摘要 |
An electronically commutated motor M includes a power supply unit 12 for converting an AC mains input to an internal dc supply, and a drive system 13 having a speed control input 16. A control unit 11 for the motor includes a dc operated controller 18 with a speed setting input and provides a control signal output 19 connected to the speed control input 16 of the motor. The controller draws power from the internal dc supply of the motor, thereby providing a compact, self-contained system requiring no other power supply for the control unit 11. |