L7805 Circuit DIY: Adjustable Power Supply Step-down Module

Everyone should be familiar with the 78XX series of three-terminal regulator tubes. These 78XX series regulator tubes can often be seen in the circuit.

The L7805 can output 5V stably. Its pins are input, ground and output from left to right. As far as its parameters are concerned, the minimum input and output voltage difference is 2V; the maximum input voltage is 35V; the maximum output current is 1.5A;

In addition to stabilizing the output voltage, the L7805 can also be used to make a voltage regulating circuit.

The circuit we are going to make today looks like this:

Not only we only need a few simple components to make such a circuit, but it is somewhat similar to the method of using LM317 to make an adjustable circuit. However, compared to LM317, the L7805 three-terminal regulator tube is easier to find on the old circuit board.

TheDIY steps are as follows:

1 Bend the pins of the L7805 chip

2 Solder the L7805 chip and 200 ohm resistor, and cut off the excess wire

3 Solder the 1K ohm potentiometer

4 According to the circuit diagram, solder the remaining wires

5 That's all!

In practical applications, we should add filter capacitors to both the input and output ends.