The Synchronous Motor/Generator consists of a 4-pole machine rated at 2 kW. Each phase of the stator winding is accessible via the connection module to allow wye or delta connections. The rotor winding is connected to two slip rings for external connection to a dc power source. A squirrel cage damper winding is inserted in the salient-pole rotor to produce induction-motor action, making the synchronous motor self-starting.

Features of the Synchronous Motor/Generator used with the Wiring Module for Synchronous Motor/Generator, Model 8508, include:

• A damping resistor connected across the rotor winding to limit induced voltage and increase the torque during motor start-up.

• A toggle switch connected in series with the rotor winding, to isolate the winding from the dc source during motor start-up.

• A normally closed push-button connected in series with the damping resistor, which enables students to measure the true exciting current.

• A full-pitch stator pole and a rotor-pole search coil to allow observation of the flux distribution.