Abstract: A power circuit for a fluorescent discharge lamp comprising a converter for producing a DC output. A voltage controlled oscillator is driven by the output from the converter, the oscillator providing a high voltage output for driving the lamp. The frequency of the output increases and decreases with increases and decreases in the powering voltage from the converter. A current detector detects the current passing through the lamp and controls the output voltage of the converter according to that current to increase the the voltage to strike the lamp and then control the voltage to give the required running current.

Abstract: When a discharge lamp is started, high voltage pulses which superpose the voltage due to LC resonance of a resonance circuit are supplied to the discharge lamp, and breakdown occurs in the discharge lamp. The pulse energy needed for the high voltage pulses is small and the output power of the resonance circuit can be decreased. After the breakdown, the energy needed for the transfer from glow discharge to arc discharge is supplied by the resonance, and the high voltage pulses used to supply the starting energy are allowed to be stopped. Thus, the starting and restriking of a discharge lamp is sure, and the starting circuit for a discharge lamp can be made more compact.

Abstract: A lamp having a lamp base, switches, AC power supply, a Philips lamp, battery, and circuit board. In addition to a conventional circuit of AC for starting the Philips lamp, there is also a loop using DC to start the Philips lamp. The loop includes the conversion, oscillation, and amplification of AC and DC, as well as an automatic switching circuit. A conductive ring clamp mounted on the Philips lamp may light up the lamp by means of the battery when there is no supply of AC.

Abstract: A compact screw-in fluorescent lamp is mounted on an ordinary Edison-type screw-base. An inverter-type ballast is integrally included with the base, thereby making the fluorescent lamp capable of being screwed into an ordinary lamp socket and to be powered therefrom by ordinary power line voltage. The fluorescent lamp is folded and has a narrowed section of glass. The inverter-type ballast, which includes a half-bridge self-oscillating inverter, is powered via a voltage doubler and powers the fluorescent lamp via an tuned L-C circuit. Light output can be adjusted by way of an adjustment means functional to adjust the inverter frequency, thereby correspondingly to adjust the magnitude of the lamp current.

Abstract: For driving gas discharge lamps (102, 104) having heatable filaments (102A, 102B, 104A, 104B), a circuit (100) has an inverter (132, 134) and a series-resonant LC oscillator (150, 158, 170) forming a self-oscillating inverter. The oscillator output provides filament-heating current through the filaments in series, and drives arc current serially through the lamps. A feedback transformer (174) with a winding (172) connected serially in the filament-heating current path controls the operation of the inverter. A voltage clamp (180, 182) limits the voltage applied to the lamps. The circuit does not require an output-coupling transformer to couple the output of the self-oscillating inverter to lamps, thus avoiding the added cost that the use of such a transformer would bring, while providing efficient, substantially fixed frequency operation of a wide variety of lamp loads, together with the ability to address a number of lamp fault modes. Alternatively, the lamps may be driven in parallel.

Abstract: A fluorescent lamp protection device, which comprises a solid state timer for controlling the state of a delay-and normal-closed contact so as to control a starter of a fluorescent lamp; the delay-and-normal-closed contact is connected in series with an auxiliary starting capacitor, and then both of them are connected in parallel with an original starting capacitor. The operation power supply of the solid state timer is a D.C. power supply provided by the instant starter of the fluorescent lamp. When the lamp is being turned on, the auxiliary starting capacitor is used for reducing the instantaneous pulse voltage applied to both ends of the fluorescent lamp so as to protect the lamp and to increase the serviceable life thereof.

Abstract: A high power factor ballast circuit for use with fluorescent lamps consisting of a power factor correcting inductor periodically saturated to store pulses of direct current energy and periodically discharge same at a regular periodic rate to power the fluorescent lamp. A bistable flip-flop circuit and an associated solid state switching device combine to periodically control the saturation and discharge of the inductor.

Abstract: A magnetic-electronic ballast consists of a symmetrical series-combination of two ordinary magnetic ballast reactors and an electronically controllable connection and cathode heating means; which connection/heating means has terminals by which to connect with two series-connected fluorescent lamps. The connection/heating means acts: i) to provide cathode heating prior to lamp ignition, ii) to constitute an open circuit as long as the lamps are properly operating, iii) to constitute a short circuit if ever any of the lamp cathode terminals were to be disconnected (or, if one of the cathodes were to become open-circuited), and iv) to cycle between a short circuit and an open circuit in case the lamps have become inoperable for reasons other than an open-circuited cathode.

Abstract: A half-bridge inverter is powered from a constant-magnitude DC supply voltage and provides at the inverter's output a first AC output voltage that is describable as a modified squarewave voltage. This first AC voltage is applied across a series-combination of a tank inductor and a tank capacitor, the junction between which is clamped to the DC supply voltage. As a result, a second AC voltage gets established across the tank capacitor; which second AC voltage is also describable as a modified squarewave voltage. However, the phasing of the second AC voltage is delayed by roughly 90.degree. degrees with respect to the first AC voltage; which results in the voltage across the tank inductor being of approximately sinusoidal waveform.

Abstract: An electronic ballast for use with fluorescent lamps including an inverter circuit for converting a direct current power source to a high voltage alternating current and starting means to inhibit operation of one of the inverter transistors until such time as fluorescent lamp is turned on. The circuitry taught eliminates substantial drain usually found at start up of inverter circuits due to the large capacitors usually found in such circuitry.

Abstract: A fluorescent lamp system including a ballast with primary and secondary windings and a switch for each electrode of the lamp system. Each switch is operable in response to the voltage across its associated lamp after its associated lamp turns on to interrupt the connection of an associated electrode to its associated heater winding and wherein at least one of said heater windings is a portion of the secondary winding.

Abstract: A high frequency electronic ballast which comprises a variable frequency oscillator (1) having its frequency controlled by inputs (10 to 15). The oscillator (1) providing complementary outputs (16, 17) which controls an inverter (4) via a driver circuit (3). The inverter output is a source for a transformer or choke (5) which directly drives a gas discharge lamp (6). In this way the frequency of operation and hence the illumination of the lamp (6) can be changed by changing the driver (3) frequency by direct control (10 to 15) of the oscillator (1) and the lamp voltage is maintained substantially constant while reducing its current flow.

Abstract: A high frequency power supply for neon and mercury luminous tubes including means for simultaneously suppressing bubbles formed in neon tubes and for minimizing migration of mercury commonly associated with the use of solid-state luminous tube power supplies.

Abstract: To permit the more cost-effective use of low voltage lamps (especially 12 Volt Halogen lamps) in track lighting systems, the power track is supplied from the power line by way of a frequency-converting power supply providing onto the track conductors a voltage of normal power line voltage magnitude (120 Volt RMS) but of an exceptionally high frequency (30 kHz). As a result, the individual step-down voltage transformer required to provide the proper low voltage for operating each of the low voltage lamps becomes very light, small and inexpensive. Yet, in contrast with situations where the whole track may be provided with low voltage from a single step-down voltage transformer, there will be no unusual limitations in respect to track length and/or the number of low voltage lamps that can be used with a given track. Moreover, there will be no problem with using regular high voltage incandescent lamps intermixed with low voltage lamps.

Abstract: In a power-factor-corrected electronic ballast, an AC/DC converter comprises a half-bridge electronic self-oscillating inverter powered from non-filtered full-wave-rectified 120 Volt/60 HZ power line voltage, and its resulting amplitude-modulated 30 kHz output voltage is applied to a series-resonant L-C circuit. The 30 kHz voltage developing across the tank capacitor of this L-C circuit is rectified and applied as direct current to an energy-storing capacitor, from which a DC supply voltage is provided to a frequency-converting ballast which, in turn, provides a substantially non-modulated high-frequency AC output voltage used for powering a gas discharge lamp via a current-limiting inductor. Trigger pulses are provided to trigger the inverter into self-oscillation at the beginning of each pulse of DC voltage provided by the unfiltered rectified power line voltage. As soon as the magnitude of the DC voltage across the energy-storing capacitor exceeds a first level, the trigger pulses cease to be provided.

Abstract: A high-frequency electronic ballast for fluorescent lamps has a first inverter for controllably providing heating power to the lamp cathodes and a second inverter for controllably providing main lamp operating power. The two inverters are separately and independently controllable, thereby: i) to permit adjustment of lamp current so as to provide full or reduced light output in accordance with requirements, ii) to permit cathode heating power to be removed under conditions of providing full light output, thereby to maximize efficiency, and iii) to permit cathode heating power to be restored under conditions of reduced light output, thereby to prevent premature lamp failure.

Abstract: A circuit arrangement for the operation of a fluorescent lamp which is connectable to an alternating-current power supply, for example, the elctrical power supply on board an aircraft, including a switch which is located between the lamp electrodes, and which is actuatable through the intermediary of a control circuit whereby the lamp electrodes are heated when the switch is closed. A measuring element which is connected to the input of the control circuit determines the decreasing voltage at least at one of the lamp electrodes, and the control circuit will open the switch for the ignition of the fluorescent lamp only when the determined voltage is essentially constant, or has reached a threshold value.

Abstract: An apparatus for operating discharge lamp. The apparatus includes a source of electrical power, switching devices for switching the electrical power, a control circuit for controlling the switching devices, a transformer having a primary winding for receiving the electrical power switched by the switching devices and a secondary winding for supplying power to the lighting apparatus, a resonant circuit including an inductor and a capacitor for regulating the frequency of the electrical power and a circuit for powering the control circuit, the powering circuit including a secondary winding on the inductor and an additional winding on the transformer connected in a differential manner.

Abstract: A fluorescent lamp system including a switch for each electrode of the lamp system wherein each switch is operable in response to the voltage across its associated lamp after its associated lamp turns on to interrupt the connection of an associated electrode to its associated heater winding.

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: An ignitor circuit for a gas discharge lamp includes a transformer and means for generating pulsatory voltages across a primary winding of the transformer to generate ignition pulses by means of a secondary winding of the transformer. The ignitor circuit further includes first means for measuring an amplitude of the ignition pulses, and second means for changing the pulsatory voltage across the primary winding, and thus changing the amplitude of the ignition pulses, in dependence on the measured amplitude of the ignition pulses. The ignitor circuit is capable of generating a suitable ignition pulse over a wide range of connection cable lengths.

Abstract: The discharge lamp operating circuit comprises two series circuits, each including two switching devices, connected in parallel with the power supply, a series circuit, including a choke coil, a first capacitor, and a parallel circuit with a discharge lamp and a second capacitor, and connected between the middle points of the one and the other series circuit, reverse-direction rectifiers connected in parallel with the corresponding switching devices, said discharge lamp operating circuit turning on and off said discharge lamp by turning on and off the switching devices alternately. In this discharge lamp operating circuit, the timing of switching the switching devices is set from the closed condition to the open condition at a time when the current flowing through the switching devices is almost at zero level.

Abstract: An electronic ballast including a dimming circuit for use with fluorescent lamps. An electromagnet located adjacent to a dual toroid coil transformer employed as part of a inverter circuit is used to control the saturation of the toroid coil to the control the on and off times of transistors included in the inverter circuitry, to limit saturation thereby controlling the intensity of the light emitted from the fluorescent lamps.

Abstract: A starter circuit is supplied with 120 volt 60 Hz power, and is coupled to a gas discharge lamp having in an interior thereof a gas and two spaced electrodes. When the starter circuit applies to the electrodes a voltage in excess of a threshold voltage, the lamp transitions from a non-conductive state in which no visible light is emitted to a conductive state in which visible light is emitted. The starter circuit includes several voltage doubler circuits coupled in series with each other between the electrodes of the lamp to form a voltage multiplier circuit. When the lamp is in its non-conductive state, the voltage doubler circuits each output a substantially DC voltage which is twice the maximum potential of the 120 volt input signal so that the voltage multiplier as a whole applies to the electrodes a significant DC voltage in excess of the threshold voltage so that the lamp transitions from its non-conductive state to its conductive state.

Abstract: A circuit for starting and operating a discharge lamp, such as a compact fluorescent lamp, at high frequency from an 60 Hz AC supply. The circuit includes a DC power supply coupled to a pair of AC input terminals for generating a DC voltage. An oscillator coupled to the DC power supply includes a drive transformers having a primary winding. A load coupled to the output of the oscillator comprises a series combination of the primary winding of the drive transformer and a tank circuit including a tank inductor and a tank capacitor. Suitable means for connecting a discharge lamp in parallel with the tank capacitor is provided. A voltage sensing circuit responsive to failure of the lamp, is coupled to an oscillator controlling circuit which reduces the output of the oscillator after a predetermined time delay by shunting the drive transformer. Upon replacement of the failed lamp, normal operation of the oscillator is resumed without having to disconnect the AC supply.

Abstract: A circuit (500) for driving two or more series-connected gas discharge lamps, having: an oscillator (518, 520, 522); and a transformer (524) with a primary winding (526) and a secondary winding (528). The transformer secondary winding has first (129A) and second (129B) points connected respectively to first (508) and second (514) output terminals across the series-connected lamps. A capacitor (532) couples the first point of the transformer secondary winding to an intermediate output terminal (112). The voltage produced by the secondary winding thus drives the lamps in series, while the pre-strike voltage produced across the secondary winding is applied across a single lamp (106) to cause it to strike. After striking, current to the intermediate output terminal (512) is limited by the capacitor (532). In this way, the voltage which needs to be produced across the secondary winding to ensure striking of all of the lamps is reduced.

Abstract: An electronic circuit for receiving input electrical power at a lower frequency and for energizing a load at a higher frequency. The electronic circuit has a rectifier for rectifying the input electrical power received on an input thereof and a pre-regulator for changing the rectified AC voltage provided by the rectifier to a source voltage. The electronic circuit further has a non-resonant inverter for providing electrical power at the high frequency to the load and includes first and second switches and is connected to the pre-regulator and to the load circuit. A logic circuit is responsive to a sensed signal representing only current flowing in the first and second switches for operating the first and second switches. The frequency of current in the load circuit varies for any substantial change in the magnitude of the source voltage, for any change in load impedance, and for any change in a set point value. A device for setting the set point value is connected to the logic circuit.

Abstract: To decrease the losses in the starting circuit for a compact fluorescent p, a positive temperature coefficient (PTC) resistor (KL) is connected in a resonance circuit of the lamp and also connected to the power supply of the lamp through a diode, polarized in blocking direction with respect to direct current, so that, before the lamp fires, a-c provided from an inverter (INV) can pre-heat the electrodes (E1, E2) of the lamp (LP), which will also cause current flow through the PTC resistor (KL); upon heating of the PTC resistor, this d-c current decreases and the voltage across the electrodes of the lamp will rise. When the lamp fires, it will drop below the supply voltage of the operating circuit for the lamp, thus causing the removal of the PTC resistor from the current carrying circuit, thereby eliminating energy loss through that resistor, and heating of the operating circuit assembly.

Abstract: In one aspect of the present invention a capacitor is placed in series with the ballast and the lamp. The capacitor lowers the impedance during lamp starting and is shorted out when final arc conditions of the lamp are reached. Method and device for improvement of lumen maintenance of high intensity discharge lamps through minimizing the wall blackening during lamp starting is disclosed. Reducing the electrode material sputtering during the thermionic arc phase of the lamp starting process was achieved by decreasing the cathode fall voltage. The cathode fall voltage in these lamps was decreased by increasing the current flowing through during the starting phase. The increase of starting current was achieved by increasing the open circuit voltage or by decreasing ballast impedance.

Abstract: The ballast is connected between the fluorescent lights and a source of power for the fluorescent lights. The source of power provides an input signal having a first waveform, usually a sine wave, at a first frequency. The ballast consists of a converter for coverting the first waveform to a second waveform at a second frequency different from the first frequency. A distribution arrangement distributes power to the fluorescent lights. The distribution system consists of a transformer, and capacitors are interposed between selected windings of the secondary of the transformer. In one embodiment, the sine wave is converted to a square wave by the converter and to a saw tooth waveform by the capacitors in the distribution arrangement so that the fluorescent lights are fed with the saw tooth waveform.

Abstract: A rapid start fluorescent lamp having an improved hot restarting time. The lamp includes the standard envelope and end cap through which electrical connection is made by conductive feedthroughs which extend through the lamp stem to the interior of the lamp. One of the feedthroughs is connected to the cathode, and the other is connected to the leads of a fuse element which is contained within an envelope to isolate the fusible element from the lamp environment. A thermally activated bimetallic element is disposed across the leads of the fuse. The other lead of the fusible element is connected to the other end of the cathode. When the bimetal element is cold, it will bridge the connection between the other feedthrough to the other end of the cathode to permit rapid starting. When the bimetal heats up, the connection of both ends of the cathode to the heating current is broken. The location of the bimetallic element within the lamp envelope but not in the fuse container permits it to open and close more rapidly.

Abstract: An improved electronic ballast inverter for a gas discharge lamp includes an oscillator having at least two switching transistors for operating the gas discharge lamp at a high frequency during steady-state operation, a triggering circuit for initiating the operation of the oscillator, and an electrical circuit connected to the oscillator for gradually increasing the base current of at least one of the switching transistors immediately after start-up in order to delay the gas breakdown and thereby to produce preheating of the gas discharge lamp during startup.

Abstract: A circuit suitable for the instantaneous starting, continuation, and interruption of current through one or more gasfilled discharge tubes, in particular fluorescent lamps, is described. The circuit and lamp heaters are energized before instantaneous control can occur. One preferred silicon controlled rectifier (SCR) is used with a bridge rectifier. The SCR has the dual role of causing the capacitor to discharge through the pulse transformer, the secondary pulse voltage of which thereby causes the arc to strike immediately upon application of gate current, and then maintianing the lamp current as long as a supply of SCR gate current is provided. A second preferred control device, a TRIAC, is used without a bridge rectifier and again has a dual role of pulse-starting and maintaining current. This type of device is more conveniently arranged to provide for a dimming function as well. Applications include "flashing" advertising signs, general illumination, and signals.

Abstract: A device for alternating the polarity of an illuminated DC fluorescent light bulb to eliminate cathodic degeneration while avoiding the visible effects of flicker to maintain a constant lighting effect.

Abstract: The present invention describes a method and apparatus for a high frequency switching gas discharge tube supply which suppresses or eliminates the "bubble effect" in gas discharge tubes containing argon-mercury gas or other gases and which eliminates the migration of mercury or other migratory gases toward one electrode over time. To prevent mercury migration to one electrode over time within an argon-mercury gas discharge tube, the DC bias is periodically reversed in direction resulting in a gas discharge tube display which is uniform in intensity of light over the length of the tube.

Abstract: For coupling one, or more, gaseous discharge lamps to a high-frequency AC power-source a ballasting (current-limiting) network employs a first capacitor, a second capacitor, and a transformer having a primary winding coupled to the high-frequency AC power-source by the first capacitor and a secondary winding coupled to the gaseous discharge lamp by the second capacitor.

Abstract: An electrical circuit used in conjunction with high power factor ballasts and quality fluorescent lamps to reduce the power consumption of a fluorescent fixture by an average of 40% with a lesser reduction of light output because of optimized current control through the discharge lamps increasing the efficacy of conversion of electricity to light, accomplishing this by means of a tuned inductor-capacitor resistor circuit, these along with a 1 to 1.3 impede current surges, transformer, add harmonics a circuit diode and feedback loop to reshape the circuit waveform for optimum performance of said lamps and optimum economic savings and payback through applicaiton of this technology to multiple fixtures in offices, factories, commercial buildings and stores.

Abstract: An electronic ballast which will repeatedly try to ignite gas discharge lamps should they fail to ignite under conditions in which they should have ignited together with means rendering said electronic ballast incapable of trying to ignite said lamps after a predetermined period and said electronic ballast being rendered capable of again trying to ignite said lamps under prescribed conditions.

Abstract: A circuit (100) for driving a plurality of gas discharge lamps (102, 104), and having: input terminals (126, 130) for connection to a source of voltage supply; output terminals (134, 136, 140) for connection to the lamps in series; an oscillator (124, 132) connected between the input terminals and the output terminals for producing a high-frequency drive voltage at the output terminals; a transformer (106) having a primary winding (108) coupled to the input terminals and having a secondary winding (114) coupled to the output terminals, the transformer secondary winding being coupled at its ends (116, 118) and at an intermediate point (120) to respective ones of the output terminals and the intermediate point (120) of the transformer secondary winding being coupled to its respective output terminal (140) by a capacitor.

Abstract: The invention circuit for a discharge lamp comprising a first switching circuit, a series resonant circuit, and a current transformer. The series resonant circuit energizes the discharge lamp by means of resonant output corresponding to the output from the first switching circuit. The current transformer incorporates the first, second, and the third windings. When the first winding inserted in the series resonant circuit is driven, the first winding outputs a predetermined amount of current to the second and third windings. The inverter circuit further comprises a second switching circuit, a pair of time constant circuits, and a control circuit. The second switching circuit controls ON-OFF operation of the first switching circuit in response to the output from the second winding.

Abstract: A device for alternating the polarity of a regulated DC power signal applied to a fluorescent light system, which device selectively reverses the polarity of a DC power signal applied to a fluorescent lamp each time the light system is turned on and an AC power signal is applied. The device selects the polarity of the DC power signal applied to the lamp such that both terminals of the lamp act as a cathode approximately an equal number of times, thus preventing premature aging and degradation of any one lamp terminal.

Abstract: A supply circuit is proposed for high-frequency operation of one low-pressure discharge lamp or several low-pressure discharge lamps connected in parallel. The switching unit includes--a power rectifier followed by an active harmonic oscillation filter and a filter capacitor and a single-phase high-frequency generator comprising a switching transistor, a switching inductance and an oscillating capacitor, said generator being supplied from said filter capacitor and being decoupled from the power supply by means of two diodes.

Abstract: A power supply with energy storage means in the form of two capacitors with energy storage means provides improved voltage regulation for the power supply and also serves to store the energy contained in voltage spikes that could otherwise deleteriously effect the power supply.

Abstract: In this invention, pulse generating means is adapted to emit a high-frequency pulse signal of a fixed duty ratio and a discharge tube is lighted by means of this pulse signal. The frequency of the pusle emitted by the pulse generating means is adjustable by adjusting means. Thus, one discharge tube lighting device of this invention can be used interchangeably for lighting discharge tubes varying in capacity. The lighting device is further capable of effecting adjustment of light in a wide range. Further, sequential potential forming means is adapted to allow a plurality of discharge tubes to be sequentially lighted with intervals. When a plurality of discharge tubes are to be lighted, therefore, the rectifying means necessary for the lighting is allowed to have only a small capacity. The high-voltage applying means for applying high voltage to the discharge tubes are connected to the electrodes disposed at the opposite terminals of the discharge tubes with connecting wires joined one each to the electrodes.

Abstract: Circuits for increasing the efficiency of fluorescent tubes by openings one side of all of the filament circuits of the tubes in response to flow of plasma current. The circuits may be employed in conjunction with the circuits of Lucetta U.S. Pat. No. 3,954,316. It should be noted that solid state relays could also be employed so that filament current, although not completely terminated, would be substantially terminated and filament losses would be inconsequential.

Abstract: In a circuit arrangement for the operation of high-pressure gas discharge lamps by means of a pulsatory supply current having a pulse recurrence frequency between 50 and 2000 Hz and a duty cycle between 0.2 and 0.8, a current having a high-frequency between 20 and 200 kHz is superimposed on the current pulses and with a modulation ratio beween 0.3 and 1. The high-frequency is an integral multiple of the pulse recurrence frequency. Thus, flickering of the lamps is avoided.

Abstract: An electronic starter for fluorescent lamps is disclosed. A Triac having a trigger electrode and having an anode and a cathode connectable to first and second filaments, respectively, of a fluorescent lamp is provided. A thermistor, a resistor, and a capacitor are connected in series across the anode and the cathode of the Triac, and a voltage responsive element, such as a bipolar Zener diode, is connected between the trigger electrode of the Triac and the junction between the resistor and the capacitor. This starter replaces conventional glow starters for fluorescent lamps, without requiring a special ballast.

Abstract: A driving circuit for a low-pressure discharge lamp, particularly a compact fluorescent lamp, features a heating transformer with two separate secondary windings, which are respectively permanently connected to the lamp electrodes, and furnish them with pre-heating current. Parallel to the primary winding of the transformer, there is connected a series circuit of an operating switch, a ballast inductor, and the discharge path formed between the lamp electrodes. The electrodes are connected to each other via a starter connected in parallel to the discharge path.

Abstract: In an inverter-type fluorescent lamp ballast adapted to be powered from a DC supply voltage consisting of a substantially non-filtered full-wave-rectified 60 Hz power line voltage, the inverter's output is a 120 Hz magnitude-modulated squarewave voltage of frequency controllable about 30 kHz. The magnitude-modulated squarewave voltage is applied across a series-connected high-Q L-C circuit. The fluorescent lamp is connected in parallel with the tank capacitor of this L-C circuit. The magnitude of the current drawn by the fluorescent lamp is a sensitive function of the frequency of the squarewave voltage and is controlled by correspondingly controlling the frequency of this squarewave voltage.

Abstract: A fluorescent lamp stabilizer circuit device of the type comprising two transistor switches is provided. The two transistor switches are alternatively switched on/off so as to control two charging circuits for providing an impulse voltage double that of power supply voltage for initiating operation of a fluorescent lamp to give off light. A resonance circuit is provided to generate a damped oscillation responsive to the impulse voltage to drop output voltage to the fluorescent lamp tube to a rated range immediately after the fluorescent lamp tube has turned on.