Energy monitoring and control system using reverse transmission on AC line

An energy monitoring and control system for use with a conventional AC source having at least one phase with a hot wire and a neutral wire, comprising:

• a control station having an input terminal and an output terminal, the input terminal being couplable to the hot wire of the AC source, and the output terminal being couplable to at least one of a plurality of controllable loads;
• each of the loads having an address and a hot connection and a neutral connection, the hot connection being coupled to the output terminal of the control station, and the neutral connection being coupled to the neutral wire of the AC source, the plurality of loads being operable to draw a supply current from the AC source;
• the control station and each load being operably coupled such that;
• (i) the control station is operable to send control commands to a desired load or a desired group of loads without affecting the other loads that are coupled to the control station;
• (ii) the control station transmits control commands to the loads by inducing at least one of a depression and a spike in the voltage supplied by the AC source to the loads in a predetermined sequential fashion;
• and
• (iii) following reception of a control command, the desired load executes the control command, resulting in a change in the supply current drawn by the loads from the AC source;
• each load including a receiver for accepting and executing control commands sent by the control station;
• the control station further including a monitor for monitoring the supply current and a comparator for confirming execution of the control commands by comparing the supply current drawn by the loads prior to the sending of a control command with the supply current drawn by the loads after execution of the control commands, the monitor and comparator thus providing a reverse transmission scheme in which information about the loads is communicated back to the control station without the need for dedicated transmitter circuits in each of the loads.

An energy monitoring and control system for use with a conventional AC source having at least one phase with a hot wire and a neutral wire, comprising:

• a control station having an input terminal and an output terminal, the input terminal being coupled to the hot wire of the AC source and the output terminal being coupled to at least one of a plurality of controllable electronic ballasts, each ballast being adapted to light at least one fluorescent lamp;
• the plurality of ballasts adapted to be connected in parallel with each other and to the AC source, each ballast having an address, a hot connection, a neutral connection, and an earth ground connection, the hot connection being coupled to the output terminal of the control station, the neutral connection being coupled to the neutral wire of the AC source, and the earth ground connection being connected to earth ground, the plurality of ballasts being operable to draw a supply current from the AC source;
• the control station and each ballast being coupled such that the control station is operable to send a control command to at least one address corresponding to a desired ballast, upon reception of which the desired ballast executes the control command, resulting in a perceptible change in the supply current drawn by the ballasts from the AC source;
• the control station including an interface for accepting and translating user commands into control commands, and a transmitter for sending control commands to the desired ballasts;
• each ballast including a receiver for accepting control commands sent by the control station and an execution means for executing control commands sent by the control station, each ballast being free of a dedicated transmitter circuit for sending to the control station a signal confirming execution of a control command;
• and
• the control station further including a monitor for monitoring the supply current drawn by the ballasts and a comparator for confirming execution of the control command by comparing the supply current drawn by the ballasts prior to the sending of a control command with the supply current drawn by the ballasts after execution of the control command.

An energy monitoring and control system for use with a conventional AC source having a hot wire and a neutral wire, comprising:

• a control station having an input terminal, an earth ground terminal, and an output terminal, the input terminal being coupled to the hot wire of the AC source, the earth ground terminal being connected to earth ground, and the output terminal being coupled to a plurality of controllable electronic ballasts, each ballast being adapted to light at least one fluorescent lamp;
• the plurality of ballasts adapted to being connected in parallel with each other and to the AC source, each ballast having an address, a hot connection, a neutral connection, and an earth ground connection, the hot connection being coupled to the output terminal of the control station, the neutral connection being coupled to the neutral wire of the AC source, and the earth ground connection being connected to earth ground, the plurality of ballasts being operable to draw a supply current from the AC source;
• the control station and each ballast being coupled such that the control station is operable to send a control command to at least one address corresponding to a desired ballast, upon reception of which the desired ballast executes the control command, resulting in a perceptible change in the supply current drawn by the plurality of ballasts from the AC source;
• the control station including:
• an interface for accepting and translating user commands into control commands;
• and
• a transmitter for sending control commands to the desired ballasts by means of a power-line communication scheme wherein the existing AC power wires serve as a transmission medium and the control station transmits control commands to the ballasts by inducing a depression in the voltage supplied by the AC source to the ballasts in a predetermined sequential fashion;
• each ballast including a receiver for accepting control commands sent by the control station and an execution means for executing control commands sent by the control station;
• the control station further including a monitor for monitoring the current drawn by the plurality of ballasts and a comparator for confirming execution of the control command by comparing the supply current drawn by the ballasts prior to the sending of a control command with the supply current drawn by the ballasts after execution of the control command;
• and
• the control station being further operable to transmit at least one predetermined master command that effects a predetermined control action in a designated group of ballasts that includes at least two of the ballasts, but that does not effect a control action in those ballasts coupled to the control station that are not part of the designated group of ballasts.