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 ...

In the old days every instrument or system had a power supply board with discrete ... Figure 10 Load regulation of the circuits of Figure 1 and Figure 3. As can be seen the simple and small ...

These two circuits provide ripple ... continues operating even as the supply voltage drops to low levels. Fig 2. With the transistors shown in Figure 1, the power-supply rejection holds well ...