230 Motors and Motor control - k3ng/k3ng_rotator_controller GitHub Wiki

The rotor software accommodates several different motor types each requiring unique interface hardware depending on motor type. Capacitor run single phase AC (typical CDE rotor), permanent magnet DC (has brushes), synchronous AC motor and stepping motors. The motor controller must be selected to match the motor type. For a PMDC motor either relays or a dual half-bridge PWM controller (search ebay for BTS7960) is suitable. For Capacitor run single phase AC relays are usual. With relays you need a separate speed controller if speed control is desired. With a typical electronic motor control PWM speed control is built in. The controller has variable frequency outputs suitable for driving a synchronous AC motor but for a driver you are on your own. Step motors are typically 2/4 phase and require suitable micro stepping driver such as the DIV268N (search ebay)

In the K3NG rotor controller all motors are operated in a simple servo loop with the motor speed and stopping point determined by feedback from a positioning device. This is usual in all the above cases with the exception of step motors. In the K3NG application the step motor us used as a brushless DC motor (BLDC) which has maximum torque at zero RPM (stall). Most DC motors that have PWM speed control have near zero torque at very low motor RPM.