Abstract: A method of operating a resistive memory device to increase a read margin includes applying a write pulse to a memory cell such that the memory cell is programmed to a target resistance state, and applying a post-write pulse to the memory cell to increase a resistance of the memory cell that is in the target resistance state, the post-write pulse being applied as a single pulse having at least n stepped voltage levels, n being an integer equal to or more than 2, and an n-th stepped voltage level of the post-write pulse is set to be lower than a minimum threshold voltage level of the target resistance state that is changed by an (n?1)-th stepped voltage level of the post-write pulse.

Abstract: The present invention discloses a lighting installation having an LED lamp (19), normally consisting of a series string of individual LED's (18), which is supplied by a rectifier (20, 200). A control circuit (23, 23 & C1) is interposed between the rectifier and the AC supply which powers the rectifier. Various circuits for filtering, power factor control, multi-phase operation and dimming, for example by phase switching, are disclosed. In particular, the control carried out by the control circuit takes place on the AC side of the rectifier. Also disclosed are the control circuit per se and a method of converting a High Intensity Discharge (HID) lamp installation into a Light Emitting Diode (LED) installation. The control circuit can take the form of an inductor, an inductor and series capacitor, a shunt inductor, a leakage reactance transformer, a constant current transformer, an autotransformer, an isolation transformer or a ferro-resonant transformer.

Abstract: Example embodiments presented herein are directed towards an electron emitter for an x-ray tube. The electron emitter comprises an electrically conductive substrate and a nanostructure material. The nanostructure material is comprised on at least a portion of the electrically conductive substrate. The nanostructure material is made of oxides, nitrides, silicides, selenides or tellurides. Such an electron emitter may be used for hybrid emission, such as Schottky emission or field emission.

Abstract: Example embodiments presented herein are directed towards an x-ray generating device. The device comprises at least one electron emitter(s) that has an electrically conductive substrate. The electrically conductive substrate comprises a coating of nanostructures. The device further comprises a heating element attached to each electrically conductive substrate. The device further comprises an electron receiving component configured to receive electrons emitted from the at least one electron emitter(s). The device also comprises an evacuated enclosure configured to house the at least one electron emitter(s), the heating element and the electron receiving component. The at least one electron emitter(s) is configured for Schottky emission when the heating element is in an on-state and the at least one electron emitter(s) is negatively biased.

Abstract: A control algorithm for operating a fluid disinfecting system by UV radiation, wherein the UV radiation is generated by at least one UV lamp including a pair of heating cathodes having a discharge voltage (UD), the UV lamp is operated by an electronic ballast unit equipped with the control algorithm for adjusting the UV power of the UV lamp by pulse-width-modulation to reduce UV power. The control algorithm decreases the current to a level (Ikmin), increases the voltage amplitude (U) above the discharge voltage (UD) until a desired UV power level is reached. The pulse width (PW) is decreased with increasing voltage amplitude (U) until PWmin is reached. The decrease in current and the increase in voltage generate an ineffective current-voltage-ratio in which excess current heats the cathode. An electronic ballast equipped with the algorithm and systems equipped with such ballasts are also disclosed.

Abstract: Imitation candle devices and systems with enhanced features enable simulation of a realistic candle flame using multiple angled light sources that illuminate a surface area of a movable imitation flame element in a controlled manner. In some implementations, the imitation candle devices further include a color detection module that adjust the color of the imitation candle device based on a sensed color of the surface a surface that the candle rests upon.

Abstract: According to one embodiment, a power conversion device includes a first switch serially connected to a second switch, a first diode serially connected to a second diode, the first switch and the first diode connected to the second switch and the second diode, an AC power supply and an inductor serially connected to a connection point between the first switch and the second switch and a connection point between the first diode and the second diode, a capacitor serially connected to ends of the first diode and the second diode connected, and a potential difference between the ends of the capacitor is used as an output voltage. The control unit supplies a pulse signal to the first switch and the second switch to provide a sinusoidal current through the AC power supply, based on a detected power supply voltage, a detected circuit current, and a detected capacitor voltage.

Abstract: Imitation candle devices and systems with enhanced features enable simulation of a realistic candle flame using multiple angled light sources that illuminate a surface area of a movable imitation flame element in a controlled manner. In some implementations, the imitation candle devices further include a color detection module that adjust the color of the imitation candle device based on a sensed color of the surface a surface that the candle rests upon.

Abstract: An AC-DC converter has a totem-pole output circuit having first and second semiconductor switches, each having a channel coupled to a switching node and having a parasitic capacitance associated with the channel. An inductor has one terminal thereof connected to a switching node. First and second bypass devices are coupled to a second terminal of the inductor and operable during at least a portion of an input voltage to allow reverse current from an output of the converter to generate soft-switching of the first semiconductor switch. An asymmetrical shunt for measuring current in a first direction and bypassing current in a second direction opposite the first direction allows accurate measurement of reverse current.

Abstract: A discharge lamp driving device includes a discharge lamp driving section configured to supply a driving current to a discharge lamp, the driving current being an alternating current for driving the discharge lamp, and a control section configured to control the discharge lamp driving section. The control section controls the discharge lamp driving section such that the driving current having a driving frequency different from a natural frequency of the discharge lamp and a frequency of 1/2n (n is a natural number) times the natural frequency is supplied to the discharge lamp.

Abstract: A household appliance (1) is provided with an electronic control device (3) configured to reduce standby consumption. The appliance includes: —an electronic control unit (20); and—a switching mode low power supply unit (6) having at least a first control terminal (11) and at least an output terminal (9) which supplies a main prefixed supply voltage (VB) to the electronic control unit (20). The switching mode low power supply unit (6) is further configured to switch between a standby state and an operating state, when it detects a prefixed voltage variation (?V) on the first control terminal (11). The electronic control device (3) is configured to connect, at least temporarily, the first control terminal (11) to the output terminal (9), or to an independent auxiliary terminal (31) having a predetermined voltage, to generate the prefixed voltage variation (?V) on the first control terminal (11) to cause the switching mode low power supply unit (6) to switch from one of the states to the other state.

Abstract: A method and semiconductor device for a resonant power converter includes logic circuitry that performs a dedicated startup sequence when power is first provided to the resonant converter. The logic circuitry can discharge the resonant capacitor, then iteratively pulse only an upper switch during a portion of the startup sequence, and measures the dead time between the half bridge signal starting to fall and the next time it finishes rising. If the dead time is greater that a startup exit value, which is based on the most recent upper switch on-time, then the upper switch on-time is incremented and the process is repeated until the dead time is less than the startup exit value, whereupon the startup logic transitions to conventional symmetric switching.

Abstract: A method for actuating a discharge lamp (LP), wherein in order to ignite the lamp a resonant circuit (L, C1) is brought into resonance or near resonance by the action of alternating current and as a result adjustment to give a predetermined amperage is performed by varying the frequency of the alternating current. For this purpose a measuring device transmits measured values of the amperage to means for controlling the frequency, and these means establish the frequency in dependence on the measured values. Before the ignition voltage is applied the electrodes of the lamp are pre-heated by the action on the resonant circuit of alternating current of a different frequency than when the lamp is ignited.

Abstract: An adapter for electrical power that includes a rectifier coupled to a transformer with a primary coil and a secondary coil. The secondary coil includes a first end tap, a second end tap, and a center tap. A first switch is coupled between the first end tap and a primary side ground. A second switch is coupled between the second end tap and the primary side ground. A controller is coupled to the first switch and to the second switch so that during one or more intervals, the first switch and the second switch are alternately open and closed a predetermined number of times, wherein the initial switch closed each interval alternates between the first switch and the second switch, and after the predetermined number of times, both the first switch and the second switch are opened for a predetermined time period.

Abstract: A lamp 10 is described comprising a burner 14 fixed to a lamp base 12. An operating circuit 50 is arranged within the lamp base 12 for supplying electrical power to the burner 14. The operating circuit 50 is electrically connected to at least one elongate contact path element 70 extending within the base. The contact path element 70 is supported within the base 12 and comprises a first portion 70a fixed within the base and a second portion 70b slidably received within the base 12. The contact path element 70 is fixed to the operating circuit 50 at a position arranged in longitudinal direction from the second portion 70b. This allows a manufacturing method, where the contact path element is fixed to the operating circuit 50 at a position arranged in longitudinal direction from the second portion, so that a longitudinal movement of the second portion is possible to compensate for manufacturing tolerances.

Abstract: A lighting device and a method for operating a discharge lamp (10) are de-scribed. The discharge lamp (10) comprises a sealed discharge vessel and two electrodes (22) to produce an arc. A driver circuit (20) delivers electrical power to the electrodes (22). In a run-up interval (56), electrical power is supplied as an alternating current IL. During the run-up inter-val (56), the waveform of the alternating current IL is changed at least once to a spot-enforcing waveform in order to change the mode of attachment of the arc to the electrodes (22) to spot mode.

Abstract: A method for operating a lamp, wherein in the preheating phase a first value of the voltage drop correlated with the reciprocal of the electrical resistance of a coil of the lamp is determined across a resistor at a first instant, and a second value of the voltage drop is determined at a second instant, may include: a) determining the difference between a first and the second value; b) b1) if the difference is greater than a first threshold value: carrying out an algorithm for lamp-type recognition; b2) if the difference is not greater than the first threshold value: c1) if the difference is greater than a second threshold value: d1) if the second value is greater than a third threshold value: determining a coil short circuit; d2) if the second value is not greater than the third threshold value: operating the lamp with the current set of operating parameters.

Abstract: A device to control luminosity of a lamp supported by a rapid start ballast, the device including a first terminal and a second terminal configured to be connected in series with the rapid start ballast and the lamp, a current divisor array, in connection with the first terminal and the second terminal, with a plurality of inductors and a commutable element, the commutable element selecting between two current paths employing the plurality of inductors, the commutable element when in a first state selecting a first one of the current paths to provide a higher luminosity setting and when a second state selecting a second one of the current paths to provide a lower luminosity setting, and a transformer in connection with the first terminal and the second terminal configured to provide heating to an electrode of the lamp.

Abstract: An electronic ballast for an electrical lamp (2) provided with a first (21) and a second filament (22), includes a heating device which is used to heat the filaments (21, 22) and includes a resonance circuit (5), and an evaluation unit (11) designed for the evaluation of at least one measuring value of an electrical parameter during pre-determinable adjustments of operating conditions of the resonance circuit (5). The number of filaments (21, 22) of the electrical lamp (2) in electrical contact with the electronic ballast (1) can be identified according to the measuring value, and the electrical lamp (2) can be switched on by the electronic ballast (1) according to the identified number. A method for operating an electrical lamp by an electronic ballast is also described.

Abstract: The invention provides an apparatus and method of switching more than one bias voltage within an electron beam tube in order to achieve electron beam cutoff. The invention is particularly useful for high-perveance electron tubes in which a large change in focus-electrode-to-cathode or anode-cathode voltage might otherwise be needed to achieve cutoff. In one embodiment of the invention, the cathode and anode bias voltages are both switched by magnitudes well within the capabilities of standard high-voltage switches to achieve beam cutoff.

Abstract: A cathodoluminescent lighting system has a light emitting device having an envelope with a transparent face, a cathode for emitting electrons, an anode with a phosphor layer and a conductor layer. The phosphor layer emits light through the transparent face of the envelope. The system also has a power supply for providing at least five thousand volts of power to the light emitting device, and the electrons transiting from cathode to anode are essentially unfocused. Additional embodiments responsive to triac-type dimmers with intensity and color-changes in response to dimmer control. A power-factor-corrected embodiment is also disclosed.

Abstract: A circuit for preheating filaments in lamps powered by an electronic ballast includes an inverter tank circuit and a preheat tank circuit. The preheat tank circuit has a preheat capacitor connected in parallel with a primary winding of a filament preheat transformer. A cut-back capacitor is connected between the preheat tank circuit and circuit ground. The filament preheat transformer has secondary windings coupled to the first and second lamp terminals to provide a filament preheat voltage. The inverter operates at a preheat frequency during a lamp preheat mode and at a steady-state frequency during a lamp steady-state mode, the steady-state frequency being lower than the preheat frequency. The preheat tank circuit has a natural resonant frequency that is approximately the same as the preheat frequency so that when the ballast is operating in the steady state mode, the filament voltage is substantially lower than when the ballast is operating in the preheat mode.

Abstract: A circuit arrangement is provided, which may include an input; an output; an inverter, configured to provide an AC supply voltage from a DC supply voltage; a control device configured to drive the inverter, the control device being configured to initiate a preheating phase once a preheating criterion has been met; a resonant circuit having a resonant inductor and having a resonant capacitor; and a transformer configured to preheat electrodes of a gas discharge lamp; wherein the primary winding of the transformer is connected in series with the resonant capacitor and is connected directly to the reference potential of the control device, and an electrical switch is coupled in parallel with the primary winding of the transformer, which switch has a control connection, which is coupled to the control device being configured to transfer the electrical switch into its electrically conducting switching state once the starting criterion has been met.

Abstract: A control circuit for a discharge lamp, which can improve the lighting performance of the discharge lamp while realizing low power consumption, and a light source device are provided. The resistance value of the variable resistor (RC1, RC2) is not switched to the low resistance (R02) for steady discharge at the fourth time t4, but is switched to the low resistance (R02) at the fifth time t5, after lowering of power supply to the filament. With such control, a change in the lamp impedance is absorbed sufficiently by the variable resistor while power supply to the filament is being lowered and, therefore, destabilization of discharge is reduced and the lighting performance is improved.

Abstract: A magnetron has an anode 3 surrounding a tubular hollow cathode 4 which contains a heater 9. The cathode is supported by radial arms at each end. At one end of the cathode, the heater is supplied with one terminal of its D.C. supply by means of a radial arm 5, which also serves to support that end of the cathode. The arm has a portion 5a offset towards the cathode, and a cover of conducting material is interposed between the heater connection and the adjacent end wall 1 of the vacuum envelope. The cover may have a folded portion so that it can be carried by the arm.

Abstract: A cathodoluminescent lighting system has a light emitting device having an envelope with a transparent face, a cathode for emitting electrons, an anode with a phosphor layer and a conductor layer. The phosphor layer emits light through the transparent face of the envelope. The system also has a power supply for providing at least five thousand volts of power to the light emitting device, and the electrons transiting from cathode to anode are essentially unfocused. Additional embodiments responsive to triac-type dimmers with intensity and color-changes in response to dimmer control. A power-factor-corrected embodiment is also disclosed.

Abstract: A fluorescent-lamp-driving device contains a driving control circuit that receives direct current power voltage and a lamp control signal for performing drive control on fluorescent lamps and converts the direct current power voltage to alternating current power voltage, and a transformer containing a winding at its primary side and windings for driving a heater and for maintaining discharge at its secondary side. The alternating current power voltage is supplied to heaters of the fluorescent lamps at their high electric potential side. The driving control circuit increases the frequency of the alternating current power supply to a frequency thereof in which voltage of the fluorescent lamps is equal to a discharge start voltage of the fluorescent lamps or less based on the lamp control signal at a period of starting-up time of the fluorescent lamps.

Abstract: The lamp uses a sealing system with a ceramic supporting element (17) having a short length LA together with a W—Nb leadthrough part (18, 19, 20) and a specially adapted glass solder (21), which is based on an Al2O3 rare earth oxide system. In this case, the W part is accommodated in the supporting part over a length LW of 1 mm, and the aspect ratio LW/DUW, formed from the length LW and the diameter DUW of the W part, is at least 10.

Abstract: An electronic dimming ballast comprises a filament turn-off circuit for controlling the magnitudes of filament voltages supplied to the filaments of a gas discharge lamp. Each of a plurality of filament windings is directly coupled to one of the filaments and is operable to supply a small AC filament voltage to the filaments. The plurality of filament windings and a control winding are loosely magnetically coupled to a resonant inductor of an output circuit of the ballast. A controllably conductive device is coupled across the control winding. When the controllably conductive device is conductive, the voltage across the control winding and the filament windings falls to zero volts. The controllably conductive device is driven with a pulse-width modulated (PWM) signal so as to control the magnitudes of the filament voltages. The filament voltages are provided to the filaments before striking the lamp, and when dimming the lamp near low end.

Abstract: In accordance with one embodiment of the present invention, there is provided a switch-mode power supply to generate the heating current for a hot-filament electron-emitting cathode. The power supply directly couples, without an output power transformer, the output from a full-bridge converter that operates at an output frequency in the range from ten Hz to tens of Khz to the output terminals of the power supply. A connection to a reference potential that minimizes the potential fluctuation of the cathode is provided by the center tap on an autotransformer connected across the output terminals, where the conductors in the autotransformer are sized for half of the emission current from the cathode rather than the much larger heating current.

Abstract: A cathodolumineseent lighting system has a light emitting device having an envelope with a transparent face, a cathode for emitting electrons, an anode with a phosphor layer and a conductor layer. The phosphor layer emits light through the transparent face of the envelope. The system also has a power supply for providing at least five thousand volts of power to the light emitting device, and the electrons transiting from cathode to anode are essentially unfocused. Additional embodiments responsive to triac-type dimmers with intensity and color-changes in response to dimmer control. A power-factor-corrected embodiment is also disclosed.

Abstract: A method and apparatus for providing electrical current to a lamp, detecting a power supply voltage outage, detecting a return of the power supply voltage, determining how long the power supply voltage outage lasted, and preheating the lamp responsive to determining that the power supply voltage outage lasted greater than a threshold amount of time.

Abstract: A dimmable ballast and methods are presented in which the operating frequency of a self-oscillating inverter is controlled according to a sensed lamp current for dimming control or cathode heating, and an AC bus voltage of the inverter is controlled to be at or below a voltage threshold value to prevent over driving operating lamps when one or more lamps are being replaced.

Abstract: The drive signal for a switchable heating transformer of an electronic ballast should be capable of being produced in a simple manner. For this purpose, the invention provides for an oscillating inverter voltage, which has a variable inverter frequency, to be tapped off, for example, at the half-bridge center point. The inverter frequency is then preferably converted into a drive signal by a charge pump (C1, C2, D1, D2). As a function of this drive signal, the heating transformer (HT) is switched. Synchronization with externally controlled sequence control of the electronic ballast is therefore also possible.

Abstract: A method for lighting a flat fluorescent lamp for a large-sized backlight unit is disclosed, to prevent a discharge interference (scattering in fluorescent discharge) when lighting a plurality of groups of cylindrical electrodes being adjacent, in which an A.C. voltage is applied to one or two groups of cylindrical electrodes through introduction wires for lighting lamp in state of being not applied to adjacent one or two groups of cylindrical electrodes, so the plurality of groups of cylindrical electrodes are sequentially switched on and off in a time-division method at a speed not to generate the flicker of lamp.

Abstract: A power supply for an insulation detector having a heating element and a temperature sensitive switch thermally coupled to the heating element, the power supply including a power circuit 120 operable to provide heating element power 102 to the heating element 32; a short protector 108 operably connected to the power circuit 120 to monitor current flow through the heating element 32; and an insulation detector sensor 110 operably connected to the power circuit 120 to monitor presence of the heating element 32.

Abstract: A system and method for developing a solid state stripper device is described that more effectively strips off negative carbon ions to produce positively charged carbon ions. In one embodiment the solid state stripping device is a self-supporting aggregate of nanotubes or Buckminster-Fullerenes. Such devices provide, among other things, carbon stripper foil for use in a tandem generator.

Abstract: The present invention applies to provide a lighting method of a high pressure discharge lamp dedicated particularly for image equipments in which re-lighting when turning ON the switch again immediately after the switch OFF is instantaneously performed even in the high pressure discharge lamp. In the transition state of transitioning from the lighted state to light off, the lamp power to be supplied to the electrodes (3), (4) is reduced to an extent an arc discharge does not disappear and maintained for a while, and thereafter, transitioned to the glow discharge after lowering the lamp temperature to a temperature capable of maintaining the glow discharge and maintaining the glow discharge for a while, and the current supply to the electrodes (3), (4) is cut at the point the lamp temperature becomes lower than or equal to the temperature at which re-lighting is possible.

Abstract: The embodiment disclosed herein relates to systems and methods to provide improvements to power delivery systems employed with lamps in general and fluorescent lamps in particular. In accordance with one exemplary embodiment, cathode current is controlled to a maximum level to quickly bring the cathode temperature up to thermionic emission temperature. After lamp ignition, a cathode voltage reduction circuit is employed to reduce voltage of the external cathode heating. Power is supplied to a power factor correction circuit via an IC, in accordance with a second exemplary embodiment. Finally, a third disclosed embodiment addresses desensitizing the lamp from various deleterious parasitic capacitive effects associated with the power delivery to one or more lamps.

Abstract: When a discharge lamp is preheated, impedance of a filament electrode of the discharge lamp is computed. In accordance with the computed impedance, preheating and lighting of the discharge lamp are controlled.

Abstract: An electronic ballast capable of extending life of the fluorescent lamp is disclosed. The electronic ballast according to the present invention comprises a DC/AC converter, a fluorescent lamp, a transformer, a preheating transformer and an AC switch. Wherein, the AC switch is turned off during a preheating period of time for the fluorescent lamp. Due to adoption of a preheating transformer in the secondary side and an AC switch for the electronic ballast according to the present invention, the voltage drop across the fluorescent lamp can be reduced during the preheating period of time, and accordingly no glow current would appear. Therefore, life of the electronic ballast can be effectively extended.

Abstract: In a current fed electronic ballast multiple lamps are operated in a parallel circuit arrangement. The ballast provides pre-heating to the cathodes of the lamps for a period of time before an open circuit voltage is ramped up to the preferred starting voltage of the lamps. An open circuit voltage controller times coordinates the pre-heating and the operating voltage. After the pre-heating phase, current is removed from the cathodes of the lamps so that electricity is not wasted to the cathodes while the lamps are lit. A single switch is used to switch cathode pre-heating on and off, regardless of how many lamps the ballast operates. A decoupling array of diodes allows the single switch to coordinate pre-heating to all the lamps.

Abstract: An apparatus for detecting the reconnection of a lamp filament to an electronic ballast driving a fluorescent lamp. A control circuit controls an inverter circuit to providing power to a filament control circuit. The filament control circuit preheats and powers the lamp filament of the one or more lamps. A pulse generator generates an input signal as a function of the number of lamp filament connected to the filament control circuit. A current sensor generates a first voltage indicative of whether a lamp filament has been reconnected to the circuit. A peak detector generates a peak voltage signal when the first voltage indicates a reconnection of a lamp filament has occurred. A sensing circuit generates a command signal to provide to the control circuit to supply power to the filament control circuit to preheat and power the lamp when the peak detector generates the peak voltage signal.

Abstract: A starter for a discharge lamp is disclosed for operation from an AC supply voltage. The starter comprises a first terminal for connection to a first lamp electrode, a second terminal for connection to a second lamp electrode, a switching element coupled between the first and second lamp electrode during operation, a control circuit coupled to a control electrode of the switching element for generating a control signal for rendering the switching element conductive and thereby allowing an AC preheat current with period T to flow through the lamp electrodes and for subsequently rendering the switching element non-conductive to generate an ignition voltage pulse between the lamp electrodes. The starter advantageously inflicts only a relatively small amount of damage to the electrodes of the discharge lamp by means of ignition voltage pulses that are applied to the discharge lamp before its electrodes are sufficiently heated (i.e.

Abstract: Apparatus and methods for measuring cathode fall in fluorescent lamps are disclosed. Together with measurements of cathode temperature, such measurements of cathode fall may inform a determination of cathode heater voltage as a function of discharge current (i.e., a cathode-heating-profile) that avoids both sputtering and excess-evaporation.

Abstract: A method for operating at least one low-pressure discharge lamp having heatable lamp electrodes, in which, during the preheating phase of the lamp electrodes, the type of lamp is identified. In this case, the temperature dependence of the electrical resistance of the lamp electrodes is exploited.

Abstract: A phase random access memory including a plurality of access transistors, each access transistor including a drain region, and a phase-changeable film shared by the plurality of access transistors. The phase-changeable film is connected to a bitline through a first electrode and connected to each respective drain region through at least one of a plurality of second electrodes.

Abstract: In accordance with one aspect of the present application, a lamp inverter circuit includes a switching portion that converts a bus voltage signal into an alternating current signal. An input portion receives the bus voltage signal, and a resonant load portion drives a lamp. A preheating portion heats the lamp prior to ignition, and thereafter renders itself inactive following ignition of the lamp. In accordance with another aspect of the present application, a method of starting a lamp includes receiving a bus voltage signal, converting the bus voltage signal into an alternating current signal, preheating the lamp to an ignition temperature, igniting the lamp and inactivating the preheating after the lamp has been ignited. In accordance with another aspect of the application, provided is a method of igniting an auxiliary lamp, including detecting a conductive state of a main lamp in a lamp ballast circuit, the detecting being by a switch that controls preheating of the main lamp.

Abstract: The disclosure includes an ignition control circuit comprising a transformer having at its secondary side an operating winding, and at least one filament winding. In a pre-heating phase, only the filament winding, which is normally connected to the filaments of a lamp, is active. In this way, the filaments of the lamp are heated first. After a predetermined time, the secondary operating winding is switched on, by a triac. This triac is a compact component producing no or little heat. The invention provides a simple and economic ignition circuit for gas discharge lamps.

Abstract: The invention relates to a novel ballast device for pre-heating, starting and operating at least one UV emitter, constructed in the form of a gas discharge lamp with two heating coils lying opposite each other in relation to a gas discharge path, whereby four electrical connections are provided in total for each of such gas discharge paths, namely two for each heating coil. According to the invention, switching means are provided for a parallel switching of both of said connectors of a heating coil, dependent upon operating conditions. A capacitive loading of the ballast device is thus avoided by means of the otherwise open connector line for the heating coil and the current feed to the coils is evenly distributed.