Abstract: A method for starting and operating a preheat type fluorescent lamp includes a source of alternating current, a fluorescent lamp having a low impedance starting mode wherein current passes through one or more starting filaments and a high impedance operating mode wherein current passes through the length of the lamp, a starting switch directing current through the starting filaments in the lamp starting mode, and an inductor ballast having a magnetically permeable core operating in a saturated condition when the lamp is in the low impedance starting mode and in a non-saturated condition when the lamp is in the high impedance operating mode.

Abstract: System for controlling operation of a plurality of gaseous discharge lamps for selectively turning on or off one or more of the lamps and producing desired lumen output of the lamps as needed, to provide for conservation of electrical energy. In the system, each of the discharge lamps is connected to a separate variable impedance ballast device, a control circuit for varying the impedance of each ballast device, and a signal processing circuit connected to each control circuit for operating the same, and a signal transmitting device for transmitting information to each of the signal processing circuits, whereby the latter circuits selectively operate the respective control circuits in response to the information received from the signal transmitting device. In a preferred embodiment, the signal transmitting device is a remote transmitter such as a radio frequency signal device for remote control of the lighting system.

Abstract: A discharge lamp is ignited in every half cycle in its operating system including a discharge lamp operating circuit provided with a low frequency alternating current power source, a single winding type current limiter. The discharge lamp is connected to the power source through the current limiter and a series circuit including a high voltage output generator is connected in parallel to the discharge lamp. The high voltage output generator operates during the lamp operation for reigniting the discharge lamp. The voltage of the low frequency alternating current power source is set to less than the required reignition voltage of the discharge lamp during its operation, whereby the lamp current stabilizer size is minimized. Further, a filament preheating circuit is arranged to use current derived from the high voltage generator. The filament preheating circuit is combined with this operating circuit and so is a time delay for assuring a stable operation.

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: High efficiency push-pull inverters minimize undesirable energy losses usually resulting from simultaneous conduction and imperfect switching of the transistor switching means. In each of the disclosed circuits, a saturable inductor and a diode are connected in parallel and across the base-emitter junction of each transistor. Voltage on the base of each transistor causes its associated saturable inductor to saturate, and the saturated inductor then terminates the flow of base current and provides a path for rapid evacuation of the charge carriers stored in the transistor base-emitter junction in order to render the transistor rapidly non-conductive. Each diode provides a drain path for current continuing to flow through its associated saturable inductor after junction evacuation. A novel triggering means initiates oscillation of the inverters.

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 control circuit comprising a series transductor coupled between an A.C. source and an A.C. discharge lamp. The control windings of the series transductor are connected to the A.C. source through a filter, a full-wave rectifier, and a substantially capacitive impedance. As a result the total reactive effect is reduced.

Abstract: Circuit for regulating the wattage drawn by a high-intensity-discharge (HID) lamp and for limiting the line current drawn by the lamp during starting to less than the line current drawn during normal lamp operation. The circuit includes a lamp current controlling means which has two operating modes, a first of which passes a less-than-nominal current to the lamp and a second of which passes a greater-than-nominal current to the lamp, with the ratio of the current of the second mode to the current of the first mode being less than 2:1. The lamp voltage is sensed and the line voltage also is sensed and these parameters are converted into separate current signals which are fed into a ramp capacitor to control the charging rate thereof. When the ramp capacitor achieves a predetermined level of charge during each half cycle of energizing potential, an AC switch is gated to shift the current controlling means from the first mode to the second mode.

Abstract: Variable inductance ballast apparatus for high-intensity discharge (HID) lamp comprises a laminated E-I core having non-magnetic gaps intermediate the E-conformed and I-conformed members. A main winding is carried on a leg of the E-conformed member to provide two closed magnetic paths. A control winding is wrapped about another of the legs and encircles only one of the closed magnetic paths. A bilateral switch connects to the control winding and is actuated by a signal-generating means which is responsive to a lamp operating condition to close the bilateral switch once each half cycle of energizing potential during normal lamp operation, with the resulting counter mmf decreasing the inductance of the ballast apparatus by a predetermined amount to control in a very accurate, simple and inexpensive fashion the average power delivered to the lamp.

Abstract: A high frequency transistor ballast is utilized to drive flourescent lamps. The electrical system of the ballast consists of a central rectifying and control panel and a high frequency inverter. There is also provided a low energy switch in the high frequency inverter system controlling the operation of the high frequency transistor ballast.

Abstract: An electrodeless RF excited gas arc lamp for pumping a laser has a lamp envelope in the form of a loop having a continuous bore containing krypton, xenon or argon. Sufficient RF power to maintain a plasma in the gas in the loop is provided by a coil around its circumference so that it is linked by the flux generated by RF voltage through the coil. The laser rod to be pumped is mounted adjacent the loop. A diffuse reflector surrounds the lamp and laser rod to reflect back toward the rod light which does not impinge directly on the rod as well as any impinging light not initially absorbed by the rod.