This is the circuit diagram of a simple UPS that can deliver 12V unregulated and 5V regulated DC. The transformer T1 steps down the mains voltage to 12V AC and then the bridge B1 rectifies it. The rectified signal is smoothed by the capacitor C1
Inverter is a device that converts 12 volts dc to 120 volts ac, which is what we use in our homes. This project will handle about 300 watts, which is perfect for lights, small T.V.'s and radio equipment.
This circuit can be primarily used for charging 12V Ni-Cd battery packs. Any way 6V and 9V battery packs can be also charged by using this circuit a little compromise on power efficiency. The built in automatic current regulator regulates the charging current to somewhat 4 amperes. When the charging current reaches 4A, the voltage across resistor R1
Multi-voltage supply circuit is a circuit which provide multiple output DC voltages i.e. 3V, 6V, 9V etc. These circuits are very useful in electronics devices where multiple voltages are required for different section of huge circuit.