초록 ▼

A control circuit for selectively energizing at least one electrical device coupled to the control circuit via a pair of conductive wires with an operating voltage. The control circuit comprises a control circuit for selectively supplying and withholding operating electrical power to at least one el

A control circuit for selectively energizing at least one electrical device coupled to the control circuit via a pair of conductive wires with an operating voltage. The control circuit comprises a control circuit for selectively supplying and withholding operating electrical power to at least one electrical device. A first current detector is connected to a control voltage and senses a current flow resulting from closure of a circuit connected to a control voltage in at least one wire of the pair of conductive wires. A second current detector is connected to the operating voltage and senses a current flow resulting from closure of a circuit connected to the operating voltage in at least one wire of the pair of conductive wires. A first switching device responds to the first current detector to disconnect the control voltage from at least one of the wires and to connect the operating voltage to the conductive pair. A second switching device responds to the second current detector to maintain operating voltage to the conductor pair. The second switching device responds to the second current detector to connect operating power to the electrical device.

대표청구항 ▼

[ We claim:] [1.]1. A control circuit for selectively energizing at least one electrical device coupled to said control circuit via a pair of conductive wires with an operating voltage between 100 volts and 250 volts, said control circuit comprising:a control circuit for selectively supplying and wi

[ We claim:] [1.]1. A control circuit for selectively energizing at least one electrical device coupled to said control circuit via a pair of conductive wires with an operating voltage between 100 volts and 250 volts, said control circuit comprising:a control circuit for selectively supplying and withholding operating electrical power to said at least one electrical device;a first current detector connected to a control voltage less than said operating voltage and sensing a current flow resulting from closure of a circuit connected to said control voltage but not connected to said operating voltage in at least one wire of said pair of conductive wires;a second current detector connected to said operating voltage and sensing a current flow resulting from closure of a circuit when connected to said operating voltage in at least one wire of said pair of conductive wires;a first switching device responsive to said first current detector to disconnect said control voltage from at least one of said wires and to connect said operating voltage to said conductive pair of wires;a second switching device responsive to said second current detector to maintain said operating voltage to said pair of conductive wires, said second switching device responsive to said second current detector to connect said operating power to said electrical device; anda delay circuit delaying connecting said operating voltage to said electrical device for a predetermined time to allow a safe transition from said control voltage to said operating voltage over said common pair of conductors.