Abstract: Ignition circuit for a gas discharge lamp. In the ignition circuit, the generating of uniform current pulses for ignition over the entire useful life of the gas discharge lamp is guaranteed. A control circuit is provided for holding constant the current-time integral of current pulses applied to the gas discharge lamp during ignition.

Abstract: A protective device for a neutron tube including an ion source having an anode (2) which is brought to a positive potential relative to a cathode (3) by means of a source supply. An ion beam accelerated by means of an acceleration electrode (5) strikes a target (6) disposed on an insulating support (9) and brought to a negative potential supplied by an HT supply. The protective device includes electric elements (11, 12) limiting the tube current and/or the target voltage, which are made unalterable by enclosing them inside the neutron tube, so that any attempt to modify the electrical parameters determining the normal operating conditions of the tube necessitates the opening of the tube.

Abstract: One or more power dimmers have a preshaped phase controlled input signal connected to their control input. The preshaped phase controlled input signal is generated from the output of a master dimmer having conventional phase control circuits operated from a manual or other control. A relay having contacts in the output circuit of the power dimmers is opened in response to the reduction of the phase controlled input signal to a value less than a given value. In an alternative embodiment, the power dimmers are replaced by an interface circuit which produces a variable frequency, pulse width modulated or other signal.

Abstract: A double dimming three-way light control system is disclosed wherein light intensity may be controlled from two different locations. Dimming switches have dimming circuitry with on/off capability as well as normally open contacts for operating a latching relay. The latching relay has two momentary contact coils associated with normally open and normally closed contacts which direct current from the two switches to the light fixtures.

Abstract: During operation of ionized vapor discharge lamps and the partial load range, the lamp current is reduced from the rated value, the drop in voltage is measured during and after the reduction of the lamp current, and when the period of constant voltage that follows the drop in voltage is reached, the lamp current is increased accompanied by simultaneous determination of the increase in voltage. The lamp current is thereupon controlled in such a way that during the partial load range operation of the lamp, the voltage value is slightly greater than that of the voltage of the period of constant voltage.

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: A three-way light dimmer switch is shown wherein the brightness of a lamp or lamps is controlled by independent light dimmer switches with each dimmer switch having its own light dimmer circuit. Each of the light dimmer switches is vertically actuated with one end of the vertical movement turning the lamp or lamps ON, and the other end of the vertical movement turning the lamp or lamps OFF. Between the limits of vertical movement, either of the light dimmer switches may vary the voltage potential received by the lamp to thereby adjust the brightness of the lamp.

Abstract: An electronic ballast for starting and operating gaseous discharge lamps from a low voltage d-c source which employs a regulated inverter providing controlled high ignition voltage, constant current warm-up and constant wattage operation for one or more lamps.

Abstract: An improved solid state electronic dimmer circuit for controlling the intensity of large electric lamps, such as theater and television lamps, in response to a low power DC control signal. The transfer characteristic of the circuit is determined by the properties of a generated precision waveform having a predetermined shape and amplitude and a fixed phase relationship to the power line voltage which, in conjunction with the DC control signal, determines the effective voltage at the output of a dimmer unit. The same precision waveform may be used to control a plurality of dimmer channels, thereby making possible precise matching of performance of all commonly controlled channels, and effecting significant savings in the cost of manufacture.