Abstract: A diagnostic apparatus for use in a light dimming circuit of the tape which selectively controls the current flow through a lighting load to adjust its luminous output. The dimming circuit has a controllably conductive device, such as a triac, connectable in series between an A.C. power source and a lighting load, and a control circuit which responds to a dimming level control signal to selectively apply a selected portion of an A.C. voltage waveform produced by the A.C. power source to the lighting load to adjust the RMS voltage across the load. The selected portion is determined by a firing angle at which the control circuit causes the controllably conductive device to conduct power during each half cycle of the A.C. waveform. The diagnostic appararus has a senior to sense the operating status of a component of the dimming circuit and/or the presence of the dimming level control signal.

Abstract: A lighting dimmer for controlling the current through a lighting load includes circuitry for applying a predetermined dimming level control signal to a control circuit in response to the absence of a dimming level control signal and the cycling OFF and ON of a circuit breaker. The dimmer further includes voltage compensation circuitry for maintaining a constant lighting load current notwithstanding short-lived changes in nominal line voltage.

Abstract: A dimmer panel for controlling the intensity of a plurality of electric light sources includes a plurality of dimming circuits. Each dimming circuit has a control circuit, a heat producing controllably conductive power switch such as a triac, and a heat producing coil such as a choke. The power switches and coils are arranged on a corrugated heat sink to minimize component temperatures in the dimming control circuit and of the power switches. The heat producing coils are remotely located from the control circuit and the power switches, so that the heat generated by the coils does not increase the temperature of the components in the control circuit or of the power switches.

Abstract: A lighting control system operates to control multiple zones of lighting through multiple dimming circuits so as to achieve any one of several desired lighting scenes. The system includes a plurality of wallbox control units which collectively operate to multiplex digital lighting control information on a communications link. Each wallbox control unit includes a plurality of zone-intensity actuators which are manipulatable to alter the information transmitted by their respective wallbox control so as to vary the lighting intensity of an associated lighting zone. A central lighting control panel includes a microprocessor adapted to receive and processes the multiplexed information transmitted on the link, and re-transmit digital lighting control information, on a second multiplex link, to the dimming circuits.