Abstract: A starting circuit for use with single phase induction motors such as capacitor run and capacitor start, capacitor run motors is shown having a triggerable semiconductor (Q1, Q2 and Q3) serially connected to the auxiliary winding (AW) across the power supply (L1, L2). A resistor (RA) is serially connected at (J1) to the main winding (MW) to form a voltage divider to aid in providing triggering current to the triggerable semiconductor. A thermistor (PTC) is connected between the gate and the voltage divider junction (J1). The triggerabIe semiconductor is shown as a triac (Q1) in certain embodiments and as back to back SCRs (Q2 and Q3) in other embodiments. In high current motors the voltage divider resistor (RA) is shown thermally coupled to the thermistor (PTC).

Abstract: A three pole relay is shown which operates in response to the flow of normal operating current across fluorescent lamps to energizes a coil which actuates a relay to open switches disposed in all of the filament lines associated with the lamp to shut off filament current while maintaining current flow across the lamps themselves.

Abstract: A solid state switch particularly useful in assisting in the starting of permanent split capacitor (PSC) motors is disclosed in which a semiconductive element is used to affect the starting torque of the motor. The semiconductive element is a disk-shaped member composed of material having a relatively low resistance at temperatures below an anomaly point and a steeply sloped positive temperature coefficient (PTC) of resistivity at temperatures above the anomaly. The PTC element is mounted within a casing which comprises two identical interfitting halves and is in electrical connection with members which are combination contacts and terminals. The terminals extend through the casing wall and are provided with contact portions which engage the PTC element along an annular portion of the element near the outer periphery thereof. One contact is provided with spring fingers adapted to react against a wall of the casing to provide desired contact force.