General Electric Company

Ssac, Inc.

Jerome R Mullaly

Kenneth C Volz

Donald D Martell

Richard W Fox, Jr

Richard W Shutt

The invention is an improved timer circuit for operating a heating or air conditioning unit which utilizes a single time delay generating circuit for delaying operation of both a compressor and a unit fan under certain operating conditions. A logic circuit for operating a fan relay is made responsive to the thermostat output and a time delay generating circuit output so that the fan relay is de-energized only in the case that the compressor has been turned off for at least the duration of a time delay generator timing period, and is in a state commensurate with a satisfactory building temperature. When the timer circuit is used in large-scale heating or air conditioning systems, the timing period of each timing circuit can be adjusted to a different duration so that a voltage lag problem on start up is avoided.

Timer circuit for heating or air conditioner unit

Disclosed is an electronic switch circuit including a switching thyristor with two switch terminals that are connected to a controlled circuit. A trigger circuit is coupled to the gate terminal of the thyristor to selectively supply trigger signals and the trigger circuit receives its power from a power supply which is connected to switch terminals and draws its energy from the controlled circuit. An energy storage capacitor in the power supply provides trigger energy when the voltage across the switch terminals is approximately zero, such as at A.C. crossovers. The thyristor exhibits zero voltage switching.

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Baldwinsville, NY, United States of America

Jerome R Mullaly