Coded communication system and method for controlling an electric lamp

A method of controlling the light level of a gas discharge lamp, comprising:

• a) receiving a sinusoidal AC voltage having a fundamental period;
• b) within a control period comprised of a predetermined, fixed number of said fundamental periods, encoding one of two commands which include
• (i) a first command for lowering of the light level by imposing a pre-selected perturbation on said AC voltage a first number of times within the control period and (ii) a second command for raising of the light level by imposing the perturbation a second, different number of times within the control period, wherein the perturbation does not significantly change the shape of the sinusoidal waveform;
• c) decoding one of said first and second commands by counting the number of occurrences of the perturbation within each control period;
• and
• d) adjusting the light level of the lamp in the direction corresponding to a decoded one of said first and second commands.

A system for controlling the light level of a gas discharge lamp, said system comprising:

• A) a transmitter for controlling changes in the light level of the gas discharge lamp, said transmitter comprising
• (i) an input for receiving an AC voltage having a sinusoidal waveform within a fundamental period,
• (ii) encoding means for imposing a pre-selected perturbation on the AC voltage a first number of times within a control period comprised of a fixed number of fundamental periods to indicate a first command to increase the light level of the lamp and for imposing the perturbation a second, different number of times within the control period to indicate a second command to decrease the light level of the lamp wherein the perturbation does not significantly change the shape of the sinusoidal waveform;
• and
• (iii) a transmitter output for outputting the encoded AC voltage from said encoding means;
• and
• B) a ballast for operating the gas discharge lamp, said ballast comprising:
• (i) a ballast input for receiving the encoded AC voltage from said transmitter output,
• (ii) decoding means for decoding the first and second commands from the encoded AC voltage received at said ballast input, and
• (iii) control means, responsive to said decoding means, for adjusting the light level of the lamp in the direction corresponding to the command decoded by said decoding means.

A system for communicating control signals for controlling the operation of an electric lamp, said system comprising:

• A) a transmitter for generating control signals, said transmitter comprising:
• (i) means for receiving a voltage signal having a waveform with a fundamental period,
• (ii) encoding means for encoding each control signal by imposing a pre-selected perturbation on said voltage signal a first number of times to indicate a first command to increase the light level or a second, different number of times to indicate a second command to decrease the light level of the lamp within a control period comprised of a fixed number of fundamental periods, wherein the perturbation does not significantly change the shape of the waveform;
• and
• B) a receiver comprising:
• (i) an input for receiving the control signals from said transmitter,
• (ii) decoding means for decoding said control signals encoded by said transmitter, and
• (iii) signal generating means for generating a signal corresponding to a decoded command.

A lamp controller for use with a coded-type remote controller, said ballast comprising:

• (i) an input for receiving a voltage signal from the coded remote controller, the voltage signal having a waveform with a fundamental period and commands encoded therein, each command being encoded by a respective occurrence signature of pre-selected perturbation in a control period of a predetermined fixed number of fundamental periods, wherein the perturbation does not significantly change the shape of the waveform;
• (ii) decoding means for detecting, within each control period, a respective occurrence signature of the pre-selected perturbation for the control commands;
• and
• (iii) means, responsive to said decoding means, for controlling operation of the electric lamp in a manner corresponding to a decoded command.