TRACK FEED BATTERY CHARGER CHANGEOVER SYSTEM

FIELD OF INVENTION

The present invention relates to a track feed battery charger changeover system. More specifically, the present invention relates to a microcontroller based track feed battery charger changeover circuit to provide safe and reliable breaking of DC battery current using AC relays. The system of the present invention connects automatically to a standby battery charger to track field battery when a primary battery charger fails and automatically reconnects to the primary battery charger when the same is rectified or replaced.

BACKGROUND ART

Many battery powered electrical vehicles and portable electronic devices requires periodic recharging of battery and one must be able to keep the battery at ideal charging conditions. Sometimes, charging may have to be carried out several times in a day. Charging is carried out by connecting the vehicle to a charger or batteries are removed from the vehicle for charging. Battery powered vehicles use battery formed by a battery pack having a plurality of rechargeable secondary batteries. The number of rechargeable batteries in the vehicles is increased to improve the efficiency and charge carrying capacity. Portable telephone, laptops etc. also use rechargeable battery packs for powering. Mainly, in control circuits such as railways electrical control circuits viz., hand signal control circuit, track field changing circuits etc., charging system is provided for uninterrupted power supply.

Some of the prior arts are:

US8319478 disclosed a dual-charger system operable to facilitate charging a battery with energy regulated by two chargers connected in parallel to the battery where one charger operates according to a voltage regulation mode and the other of the two chargers operates according to a current regulation mode.

US20120181983 relates to a charger system for use in a vehicle to charge a vehicle battery includes a first charger and a second charger, for preparing the source energy for use in charging the battery.

US20110133701 provides a dual-mode charger circuit includes a first charge circuit and a second charge circuit connected in parallel between a power source and a battery, to charge the battery under a slow charge mode and a quick charge mode.

Also exists in prior art a battery power pack which uses a central processing unit to control a charger. Further known in prior art is a device for charging one or two batteries provided in an automobile. Often these battery charging operations requires manual involvement of a user. Also known is a charging apparatus having a controller to control the charging and discharging of a secondary battery. Further, existing battery changeover systems are suited to remove the dangerous and time-consuming battery changeover at charging stations. Normally to connect/disconnect DC circuits like battery bulky, expensive DC relays are required to withstand the arcing while making and breaking of relays.

Thus there exists a need for a system that automatically reconnects to a secondary battery when a primary charging fails. Especially, in case of control circuits such as railways electrical control circuits viz., hand signal control circuit, track field changing circuits etc., soon after the primary charger fails, the charging system reconnects automatically to the secondary chargers so that avoids all disadvantages and drastic effects caused by using prior art mentioned charging system. The present invention provides battery charger changeover circuit providing safe and reliable breaking of DC battery current using small, less expensive AC relays.

OBJECTS OF INVNETION

One or more of the problems of the conventional prior art may be overcome by various embodiments of the system and method of the present invention.

It is the primary object of the present invention to provide a microcontroller based track feed battery charger changeover circuit for providing safe and reliable breaking of DC battery current using AC relays.

It is another object of the present invention, wherein the microcontroller based track feed battery charger changeover system connects automatically to a standby battery charger to track and charge field battery when a primary battery charger fails and automatically reconnects to the primary battery charger when the same is rectified or replaced.

It is another object of the present invention, wherein the failure of battery charger is sensed through potential free normally-open 'NO' contact in the battery charger.

It is another object of the present invention, wherein when one of the battery chargers fails input supply to both the battery chargers is disconnected by the microcontroller through the relay contacts and thereby the charging current of the battery becomes zero.

It is another object of the present invention, wherein small, less expensive AC relays are used to make and break the DC battery circuit.

It is another object of the present invention, wherein the making and breaking of the DC battery circuit using relays is enabled by switching the DC battery circuit in OFF load conditions using the microcontroller.

It is another object of the present invention, wherein one of the relays normally closed contacts is used to connect/disconnect both the battery chargers.

SUMMARY OF INVENTION

Thus according to the basic aspect of the present invention, there is provided a track feed power source charger changeover system comprising:

power source; at least two power source chargers; power supply circuit; microcontroller; one or more relay contacts; one or more voltage divider resistor networks; and one or more light emitting diodes (LEDs), wherein the power source chargers are provided with at least three terminals, wherein when one of the power source charger is off, voltage across the resistor of one of the voltage divider resistor network increases, wherein change in the voltage is sensed by the microcontroller which disconnects he failed power source charger from the power source by opening one of the relay contact, wherein the microcontroller closes the other relay contact to charge the power source from the other power source charger, and wherein when the failed power source charger is rectified the change in voltage across the resistor is sensed by the microcontroller which reconnects the rectified power source charger to charge the power source after disconnecting the other power source charger.

It is another aspect of the present invention, wherein the power source is a battery.

It is another aspect of the present invention, wherein the power source is charged by connecting the first terminals of the power source chargers to the power source through the respective relay contacts of the power source chargers.

It is another aspect of the present invention, wherein the second terminals of the power source chargers are potential free NO (normally-open) relay contacts for sensing off condition of the power source chargers.

It is another aspect of the present invention, wherein the third terminals of the power source chargers are supply terminals connected through the relay contact for the power source chargers to supply voltage of 110 volts AC.

It is another aspect of the present invention, wherein the second terminals of the power source chargers are connected to the respective voltage divider resistor networks.

It is another aspect of the present invention, wherein the microcontroller is provided with power supply preferably 5 volts DC supply to sense off condition of the power source chargers.

It is another aspect of the present invention, wherein the voltage across the resistor increases from 0 volts to 3.5 volts.

It is another aspect of the present invention, wherein when the other power source charger is off, the change in voltage across the resistor is sensed by the microcontroller which disconnects the failed power source charger from the power source by opening the relay contact.

It is another aspect of the present invention, wherein when the power source charger is off, input supply to the power source chargers is disconnected by the microcontroller through the relay contacts thereby the power source charging current becomes zero.

It is another aspect of the present invention, wherein when the power source charging current becomes zero, AC relay is used for opening the power source circuit.

It is another aspect of the present invention, wherein charging of the power source by the power source chargers are indicated by the LEDs.

It is another aspect of the present invention, wherein the power supply circuit comprising: bridge circuit; one or more capacitors; and voltage regulator, wherein the capacitor provides constant current to charge the capacitor, wherein the bridge circuit consisting of diodes and Zener diodes rectifies 110 volts AC input supply and maintains the supply voltage across the capacitor to 24 volts DC, wherein the relays are provided with power supply of 24 volts, and wherein the voltage regulator converts the 24 volts DC supply to 5 volts DC supply.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURE

Figure 1: illustrates the circuit diagram of the system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING FIGURE

The present invention as herein described relates to a microcontroller based track feed battery charger changeover circuit for providing safe and reliable breaking of DC battery current using AC relays. The system of the present invention connects automatically to a standby battery charger to track field battery when a primary battery charger fails and automatically reconnects to the primary battery charger when the same is rectified or replaced.

Connection and working details:

The track feed battery charger changeover system comprising of power source (23); at least two power source chargers (13 and 14); power supply circuit; microcontroller (20); one or more relay contacts (15, 21 and 22); one or more voltage divider resistor networks (16, 17 and 18, 19); and one or more light emitting diodes (LEDs). The power source is a battery.

Referring to Figure 1, the two battery chargers BC1 (13) and BC2 (14) are provided with three terminals each. First terminals namely BCT1 and BCT2 of BC1 and BC2 respectively are used for charging the battery (23). The BCT1 and BCT2 terminals are connected to the battery (23) through the relay contacts (21) for BC1 and (22) for BC2. Second terminals namely RC1 and RC2 of BC1 and BC2 respectively are potential free NO (normally-open) relay contacts. When the battery charger fails these relay contacts are closed. Failure of battery charger is sensed through these relay contacts. Third terminals are the supply terminals connected through the relay contact (15) for both the battery chargers BC1 and BC2 to supply voltage of 110 volts AC.

The supply voltage of 110 volts AC is converted to stable 24 volts DC by the power supply circuit. The power supply circuit comprises of bridge circuit; one or more capacitors; and voltage regulator (11)0. The capacitor (2) provides constant current to charge the capacitor (10). The bridge circuit consisting of diodes (5and 6) and Zener diodes (7 and 8) rectifies the AC input supply and maintains the supply voltage across capacitor (10) to 24 volts DC. The relays (15, 21 and 22) are provided with power supply of 24 volts. The voltage regulator (11) provided with three terminals converts the 24 volts DC supply to 5 volts DC supply.

The microcontroller (20) is provided with 5 volts DC supply from the regulator (11) to sense the failure of the battery chargers through RC1 and RC2 terminals. RC1 terminal is connected to the voltage divider resistor network (18 and 19). RC2 terminal is connected to the voltage divider resistor network (16 and 17). When the battery charger BC1 (13) is healthy, voltage across the resistor (18) is zero volts. When the battery charger BC1 (13) fails/ is off, the voltage across the resistor (18) increases from 0 to 3.5 volts. The change in voltage is sensed by the microcontroller (20) as failure of the battery charger BC1 (13). Similarly, failure of the battery charger BC2 (14) is sensed through the change in voltage across the resistor (17). The relay (21) normally closed contact is used to connect/disconnect the battery charger BC1 (13) and the relay (22) normally open contact is used to connect/disconnect the battery charger BC2 (14).When the battery charger BC1 (13) fails/is off, the failure is sensed by the microcontroller (20) through the resistor (18) which disconnects the failed battery charger BC1 (13) from the battery (23) by opening the relay contact (21). Simultaneously the microcontroller (20) closes the relay contact (22) to charge the battery from the battery charger BC2 (14). When the battery charger (BC1) is rectified the change in voltage across resistor (18) is sensed by the microcontroller which reconnects the rectified battery charger BC1 (13) to charge the battery (23) after disconnecting the battery charger BC2 (14).

When the battery charger BC1 (13) fails, input supply to both the battery chargers BC1 (13) and BC2 (14) is disconnected by the microcontroller (20) through the relay contacts (15). As input supply is disconnected battery charging current becomes zero. The charging of the battery by the battery chargers are indicated by the LEDs. As there is no battery charging current, normal AC relay can be used for opening the battery circuit. Thereafter, the microcontroller (20) connects the battery charger BC2 (14) to the battery (23) through the relay contact (22). The relay contact (22) is also AC relay as the battery charging current is still zero. The microcontroller (20) connects the supply voltage to both the battery chargers BC1 (13) and BC2 (14) through the relay contact (15). The making and breaking of the DC battery circuit using relays is enabled by switching the DC battery circuit in OFF load conditions using the microcontroller. The present invention thus provides the microcontroller based track feed battery charger changeover system that connects automatically to the standby battery charger to track and charge field battery when the primary battery charger fails and automatically reconnects to the primary battery charger when the same is rectified or replaced. Also, the battery charger changeover circuit ensures safe and reliable breaking of DC battery current using small, less expensive AC relays.

WE CLAIM:

1. A track feed power source charger changeover system comprising: power source (23);

at least two power source chargers (13 and 14);

power supply circuit;

microcontroller (20);

one or more relay contacts (15, 21 and 22);

one or more voltage divider resistor networks (16, 17 and 18, 19); and

one or more light emitting diodes (LEDs),

wherein the power source chargers (13 and 14) are provided with at least three terminals,

wherein when one of the power source charger (13) is off, voltage across the resistor (18) of the voltage divider resistor network increases, wherein change in the voltage is sensed by the microcontroller (20) which disconnects the failed power source charger (13) from the power source (23) by opening the relay contact (21), wherein the microcontroller (20) closes the relay contact (22) to charge the power source (23) from the other power source charger (14), and wherein when the failed power source charger (13) is rectified the change in voltage across the resistor (18) is sensed by the microcontroller (20) which reconnects the rectified power source charger (13) to charge the power source (23) after disconnecting the other power source charger (14).

2. The track feed power source charger changeover system as claimed in claim 1, wherein the power source (23) is a battery.

3. The track feed power source charger changeover system as claimed in claim 1, wherein the power source (23) is charged by connecting the first terminals of the power source chargers (13 and 14) to the power source (23) through the relay contact (21) for the power source charger (13) and the relay contact (22) for the power source charger (14).

4. The track feed power source charger changeover system as claimed in claim 1, wherein the second terminals of the power source chargers (13 and 14) are potential free NO (normally-open) relay contacts for sensing off condition of the power source chargers.

5. The track feed power source charger changeover system as claimed in claim 1, wherein the third terminals of the power source chargers (13 and 14) are supply terminals connected through the relay contact (15) for the power source chargers (13 and 14) to supply voltage of 110 volts AC.
6. The track feed power source charger changeover system as claimed in claim 4, wherein the second terminals of the power source chargers (13 and 14) are connected to the voltage divider resistor networks (18, 19) and (16, 17) respectively.

7. The track feed power source charger changeover system as claimed in claim 1, wherein the microcontroller (20) is provided with power supply preferably 5 volts DC supply to sense off condition of the power source chargers (13 and 14).

8. The track feed power source charger changeover system as claimed in claim 1, wherein the voltage across the resistor (18) increases from 0 volts to 3.5 volts.

9. The track feed power source charger changeover system as claimed in claim 1, wherein when the other power source charger (14) is off, the change in voltage across the resistor (17) is sensed by the microcontroller (20) which disconnects the failed power source charger (14) from the power source (23) by opening the relay contact (22).

10. The track feed power source charger changeover system as claimed in claim 1, wherein when the power source charger (13) is off, input supply to the power source chargers (13 and 14) is disconnected by the microcontroller (20) through the relay contacts (15) thereby the power source charging current becomes zero.

11. The track feed power source charger changeover system as claimed in claim 10, wherein when the power source charging current becomes zero, AC relay is used for opening the power source circuit.

12. The track feed power source charger changeover system as claimed in claim 11, wherein charging of the power source by the power source chargers are indicated by the LEDs.

13. The track feed power source charger changeover system as claimed in claim 1, wherein the power supply circuit comprising: bridge circuit; one or more capacitors; and voltage regulator (11),

wherein the capacitor (2) provides constant current to charge the capacitor (10), wherein the bridge circuit consisting of diodes (5 and 6) and Zener diodes (7 and 8) rectifies 110 volts AC input supply and maintains the supply voltage across the capacitor (10) to 24 volts DC, wherein the relays (15, 21 and 22) are provided with power supply of 24 volts, and wherein the voltage regulator (11) converts the 24 volts DC supply to 5 volts DC supply.