6V to 12V Converter

6V to 12V Converter Circuit

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.

PARTS LIST
R1	2.2KΩ 1/4W
R2	4.7KO 1/4W
R3	4.7KO 1/4W
R4	2.2KO 1/4W
R5	1KO 1/4W
R6	1.5KO 1/4W
R7	33KO 1/4W
R8	10KO 1/4W
C1	0.1µF Ceramic Disc Capacitor
C2	0.1µF Ceramic Disc Capacitor
C3	470µF 25V Electrolytic Capacitor
D1	1N914 Diode
D2	1N4004 Diode
D3	12V 400mW Zener Diode
Q1	BC547 NPN Transistor
Q2	BC547 NPN Transistor
Q3	BD679 NPN Transistor
Q4	BC547 NPN Transistor
L1	See Notes
MISC	1 Heatsink For Q3, Binding Posts (For Input/Output), Wire, Board

Notes

* L1 is a custom inductor wound with about 80 turns of 0.5mm magnet wire around a toroidal core with a 40mm outside diameter.
* Different values of D3 can be used to get different output voltages from about 0.6V to around 30V. Note that at higher voltages the circuit might not perform as well and may not produce as much current. You may also need to use a larger C3 for higher voltages and/or higher currents.
* You can use a larger value for C3 to provide better filtering.
* The circuit will require about 2A from the 6V supply to provide the full 800mA at 12V.

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