Abstract: A system for changing the light level in one or more lighting fixtures connected to a control device such as a timer or lighting panel using only conventional power relays in the timer or lighting panel, wherein the conventional power relays are used to turn power on and off to control circuits and also to send predefined messages to receiving modules installed in the lighting fixtures.

Abstract: An electrical control system consisting of two or more electrical transmitting devices each capable of transmitting synchronized messages consisting of electrical pulses to devices connected to one or more of the three phases of the AC power lines in a typical three phase power system. The synchronized transmitters are each connected to neutral and to one or more of the three phases, A, B, and C, or across two of the phases, of different circuit breaker panels in a typical three phase power system, and are capable of transmitting messages to one or more of the three phases. The transmissions from the two or more transmitters are synchronized such that the transmitted pulses from each transmitter are transmitted at the same time to produce a message that can be received correctly at any receiving device connected to any of the connected circuit breaker panels.

Abstract: Circuits and methods for transmission of digital data between two or more devices via powerline particularly suited for use in high attenuation, high noise commercial/industrial powerline environments, including transmission of pulses generated by a capacitor charged in the positive half cycle of the sine wave and discharged during the negative half-cycle, placing the pulse at one of two predetermined signal timing positions related to zero voltage crossing points or to previously transmitted pulses so that the pulses are substantially in the powerline temporal quiet zone near zero crossing and so that the powerline voltage at the time of the pulse is additive to the capacitor voltage.

Abstract: A transmitting controller is connected to a powerline and on command places a reference signal and a series of signal pulses in the powerline at a series of signal timing positions related to zero voltage crossing points so that the signals pulses are substantially in the powerline temporal quiet zone near zero crossing. The signal pulses are produced from a pair of capacitors and switches which are each sequentially charged a first polarity from the powerline and is discharged in the powerline at the opposite polarity so that the powerline voltage at the time of the pulse is additive to the pulse voltage. The receiving controller is connected to the powerline and has a filter circuit therein which filters away the powerline AC signal and noise to leave the reference and signal pulses. The signal pulses are compared to the position of starting reference pulses to determine in which signal timing position the pulses have occurred.

Abstract: A transmitting controller is connected to a powerline and on command places a reference signal and a series of signal pulses in the powerline at a series of signal timing positions related to zero voltage crossing points so that the signals pulses are substantially in the powerline temporal quiet zone near zero crossing. The signal pulses are produced from a pair of capacitors and switches which are each sequentially charged a first polarity from the powerline and is discharged in the powerline at the opposite polarity so that the powerline voltage at the time of the pulse is additive to the pulse voltage. The receiving controller is connected to the powerline and has a filter circuit therein which filters away the powerline AC signal and noise to leave the reference and signal pulses. The signal pulses are compared to the position of starting reference pulses to determine in which signal timing position the pulses have occurred.

Abstract: A transmitting controller is connected to a powerline and on command places a reference signal and a series of signal pulses in the powerline at a series of signal timing positions related to zero voltage crossing points so that the signals pulses are substantially in the powerline temporal quiet zone. The receiving controller is connected to the powerline and has a filter circuit therein which filters away the powerline AC signal and noise to leave the reference and signal pulses. The signal pulses are compared to the position of starting reference pulses to determine in which signal timing position the pulses have occurred. Digital data is communicated over the powerline in accordance with the nature placement of the data pulses related to the reference pulse positions. The timing zone for transmission and signals is preferably about 500 to about 1000 microseconds away from zero voltage crossing.