You can salvage some nice motors out of optical drives but they can be tricky to control ... Arduino and has a couple of posts explaining the concept and demonstrating how it works. His test ...

At last, some 'spare' time this weekend, and I learned two things about SCR dc motor control: Permanent magnet dc motors need ...

But [Playful Technology] wanted to control the hands with an Arduino directly and ... detach the electromagnet from the rest of the circuit and control it yourself. The module he used had a ...