) used
in the system of the in\cntion which involves a main card operative connection is shown
accompanying Figure 7.
Reference is now invited to accompanying Figure 4, which shows that the switching
module (A W-3) includes a switching card (SC). An embodiment of the switching card
(SC) is further illustrated in greater detail in accompanying Figure 8
In Figure 9A. 9B and 9C the external look according to and embodiment of the
switching modules I (SW-1), switching modules 2 (SW-2) and switching modules 3
(SW - 3) arc illustrated.
It is thus possible by way of the present invention to provide for a system for power
supply to telephone exchange and the like whereby the telephone exchange/service
provider will be ble to provide better service by way of ensuring no shut down of the
importantly, the above system of power supply to telephone exchange from being shut
down and/or damage to the exchange batteries by automatic operation of S.M.P.S
modules of power plant even in situations including (i) when the running modules of
power plant is in fault condition; (ii) when A.C. supply voltage is not available for a long
time and (iii) in case of any phase failure.
The system is directed to improvement in communication through telephone throughout
the countr) and outside and enables operating of the exchanges free of shut down
problems and thereby facilitates generating of increased revenue by the service provider.
WE CLAIM:
1. A system for power supply to telephone exchange comprising :
a power plant adapted to generate required D.C. supply to a telephone exchange and to
charge the exchange hatterics;
said power plant comprising at least four S.M.P.S(switching mode power supply)
modules wherein two constitute running modules and the other two constitute reserve
modules;
an AC supply source opcralively connected to said power plant;
an audible niarm menus lo indicate low exchange battery voltage;
means to protect the telephone exchange from unwanted shut down comprising at least
one ol' the (i) means to continue supply to the exchange when said running
modules ol ihe power plant are faulty (ii) means to continue supply to the
exchange when the A.C. supply Voltage is not available for a long time : and (iii)
means to continue supply to the exchange when there is any phase failure in the
supply line .wherein the system operates by establishing operative connections,
for the first switching module comprises a display card and a mother card based
oper.itive connection . the operative connection for second switching module
comprise a displa) card and a mother card based operative connection, third
switching inodule comprise a display card and a mother card based operative
connection.
2. A s\stem for power supply to telephone exchange as claimed in claim 1 wherein
said means to continue supply to the exchange when said running modules of the
power plant are faulty comprises:
mcan^ lo momlor (he fall in the exchange battery voltage in such situation;
a sw itching rnockile adapted to put ON the said reserve modules when the
'jxchange baltcr\ xoltages falls to a predetermined lower level.
}. A sxstem for power supply to telephone exchange as claimed in anyone of the
ckiinis 1 to ': wherein said means to continue supply to the exchange when the
A.( suppK v ollage is not available . for a long time comprises:
Means to monitor the fall in the exchange battery voltage in such situation:
.1 switchinL module adapted to put ON an engine alternator to supply voltage to the
reserve nuKlules wlncli v\ill charge the exchange battery and when the A.C. supply
voltage is ;h',ain axailable lo put Ol'l' the engine alternator and the supply to the modules
is restored
4 A --^ stem for p(nscr supply to telephone exchange as claimed in anyone of claims
I 1.. .1 wher-m said means lo continue supply to the exchange when there is any
pha- e failun In ihe supply line comprises:
Means to iiii)nitor llie fall in the exchange battery voltage in such situation;
1 switchin. mcKiul- adapted to automatically put ON an engine alternator to supply
voltage l( le rese j modules which will charge the exchange battery in case of any
ohase faili _• and \ lieii the phase failure is rectified and A.C. supply voltage is again
available to automatically put OFF the engine alternator and restore the supply to the
modules.
5. A system for power supply to telephone exchange as claimed in anyone of
claims 1 to 4 comprising:
a power plant adapted to generate required D.C. supply to a telephone exchange and to
charge the exchange batteries;
said power plant comprising at least four S.M.P.S modules wherein two constitute
running modules and the other two constitute reserve modules;
an AC supply source operatively connected to said power plant;
means to protect the telephone exchange from unwanted shut down comprising
(i) means to monitor the fall in the exchange battery voltage in such situation;
(ii) a first switching modules adapted to put ON the said reserve modules when
the exchange battery voltages falls to a pre determined lower level due to the
running modules of the power plant being faulty;
(iii) a second switching module adapted to automatically put ON an engine
alternator to
supply voltage to the reserve modules which will charge the exchange battery
when the AC supply voltage is not available for a long time and when AC
supply voltage is again available to automatically put OFF the engine
alternator and the supply to the modules is restored; and
(iv) a third switching modules adapted to automatically put ON an engine
alternator to supply voltage to the reserve modules which will charge the
exchange battery in case of any phase failure and when phase failure is
rectified and AC supply voltage is again available to automatically put OFF
the engine alternator and restore the supply to the modules;
6. A system for power supply to telephone exchange as claimed in anyone of claims
] to 4
comprising display means preferably LED based display system for continuously
displaying the monitored exchange battery voltage.
7. A system for power supply to telephone exchange as claimed in claim 1 wherein
the alarm is adapted to be activated when the exchange battery voltage is 48
Volts.
8. A system for power supply to telephone exchange as claimed in anyone of
claims 1 to 7 wherein said switching modules are adapted to be activated when
the decreasing exchange battery voltage is about 47+/-1 Volts.
9. A system for power supply to telephone exchange as claimed in any one of the
claims 1 to 13 wherein the switching module comprises indicator means to
indicate On and OFF conditions.
10. A system for power supply to telephone exchange substantially as herein
described and illustrated with reference to the accompanying figures.

Thus according the basis aspect of the present invention there is provided a system for
power supply to telephone exchange comprising:
A power plant adapted to generate required D.C supply to a telephone exchange and to
charge the exchange batteries;
Said power plant comprising atleast four S.M.P.S. Modules wherein two constitute
running modules and the other two constitute reserve modules;
An A.C supply source operatively connected to said power plant;