Most breadboards are not equipped with a power supply circuit. Every electronic enthusiast uses a breadboard since they are a fundamental tool to develop in a fast and easy way. Some problems arise when we need to work with devices not powered from the USB port or that need other supply voltages than 5V, so I decided to add a simple power supply to my large breadboard.
I’m using an external hard disk 12Vdc wall adapter in conjunction with my board so that I have always available these outputs:
- 12Vdc – the same as the wall adapter
- 9Vdc
- 5Vdc
- variable voltage
Not bad for a 9cm x 4cm board!
Schematic
The schematic is pretty simple with very low component count
IC1 and IC2 are classic LM78** fixed voltage family IC used quite everywhere, instead IC3 is an LM317 variable voltage regulator, also this one quite common. I’ve inserted an ON-OFF switch and a protection fuse to manage the function and some LEDs to monitor the output.
There is the PCB drawing ready to be printed out: BB_SUPPLY
Component placement
I hope you’ve enjoyed this project, and please share it!