6 to 12 Volt Power Supply Inverter

This inverter circuit can provide up to 800mA of 12V power from a 6V supply. For example, you could run 12V car accessories in a 6V (British?) car. The circuit is simple, about 75% efficient and quite useful. By changing just a few components, you can also modify it for different voltages.

Part List:

R1, R4 2.2K 1/4W Resistor

R2, R3 4.7K 1/4W Resistor

R5 1K 1/4W Resistor

R6 1.5K 1/4W Resistor

R7 33K 1/4W Resistor

R8 10K 1/4W Resistor

C1,C2 0.1uF Ceramic Disc Capacitor

C3 470uF 25V Electrolytic Capcitor

D1 1N914 Diode

D2 1N4004 Diode

D3 12V 400mW Zener Diode

Q1, Q2, Q4 BC547 NPN Transistor

Q3 BD679 NPN Transistor

L1 See Notes

MISC Heatsink For Q3, Binding Posts (For Input/Output), Wire, Board

source:LINK