Abstract: Circuits are disclosed for use in a gaseous-discharge lamp lighting system which provide starting pulses to the lamp and/or a source of auxiliary light. One circuit provides starting pulses and/or auxiliary light until the gaseous-discharge lamp approaches its normal operating condition, while other circuits terminate these functions once the gaseous-discharge lamp ignites.

Abstract: A network for the development of a square wave in a first time period as set by the timing occurrence of a first voltage to a predetermined threshold level and another network for the development of a square wave in a second time period as set by the timing occurrence of a second voltage to a predetermined threshold level. One square wave is chopped at a high frequency rate and the second square wave is chopped at the same high frequency rate, but by a chopping signal which is polarity inverted in phase from the first chopping signal. One of the chopped signals is polarity inverted before being combined with the other chopped signal to form a composite voltage. Separate lamp control networks can select between the two chopped signals to control dimming networks. The two chopped signals can overlap in time occurrence without interfering with the operation of each other.

Abstract: A regulation circuit for providing timing gate signals to the dc power section of a power supply, the regulation circuit utilizing phase angle conduction of a programmable unijunction transistor. The conduction angle is determined by the occurrence of the cycles of the ac source voltage unless earlier conduction is determined by the sensed dc voltage. Early conduction occurs when the control voltage to the PUT is allowed to build up beyond a predetermined level when the sensed dc voltage is low. When the sensed dc voltage is high, an electronic switch closes to discharge a storage element to prevent control voltage build up and, hence, early conduction. Ac source voltage failure also causes closing of the electronic switch to prevent undue regulation of the power section output at such times and to permit storage capacitors therein to maintain a dc output until source voltage is reestablished.

Abstract: A circuit for providing a dc pulse, such as to a gated semiconductor for at least partial bypass of a ballast element connected to an HID lamp, the pulse being developed within a time range of an associated ac voltage. A first timer operably connected to the ac voltage produces a first dc output pulse and a second timer connected to the output of the first timer produces the circuit dc pulse output. Reduction of a threshold control voltage of the first timer permits a time constant network connected thereto to advance the conclusion of the output of the first timer forward within its operational range. A time constant network connected to the second timer has charge current added to it from the first timer control voltage, the amount of such current decreasing with an advance positioning of the output of the first timer, thereby increasing the slope of the charge-up voltage of the second time constant network and shortening of the related square wave or dc pulse output from the second timer.

Abstract: A dimmer circuit for a high intensity, gaseous discharge lamp having a ballast with a reactive portion, the current bypass or partial bypass of which determines the brightness of the lamp, the bypass being controlled by gated bypass means, preferably in the form of a triac, driven by the photodrive element of an optocoupler, the light emitting diode element of the optocoupler receiving pulses and actuating the photodrive element for passing a gate trigger signal to the gated bypass means.

Abstract: A dimmer circuit for providing gate signal to a gated semiconductor connected for at least partial bypass operation of a ballast element of an HID lamp, the gate signal being derived from a high frequency voltage in a predetermined range. The high frequency voltage is separated from other frequencies and converted to a voltage proportional to the frequency. The voltage is then converted to a pulse within the timed operational limits of the line voltage for gating the semiconductor, and hence producing a brightness of the lamp between predetermined limits of full dim to full bright. Preferably, the high frequency voltage carrying the control information arrives superimposed on the line voltage to thereby avoid having to use a separate set of leads to the lamp to provide light level control signalling.

Abstract: A circuit for providing remote control at a plurality of locations for a lighting system, such control functions including on/off, dimming intensity and rate of dimming. Visual indication of take control is also provided.

Abstract: Circuits are disclosed for use in a gaseous-discharge lamp lighting system which provide starting pulses to the lamp and/or a source of auxiliary light. One circuit provides starting pulses and/or auxiliary light until the gaseous-discharge lamp approaches its normal operating condition, while other circuits terminate these functions once the gaseous-discharge lamp ignites.

Abstract: An automatically variable d.c. voltage source supplies a control signal to a dimmer circuit that controls the brightness of a high intensity gas discharge lamp in response to a varying d.c. voltage. The automatically variable d.c. voltage source produces a varying d.c. voltage at its output which is functionally related to the difference between a voltage from a stable reference voltage source and a voltage produced by a photocell circuit which is responsive to the light level of an area illuminated by the lamp controlled by the dimmer circuit. The variable d.c. source includes circuitry for indicating relamping conditions.