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US 3,940,634 AGranted
Solid state AC power relay
AssigneeRockwell International Corporation
InventorMartin L. Grogan
Life of this patent
Estimating the term…
Abstract
A trigger type device employing a pair of oppositely poled SCR's or a triac, provides bidirectional control of AC power through a simple circuit comprising a pair of rectifying diodes and an opto-electronic coupler.
Claims6
A solid state AC power relay comprising:
- bidirectional trigger switching means having two power terminals for passing AC current between an AC load and AC power source when triggered into conduction by a gate current during each AC alternation and a gate terminal for receiving said gate current;
- a pair of rectifying diodes, with commonly connected cathodes, connected in series between said power terminals;
- an optoelectronic coupler;
- a three terminal control element having a controllable current path between two of its terminals for passing said gate current between the AC power source and said gate terminal under the control of an input signal applied to its third terminal, said third terminal being connected to said commonly connected cathodes via the phototransistor of said coupler so that said input signal is enabled to flow therebetween only when the light emitting diode of said coupler is energized, and
- an RC charging circuit connected in series with said phototransistor between its collector and said commonly connected cathodes comprising a resistor in parallel with a series combination of a resistor and capacitor.
2 more elements
A solid state AC power relay comprising:
- bidirectional trigger switching means having two power terminals for passing AC current between an AC load and AC power source when triggered into conduction by a gate current during each AC alternation and a gate terminal for receiving said gate current;
- a pair of rectifying diodes, with commonly connected cathodes, connected in series between said power terminals;
- an optoelectronic coupler;
- a three terminal control element having a controllable current path between two of its terminals for passing said gate current between the AC power source and said gate terminal under the control of an input signal applied to its third terminal, said third terminal being connected to said commonly connected cathodes via the phototransistor of said coupler so that said input signal is enabled to flow therebetween only when the light emitting diode of said coupler is energized, and
- two diodes, with commonly connected anodes, connected in series between said power terminals and a zener diode whose anode and cathode are connected respectively to the aforesaid commonly connected anodes and the collector of said phototransistor.
2 more elements
Dependencies are inferred from the claim text.