Small circuit powered in car

[zunebuggy]

I have a circuit that is powered by a 2032 watch battery. I want to use this circuit in my car, but I don't want to use the watch battery. Does anyone have a circuit schematic that will drop the 12V down to the 3V that the circuit uses?

Thank you.

 

[davenn]

I have a circuit that is powered by a 2032 watch battery. I want to use this circuit in my car, but I don't want to use the watch battery. Does anyone have a circuit schematic that will drop the 12V down to the 3V that the circuit uses?

Thank you.

Look up LM317 datasheet on google

in the data sheet there will be circuit examples of how to vary the output of the regulator
all you need to know

cheers
Dave
VK2TDN