Chopped light relay keyer

Claim 2

A protective circuit for an intermittent light energy source comprising: first means for emitting electrical energy in response to said intermittent light energy; and second means for controlling the operation of said source in response to the electrical energy emission of said first means; third means for adjusting the response time of said second means to the emission from said first means.

Claim 3

The protective circuit according to claim 1, wherein said second means comprises a transistor having a base, collector, and emitter; said first means being coupled to said base so that light impingement on said first means will cause an electrical energy emission applied to the base of said transistor causing said transistor to conduct.

Claim 4

The protective circuit according to claim 2 wherein said second means further comprises an emitter-collector circuit relay means coupled in the emitter and collector circuit; said relay means being actuated in response to conduction of said transistor.

Claim 5

The protective circuit of claim 3 wherein said first means comprises a phototransistor having a base, collector and emitter: said first named transistor base being coupled to one of said phototransistor emitter and collector so that light impingement on the phototransistor base will cause energy emission to said transistor base.

Claim 6

The protective circuit according to claim 4 wherein said third means comprises a potentiometer coupled to said one phototransistor emitter and collector and having a slide element; differentiating means; said slide being coupled through said differentiating means to said transistor base so that upon light impingement on said phototransistor base a spike voltage is applied to said transistor base corresponding to the position of said slide on said resistor.

Claim 7

The protective circuit according to claim 5 wherein said relay means is coupled between said phototransistor collector and said transistor collector, and said potentiometer is coupled to said phototransistor emitter.

Claim 8

The protective circuit of claim 5 wherein said differentiating means comprises a capacitor coupled between said slide and said transistor base and a resistor coupled across said transistor base and said transistor emitter.

Claim 9

The protective circuit according to claim 7 including a filter capacitor coupled across said transistor collector and emitter.

Claim 10

A protective circuit for a projector having a sequentially framed light energy output comprising a phototransistor having a base, collector, and emitter; said base being subject to the output of the projector and being biased thereby to cause conduction between said emitter and said collector at a rate corresponding to said sequential frame occurrence; a transistor having a base, collector, and emitter; a transistor emitter-collector circuit; a relay coil being coupled in said transistor emitter collector circuit; a capacitor being coupled across said transistor emitter and collector; a power source being coupled across said relay and capacitor whereby said power source will charge said capacitor through said relay when said transistor is non-conductive; a differentiating circuit being coupled between said phototransistor emitter and said transistor base whereby a spike signal will be generated and applied to said transistor base when said phototransistor conducts; a power circuit for applying power to the projector; a relay contact switch in said power circuit responsive to current flow in said relay coil to close said power circuit to said projector and responsive to attenuated current flow in said relay coil to open the power circuit to power projector.

Claim 11

A protective circuit for a projector having a sequentially framed light energy output comprising a phototransistor having a base, collector, and emitter; said base being subject to the output of the projector and being biased thereby to cause conduction between said emitter and said collector at a rate corresponding to said sequential frame occurrence; a transistor having a base, collector, and emitter; a transistor emitter-collector circuit; a relay coil being coupled in said transistor emitter collector circuit; a capacitor being coupled across said transistor emitter and collector; a power source being coupled across said relay and capacitor whereby said power source will charge said capacitor through said relay when said transistor is non-conductive; a differentiating circuit being coupled between said phototransistor emitter and said transistor base whereby a spike signal will be generated and applied to said transistor base when said phototransistor conducts; a power circuit for applying power to the projector; a relay contact switch in said power circuit responsive to current flow in said relay coil to close said power circuit to said projector and responsive to attenuated current flow in said relay coil to open the power circuit to power projector.

Claim 12

The apparatus of claim 9 including a potentiometer coupling the phototransistor emitter and said differentiating circuit whereby the response time between interruption of the projector sequential framing and the relay coil current attenuation is adjustable.