Single relay control positive and negative and speed control circuit schematic

Adjustable capacitor Murata genuine original

1206RGB (single)

Single chip microcomputer STM32L151CCU6

Idea: Using a single-pole double-throw relay to control the motor's forward and reverse design is very good, but how to make the motor stop and speed regulation is not easy to think of. Let the motor stop, you can use the triode to open and close the circuit, MOS tube can also. This can be achieved by combining them.

Schematic:

After the actual welding circuit board test, the purpose of forward and reverse and speed regulation can be achieved.

The relay type used is: TQ2-5V, and TX2-5V is also available.