Emergency alert system signal handling method and apparatus
First Claim
1. A communication system including a transmission channel, a relay having first and second states, an operating power port, a first signal input port, a second signal input port and a signal output port, a power supply for supplying power to the relay to place the relay alternately in the first and second states, first and second sources of program material to be selectively and alternately transmitted in the channel, the first and second sources of program material characterized by at least one program material frequency, the first signal input port of the relay coupled to the first source of program material, the signal output port of the relay coupled to the transmission channel, a first inductance for coupling the power supply to the operating power port, the relay including a second inductance for controlling the relay state, and first and second capacitances for coupling the second source of program material to the second signal input port.
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Accused Products
Abstract
A communication system includes a transmission channel, a relay having first and second states, an operating power port, a first signal input port, a second signal input port and a signal output port. A power supply supplies power to the relay to place the relay alternately in the first and second states. The system further comprises first and second sources of program material to be selectively and alternately transmitted in the channel. The first and second sources of program material are characterized by at least one program material frequency. The first signal input port of the relay is coupled to the first source of program material. The signal output port of the relay is coupled to the transmission channel. A first inductance is provided for coupling the power supply to the operating power port. The relay includes a second inductance coupled across the power port for controlling the relay'"'"'s state. First and second capacitances are provided for coupling the second source of program material to the second signal input port.
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Citations
21 Claims
- 1. A communication system including a transmission channel, a relay having first and second states, an operating power port, a first signal input port, a second signal input port and a signal output port, a power supply for supplying power to the relay to place the relay alternately in the first and second states, first and second sources of program material to be selectively and alternately transmitted in the channel, the first and second sources of program material characterized by at least one program material frequency, the first signal input port of the relay coupled to the first source of program material, the signal output port of the relay coupled to the transmission channel, a first inductance for coupling the power supply to the operating power port, the relay including a second inductance for controlling the relay state, and first and second capacitances for coupling the second source of program material to the second signal input port.
- 17. A communication system including a transmission channel, a plurality of relays, each relay having two states, an operating power port, a first signal input port, a second signal input port and a signal output port, a power supply for placing the relays alternately in the first and second states, the plurality of first sources of program material and single second source of program material to be selectively and alternately transmitted on the transmission channel, each of the plurality of first sources of program material and the second source of program material characterized by a respective program material frequency, the first signal input port of each relay coupled to a corresponding first source of program material, the signal output port of each relay coupled to the transmission channel, a plurality of first inductances for coupling the power supply to a corresponding operating power port, each relay including a second inductance for controlling the state of the respective relay, each second inductance coupled to the operating power port of the respective relay, a plurality of first capacitances and a plurality of second capacitances for coupling the second source of program material to the second signal input ports of the plurality of relays.
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19. A communication system including a transmission channel, a modulator having an IF loop and a relay coupled to the IF loop, the relay having two states, the modulator having an operating power port coupled to the relay to receive power to control the state of the relay, a first signal input port coupled to the relay, a second signal input port coupled to the relay, and a signal output port coupled to the relay, a power supply for supplying power to the relay to place the relay alternately in the first and second states, first and second sources of program material to be selectively and alternately transmitted in the channel depending upon the state of the relay, the first and second sources of program material characterized by at least one program material frequency, the first signal input port coupled to the first source of program material, the modulator coupling the signal output port to the transmission channel, a conductor for coupling the second source of program material and the power supply to the modulator, a first inductance for coupling the power supply to the conductor, a second inductance for coupling the conductor to the power port of the modulator, a first capacitance for coupling the second signal input port to the conductor, and a second capacitance for coupling the second source of program material to the conductor.
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20. A method for switching between first and second sources of program material to be alternately transmitted in a transmission channel, the method including providing the transmission channel, providing the first source of program material, providing the second source of program material, providing a relay having two states, an operating power port, a first signal input port, a second signal input port, and a signal output port, providing a power supply for operating the relay, coupling the first signal input port to the first source of program material, coupling the signal output port to the transmission channel, coupling the power supply through a first inductance to a second inductance included in the relay for controlling the relay state, coupling the second source of program material to the second signal input port through first and second capacitances, and supplying power to the second inductance to switch the relay from a first state in which the first source of program material is transmitted in the channel to a second state in which the second source of program material is transmitted in the channel.
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21. A method for switching between a plurality of first program sources of program material and a second source of program material to be alternately transmitted in a transmission channel, the method including providing the transmission channel, providing the plurality of first sources of program material, providing the second source of program material, providing a plurality of relays, each relay having two states, an operating power port, a first signal input port, a second signal input port, and a signal output port, providing a power supply for operating the relays, coupling the first signal input ports to respective first sources of program material, coupling the signal output ports to the transmission channel, coupling the power supply through a plurality of first inductances to a respective second inductance included in each relay for controlling the respective relay state, splitting the second source of program material into a plurality of second sources of program material, coupling each of the plurality of second sources of program material to respective second signal input ports through a respective first and second capacitance, and supplying power to all of the second inductances to simultaneously switch the relays from respective first states in which the first sources of program material are transmitted in the channel to respective second states in which the second source of program material is transmitted in the channel.
Specification