Abstract: An electromagnetic relay having a three part housing. A first or base housing part positions a magnet coil and a stationary magnet pole piece. A second or front housing part positions springs for positioning the coil in the base part, provides a seat for armature return springs and a guide for an assembly including a magnetic armature. A third or a middle housing part maintains the return springs and armature assembly assembled in the front housing part. The front and middle housing parts have rectangularly shaped confronting surfaces which are spaced so the areas of engagement between the middle housing part and the front part are limited to the areas at the four corners of the front and the middle housing parts. The relay also includes a movable contact actuator that is held captive by a cover for the relay.

Abstract: A low cost electromagnet assembly for a relay. The assembly includes an I-shaped stationary magnet that extends through a passage in a magnet coil and a U-shaped armature assembly with the armature assembly. The armature assembly includes a molded armature guide having projections on a rear wall of the guide arranged to actuate a plurality of switch plungers, side walls extending from the rear wall defining a cavity and an opening in the rear wall exposing a portion of the cavity at the rear wall side of the guide. The assembly also includes the U-shaped armature having a body portion positioned in the cavity and an elastomeric pad position between the armature body portion and the rear wall and a conical spring between the body and guide for absorbing shock created when the electromagnet is deenergized.

Abstract: An anti-telegraph circuit for locking out the circuit controlling the flow of direct current in a coil winding of an electromagnetically operated switching device, such as a contactor, from an alternating current source whenever improper control voltages are present which would cause repeated operations of the armature picking up and falling out of its sealed position.

Abstract: A self-powered solid state overload relay having current transformers energized by current to a motor to be protected. The transformer has secondary windings connected through diodes to charge a capacitor in a circuit which senses the magnitude of motor current and capacitors in a trip-reset circuit which causes the circuit to be interrupted when the motor current exceeds a pre-programmed value. The diodes in capacitor charging circuits are poled so that the capacitor in the sensing circuit and the capacitor trip-reset circuit are charged by opposite polarity rectified half wave current pulses.

Abstract: A self-powered solid state overload relay circuit having current transformers energized by conductors supplying current to a multiphase alternating current motor. The transformers have secondary windings connected to charge a capacitor with a voltage indicative of the magnitude of the maximum current in the motor windings. The circuit includes presetable impedance circuits which permit the circuit to be easily programmed to respond to a range of abnormal motor currents in the winding in motors of varying size and service factor ratings, components which are arranged to duplicate the operation of melting alloy and bimetal type overload relays in an automatic or in a trip-free manual reset mode, a light emitting device which visually indicates when the relay is in a tripped state, and components which cause the relay to be insensitive to ambient temperature variations.