Abstract: The above and other objects, advantages and capabilities are achieved in one aspect of the invention by an output circuit for an electronic ballast system. The circuit includes N sets of output connections for accepting N lamps. The lamps are driven by an output autotransformer coupled to the lamps through a feedback winding that is used to apply a feedback signal to an inverter drive circuit. Capacitive impedances are coupled across the lamps so that the capacitances, the lamp filaments, the feedback winding, and the output transformer form a circuit loop. The capacitances are chosen to have an impedance, at the inverter operating frequency, less than the pre-ignition impedance of the lamps and greater than the post-ignition impedance.

Abstract: An electronic ballast-inverter circuit for powering one or more fluorescent lamps or the like includes two identical circuits operating at different DC offsets, each circuit including a tank circuit composed of a primary winding of the power transformer and a capacitor such that each tank circuit resonates at the same frequency, and including a switching transistor connected to each tank circuit. These two transistors are operative on alternate half cycles of the sine wave generated by the inverter, so as to obtain the push-pull operation needed by the inverter. Each circuit includes a base drive current source for each transistor that is controlled by the polarity of an additional primary winding of the power transformer. For improved efficiency, the circuit is designed to be operable from an unsmoothed DC voltage source.

Abstract: An energy efficient lighting unit is described designed for functional similarity to the incandescent light used in the home. The lighting unit utilizes a metal vapor arc lamp as the main source of light supplemented by a standby filamentary light source. The lighting unit includes means for converting 60 hertz ac to dc, and a dc energized operating network containing a three transistor switch. The transistor switch is used to provide dc and low frequency (120 Hz) energization to the filament, and high frequency energization for both filament and arc lamp. The high frequency energization, which starts and transitions the arc lamp, is discontinued after the arc lamp is started. In the final run state, the arc lamp, which is serially connected with the filament across the dc supply, is ballasted by the filament.

Abstract: A high frequency oscillator-inverter ballast-ignition system for a discharge lamp includes a leakage reactance transformer that forms a part of the oscillator-inverter and also couples same to the discharge lamp. An impedance element electrically couples the primary and secondary windings of the transformer in additive phase to provide more reliable lamp ignition over a wider range of voltage and temperature than was heretofore possible. The preheat time period of the lamp cathodes can be better controlled by a proper choice of the transformer heater winding turns.

Abstract: An energy efficient lighting unit is described designed for functional similarity to the incandescent light used in the home. The lighting unit utilizes a metal vapor arc lamp as the main source of light supplemented by a standby filamentary light source. The lighting unit includes means for converting 60 hertz ac to dc, and a dc energized operating network containing a three transistor switch. The transistor switch is used to provide dc and low frequency (120 Hz) energization to the filament, and high frequency energization for both filament and arc lamp. The high frequency energization, which starts and transitions the arc lamp, is discontinued after the arc lamp is started. In the final run state, the arc lamp, which is serially connected with the filament across the dc supply, is ballasted by the filament. The transistor switch is controlled in its operation by an integrated circuit.

Abstract: A lightweight, transistorized, inverter circuit is particularly adapted for starting and operating a screw-in compact fluorescent lamp intended for incandescent lamp replacement. Household-type AC is converted to DC with one terminal connected to the center tap of a transformer primary through a choke which constitutes a high impedance at the operating frequency. A tuned circuit capacitor is connected across the transformer primary and a current-limiting capacitor and the lamp to be operated are connected in series across the transformer primary. A pair of transistors are connected in push-pull arrangement between the end portions of the transformer primary and the other terminal of the DC source, with the base electrodes of the transistors connected to the transformer secondary winding so that the push-pull connected transistors oscillate at the tuned circuit resonant frequency which is determined by the inductance of the transformer primary winding and the total capacitance of the connected capacitor means.

Abstract: Applicant has provided a ballast circuit for fluorescent lights made up of the combination of (1) a source of electrical energy, (2) a resonant circuit, (3) a switch means for connecting the source of electricity to the resonant circuit, (4) means to connect the resonant circuit to a load, (5) a resonant current monitor controlling the switch means in synchronism with the resonant current so that the switch means switches the resonant current when the resonant current passes through zero.The resonant current monitor is a current transformer having a primary winding connected in series with the resonant circuit and two secondary windings connected to the bases of the two switching transistors in a two transistor inverter circuit at a polarity that will switch one of the transistors on and the other off at the time current passes through zero.

Abstract: A starter for igniting a gas and/or vapor discharge tube (1) comprising two main electrodes 53, 54 and an auxiliary electrode 70. The discharge tube is connected to an inductive stabilization ballast 52. The starter applies an ignition voltage between the auxiliary electrode and a main electrode of the discharge tube. Tube ignition is promoted by connecting a capacitor 55 in series with a semiconductor switching element 58 across the starter input terminals A,B so that - in addition to the said ignition voltage - an increased voltage is generated between the two main electrodes of the discharge tube by cooperation of the inductive ballast and the capacitor.

Abstract: A stabilized dimming circuit for an electronic ballast system. The dimming circuit includes a transformer having a variable inductance primary included as a part of a feedback loop comprising a push-pull inverter and an output transformer for supplying a drive signal to a lamp filament. As the inductance of the primary is varied (decreased), the amount of feedback applied to the inverter is varied (increased) and the lamp brightness dimmed accordingly. The secondary of the dimming transformer is included in a loop that is completed by a secondary winding of the output transformer and a lamp filament. Because the voltage induced in the secondary of the dimming transformer is held relatively constant, the voltage applied to the filament is stabilized in spite of varations in the amount of power supplied to the lamp.

Abstract: An inverter ballast for fluorescent lamps utilizing a resonant circuit coupled to the lamp and operated from a source of DC power through transistors. The transistors are controlled by a sensing means in the resonant loop which insures that the transistor switch at zero current. Furthermore, the coupling means for the load controls a source of heater voltage to the anodes of the fluorescent light which operate at very low current, an antisaturation circuit made up of separate windings are on the current transformer and connected to the switching transistor bases and through diodes to the power supply to prevent "shoot through" current in the transistors. An autotransformer is used as a high leakage reactance transformer; and a circuit is provided to prevent overload of the resonant circuit in case of lamp failure. Shoot through currents are prevented, and overload of the resonant circuit is prevented, and an autotransformer coupling of the resonant circuit to the load is used.

Abstract: A delayed starting circuit for an electronic ballast system that includes an inverter coupled to a secondary voltage source. The starting circuit includes a voltage divider having an input coupled to a charge storage capacitance in the voltage source and an output coupled through a semiconductor switching device to an input of the inverter. The switching device remains non-conductive until the capacitance has been substantially charged, thereby protecting the inverter from transients encountered as a surge of charge is delivered to the capacitance subsequent to the initial energization of the ballast circuit.

Abstract: A power supply for electrostatic apparatus provides a high voltage output. The high voltage output is provided by the half wave rectification and filtering of a pulse signal from a secondary winding of a high voltage pulse transformer. The primary winding side of the high voltage pulse transformer is connected in a series loop circuit with a capacitor and a switching device. The capacitor is charged through an input choke connected to a DC supply source. The switching device is triggered after the capacitor is charged such that the capacitor is discharged through the primary winding of the high voltage transformer. The inductive collapse of the high voltage output transformer provides for the turnoff of the switching device and also serves to partially recharge the capacitor. The half wave rectified high voltage output of the power supply is obtained from the recovery pulse of the high voltage pulse transformer.

Abstract: A high efficiency controlled direct current source for operating high pressure mercury or metal halide lamps for use as substitutes for ordinary incandescent lamps. The circuit includes a voltage sensitive circuit for pulsed starting of the arc discharge lamp as well as for the activation of an auxiliary incandescent filament during the warm-up or hot restart of the arc.

Abstract: A power supply system for operating fluorescent lamps in a hazardous atmosphere comprises a 1 kHz to 500 kHz constant current power supply which feeds primary windings of transformers which are connected together in series. Fluorescent lamps are connected across the transformer secondary windings. A voltage control circuit is connected to the supply supply output to ensure that the amount of electrical energy supplied to the transformers cannot ignite the atmosphere under any normal or fault condition. Capacitors are connected in series with the transformer primary windings to reduce the circuit reactance so that, for a given level of supply voltage, an increased number of lamps can be fed with starting voltage. Due to the substantially constant current which is fed through the transformer primary windings, the situation cannot occur that the firing of one lamp prevents the others from firing. The transformers preferably include windings to feed heaters of the lamps.

Abstract: A lighting inverter for operating an electrical discharge lamp from a direct current power source. The inverter includes a resonant feedback inverter which converts the output of the d.c. power source to an alternating current output and regulates the a.c. inverter output voltage level by varying the frequency thereof. A ballast filter is coupled to the regulated output of the resonant feedback inverter and is formed by a series circuit of a ballast inductor and a ballast capacitor. Connected across the capacitor is the discharge lamp. Appropriate circuit parameters such as ballast inductance, ballast capacitance, inverter operating frequency, and the inverter resonant frequency are selected to maintain almost unity power factor at the input to the ballast filter.

Abstract: An illumination control system for gas discharge lamps which can be dimmed is provided in which a central inverter produces sinusoidal output voltage at about 23 kHz. The amplitude of the inverter output is adjustable to dim the lamps. A transmission line consisting of spaced wires having respective thick insulation sheaths distributes the high frequency power to remotely located assemblies of ballasts and lamps. A high power factor rectifier network is disclosed for providing a d-c input to the inverter from the 50/60 Hz mains. Several ballasts are disclosed, which consist principally of circuits using passive linear components. Some of the ballasts disclosed are conjugate ballasts which are those made of complex conjugate impedances which resonate with or near the input power frequency. Some ballasts disclosed are non-linear when the lamp is out in order to limit the open circuit voltage. The ballasts disclosed all have the following characteristics:(a) good power factor (above 0.

Abstract: A laser head uses nitrogen gas to provide output in the far ultraviolet region of radiation. The laser is supplied from an energization system including low voltage and high voltage sections. The low voltage section is supplied from a low d-c voltage, stepped up over a transformer and applied as pulses to a high voltage section, including a voltage doubler circuit. The doubler circuit includes two diode assemblies, and this circuit provides the high voltage pulses for energizing the laser head when a spark gap breaks down. The opposed electrodes of the laser head each have a serrated edge, and the serrated edges face each other to effect a pre-ionization of the gap between the electrodes. A capacitor, coupled across the laser head electrodes, has a particular construction to withstand the repeated, very rapid discharges occasioned for firing the laser, and this capacitor contributes to a laser construction which is truly portable.

Abstract: A highly energy efficient lighting system for fluorescent lamps is provided comprising a blocking oscillator having a dimmer for reducing power consumption. In one embodiment a built in power supply transformer and a battery charger provides for AC operation, portability, and emergency lighting situations. The fluorescent lamp is excited in an energy efficient manner by a high frequency blocking oscillator circuit and the dimmer permits reduction of light output reducing power drain even further thereby enabling longer battery operation, reduced size, and reduced operation costs. Also the dimming feature is important in establishing a proper mood simulating candlelight, etc.

Abstract: A high power factor conversion circuit suitable as a ballast circuit for lamps includes a full-wave rectifier coupled to an AC potential source and providing a pulsating DC potential. A high frequency inverter is coupled to a load circuit and to a feedback rectifier circuit supplying a rectified high frequency potential to an energy storage feedback circuit which provides energy in a manner to inhibit a decline in the pulsating DC potential thereby providing a substantially uniform DC potential to the high frequency inverter.

Abstract: The present disclosure relates to a power supplier for a magnetron for use in electric appliances, such as a microwave oven. The power supplier of the present disclosure has a solid state frequency converter which changes commercial A.C. power to A.C. power at a high frequency, which A.C. power is increased in voltage in a step-up transformer and then fed to the magnetron. The power supplier further has a control system which stabilizes the power to be applied to the magnetron with respect to a preselected reference level and a power supplier protecting circuit for protecting the power supplier from an unexpected low voltage occurring in the commercial power source.

Abstract: To prevent spurious responses of a semiconductor switching element used in triggered magneto-type semiconductor ignition-switching systems, primarily due to noise signals introduced by the magneto, the control circuit for the ignition system includes a common, parallel connected R/C compensation circuit, connected through decoupling diodes to the ignition trigger pulse sources for the respective cylinders and the grounded main terminal of the switching element to supply a compensating voltage which suppresses noise voltages which increases with increasing speed of the internal combustion engine and thus dynamically compensates for generated noise pulses.