A digital circuit is formed by transistors operable in an unsaturated state. A pair of first transistors are connected in a differential relationship with their emitters commonly connected. A pair of second transistors are also connected in a differential relationship and have their emitters connected in common and their collectors connected respectively to the bases of the first transistors. At least one of the first transistors is connected to the bases of the second transistors to form a feed...

A circuit breaker having a simple overload triggering mechanism of a thermostat element clamped at one end by a threaded rod, a leaf spring, and a recess in the housing. The other end of the thermostat element is notched to receive and engage a trip arm which is released to cause opening of the breaker contacts by bending of the thermostat element under overload current conditions.

A power circuit in which a commercial AC power is supplied to an active filter through a rectifying circuit and a DC power is supplied directly to the active filter by the use of a switching mechanism for switching over between the commercial AC power and the DC power. The resistor for setting the voltage between the input and output terminals of the active filter is divided into two parts to one of which a transistor is connected in parallel. The transistor is turned on or off by the switchover...

An annunciator circuit comprising means for generating an output level signal in response to a sensed abnormal signal condition, an audible alarm, and means for actuating the audible alarm upon initial recognition of the output level signal from the generating means and only for the duration of the output level signal. Acknowledgement means electrically coupled to the alarm actuating means is also provided for deactuating the audible alarm only while the abnormal signal condition is sensed and f...

A ballast circuit for operating at least one gaseous discharge lamp from a high voltage input utilizing a transformer having two secondary windings, which may be used with either a high or low voltage input. The transformer also includes a primary winding, one side of which is connected to the junction of the first and second secondary windings. The other side of the primary winding is connected to ground, as is the fixture in which the at least one lamp is mounted. This provides a lamp power ci...

In a multi-frequency receiver for use in telecommunications system, tones within the audio frequency range are received. The tones transmitted are separated, amplified, and shaped into square waveform for further processing. The pulse shaping or limiting, associated with amplifications produces square wave outputs of unvarying amplitude in response to sine wave inputs of varying amplitude. A common base voltage midway between the plus and minus voltage supplies is provided for both limiters. In ...

The disclosure relates to a motor protection circuit utilizing PTC sensors and all solid state circuitry to provide protection to a motor circuit and the like. The protection circuit is capable of providing protection for a plurality of devices simultaneously. The sensor circuits can be connected either serially or in parallel and provide equivalent results. This invention relates to a protection circuit for use with motors and the like and more specifically to an all solid state protection circ...

A precision passive tachometer circuit including a capacitor, a zener diode, and an ammeter combined in such a way as to provide a meter deflection that is directly proportional to the angular speed of the device monitored.

A circuit breaker wherein electrical arrangement for detecting excess current in and switching or breaking power supply contacts for associated circuit and mechanical arrangement for transmitting ON-OFF operation or contact switching operation to the contacts are separately disposed as electrically insulated by a separation wall in a chassis for integrally housing the both arrangements. The separation wall has only two narrow apertures for allowing the motion responsive to detected excess curren...

A lateral region detects the saturation condition and provides overflow negative feedback or a trigger preparation voltage.