Abstract: A ballast circuit is disclosed for inductively providing power to a load. The ballast circuit includes an oscillator, a driver, a switching circuit, a resonant tank circuit and a current sensing circuit. The current sensing circuit provides a current feedback signal to the oscillator that is representative of the current in the resonant tank circuit. The current feedback signal drives the frequency of the ballast circuit causing the ballast circuit to seek resonance. The ballast circuit preferably includes a current limit circuit that is inductively coupled to the resonant tank circuit. The current limit circuit disables the ballast circuit when the current in the ballast circuit exceeds a predetermined threshold or falls outside a predetermined range.

Abstract: Disclosed is a lighting system capable of preventing damage to an outer-tube resulting from an outer-tube discharge that often occurs at the end of useful life of a lamp. The lighting system includes: a metal halide lamp having an arc tube housed within an outer tube; and a lamp .lighting device for operating the metal halide lamp. The lamp lighting device includes: a power supply unit operable to supply an electric power to the metal halide lamp; a detecting unit operable to detect an electrical property of the metal halide lamp; a judging unit operable to judge, based on the detected electrical property, whether a currently occurring discharge is an outer-tube discharge; and an instructing unit operable to instruct the power supply unit to suspend or reduce the electric power supply to the metal halide lamp upon a judgment that the currently occurring discharge is an outer-tube discharge. The detection unit detects a lamp voltage.

Abstract: Circuit arrangement having a converter without a transformer but with an inductor for the pulsed operation of dielectric barrier discharge lamps The circuit arrangement according to the invention comprises an inductor-type converter for the pulsed operation of dielectric barrier discharge lamps (EL). The invention proposes both a half bridge variant and a full bridge variant. By selecting the inductance value of the inductor (L), it is possible to influence the edge steepness of the pulses, in the case of more than one inductor even independently for the rising and falling edges.

Abstract: A DC-DC converter reduces a surge voltage developed across a switching element (30) in making the voltage conversion with the use of a transformer (20) inherently having considerable leakage. A snubber circuit is included to absorb the surge energy and transferring it to a load, or output end of the converter, reducing the surge voltage across the switching element (30). A snubber capacitor (51) is provided to absorb the surge energy developed by the transformer (20) when the switching element (30) is off. Thus absorbed energy is collected in a storage capacitor (53) through a reactor (54) while the switching element (30) is on and off, and is then transferred from the storage capacitor (53) to the load, i.e., the output side of the converter, leaving only a minimum voltage being applied across the switching element (30).

Abstract: A ballast circuit is disclosed for inductively providing power to a load. The ballast circuit includes an oscillator, a driver, a switching circuit, a resonant tank circuit and a current sensing circuit. The current sensing circuit provides a current feedback signal to the oscillator that is representative of the current in the resonant tank circuit. The current feedback signal drives the frequency of the ballast circuit causing the ballast circuit to seek resonance. The ballast circuit preferably includes a current limit circuit that is inductively coupled to the resonant tank circuit. The current limit circuit disables the ballast circuit when the current in the ballast circuit exceeds a predetermined threshold or falls outside a predetermined range.

Abstract: An electronic ballast circuit includes a programmable processor. The processor is programmed to vary operating parameters of the ballast circuit to accommodate operation of different types and/or sizes of lamps. Ballast circuit operating parameters that can be varied by the programmable processor include component parameters, such as inductance and resistance, and the frequency at which the ballast circuit is oscillated. The processor can be programmed to produce an oscillating processor signal which is used to produce a corresponding oscillating power signal to ignite and/or sustain ignition of the lamp. A voltage monitor and a current monitor are employed to monitor the operating condition of the lamp. The monitor outputs are used by the processor to optimize circuit operation.

Abstract: A DC-DC converter has switching means which generates a continuous switching voltage having a specified period from an input voltage and outputs the generated switching voltage, output voltage generating means which receives the switching voltage at an inductor and generates an output voltage obtained by rectifying and smoothing a voltage generated in the inductor, lamp signal generating means which generates a lamp signal and outputs the generated lamp signal, and control means which performs an arithmetic operation using a current signal relative to a current flowing in the inductor, an error signal relative to the output voltage, and the lamp signal to generate a control signal for controlling the operation of the switching means and outputs the generated control signal to the switching means.

Abstract: An ignition system for a high-frequency high-intensity discharge lamp system of a type used for location-lighting during filming or other entertainment venues includes a transformer with a pair of secondary windings, each having a primary winding closely interwound. The secondary windings, which are connected between the steady-state power source and the discharge lamp, are wound for producing opposing magnetic fields with substantial flux cancellation. The primary windings are wound to produce voltage amplification and connected to an ignition circuit adapted to produce high-voltage ignition spikes to turn on the discharge lamp. The system also includes a resonant circuit between the steady-state power source and the transformer. The ignition and resonant circuits are temporarily energized to produce a voltage for igniting the lamp.

Abstract: A lamp assembly configured to inductively receive power from a primary coil. The inductively powered lamp assembly includes a lamp circuit including a secondary and a lamp connected in series. In a first aspect, the lamp circuit includes a capacitor connected in series with the lamp and the secondary to tune the circuit to resonance. The capacitor is preferably selected to have a reactance that is substantially equal to or slightly less than the reactance of the secondary and the impedance of the lamp. In a second aspect, the inductively powered lamp assembly includes a sealed transparent sleeve that entirely encloses the lamp circuit so that the transparent sleeve is fully closed and unpenetrated. The transparent sleeve is preferably the lamp sleeve itself, with the secondary, capacitor and any desired starter mechanism disposed within its interior.

Abstract: An efficient power conversion circuit for driving a fluorescent lamp uses a pre-regulator to generate a regulated voltage with a relatively high level of ripple voltage. The regulated voltage can be varied to provide dimming of the fluorescent lamp. The regulated voltage is provided to a direct drive inverter. The direct drive inverter uses driving signals of fixed pulse widths to generate an output voltage to drive the fluorescent lamp. The output voltage has relatively long on-time durations so that the difference between the peak lamp current and the average lamp current is reduced, thus reducing a lamp current crest factor for improved lamp lighting efficiency.

Abstract: A ballast circuit is disclosed for inductively providing power to a load. The ballast circuit includes an oscillator, a driver, a switching circuit, a resonant tank circuit and a current sensing circuit. The current sensing circuit provides a current feedback signal to the oscillator that is representative of the current in the resonant tank circuit. The current feedback signal drives the frequency of the ballast circuit causing the ballast circuit to seek resonance. The ballast circuit preferably includes a current limit circuit that is inductively coupled to the resonant tank circuit. The current limit circuit disables the ballast circuit when the current in the ballast circuit exceeds a predetermined threshold or falls outside a predetermined range.

Abstract: A high-pressure discharge lamp (Lp) is fed with a square-wave current from an operating appliance. In order to reduce overshoots during the commutation of the lamp current, the set current value for the regulating device (5, 6) which is contained in the operating appliance is briefly reduced in the area of the commutation.

Abstract: The invention relates to a ballast for a lamp having an inverter which includes at least one switch (S1; S2), and having a drive circuit (10) for alternately opening and closing the at least one switch (S1; S2) wherein the drive circuit (10) is designed to drive the at least one switch (S1; S2) alternately at at least two different frequencies (&ohgr;a, &ohgr;b). It also relates to a method for operating a ballast for a lamp having an inverter which comprises at least one switch (S1; S2), and having a drive circuit (10) for alternately opening and closing the at least one switch (S1; S2) wherein the drive circuit drives the at least one switch (S1; S2) alternately at at least two different frequencies (&ohgr;a, &ohgr;b).

Abstract: An operating circuit for a discharge lamp (LP) having preheatable electrodes includes a device (C14, T11, T12, T13, G) for preheating the electrodes. The device includes a resonant circuit (C14, T11) which oscillates during preheating. During operation, the operating circuit produces an AC voltage having a frequency that is moved through a frequency range, records the response of the resonant circuit (C14, T11) by measuring an electrical variable (UC14), and identifies the resonant frequency of the resonant circuit (C14, T11) from the electrical variable (UC14), and preheats the electrodes by setting the frequency of the AC voltage to the resonant frequency.

Abstract: A hot-restrike ignition system for a high-frequency high-intensity discharge lamp includes a resonant circuit that is connectable across the lamp in parallel with a ballast circuit that is used to provide steady-state current for the lamp. The resonant circuit is temporarily energizable for producing a voltage sufficiently high for hot-restrike ignition of the lamp. The resonant circuit has two parts. The first part provides a voltage waveform with frequency approximating the steady-state voltage frequency and amplitude sufficient when combined with the steady-state voltage to produce glow discharge, and the second part provides a voltage waveform that is lower in repetition rate but of sufficiently high voltage to initiate hot-restrike ignition in the lamp.

Abstract: A lamp assembly configured to inductively receive power from a primary coil. The lamp assembly includes a lamp circuit including a secondary and a lamp connected in series. In a first aspect, the lamp circuit includes a capacitor connected in series with the lamp and the secondary to tune the circuit to resonance. The capacitor is preferably selected to have a reactance that is substantially equal to or slightly less than the reactance of the secondary and the impedance of the lamp. In a second aspect, the lamp assembly includes a sealed transparent sleeve that entirely encloses the lamp circuit so that the transparent sleeve is fully closed and unpenetrated. The transparent sleeve is preferably the lamp sleeve itself, with the secondary, capacitor and any desired starter mechanism disposed within its interior.

Abstract: A microwave oven includes a filter unit having choke coils disposed on ground lines, to which low and high voltage units are grounded, and on a power line connected to a controller so as to block high frequency noise. Impedances of the ground and power lines are greatly increased by the choke coils. Accordingly, noise is prevented from being radiated to the outside through the ground lines, and from flowing to the controller through the power line, thus allowing the controller to perform a stable operation.

Abstract: An electrodeless discharge lamp system includes an excitation coil placed in proximity of the electrodeless discharge lamp, a resonance circuit for supplying appropriate power to the excitation coil, and a high frequency power source driver and wherein, the combined output is achieved by operating the parallel connected power sources in synchronization or approximately in synchronization with each other.

Abstract: Free-running half-bridge inverter (HP) for operating gas discharge lamps having a current transformer as a feedback device. The half-bridge transistors (T1, T2) are essentially voltage controlled transistors (MOSFET). The drive circuits (1, 2) for the half-bridge transistors (T1, T2) contain a voltage threshold value switch (D2, R2) which, on reaching its voltage threshold, essentially carries a current which is proportional to the load current of the half-bridge inverter (HB).

Abstract: A ballast circuit for driving a fluorescent lamp is provided. The ballast circuit comprises: a self-oscillating circuit; and a series resonant circuit. The series resonant circuit comprises: an inductor; a capacitor; and two diodes. The arrangement of the series resonant circuit: a) causes less power to be dissipated by first and second lamp cathodes when a lamp is coupled to the ballast circuit and increases lamp life, b) protects the ballast circuit from self-destruction when no lamp is coupled to the ballast circuit, and protects the ballast circuit from self-destruction when either the first, second, or both cathodes of a lamp coupled to the ballast circuit have failed.

Abstract: A brightness-regulating voltage-transforming circuit includes a pulse-width modulator (PWM); a transformer connected at a secondary side to a high-pressure discharge lamp; a voltage-transforming circuit having two transistors connected at bases to outputs of the PWM for the latter to control working frequencies thereof; and a brightness control circuit including a transistor connected at a collector to a middle tap of the transformer and at a base to the PWM for the PWM to control the lamp brightness, and a diode connected at an end to a juncture of a primary side of the transformer and an end of a buffer inductance, and at another end to a voltage source. When the transistor of the brightness control circuit is cut out, energy stored in the buffer inductance is regenerated and sent to the voltage source via the diode, enabling the lamp to have reduced noise interference and increased working efficiency.

Abstract: A metal halide magnetic/electronic ballast with a compensation function for adjustment in autotransformer output voltage, which applies the compensation in various steps of voltage, to maintain the power constant. The metal halide ballast provides constant monitoring of the autotransformer input voltage, enabling the level to be stepped by triac switching. The triac switching is controlled by a switching control provided by a microcontroller. Less components are required, making the present invention simpler, less expensive to manufacture and more reliable.

Abstract: A gas discharge lamp assembly is provided wherein the regulator housing and the ballast housing are placed remote from each other. Further, an ignitor and a capacitor are added to the circuitry of the ballast housing to allow for the regulator's remote placement. Such gas discharge lamps are typically between 1000 Watts and 2000 Watts.

Abstract: A light fixture with a submersible enclosure for an electric lamp (e.g, HID lamp) is disclosed. The fixture includes a ballast for supplying power to a high intensity discharge lamp. A submersible enclosure seals the lamp from water in normal operation. The fixture includes a water-sensitive circuit having a conductance that increases in response to water that leaks into the enclosure for conducting current from the ballast and limiting the ballast voltage. Alternatively, the submersible enclosure may contain a power lead for supplying power to an electrical load such as a lamp ballast, a non-ballasted lamp, or a color wheel. The power lead includes a fuse region that corrosively reacts in the presence of leaked water in the container, so as to sufficiently wither away the fuse region and terminate power to the load. The foregoing alternative versions may advantageously be combined.

Abstract: A discharge lamp circuit includes a power source for creating a current flow. A ballast is electrically connected to the power source and controls the current flow produced by the power source. A capacitor is electrically connected in the ballast. At least one discharge lamp is connected in series with the capacitor. The current flow passes through the discharge lamp during normal operation of the discharge lamp circuit. The ballast includes a switching circuit, electrically connected to the capacitor and the discharge lamp. The switching circuit provides an alternate path for the current flow during a starting operation of the discharge lamp circuit. The switching circuit provides the alternate path in accordance with a charge associated with the capacitor. The charge associated with the capacitor increases when the current flow passes through the alternate path.

Abstract: A discharge lamp operating apparatus includes a discharge lamp and a driving circuit of the discharge lamp. The driving circuit can vary power to be supplied to the discharge lamp and has a function to turn off the discharge lamp at a supplied power value above a supplied power value at which unstable discharge occurs in the discharge lamp.

Abstract: A ballast circuit operable with a triac based controller circuit, the ballast circuit (100) includes a rectifier (115) configured for operative connection with an associated triac based circuit (110) for converting AC current to DC current, a capacitor assembly (137) coupled to the rectifier (115), a first connection (150) between the rectifier and the capacitor assembly (137), a converter (153) coupled to the rectifier (115) for converting the DC current to AC current, a gate drive arrangement coupled to the converter for controlling the converter (153), a resistance-inductance circuit (163) coupled to the converter (153), and a second connection (165) between the capacitor assembly (137) and the resistance-inductance circuit (163). The converter (153) induces AC current in the resistance-inductance circuit (163).

Abstract: A combination-type high frequency inverter connects an isolation leakage transformer, a smoothing condenser, a resonance condenser, a first field-effect transistor and a second field-effect transistor to a diode bridge and rectifies the voltage of an AC power source in a non-smoothing rectification manner. A load circuit has a secondary winding of an isolation leakage transformer, a fluorescent lamp and a condenser. The ‘on’ duration of the first field-effect transistor is variable. The duration of on-duty of the second field-effect transistor is fixed. Adjusting charge voltage on the smoothing condenser changes the high frequency output voltage and the load characteristics. Load characteristics, optimal for the current mode, are given to the fluorescent lamp, in accordance with whether the flourescent lamp is in either start-up or luminance mode.

Abstract: A personal electronic device includes and inverter having a single inductor for powering an EL lamp and a buzzer. The lamp and the buzzer are coupled together to the output of the inverter and are in parallel with each other or are coupled in series between a source of direct current and ground.

Abstract: A ballast for powering a gaseous discharge lamp that has a required minimum ignition voltage and a permissible maximum ignition voltage. Via a cable through which ignition voltage pulses are delivered to the lamp. The ballast has a first state of operation wherein a first reactive energy source charges parasitic loading capacitance of the cable to a voltage that does not exceed the permissible maximum voltage of the lamp when the parasitic loading capacitance of the cable is within a first predetermined range of capacitances. The ballast has a second state of operation wherein the second reactive energy source charges the parasitic loading capacitance of the cable to at least the required minimum ignition voltage of the lamp when the parasitic capacitance of the cable is within a second predetermined range of capacitances.

Abstract: An electronic ballast for a gas discharge lamp has a power source section for receiving a commercial AC to provide a DC voltage, and an inverter section, in response to a pair of switching driving signals, for switching and transforming an output voltage of the power source section at a high speed as an AC power source that is supplied to the gas discharge lamp. For controlling the switching of the inverter section, an inverter controlling section generates a pair of switching driving signals respectively having a predetermined dead time in a switching-ON time interval with a phase difference of 180 degrees from each other to supply them to the inverter section.

Abstract: An emergency ballast for a low profile fluorescent lamp fixture including an AC ballast including an end of lamp life shut down circuit. The emergency ballast includes a timing circuit which operates when AC power is restored to the lamp fixture after the fixture has operated for some period of time due to AC power failure. The timing circuit delays the application of AC power to the AC ballast for a given period of time (conveniently about 5 seconds) during the cessation of operation of the emergency ballast because of the restoration of AC power.

Abstract: An electronic ballast for use in illuminating a lamp includes a voltage reference generator that uses a plurality of current amplifiers and resistors having substantially identical resistance characteristics to remain stable in response to temperature variations and despite resistance process dispersion. The reference voltage generator further includes an ON/OFF controller and a dimming function that may be controlled via a single input terminal. Additionally, the dimming function uses a capacitor to prevent abrupt changes in an input signal from causing abrupt changes in a feedback signal that controls an output frequency of the ballast.

Abstract: A power supply is provided for illuminating an electro-luminescent lamp with a constant current and frequency drive signal having a predetermined limiting voltage level for compensating changes in the electro-luminescent lamp characteristics. The power supply operates from an AC or DC input voltage power source and includes an electronic ground fault current interrupter circuit means with remote reset capability to provide protection for the power supply and against user injury. An auto line AC voltage selection circuit senses and selects the proper voltage operating configuration without operator intervention. The status of an LED in conjunction with the status of the electro-luminescent lamp is used as an internal diagnostic aid to assist a user in isolating fault conditions. External signals from a lighting control panel are coupled via an input control circuit to the power supply to provide special lighting effects.

Abstract: The invention relates to a circuit arrangement for operating at least one discharge lamp, which has a half-bridge inverter (T1, T2, A) with a downstream load circuit (LD, CR) and has a half-bridge capacitor (CK) and also a monitoring apparatus for monitoring a change in the voltage drop across the half-bridge capacitor (CK) which is caused by the occurrence of a rectifying action in the at least one discharge lamp LP. According to the invention, the monitoring apparatus has a first RC element (R1, C1) and a second RC element (R2, C2), which are connected to one another by a threshold switch (DC), and means for detecting the switching state of the threshold switch (DC). The first RC element (R1, C1) is connected to the center tap of the half-bridge inverter, and the second RC element (R2, C2) is connected to the half-bridge capacitor (CK).

Abstract: The invention relates to a high-pressure discharge lamp having a base at one end and whose return conductor (13) is protected with the aid of a bidirectional trigger (D) against high induced voltages of the radio interference suppression reactor (L1) connected to the return conductor (13).

Abstract: A drive circuit for an EL element is provided which suppresses abrupt discharge from the EL element. A coil and a first switch element are connected between a power terminal VDD and a power terminal VSS. The first switch element is intermittently turned on to charge an induced voltage occurring on the coil to the EL element through an H bridge circuit. Then, a second switch element is intermittently turned on to intermittently discharge the charge on the EL element through the coil, thereby suppressing abrupt discharge from the EL element.

Abstract: An electronic ballast is powered from a constant-magnitude DC supply voltage and provides a high-magnitude high-frequency voltage at a ballast output across which are connected two lamp-ballast series-combinations, each consisting of an instant-start fluorescent lamp series-connected with a ballasting capacitor. An auxiliary capacitor is connected in series with the ballast output, thereby having the total ballast output current flowing through it and causing an auxiliary high-frequency voltage to develop across its terminals. The constant-magnitude DC supply voltage is provided via a series-combination of a power-line-connected rectifier delivering an unfiltered full-wave-rectified power line voltage across a pair of rectifier DC terminals and an auxiliary DC power supply delivering an auxiliary DC voltage across a pair of auxiliary DC terminals from which, under open circuit condition, is available a DC voltage of magnitude equal to the peak magnitude of the full-wave-rectified power line voltage.

Abstract: Control circuitry causes a fluorescent lamp to flash by cycling the primary of the lamp ballast reactor at a desired cycle rate. This results in the average lamp wattage output being generally about 40% to 60% Go its normal wattage rating. This results in a correspondence reduction in lumen output. In such flashing, the intensity or light output of each flash is approximately the same as its normal, continuous light output.

Abstract: An improved ballast circuit for use with a compact fluorescent lamp includes an EMI filter, a rectifier and a voltage amplification stage, an active resonant circuit, a dimming circuit, and a power factor correction stage which is connected in parallel to a lamp load. In one embodiment, the ballast circuit operates in cooperation with a three way switch to adjust the light output of the lamp to three discrete levels corresponding to each setting of the three way switch. In another embodiment the ballast circuit includes a feedback capacitor which provides a feedback path for a portion of the high frequency current to the rectifier and voltage amplification stage. In still another embodiment, the ballast circuit is configured to accept input from a triac or a SCR device. In all of the embodiments, the dimming circuit works with the active resonant circuit to vary the amount of power that is supplied to the lamp load.

Abstract: An electronic power supply (10) comprising a rectifier circuit (100) and a voltage converter circuit (200). Voltage converter circuit (200) comprises a first inductor (220), a second inductor (230), an electronic switch (240), a control circuit (300), a first rectifier (250), a second rectifier (260), a first capacitor (270), and a second capacitor (280). First inductor (220) and second inductor (230) may be implemented either as separate inductors or as coupled inductors. Power supply (10) efficiently provides a high output voltage with greater efficiency than conventional boost converters.

Abstract: There is provided an inverter circuit for a discharge tube which does not degrade a lighting brightness of a discharge tube even if a driving frequency is increased in order to miniaturize a step-up transformer and so forth, or which does not degrade a lighting brightness of a discharge tube, this is because a voltage applying to a discharge tube is decreased even if peripheral parasitic capacitance of the discharge tube is increased. The inverter circuit for the discharge tube comprises a high frequency oscillating circuit OS and a step-up transformer for boosting an output of the OS, and the discharge tube DT is connected to a secondary side thereof.

Abstract: A circuit arrangement for igniting and operating a high-pressure discharge lamp is provided with a switching device, inductive device and a rectifier which together form a Buck converter, connected to input terminals for connection to a supply source and output terminals for connection of the lamp. The lamp is supplied with a current through periodic switching of the switching device alternatively into a conducting and a non-conducting state by means of a switch-on and switch-off signal, respectively. The inductive device includes a primary and a secondary winding with the secondary winding forming part of an integration network for generating the switch-off signal. The secondary winding also forms part of a voltage divider network for generating the switch-on signal. A very simple circuit arrangement is thereby achieved.

Abstract: A modular ballast system particularly suited for strip lighting installations has ballast modules on opposite ends of each fluorescent lamp tube, each module having lamp connectors for receiving the end pins of the fluorescent lamp, capacitance and inductance elements connected to the lamp connectors in each module, and jumper conductors interconnecting the capacitance and inductance elements of the modules to define a bridge type ballast circuit for powering the fluorescent lamp. Each ballast module can be made small and lightweight with a single inductor and capacitor forming two legs of a four leg bridge type ballast. Pairs of ballast modules can be connected back-to-back to transmit electrical power without external wiring to successive fluorescent lamps along the strip.

Abstract: A series-fed light monitoring system, used for example for runway lights at airports, and fed by a low-frequency feeding current, comprises at least one series loop having one or more loading points connected in series in the form of fittings with lamps or the like, each loading point being connected to the loop via transformer coupling comprising in series a high-frequency transformer, a switch and a choke. The switch and the choke are connected in series in the series loop and the high-frequency transformer is connected on the primary side to the series loop and on the secondary side to the loading point. The choke has an inductance so as not to hinder a low-frequency feeding current in the loop but provide high impedance at the switching frequency.

Abstract: The light output of an electroluminescent panel is increased by using resonant transformation to increase the operating voltage across the panel to a level greater than the source or input voltage. This is accomplished by connecting the electroluminescent panel into a series resonant circuit whose capacitance value is made up at least in part of the intrinsic capacitance of the electroluminescent panel itself, and by choosing the inductance and capacitance values of the series resonant circuit to produce the desired output voltage across the electroluminescent panel. The resulting circuit is simple and low in cost, does not significantly add to the operating losses of the system, and takes advantage of the intrinsic capacitance of the panel in providing the desired resonant transformation.

Abstract: A DC power supply for a gas discharge lamp includes a high voltage starting circuit for supplying high voltage pulses to effect initial energization of a gas discharge lamp, a lower voltage running circuit for supplying a desired average lamp operating current at a substantially constant current to the gas discharge lamp, and a transformer having a primary connected in the high voltage starting circuit and a secondary connected in the lower voltage running circuit. The transformer provides an inductance which acts as a current source inductor to supply current to the gas discharge lamp.

Abstract: A field emission device (10) has an anode (18) that is used to attract electrons emitter by an emitter (13). An inductor (19) is coupled in series between the anode (18) and a voltage source (21) in order to prevent arcing between the anode (18) and the emitter (13) of the field emission device (10).

Abstract: A device for operating a gas discharge lamp (11) which is triggered by pulses which are transmitted by a starting device (14). In order to isolate the electrical components of a ballast (12) or a power supply apparatus (10) during the starting process, a reactor (13) which is constructed as a saturable reactor is provided in the ballast. The inductance of the saturable reactor is reduced by the operating current flowing after starting of the lamp (11). The device according to the invention is particularly suitable for starting high-pressure gas discharge lamps, the starting power of the lamp (11) made available by the starting device (14) being made virtually completely available.

Abstract: A fluorescent lamp starter circuit includes a relay which forms a first circuit loop to detect the input voltage and to switch the relay from the normally-closed position to the normally-open position once the input voltage reaches the threshold level. The switching of the relay to the normally-open position opens the first circuit loop and closes a second circuit loop constituted partly by the relay to allow current to flow through and heat up the electrodes of the fluorescent lamp. After a certain time period, the relay, which is controlled by the discharging of a capacitor, is switched back to the normally-closed position to open the second circuit loop. The electrodes of the fluorescent lamp, after having been heated, begins to emit electrons and this lowers down the impedance that it represents so that the voltage across the first circuit loop is not sufficient to actuate the relay so as to maintain the relay at the normally-closed position.