Here are 4 simple 12V power supply circuits with output voltages around 12V. First power supply circuit is built with BD139, one zener diode and a few passive components. Each of the schematic is very ...

Sometimes you want to have specific modules in your lab that are not available off the shelf — a compact DC dimmer/regulator ... See the simplified schematic: Dimming a 12-V (0.72-W) LED sign module ...