Prior to the advent of the adjustable-speed drive (ASD), the polyphase induction motor operated as a constant-speed motor. Figure 1 shows the well-known torque and current curves versus speed for the ...

A single-speed motor has one rated speed at which it runs when supplied with the nameplate voltage and frequency. A multispeed motor will run at more than one speed depending on how you connect it to ...

PSC motors rely on the rotating magnetic field that is generated by the applied alternating voltage and corresponding alternating current to turn the rotor. The magnetic field rotates at 3,600 rpm (60 ...

Every service technician should have at least one multi-speed motor in his or her truck, to help in making acceptable substitutions in the field. Multi-speed motors come in two basic varieties. The ...

A brushless-DC motor is common in ceiling fan and pan-tilt-zoom (PTZ) camera designs. But you can’t use the same brushless-DC motor solution for both of these end products. A ceiling fan driver ...