Electronical 6V to 12V Converter Circuit Diagram

      This is the Simple Electronically 6V to 12V Converter Circuit Diagram. 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. 

Electronical 6V to 12V Converter Circuit Diagram

Parts

R1, R4           2    2.2K 1/4W Resistor   
R2, R3           2    4.7K 1/4W Resistor   
R5    1            1K 1/4W Resistor   
R6    1            1.5K 1/4W Resistor   
R7    1            33K 1/4W Resistor   
R8    1            10K 1/4W Resistor   
C1,C2            2    0.1uF Ceramic Disc Capacitor   
C3    1            470uF 25V Electrolytic Capcitor   
D1    1            1N914 Diode   
D2    1            1N4004 Diode   
D3    1             2V 400mW Zener Diode   
Q1, Q2, Q4    3    BC547 NPN Transistor   
Q3    1           BD679 NPN Transistor   
L1    1           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.