Digital time delay relay utilizing logic elements

Claim 1

A solid-state relay, comprising: a. control means for actuating solid-state contact means to change state; and b. a pair of complementary solid-state contact means interconnected with said control means one of which is generally opened and the other of which is generally closed, said control means actuating each of said solid-state contact means to change state in which case said contact means which is closed will always open before said contact means which is opened will close, each said solid-state contact means comprising a light emitting means interconnected with said control means which produces light in relationship to a signal from said control means, each said contact means also comprising light sensitive resistance means disposed in light accepting relationship with said light emitting means for changing resistance between a higher and lower value of resistance in relationship to the change of light in the vicinity of said resistance means, said light sensitive resistive means controlling the state of said contact means, a predetermined amount of change of said resistance causing said associated contact means to change state, said change of said resistance from said lower value of resistance to said higher value of resistance occurring at a different rate than said change of resistance from said higher value of resistance to said lower value of resistance consequently causing one said contact means to open before said other contact means closes.