Carrier current communications system
First Claim
1. A carrier current communications system for buildings having an AC power distribution system, comprising:
- (a) a central station having means for receiving signals over the AC power distribution system on a first radio frequency and means for transmitting signals over the AC power distribution system on a second radio frequency,(b) a plurality of remote stations having means for transmitting and receiving signals over the AC power distribution system on the first and second radio frequencies, respectively,(c) first wire means for coupling the receiving means at the central station to the AC power distribution system, having significant reactive impedance,(d) second wire means for coupling the transmitting means at the central station to the AC power distribution system, having significant reactive impedance,(e) first capacitive tuning means for substantially tuning out the impedance of the first wire means at the receiving radio frequency, and(f) second capacitive tuning means for substantially tuning out the impedance of the second wire means at the transmitting radio frequency.
0 Assignments
0 Petitions
Accused Products
Abstract
A plurality of transmitters and receivers arranged for carrier current communications are generally placed throughout a large building. The transmitters and receivers are coupled to selected portions of the power distribution system. The selected portions are stairwell exit and lighting risers emanating from the same location of contiguous circuit breakers. Coupling circuits are applied to both remote transceivers and the central station transceivers. These circuits insure that remote station receivers always present high impedance to the power line at the carrier frequencies and that remote transmitters do not load the lines. At the central station, a bridge arrangement of the networks couples energy to and from the lines, with additional isolation between receiver and transmitter circuits. Mutual interference of transmitted and received signals are avoided by taking advantage of the impedance in the length of line from the central station to coupling and line conditioning circuits, and capacitor tuning to the center frequency of the transmitter line and to the center frequency of the receiver circuits. Low impedance at the common bus allows the signals to be readily transmitted to the risers.
-
Citations
12 Claims
-
1. A carrier current communications system for buildings having an AC power distribution system, comprising:
-
(a) a central station having means for receiving signals over the AC power distribution system on a first radio frequency and means for transmitting signals over the AC power distribution system on a second radio frequency, (b) a plurality of remote stations having means for transmitting and receiving signals over the AC power distribution system on the first and second radio frequencies, respectively, (c) first wire means for coupling the receiving means at the central station to the AC power distribution system, having significant reactive impedance, (d) second wire means for coupling the transmitting means at the central station to the AC power distribution system, having significant reactive impedance, (e) first capacitive tuning means for substantially tuning out the impedance of the first wire means at the receiving radio frequency, and (f) second capacitive tuning means for substantially tuning out the impedance of the second wire means at the transmitting radio frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
Specification