System for detection of the phase of an electrical signal on an alternating circuit power line
First Claim
1. A system for detecting a modulated signal on a remote local power line supplied with power from a main power line having an alternating voltage, said alternating voltage having a known phase defined as a reference phase comprising:
- a transmitter for generating a first signal having a stable frequency and modulated with a second signal derived from the reference phase voltage of the main power line;
said transmitter operably connected to said main power line for transmitting said modulated first signal over said power line;
a receiver operable to receive said first signal and its modulation to detect therefrom modulating second signal derived from the reference phase voltage for phase comparison with the phase of an alternating voltage on the local power line;
said receiver being operably connected to said remote power line spaced apart from the location at which the transmitter is connected to said main power line.
1 Assignment
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Accused Products
Abstract
A data transmission system for power line carriers includes a transmitter which generates a stable carrier frequency at a bandwidth of less than one hertz. The transmitter is connected to the power line to transmit the generated frequency over the power line to a receiver. The receiver implements filters of a bandwidth of one hertz or less to attenuate any signals that do not correlate with the generated frequency. Information on the phase of the power line to which the transmitter is connected is represented in the form of a generated signal which modulates the stable frequency generated by the transmitter on the power line. The receiver is located on another portion of the power line and compares the phase information from the transmitter with the phase of the power line to which the receiver is connected and displays the resulting comparison for interpretation.
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Citations
10 Claims
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1. A system for detecting a modulated signal on a remote local power line supplied with power from a main power line having an alternating voltage, said alternating voltage having a known phase defined as a reference phase comprising:
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a transmitter for generating a first signal having a stable frequency and modulated with a second signal derived from the reference phase voltage of the main power line; said transmitter operably connected to said main power line for transmitting said modulated first signal over said power line; a receiver operable to receive said first signal and its modulation to detect therefrom modulating second signal derived from the reference phase voltage for phase comparison with the phase of an alternating voltage on the local power line; said receiver being operably connected to said remote power line spaced apart from the location at which the transmitter is connected to said main power line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for measuring the phase angle of alternating voltage on a local power line relative to the phase of alternating voltage on a main power line which supplies power to the local power line, the phase of the alternating voltage on the main power line being defined as a reference phase end the phase of the alternating voltage on the local power line being defined as a local phase, comprising:
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a transmitter operably connected to the main power line for transmitting a first signal over said main power line; said transmitter including means for detecting the reference phase voltage and for generating said first signal, the first signal having a stable frequency and being modulated with a second signal derived from the reference phase voltage; a receiver operably connected to the local power line for receiving the first signal and its modulation; said receiver including means for detecting the local phase voltage of the local power line; said receiver including means for detecting the modulating second signal derived from the reference phase voltage from the received signal and measuring the phase angle of the local phase voltage relative to the second signal; and means on said receiver for displaying the measured phase angle.
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Specification