Compressor minimum off-time switch for series connection with delay-on-break feature

A series connectable electric signal-responsive alternating current switch apparatus for connection in one side of an electrical circuit to an alternating current utilization device comprising:

• a) a full-wave rectifier circuit having a first input terminal, a second input terminal, a first output terminal, and a second output terminal, said first input terminal and said second input terminal serving as terminals for series connection of said switch apparatus in one side of said electrical circuit to said alternating current utilization device,
• b) an electrical impedance device connected between said first input terminal and said second input terminal,
• c) a thyristor with an anode and a cathode connected to pass current from said first to said second output terminal, said thyristor having a control electrode for switching it from a low conductivity to a high conductivity in response to a signal applied to said control electrode,
• d) a control circuit connected to receive power solely from said full-wave rectifier circuit and to be responsive to an electrical potential between said first input terminal and said second input terminal, said control circuit including means for generating a control signal as a predetermined function of said electrical potential, said full-wave rectifier circuit supplying sufficient current to said control circuit through said first output terminal and said second output terminal as necessary to eliminate the need for a battery power source, and
• e) means for applying said control signal to said control electrode.

Compressor minimum off-time switch apparatus having no battery supplemental power source and only two external wires or terminals for series connection with a thermostat, a contactor, and a low voltage alternating current power supply therefor in an air conditioning system comprising:

• a housing with only two external wires;
• a full wave rectifier having a first input terminal connected to the first of said only two external wires and a second input terminal connected to the second of said only two external wires;
• an electrical impedance of from 100 to 5,000 ohms connected between said first input terminal and said second input terminal;
• said full wave rectifier having a first output terminal and a second output terminal, a semiconductor switch element connected therebetween;
• circuit means including a timer and connected to be powered solely from said first output terminal and said second output terminal for causing a delay on operating action for said semiconductor switch element in the event of a power interruption, but in the event of a thermostat interruption causing only a delay on release action for said semiconductor switch element, said full-wave rectifier circuit supplying sufficient current to said control circuit through said first output terminal and said second output terminal as necessary to eliminate the need for a battery power source.