The schematic in figur is the circuit of 600W UPS. Stay powered and radio during a power failure. Output frequency – 50 Hz, Power Consumption 600 Watts, the shape of the output signal – sinusoidal, the efficiency – 98%. The device contains an auto power off at the mains, followed by automatic switch-off with the appearance of tension.
Uninterruptible power supply provides output power to 220 watts (load current up to 1A). In the mode switch SB1 12/220 – the battery voltage is applied to a given multivibrator Q3 Q4 50 Hz, which builds up powerful keys Q1, Q6, amplified and fed to transformer T1. With the secondary winding T1 voltage of 220 V and 50 Hz filters L1 C1 C2 goes to the load.
This schematic is simply a basic system of UPS (uninteruptible power supply). The main schematic gives a continuous regulated 5 Volt result with an not regulated 12 Volt supply. Regarding electricity line fail the battery will take control, without any surges within the regulated supply.
These schematic may possibly customized for the purpose of different regulated and even unregulated voltages with the use of different regulators and rechargeable batteries. For a about 15 Volt regulated supply use a couple of twelve Volt electric batteries using series along with a 7815 regulator. There flexibility on this schematic.