With these mods, this circuit will last quite a long time, especially if you make things easier for the relay by turning off power to the motor before switching directions. It is simple and effective ...

Here is a motor speed sensor module, the major goal is to check the rate of an electric motor. The module can be used in association with a microcontroller for motor speed detection, pulse count, ...

There’s many complex systems for automatically pointing a telescope at an object in the sky, but most of them are too expensive for the amateur astronomer. [Kevin]’s Arduino ST4 interface lets you ...