First choice of Fixed Regulator using family IC-78xx. It is easy to use, cheap, popular for a long time.
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.
The simple 6V Power supply circuit. We have a lot of circuits for you. Some ideas may be good for you. All circuits use normal component, easy making.