UPS Power Supply

UPS Power Supply circuit can be use for regulated and unregulated voltages with different regulators and batteries. For 15-volt regulated supply tariffs to use two 12 volt batteries in series and the 7815 controller. There are a lot of flexibility in the circuit.

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TR1 has a primary power supply is 240 volts local UK. The secondary winding must be rated at least 12 volts at 2 amps, but may be higher, eg 15 volts. FS1 is a slow type, and protects against short circuits at the end, or even a defective cell in a rechargeable battery. LED 1 lights up only when power is present, with a power failure LED turns off and the output voltage is maintained by the battery. The circuit below simulates a working circuit with mains power applied:

Between terminals VP1 and VP3 nominal unregulated food is available and a source of 5 volt regulated power between VP1 and VP2. The resistance R1 and D1 are the way of battery B1. D1 and D3 avoid LED1 lights in a position to have. The battery is designed for trickle charging, the charging current is defined as follows: -

(VP5 - 0.6) / R1

when VP5 is not regulated DC supply voltage.

D2 is included in the circuit, without the D2 would be free of any voltage battery power, without the current restrictions, which could cause damage and overheating of some rechargeable batteries.