Abstract: A lighting system made up of a plurality of light fixtures which each produce a light beam, in which each of a plurality of varying devices, each having an input and an output, and each capable of varying at least one parameter of the light beam from at least one of the light fixtures, is responsive to a first value received at the input, where the first value corresponds to the desired adjustment of a parameter of the light beam. Each of the varying devices is also capable of generating a second value which represents status information, and transmitting the second value via the output. A controller produces the first value and sends it to an output which is coupled to the input of the varying device. A monitoring device has an input and is separate from the controller, and its input is coupled to the output of the varying device.

Abstract: Lamp dimmers are disclosed in which, in the course of varying average power supplied to the lamp load, the semiconductor power control devices transition between one and the other of substantially conductive and non-conductive power conditions, the duration of the transition by the power control devices themselves is increased beyond the minimum possible duration to reduce generated EMI. The dimmers disclosed provide for varying the direction, duration, shape, and phase angle of transitions.

Abstract: A light dimmer is provided in which semiconductor power devices for each of the polarities of an alternating current supply are coupled between the alternating current supply and a lamp load. In the course of varying average power supplied to the lamp load, the semiconductor power devices transition between an initial one and a subsequent other of substantially conductive and non-conductive power conditions. The duration of the transition by the power device is increased beyond the minimum possible duration to reduce generated EMI. Methods of restoring each power device to its initial condition, including during a subsequent half-cycle, are described.

Abstract: A lighting control system distributes both the alternating current supply and control signals representing desired adjustments to fixture parameters, such as intensity, via connections including power contacts and, for control signals, an electrically isolating coupling comprising an effective source and detector.

Abstract: A light dimmer with semiconductor power devices coupled between an alternating current supply and a lamp load, in the course of varying average power supplied to the lamp load, transitions the power devices under load between one and the other of substantially conductive and non-conductive conditions, increasing the duration of the transition by the power device itself from the minimum possible duration to reduce generated EMI. Undesirable effects of the high current demands of cold lamp filaments are reduced by initially increasing the conductive portion of half-cycles, relative to the proportion required to produce the desired amount of average power, while avoiding transitions at phase angles that would produce excessive losses. A transition shape may be employed in this mode and in normal operation that maximizes audible lamp noise suppression for a given level of thermal losses.

Abstract: A light dimmer, especially useful for entertainment lighting, provides a high degree of stability in dimmer performance by employing a high level of analog negative feedback and correcting for the undesirable effects on dimmer "curve" by precompensating the input value while it is digital. A lighting control system distributes both the alternating current supply and control signals representing desired adjustments to fixture intensity via a housing common to multiple enclosures. Each enclosure contains at least one dimmer and mechanically engages the housing, from which it obtains a power input via power contacts and a control signal via an electrically isolated coupling comprising an effective source on the housing and detector on the enclosure.

Abstract: An electronic dimming apparatus adapted for use in a distributed dimmer system, the distributed dimmer system comprising at least one alternating current supply; a plurality of lamp loads at spaced apart locations; a plurality of dimmer enclosures, the dimmer enclosures adapted to be located at spaced-apart locations in proximity to the lamp loads, each of the dimmer enclosures containing at least one semiconductor power controller coupled between a power input and a power output, the power output coupled to at least one of the lamp loads by at least one power connector; elongated power conductors coupling the power input of each of a plurality of the dimmer enclosures to the alternating current supply, at least a portion of the elongated conductors disposed within an elongated, substantially rigid enclosure, the enclosure mounting a plurality of power connectors at spaced-apart locations; and a trigger for variably controlling the average power supplied to the lamp load, the trigger responsive to at least a

Abstract: An improved dimming apparatus adapted for use in distribution dimming systems, in which dimmer enclosures each containing at least one semiconductor power controlling means are located in a plurality of spaced apart locations, each such enclosure located in proximity to at least one of its associated lamp loads. The disclosed dimming apparatus achieves unique advantages in the application through the use of a semiconductor power controlling means capable of modulating the instantaneous amplitude of the voltage or current supplied to the lamp load under the active control of its control input, a signal being applied to the control input of the power controlling means such that an output waveform is supplied to the lamp load in which at least one transition between a substantially off condition and a substantially on condition occurs during substantially each discrete half-cycle of the AC source and the duration of the transition is increased to suppress electro-magnetic interference.

Abstract: An electronic dimming apparatus includes a semiconductor power controller which couples a lamp to an alternating current source and variably controls the average power supplied to the lamp by adjusting the relative proportion of each half-cycle in which the power controller is in a conductive condition. The semiconductor power controller is controlled by the output of a transition controller which in turn is connected to a triggering circuit. The triggering circuit is responsive to a first input condition corresponding to desired average power and also responsive to the zero-crossing of the alternating current waveform. The transition controller gradually changes the condition state of the semiconductor power controller between non-conduction and conduction and controls the voltage across the lamp load to maintain a stable rate of voltage change despite lamp impedance variations, thus reducing electromagnetic interference.

Abstract: In a lighting console which provides outputs to dimmers which include master controls for at least two scenes and channel controls for each of a plurality of channels with the channel controls including at least a first and second scene preset potentiometer, the channel controls and master controls cooperating to allow presetting, and which also includes a buss, with one of the preset potentiometers for each of a plurality of the channels connected to the buss and an output from the master controls being used through suitable amplifiers to drive the buss, a plurality of nondestructive current limiting fault isolating devices are provided for each scene, each connected between the master and at least one of the preset potentiometers for that scene. As a result, the effects of a fault causing abnormal currents to flow which develops after the fault isolating means will not disrupt the operation of channel potentiometers connected to other fault isolating means.

Abstract: The disclosure relates to an electronic dimmer with specific computer control especially for theatrical productions with an emphasis upon improved electronic processing especially a parallel access memory.

Abstract: A split cross fader for the control of theatre lighting in which functions previously found only in separate master control units and cross fader units are combined into a single device which permits operation as a scene master, as a cross fader and also permits pile-on operation with smooth fading between each scene condition commanded.