En route to getting the off-the-peg DC-51 motor speed controller to better suit my small milling machine, I had a go at working out what the circuit is. Approx circuit of DC-51 motor speed controller ...

I have been trying to fix a little old milling machine I bought (and here), and needed a replacement motor controller. It is a Clarke DCM10, a variant of Sieg’s X1, sometimes knows as a ‘micro mill’.

To successfully integrate the drive into the system, the controller must provide full functionality for motor control. The more functions the drive itself can implement, the fewer add-ons and ...