Abstract: A device and method(s) for implementing an AC line-powered primary-tap switching power supply which is easily or automatically switchable between a first configuration which supports a first input voltage, e.g., a 120 VAC input voltage, and a second configuration which supports a second input voltage, e.g., a 240 VAC input voltage, which is an integer multiple of the first input voltage, is described.

Abstract: Systems for reducing the power consumption of fluorescent lights are provided. The systems can be used in new construction as well as retrofitted into existing buildings employing overdriven fluorescent lights without significantly affecting the operation of utility power lines. In preferred embodiments, the systems provide substantially constant light output during start-up and low voltage conditions.

Abstract: A multiple lamp instant start ballast system has multiple fluorescent lamps and a ballast. The lamps have substantially similar current characteristics. The ballast has a ballast circuit operable to supply instant start starting voltages and operating currents, with the voltages and currents being approximately equal in magnitude and differing in phase by 360°/n, where n is the number of lamps. By connecting the ballast output leads to the first end of each lamp, the second ends of the lamps may be connected together creating a balanced n-phase system. Thus, wiring between the ballast and the second ends of the lamps is unnecessary. An improved light fixture adds a chassis and lamp sockets to the multiple lamp instant start ballast system described. The standard wire-way and wire-way cover are obviated since no wiring need be run to the second ends of the lamps. Wiring may be reduced by locating the ballast adjacent to the lamp first ends.

Abstract: A voltage controller for use with a fluorescent-lighting system, the controller including a three-phase transformer having three auto-transformer windings each for developing two reduced voltages, three contactors for selectively coupling the full voltage and the reduced voltages to the lighting system, the contactors being switched in closed-transition fashion to avoid power interruptions, and another contactor for opening the winding-neutral connections during voltage switching to avoid shorting the transformer.

Abstract: A three phase voltage controller for controlling the voltage applied to a three phase load. The controller includes three autotransformers which have a plurality of output taps for stepping down the output voltage. Contacts to the taps are selected for a high output voltage and a low output voltage with the contacts selected either manually or automatically. In the automatic mode, time delay is provided in switching from a high output voltage to a low output voltage, and a re-cycle timer is provided to re-cycle from a low voltage to the high voltage temporarily. Single phase control contactors are provided to remove voltage from one or more output lines for load shedding. Circuit breakers are provided for removing the controller and for directly applying the input line voltage to the output line.

Abstract: Circuits and auxiliary elements for use with a device for controlling the emission of light pulses from a flash unit, which light pulses are produced by the discharge of current pulses from a capacitor, the device including a light sensing element for receiving light produced by the flash unit and reflected from an object in the light path. One such circuit includes two zener diodes for providing threshold voltages for use in comparing the output of the light sensing element. Another such circuit compensates for nonlinearities in the response of certain components of the device.