Reduce 12V battery to 6V for small circuit. You will love it same us.
The circuit that see this is power supply 6V to 9V (Input 12V) of a calculator. That have preventing something through the circuit in. The part that perform to heal strong a picture uses the integrated circuit op-amp multi-purpose 741 numbers in the character comparator mode.
This is a basic unregulated Dual DC 6V Power Supply circuit. The output includes +6VDC, Ground, and -6VDC terminal. In the circuit below we use easily a little electronics components and so cheap.