Power switching circuit
First Claim
1. A power switching circuit for use with electrical appliances driveable by a power source comprising:
- a. input signal means for receiving signal indicia representative of appliance operation;
b. timing means for initiating the time out of a predetermined interval, said time out commencing upon each signal indicia received by said input signal means, said timing means being coupled to said input signal means, said timing means outputting a signal responsive to said interval, said output signal being in a first state during said interval and changing to a second state following the termination of said interval;
c. a power switch connected to the electrical appliance, said power switch including control means for connecting and disconnecting the electrical appliance from the power source; and
d. isolation means for coupling the output signal of said timing means and the control means of said power switch whereby said control means disconnects the electrical appliance from the power source when the output signal of said timing means is in the second state thereof.
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Accused Products
Abstract
An automatic power switching circuit for controlling the application of electrical power to an electric typewriter or like apparatus. Radiated electrical energy emanating from alternating current machinery is transmitted to an input antenna by the touch of the operator. The input alternating current signal is shaped to produce electrical signal indicia responsive to the operator'"'"'s contact with the apparatus. The input signal is transmitted to a timing circuit to initiate the time-out of predetermined delay following which an output signal will be generated and the apparatus will be disconnected from the power source in the absence of human contact during the delay interval.
13 Citations
10 Claims
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1. A power switching circuit for use with electrical appliances driveable by a power source comprising:
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a. input signal means for receiving signal indicia representative of appliance operation; b. timing means for initiating the time out of a predetermined interval, said time out commencing upon each signal indicia received by said input signal means, said timing means being coupled to said input signal means, said timing means outputting a signal responsive to said interval, said output signal being in a first state during said interval and changing to a second state following the termination of said interval; c. a power switch connected to the electrical appliance, said power switch including control means for connecting and disconnecting the electrical appliance from the power source; and d. isolation means for coupling the output signal of said timing means and the control means of said power switch whereby said control means disconnects the electrical appliance from the power source when the output signal of said timing means is in the second state thereof. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A power switching circuit for use with electrical appliances driveable by a power source comprising:
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a. an input antenna; b. a first electrical translating member having base, collector and emitter regions, the base region of said first electrical translating member coupled to said input antenna; c. a second electrical translating member having base, collector and emitter regions, the base and collector of said second electrical transmitting member being connected to the collector and emitter respectively of said first electrical translating member; d. timing means for initiating the time-out of a predetermined interval, said time-out commencing upon the receipt of signal indicia by said input antenna, said timing means including threshold and discharge means for generating and detecting a threshold signal, said timing means producing an output signal responsive to the detection of said threshold signal, said timing means being coupled to the collector of said first electrical translating member, said threshold and discharge means being coupled to the emitter of said second electrical translating member; e. charging means for controlling the rate of charging of said threshold signal, said charging means being connected to said threshold; f. a power switch connected to the electrical appliance, said power switch including control means for connecting and disconnecting the electrical appliance from the power source; and g. isolation means for coupling the output signal of said timing means and the control means of said power switch whereby said control means disconnects the electrical appliance from the power source when the output signal of said timing means is responsive to the discharge of said threshold signal. - View Dependent Claims (8, 9, 10)
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Specification