Abstract: High-efficiency inverter circuits, particularly half-bridge devices, are especially suitable for energizing gas discharge lamps. The inverters preferably employ a series-connected combination of an inductor and a capacitor to be energized upon periodic transistor conduction. Transistor drive current is preferably provided through the use of at least one saturable inductor to control the transistor inversion frequency to be equal to or higher than the natural resonant frequency of the inductor and capacitor combination. The inverters can develop high output voltages to supply external loads connected to the inductor-capacitor combinations.

Abstract: A small electronic module to regulate the power delivered to a lamp or similar appliance is plugged into the household electrical outlet and the lamp to be controlled is, in turn, plugged into the module. Each time the lamp is touched the power to the bulb increases by one step, typically in the sequence OFF, DIM, INTERMEDIATE, FULL, OFF. The module device operates by sensing the capacitance change when the lamp is touched and communication between the lamp and the device occurs through the lamp cord.

Abstract: The present invention consists of a modulation circuit used in a digital application. The modulation circuit is designed to provide an LED with a more analog type signal. This in turn causes the LED to emit a signal that is peaked rather than a constant square wave providing a better conversion frequency to the fundamental frequency.

Abstract: A source of 120 Volt/60 Hz power line voltage is full-wave-rectified and yields an unfiltered DC voltage pulsed at 120 Hz rate. This pulsed DC voltage is applied to an inverter of a type that must be triggered into oscillation. At the beginning of each of the DC voltage pulses, the inverter is triggered into oscillation; and at the end of each of the DC voltage pulses, the inverter ceases to oscillate frm lack of adequate voltage to sustain oscillation.The output of the inverter is a 30 kHz squarewave voltage amplitude modulated at the 120 Hz rate. Across the inverter output is connected a high-Q series L-C circuit resonant at about 30 kHz. A fluorescent lamp is connected in parallel with the tank capacitor of the L-C circuit.

Abstract: The present invention provides a power supply for lighting an incandescent lamp with high-brightness, comprising connecting a time constant circuit, rectifier, switching device so that the output of the rectifier is supplied to an incandescent lamp through the impedance for a period, determined by the time constant circuit, and that the switching device conducts and shorts the impedance after a lapse of the period to allow the incandescent lamp to receive the output of the rectifier by bypassing the impedance.

Abstract: A method and apparatus are provided for operating a fluorescent lamp illumination control sytem which comprises an AC voltage source for supplying power to an electrical load comprising a standard transformer-ballast unit driving a fluorescent lamp or lamps which have externally heated cathodes, and a power controller, which includes a capacitive synchronous switch formed by an electronic switch and shunt capacitor, for controlling the "on" time of the lamp or lamps to thereby vary the luminance output thereof to values less than the nominal rated value. The invention provides heating of the lamp cathodes prior to arc ignition, provides arc ignition at a lower arc current level than that for full-on operation, and provides for subsequently gradually increasing the arc current after the arc is struck to a value providing the desired illumination level.

Abstract: A solid state ballast for starting and operating a plurality of fluorescent lamps comprises a plurality of parallel connected, series LC circuits each coupled by a capacitor to a lamp so that voltage existing across the series capacitors is applied across the lamps and driven by an inverter at a DC power source voltage and at a selected frequency high enough to develop a lamp starting voltage but substantially below their resonant frequency. After starting the resonant frequency of the LC circuits is reduced substantially below the selected frequency by the added capacitive reactances of the coupling capacitors whereby the destructive high voltage at the upper and lower resonances is avoided and the independent selection of the values of L and C and the coupling capacitors to control starting voltage and conduction after starting at the selected frequency is provided.

Abstract: An arrangement including a frequency converter (4) and a discharge lamp (10) connected thereto wherein the frequency converter (4) is of a type whose output frequency is at least 80 kHz, while the lamp is a low-pressure sodium vapor discharge lamp. This lamp supply system provides a high luminous efficacy for the lamp.

Abstract: A spark plug for an ignition system has a ring gap between two electrodes. A first electrode has a ring shape defining a central opening. A second electrode is positioned within the central opening of the first electrode. An insulating material is positioned between the first and second electrodes so as to provide a surface for a spark path between the first and second electrodes. The insulating material is spaced from the electrode so as to provide therebetween an air gap for increased sparking.

Abstract: A lighting system for a suspended ceiling comprises a plurality of power conditioning units permanently wired-in with the 120 Volt/60 Hz power line and mounted in various suitable locations on the permanent ceiling above the suspended ceiling. Each such power conditioning unit provides a power-limited Class-3 high-frequency voltage at an output receptacle and is operable to power a special fluorescent lighting fixture by way of a light-weight flexible two-wire detachable connect cord. Special fluorescent lighting fixtures are mounted in the suspended ceiling, with each such lighting fixture being powered from a power conditioning unit mounted somewhere nearby on the permanent ceiling above.

Abstract: An inverter circuit, comprising a control circuit for improving the switching off of transistors (1 and 2). The control circuit includes a secondary winding (16) for an inductive winding (7) included in a load circuit, said secondary winding being connected in series with a winding (17) for a base control transformer (3) of transistors (1 and 2). The control circuit closes itself by way of a diode (21 or 20) and transistor (1 or 2). Thus, a voltage induced in secondary winding (16) indicating the rate of decrease of the collector current of transistor (1 or 2) improves or accelerates the switching off of transistor (1 or 2) when the hazard of simultaneous conduction of transistors increases e.g. as a result of the reversal of loading state or variation of individual characteristics (such as storage time) of transistors.

Abstract: There is disclosed an ignition control circuit of the type which facilitates the storage of energy in an external inductive load during a dwell period and the release of the stored energy from the inductive load through a spark gap at the end of the dwell period. The circuit includes switch means for conducting current through the inductive load during the dwell period, and an integrated circuit for turning the switch means on during the dwell period and off at the end of the dwell period. The integrated circuit includes an output transistor for controlling the switch means, a current source for driving the output transistor, and control means for enabling the current source during the dwell period and disabling the current source at the end of the dwell period.

Abstract: To insure starting of an oscillatory circuit for fluorescent lamp operation scillating, for example, at about 35 kHz, two transistors are serially connected across the output of a rectifier adapted for connection to an a-c network, and the oscillatory circuit is additionally coupled to one of the a-c terminals of the rectifier, to apply to one of the transistors a triggering voltage which recurs with each undulation of the a-c network. The serially connected transistors each have an emitter resistor, which may be a PTC resistor, to balance currents through the transistors and eliminate unbalancing effects of manufacturing tolerances in the transistors. The PTC resistors additionally have current deviation regulating function.

Abstract: A high frequency ballast circuit is provided having first and second power input terminals and first and second power output terminals. The high frequency ballast circuit is powered by an input voltage source, such as an off-line, filtered, rectified dc voltage source. The high frequency ballast circuit has a starting mode and operating mode. The high frequency ballast circuit comprises: a power oscillator circuit having power oscillator first and second output terminals, for converting power coupled from the high frequency ballast circuit first and second power input terminals to a relatively high frequency, quasi-sinusoidal, current-limited voltage source applied between the power oscillator first and second output terminals. A starting circuit for interposing a periodic voltage pulse between the power oscillator first output terminal and the lamp load. The periodic voltage pulse is adapted to exceed the ionization potential of the lamp load during the starting mode.

Abstract: An electronic transformer system for illuminating neon lamps includes a counterphase oscillator coupled to a leakage reactance power transference transformer. The power transference transformer has a secondary wound on a multiple section bobbin in which adjacent sections are separated from each other by a dielectric material. The leakage reactance power transference transformer has a feedback winding which is coupled in series to the primary winding of a pulse generator base driving transformer. The pulse generator base driving transformer in turn provides periodic pulses to the counterphase oscillator to reverse current flow in the primary of the leakage reactance power transference transformer. The electronic transformer system may be powered by commercial alternating current through a full wave rectifier, or by a direct current power supply.

Abstract: The present invention provides a device for regulating an ac current circuit using a magnetic relay which is suitable for use in an incandescent lamp circuit or electric motor circuit to eliminate or reduce inrush-current. The present device comprises connecting power switch, diodes, series resistance and relay such that, after closing the power switch, an ac current first flows to a load through the series resistance for a brief time, then to the load through the contacts of the relay after a lapse of the brief time by bypassing the series resistance.

Abstract: A driving system for a plasma panel display which uses VFETs for output switches controls the transition time of an output waveform to a constant time. Transformerless circuitry for communicating low voltage digital logic signals across a floating boundary to VFET control circuitry is provided. Low voltage control circuitry is isolated from high voltage sources by semiconductor circuitry which eliminates the need for transformer isolation techniques. In an alternative embodiment, the transition of an output waveform is controlled at a constant slew rate.

Abstract: An exclusive plug for artistic table lamps comprising main parts, namely a signal input line, two voltage output lines, a demagnetizing wire, a light-adjustment and switch-actuating operational circuit, and electric power indication light, of which the signal input line and two voltage output lines use a co-axial core cable, and a demagnetizing wire is provided around this three-core cable. The light adjustment and switch-actuation operational circuit is installed in the body of the plug, thus making the plug of this invention, when used in conjunction with a general artistic table lamp, convert the overall external surface of the common artistic table lamp stand into a touch induction surface. This device is completely applicable to the artistic table lamp, no matter whether the table lamp stand is made of a material of low induction coefficient like ceramics, pottery, marble, glass, wood, plastics etc., or even of metallic materials.

Abstract: A light adjustment and switch structure for artistic table lamps, applicable to a touch induction surface of the artistic table lamp socket, as the entire external surface of this socket is set as a touch induction surface made of a material having a good external appearance but with a low induction coefficient such as of ceramics, pottery, marble, glass, wood, plastics, acrylics, etc. . . . in order to make the design of the external appearance of the artistic table lamps not involve any serious considerations over factors such as the position and size of this switch.

Abstract: A transformer (T) with a primary winding (L1) and a secondary winding (L) coupled to the primary winding. A capacitive element (C) is coupled to the secondary winding for providing an increased output voltage level and an increased output current level from the transformer. The capacitive element may be either of distributed or lumped parameter structure. A reduction in the number of secondary winding turns may be compensated for with the capacitive element to maintain the same voltage output level as was obtained prior to reduction in secondary winding turns and also to obtain an increased current output level by virtue of the presence of the capacitive element and/or the reduction in the number of secondary winding turns. Such reduction in secondary winding turns reduces the physical size of the transformer as well as reducing its copper losses, and also reduces its cost of fabrication.

Abstract: An electronic ballast for a discharge lamp (8) for restricting and stabilizing the lamps current. The ballast comprises a high frequency oscillator for connection to a D.C. supply which consists of two transistors (1,2) connected in series, with a base drive transformer (3) coupled between them to bring the transistors (1,2) into alternating phase operation. A resonance circuit connected in series with the primary winding (4) of the transformer (3), comprises an inductor (7), resonance capacitors (10 and 11) and a capacitor (9) coupled in parallel with the lamp (8). The lamp (8) is, in turn, connected in series with the resonance circuit. In addition, a filter capacitor (c) having a high charging ability is coupled between the terminals of the D.C. supply. The resonance capacitors (10 and 11) are connected in series between the terminals of the D.C.

Abstract: In an inverter controlled with a firing unit connected to switches and defining an operating frequency, a resonant frequency of a series oscillating circuit of the inverter connected to one of the switches is placed below this operating frequency. Given this operating situation, a short of the d.c. voltage source is impossible. Given, for example, unfavorable component tolerances, however, the operating frequency can be moved close to the resonant frequency and cause impermissibly high voltages at the components. Such a voltage rise is limited according to the invention by means of a voltage-dependent resistor. It preferably lies in series with a capacitor and takes care of a voltage-dependent shift of the resonant frequency.

Abstract: A high frequency ballast circuit for a discharge lamp particularly of the so-called energy saving type adapted to fit into conventional incandescent lamp sockets. The circuit comprises an inductive choke and a transistor switching device connected in series with the lamp and a rectified source of AC supply. The transistor is switched with a high frequency, preferably asymmetrically square, waveform and a diode having a direction of conduction opposite to that of the transistor is connected in shunt across the series-connected choke and lamp. The circuit enables lightweight air core coils to be used for the inductive choke facilitating integral combination of the circuit and discharge lamp into a lamp unit having the same general configuration as a conventional incandescent lamp.

Abstract: A power supply apparatus for a fluorescent lamp comprises an inverter circuit for converting AC line power to a high-frequency drive voltage having a square waveform, this high-frequency drive voltage being applied to a fluorescent lamp through an inductor and a capacitor connected in series to form a series-resonance circuit which provides a ballast impedance after ignition of the fluorescent lamp has been achieved. A sufficiently high voltage to ensure reliable ignition of the fluorescent lamp is ensured by a ringing oscillation which is produced across another capacitor, connected across the lamp, when the fluorescent lamp is in the high-impedance state prior to ignition.

Abstract: A lighting circuit for an electric discharge lamp according to the present invention is constructed in such a way that a switching device is provided at an output terminal of a high frequency inverter which produces a substantially sinusoidal output voltage, and that, by controlling this switching device, an output to the low pressure electric discharge lamp is stopped at the rising part of the abovementioned output voltage in its half cycle, while the output is supplied to the low pressure electric discharge lamp at the voltage level in the vicinity of the maximum instantaneous value thereof. By use of the high frequency inverter of a smaller capacity and less radio noise than those in the conventional device, the operating efficiency of the low pressure electric discharge lamp can be increased.

Abstract: A high frequency drive circuit operating as a push-pull, Class C oscillator for driving a high-intensity, gaseous discharge lamp and avoiding the use of a relatively large ballast coil. A highly stable power supply for operating in conjunction with such circuit is also provided.

Abstract: A display dimming circuit is disclosed which provides a coordinated automatic display brightness level adjustment for a plurality of instruments associated within the same general region. Its use in an aircraft cockpit, for example, allows the left, or captain's instruments, to be coordinated to be responsive to the ambient light in that region of the cockpit and the co-pilot's bank of instruments, or right region, of the aircraft is separately coordinated such that both regions exhibit appropriate brightness levels on all instruments. In this manner, gas discharge displays, for example, are installed adjacent cathode ray tube displays or vacuum fluorescent displays and all are effectively maintained at an appropriate lighting level.

Abstract: A method of eliminating discomforting flickering when viewing X-ray films in a light cabinet using fluorescent lamps, and a flicker-eliminating circuit for use in the light cabinet.

Abstract: A vacuum fluorescent display is provided with control means for turning on the display elements by means of a control signal which is in phase with the AC voltage supplied to the cathode of the display. The control signal has a duty cycle which is symmetrical about the zero crossing points of the AC voltage. As a result, the display produces light output only during time periods that are symmetrical about the zero crossings of the AC voltage. In this manner, uniform brightness of the display is perceived.

Abstract: The ozonization installation comprises a group of n ozonizers supplied with energy by a common source in a successive alternating voltage wave train mode, the application of the wave trains being controlled by a control device. The latter produces initiating signals which selectively enable the passage of the electric energy in the form of wave trains coming from the common source to the ozonizer. The installation comprises a servo system chain comprising devices for controlling the duration of the initiating signals by means of a set signal, having regard to the total ozonization produced by the n ozonizers. This duration corresponds to that of each successive wave train. Synchronization devices are provided for connecting the common energy source to solely one ozonizer at a time.

Abstract: An efficient power supply employs a high current switching transistor to pulse a flashlamp for optical pumping in lasers, such as an Nd:YAG laser at high pulse repetition frequencies. The pulsing circuit offers a simple, flexible, and precise means of pump pulse control. Flashlamp simmer current is provided from the constant dc voltage source with a resistor in parallel with the switching transistor.

Abstract: A discharge lamp circuit in which the lamp is substantially instantaneously started and in which the power consumption of the lamp after starting is reduced with substantially no vibration due to piezoelectric effects and caused by currents flowing through a nonlinear dielectric element. An inductive stabilizer is connected in series with one of the filaments of the discharge lamp and a nonlinear circuit is connected in parallel with the filaments of the discharge lamp. The nonlinear circuit is composed of a nonlinear dielectric element and a bidirectional switching means connected in parallel with the nonlinear dielectric element. A reverse-conductive circuit is connected in series with the nonlinear circuit and in parallel with the filaments of the discharge lamp, the reverse-conductive circuit including a reverse-conductive semiconductor switch mean which is conduction-controlled in the forward direction but which is always conductive in the reverse direction.

Abstract: An electronic ballast for energizing fluorescent lamps comprising a converter including a rectifier and a filter for converting an alternating source voltage into a direct current voltage, a network including first and second switching transistors, a tank circuit having a primary winding of a transformer, a secondary winding of the transformer for providing feedback of a portion of the voltage developed across the tank circuits and a bias circuit coupled between the opposite ends of the secondary winding and the emitters of the transistor for alternatively applying bias to the transistors, the network serving to convert a direct current voltage into an amplified sinusoidal voltage having a high frequency, and fluorescent lamps connected in a series configuration coupled across the primary winding.

Abstract: An energy efficient lighting unit is described designed for functional similarity to the incandescent light used in the home. The light 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 comprising an inverter operating at above audible frequencies (e.g. 30-40 KHz). The operating network produces a sequence for the arc lamp and the standby filamentary light source appropriate to each operating state of the arc lamp.

Abstract: The invention relates to a device for regulating the power in electrical apparatuses, especially fluorescent lighting fittings. To each apparatus (6) is connected an inverter (1-5, 7-11; 12; 13) in which the control circuit of the oscillator transistor (1) is provided with an adjustable RC circuit (8, 9).The power of a plurality of apparatuses included in the same group can be adjusted through one pair of conductors by connecting in parallel with the RC circuit (8, 9), on one hand, the contacts of a relay (10) and, on the other hand, an opto-insulator (11) whereby the relay (10) is connected to one conductor of the pair of conductors and the opto-insulator (11) to the other conductor.

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: In a glow plug energization control circuit wherein the output voltage produced from a glow plug temperature simulator composed of a charging/discharging circuit is compared with a reference voltage from a reference voltage generator and heating of the glow plug is controlled in accordance with the result of the comparison, the voltage developed across the glow plug is applied to the charging/discharging circuit to charge a capacitor thereof and the level of the reference voltage is changed in response to changes in the voltage of the voltage source by which the glow plug is heated.

Abstract: An ignition system utilizes a bipolar activated magnetic pulse timer which effectively makes operation of the timer independent of the automotive supply voltages. Such system utilizes a distributed parameter component which may be utilized as a shunt across the ignition transformer secondary winding and also as a high voltage ignition distribution cable. The use of the distributed parameter component as a shunt enables extremely high energy levels to be generated. The use of the distributed parameter component as a distribution cable enables high energy levels to be transferred to the igniters without radio noise induction in a contiguous radio receiver.

Abstract: Unitary light source comprises compact HID lamp and starting and operating circuit therefor operable from household AC energizing potential. The HID lamp is ballasted by incandescent filament means which also provides the major portion of developed light during HID warm up and after power interruption. The ballast filament and input terminals of a full-wave rectifier connect in series across the light source input terminals and the HID lamp connects across the rectifier output. A low-impedance path means and high-voltage pulse generator, which includes a high-voltage electrode operatively associated with the HID lamp, connect across the rectifier input. Initially, the voltage developed across the rectifier input is relatively high and the pulse generator and low-impedance path means are responsive thereto to devleop high voltage pulses and also provide a low impedance path in series with the ballast filament to cause it to incandesce brightly.

Abstract: In order to effect stabilized dimming of a fluorescent lamp, that is, in order to vary the power level supplied the lamp while maintaining a substantially constant filament voltage, a first, variable, inductance is included as an element of oscillator (inverter) feedback loop. The voltage across the variable inductance is clamped and coupled to a second inductance so that a voltage appears across the second inductance in proportion to the voltage appearing across the variable inductance. The voltage appearing across the second inductance is applied to the lamp filament so as to constitute a dominant component of the lamp filament voltage.

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 power supply for an electric insect trap having an electrocution grid and a fluorescent lamp for attracting insects to the grid employs an inverter to generate a high frequency alternating voltage. The alternating voltage is applied across the primary winding of a first transformer having a secondary winding for development of a current-limited voltage for operating the lamp. Due to large inductance, the secondary winding functions as a constant current source to the lamp, so that lamps having different voltage characteristics may be used in the same circuit. A high voltage transformer has a primary driven by the limited lamp current to produce a high voltage for the electrocution grid across its secondary winding. Current limiting is achieved, in part, by providing a selected amount of flux leakage between the primary and secondary windings of the first transformer.

Abstract: An electric light controller means particularly adapted for use with an array of lamps to produce a distinctive "fluttering" effect, which is the combined visual sense of movement wrought by a sequential chaser together with the substantially random flickering effect associated with a natural flame. The controller is particularly useful in decorative display arrangements, including advertising displays, theatre marquees, and the like for the purpose of attracting attention and notice.

Abstract: An electronic ballast employs an electronic inverter which drives a main power transformer across the output of which terminations are connected for a plurality of fluorescent lamps. A high impedance capacitor is connected in parallel across at least one and less than all of the fluorescent lamps. An auxiliary transformer is interposed between the output of the main power transformer and the cathode elements of the fluorescent lamps. Upon start-up, the high impedance capacitor initially creates a bypass around lamps with which it is connected in parallel to thereby apply the entire high voltage output of the power transformer to start the remaining lamps. Once these lamps are started the voltage drop thereacross is reduced to allow the high voltage output to bypass the high impedance capacitor and start the lamps connected in parallel therewith. The auxiliary transformer provides good magnetic coupling and low voltage to the cathode elements of the fluorescent lamps.

Abstract: An electronic ballast for energizing one or more gaseous-discharge lamps and for regulating the power consumed thereby, the ballast including a power supply for providing a source of DC power between a pair of outputs, a pair of transistors connected as switches in series between the power-supply outputs, the transistors for selectively coupling to the juncture thereof positive and negative potentials, a voltage-conditioning and current-limiting network for energizing the lamp from the potential developed between the transistor juncture and a power-supply common, and a pulse generator for developing pulses for driving each of the transistors in turn whereby a potential is developed at the transistor juncture which alternates as positive-going and negative-going pulses each separated by a dead time, the pulse generator for monitoring the power consumption level of the lamp and responsive thereto operative to vary the frequency and/or the width of the transistor driving pulses whereby the lamp consumption is re

Abstract: A power supply for an ac discharge lamp utilizes a switching transistor for turning on and off the dc current from a dc power circuit. The dc current is then fed to a low pass filter for supplying the dc power to the lamp with alternating polarity. A voltage and a current sensing circuits effective to control the dc power to a substantially constant level is connected to a control circuit for controlling the on and off times of the switching transistor. In such a power supply, the voltage and current sensing circuits are made up of transformers whereby the high-voltage circuit section is effectively separated and insulated from the low-voltage circuit section so as to prevent any possible electrical shocks.

Abstract: A lamp consists of a high voltage power supply 5 mounted on an evacuated envelope 1. The lamp glows when electrons from a cathode 2 strike a phospher coating 4 on the inside surface of the envelope. The lamp is mounted so that it can be separated from the power supply and provision is made to inhibit the generation of the very high anode potential by the power supply unless it is correctly mounted on the envelope.

Abstract: This invention concerns to a power supply arrangement which comprises, substantially, a power source circuit, a voltage converter circuit for converting a direct current voltage from the direct current power source circuit into an alternating current voltage, and a rectifier circuit for rectifying the alternating current voltage to a high direct current voltage to be applied to a load. The voltage converter circuit includes an oscillating transformer and an oscillation switching element. The oscillating transformer is provided with only two windings, and these windings are effectively employed to activate the voltage converter circuit.

Abstract: A method and circuit for operating an incandescent lamp are disclosed in which the operating voltage applied to the lamp alternates in a regular and abrupt manner between forward and reverse polarities. The magnitude of the voltage is substantially the same for the two polarities and, therefore, the luminosity of the lamp is substantially constant. However, lamp life is increased as compared to standard DC operation since the alternating polarity of the operating voltage reduces the rate at which the lamp fails due to lamp filament breakage.

Abstract: An electric arc lamp in combination with an electronically controlled incandescent filament to provide auxiliary illumination during warm-up and hot restart of the arc lamp, the filament control circuit being responsive to the arc lamp voltage and current and operative in three modes, full off, full on, and switching on and off the latter so as to allow capacitive and inductive coupling of energy into the arc lamp for the purpose of starting it and bringing it into the arc mode of operation.