Abstract: A ballast circuit for a compact fluorescent lamp includes a down-converter for operating the lamp with a DC current during stationary operation. The ballast circuit is equipped with an additional inductor. The choke of the down-converter and the additional inductor jointly ignite the lamp. During stationary operation, the additional inductor conveys no current.

Abstract: A circuit arrangement for operating at least one high-pressure discharge lamp with a high-frequency alternating voltage, the circuit arrangement having a voltage converter (W) with an alternating voltage output (j10, j11), a load circuit which is connected to the alternating voltage output (j10, j11) and which has at least one lamp inductor (L1), a coupling capacitor (C1) and terminals (j12, j13) for at least one high-pressure discharge lamp (LP), and a starter (Z) with a high-voltage source and a high-voltage DC output (j14, j15) for starting a gas discharge in the at least one high-pressure discharge lamp (LP). The coupling capacitor (C1) is connected to the high-voltage DC output (j14, j15) via a charging resistor (R1).

Abstract: Disclosed is a lower pressure xenon lamp (12) and the driver circuitry therefor for producing relatively short bursts of intense light from the lamp (12). The lamp (12), including its associated driver circuitry (50) can be used in theatrical, stage, movie and/or video production to simulate, among other things, bursts of lighting. The lamp (12) is installed in a fixture together with a power supply (20) and a control system (50) is provided for controlling when the lamp (12) is turned on and off. Preferably, the control system (50) includes manually operated switches (53, 57, 54) and preferably one or more controllers (50) can be coupled together in a series fashion, should it be desired to control the lamp (12) for a greater number of time cycles then permitted by a single controller (50). Alternative power supplies (20) are disclosed. One power supply (20) permits the intensity of the flashes of light (12) to be controlled.

Abstract: A device for lighting a discharge lamp comprises a rectifier, a switching circuit having a semiconductor element to be connected to said rectifier; a direct power supplying circuit having a rectifying circuit and filtering circuit each connected to said switching circuit; and a discharge lamp and a starter which are connected after said filtering circuit; said starter having a transformer and a smoothing capacitor for generating a high voltage is provided, which has a circuit having a switching element and a resistance connected in series provided between the smoothing capacitor and said discharge lamp and further has a second capacitor connected parallel to said discharge lamp.

Abstract: An ignitor is provided to predictably and reliably start a conventional HID lamp, or to start or restart an HID lamp having a hot strike capability such as a high pressure xenon HPS lamp or similar lamp. The ignitor is configured to prevent the premature triggering of a semiconductor switch in a hot restrike circuit due to unwanted high voltage pulses generated by a conventional HID lamp starter circuit in the ignitor. An ignitor is provided that can be used with lag-type ballasts. Another ignitor is provided that can be used with a lead-type ballast which generates a DC bias across the ballast capacitor.

Abstract: A high-pressure gas discharge lamp is connected on one side to a lead across the secondary winding of a starter transformer and to a second lead on the second side. Starting energy is applied with a pulse. For this purpose, a controllable switch which becomes conducting on reaching a certain voltage or is connected by a drive is provided in series with the primary winding. A capacitor connected in parallel to the series connection is charged by voltage U between the input terminals across a resistor connected in series and a diode. An input circuit provided between these input terminals of the starter has a capacitor, a protective element or a combination of the two for protection against voltage peaks.

Abstract: A circuit arrangement for igniting a high pressure discharge lamp includes a secondary winding of a pulse transformer which is at least partially capacitively shunted forming a tuned filter. The tuned filter preferably forms a band pass filter for passing the second harmonic of the signal produced by a pulse generator. An increase in the supply of current during take-over results thereby minimizing the time required for ignition.

Abstract: The invention relates to circuitry for the operation of a high-pressure dharge lamp including a voltage transformer (T1, T2), preferably a push-pull transformer, a transformer (TR1) connected to the output of the voltage transformer (T1, T2), a pulse ignition device, and a load circuit designed as a ocrial resonance circuit (L1, C1) into which the high-pressure discharge lamp (LP) is switched. The transformer (TR1) possesses at least two secondary windings (w1c, w1d), wherein the first secondary winding (w1c) switches into the load circuit and the second secondary winding (w1d) is connected to the pulse ignition device at the voltage input. The ignition voltage output of the pulse ignition device is designed to be connected to an auxiliary ignition electrode (ZE) of the high-pressure discharge lamp (LP).

Abstract: Disclosed is a low pressure xenon lamp (12) and the driver circuitry therefor for producing relatively short bursts of intense light from the lamp (12). The lamp (12), including its associated driver circuitry (50) can be used in theatrical, stage, movie and/or video production to simulate, among other things, bursts of lighting. The lamp (12) is installed in a fixture together with a power supply (20) and a control system (50) is provided for controlling when the lamp (12) is turned on and off. Preferably, the control system (50) includes manually operated switches (53, 57, 54) and preferably one or more controllers (50) can be coupled together in a series fashion, should it be desired to control the lamp (12) for a greater number of time cycles then permitted by a single controller (50). Alternative power supplies (20) are disclosed. One power supply (20) permits the intensity of the flashes of light (12) to be controlled.

Abstract: A discharge lamp lighting device according to the present invention includes: a discharge lamp including an electrode; and a lighting circuit for lighting the discharge lamp, the lighting circuit being connected to the discharge lamp, wherein the discharge lamp includes a conductor at least partially surrounding the electrode, and the lighting circuit provides a potential for the conductor that is higher than an average potential of the electrode.

Abstract: A ballast for powering a high intensity discharge lamp including an ignitor and a resonant circuit. Ignition pulses produced by the ignitor are added to a boosted low frequency voltage produced by the circuit operating near its resonant frequency during start up of the lamp. The circuit is disabled after a predetermined period of time has elapsed following ignition of the lamp. Application of the signal precedes application of the ignitor pulses to the lamp. Disablement of the circuit can render the ignitor inoperable.

Abstract: On one side, a high-pressure gas discharge lamp (10) is connected, by way of the secondary winding (16) of an ignition transformer (14), to a line (11) and, on its second side, to a second line (12). It is therefore connected to a first voltage U.sub.1. A third line (13) delivers a further voltage U.sub.2. The ignition energy is supplied with the aid of a pulse. For this purpose, a spark gap (17) is provided in series with the primary winding (15), which gap abruptly becomes conductive when the breakdown voltage is attained. A first capacitor (18) that is charged by the voltage U.sub.2 by way of a resistor (20) connected in series is disposed in parallel to the first capacitor. The series connection of a second capacitor (19) and a diode (22) is provided in parallel to the first capacitor. The connecting point of the second capacitor and the diode is connected to the second line (12) by way of a resistor (21). This second capacitor 19 is charged by the voltage U.sub.1.

Abstract: A reduced cycle ignitor circuit for a high intensity discharge lamp incorporating a thermally timed, cycled operation which provides intermittent starting pulses for the high intensity discharge lamp. The ignitor circuit comprises a capacitor and semiconductor connected in series with a ballast transformer. The ignitor circuit further comprises a series connected resistor and thermostat, having thermally operated, normally closed electrical contacts, through which current is conducted to charge the capacitor. The thermostat is thermally coupled to the resistor. During operation, current flows through the series connected resistor and thermostat and charges the capacitor to a breakover threshold voltage level of the semiconductor. At that point, the semiconductor conducts and the energy stored in the capacitor is discharged through the semiconductor and a winding of the ballast which, through auto-transformer action, generates a high voltage pulse to start the high intensity discharge lamp.

Abstract: A gas discharge ballast circuit comprises a resonant load circuit including a resonant inductance, a resonant capacitance, and circuitry for connection to at least one gas discharge lamp. A d.c.-to-a.c. converter circuit is coupled to the load circuit for inducing an a.c. current in the circuit. It comprises first and second converter switches serially connected in the foregoing order between a bus conductor at a d.c. voltage and a reference conductor, and connected together at a common node through which the a.c. load current flows. The first and second converter switches each comprise a control node and a reference node, the voltage between such nodes determining the conduction state of the associated switch. The respective control nodes of the first and second converter switches are interconnected. The respective reference nodes of the first and second converter switches are connected together at the common node.

Abstract: An arc lamp igniter circuit (10) employs a resonant inverter circuit (16) to convert low-voltage DC to a relatively high-voltage, 80 kilohertz sinusoidal AC voltage that is rectified and voltage-doubled (42, 44, 46) to about 2,500 volts DC for repetitively charging an igniter capacitor (50) until it discharges through a spark gap (58) and a primary winding (54) of a compact, low-mass igniter transformer (52). A secondary winding (56) of the igniter transformer provides repetitive 20 kilovolt pulses, which are sufficient to ionize a metal halide arc lamp (14), causing it to ignite and produce intense illumination.

Abstract: In an ignition circuit for a high-pressure discharge lamp having a pulse generating circuit in which ignition pulses are generated by a voltage-dependent breakdown element and a pulse transformer, a bandpass circuit has been inserted between the secondary winding of the pulse transformer and the discharge lamp. The bandpass filter is tuned to the fundamental frequency or a harmonic of the pulses generated by the pulse generation circuit.

Abstract: A circuit arrangement for igniting a high pressure discharge lamp includes a secondary winding of a pulse transformer which is at least partially capacitively shunted forming a tuned filter. The tuned filter preferably forms a band pass filter for passing the second harmonic of the signal produced by a pulse generator. An increase in the supply of current during take-over results thereby minimizing the time required for ignition.

Abstract: A high power factor electronic ballast for operating a high pressure gas discharge lamp comprises a boost converter function and a buck function. The boost converter function and the buck function have common components. The combination boost-buck converter reduces parts count, as compared to the parts count required for the separate boost and buck circuits of the prior art, by making some components of the single circuit act simultaneously in both the boost and buck functions. The rigid forcing of the ac input current waveform to follow the ac input voltage waveform is relaxed, to give performance priority to the buck function for the common components. Harmonics are allowed to enter the system in moderation in return for a less expensive and more reliable system that does not compromise lamp power control.

Abstract: A single, integrated circuit combining both a restrike ignitor and a digital timer cutout which generates high voltage pulses for starting and restarting high intensity discharge lamps, including high pressure sodium lamps, without generating an excessive amount of heat.

Abstract: The present invention provides a rare gas discharge fluorescent lamp device which is long in life and high in brightness and efficiency. The lamp device basically comprises a rare gas discharge fluorescent lamp wherein rare gas is enclosed in the inside of a glass bulb which has a fluorescent layer formed on an inner face thereof and has a pair of electrodes at the opposite ends thereof. In one embodiment, it further comprises a dc power source and a resonance circuit for generating pulse-like voltage across the pair of electrodes having the time rate of energization time to a period higher than 5% but lower than 70% and the energization time within a period shorter than 150 .mu.

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: A control module and method controls the operation of a fluorescent lamp in a circuit in which the lamp is connected to a ballast and energized by alternating half-cycles of power supplied from an AC power source. The fluorescent lamp has cathodes and a medium which emits light energy when energized into a plasma. A controllable switch conducts half-cycles of AC current through the cathodes and commutates into a non-conductive condition. A sensor supplies sensing signals related to an electrical condition at the cathodes. A state transition controller controls the switch. The state transition controller establishes a power-up, warm-up, ignition and fire operational states and transitions between the states in response to the electrical condition sensed and the time duration of those conditions. The lamp lights more reliably, premature failure of the ballast and cathodes is prevented due to overheating, and the lamp is controlled effectively by input signals in the form of short power interruptions.

Abstract: A ballast circuit for a gas discharge lamp comprises a resonant load circuit incorporating a gas discharge lamp and including first and second resonant impedances whose values determine the operating frequency of the resonant load circuit. A d.c.-to-a.c. converter circuit is coupled to the resonant load circuit so as to induce an a.c. current in the resonant load circuit, and comprises first and second switches serially connected in the mentioned order between a bus conductor at a d.c. bus voltage and ground, and having a common switch node through which the a.c. current flows. A bridge capacitor has one end connected to ground. First and second feedback circuits regeneratively control the first and second switches, respectively, in response to a.c. current in the resonant load circuit.

Abstract: A hot restart circuit for a high intensity discharge lamp includes a storage capacitor and SCR connected across a tapped portion of a ballast with a breakdown device to start the SCR. A charging circuit for the storage capacitor includes a diode, a pumping capacitor and an RF choke in series from the ballast tap to the AC line, and a further diode interconnecting the capacitors. The pumping capacitor increases the charge on the storage capacitor in a stepwise fashion until breakdown voltage is reached, whereupon starting pulses are applied to the lamp. A positive temperature coefficient (PTC) resistor stops the flow of charging current to the capacitors after a predetermined interval, thereby terminating the reignition pulses and protecting the starting circuit from damage in case the lamp fails to reignite. In an alternative embodiment, a MOSFET gated by an RC timing circuit removes charge from the storage capacitor in order to terminate the reignition pulses after a predetermined interval.

Abstract: Included in a ballast circuit arrangement for a gas discharge lamp is a ballast transformer arrangement receptive of an input power signal and providing an output, ballast voltage. Further included is a pulse transformer having a secondary winding in serial circuit with the lamp for impressing a high voltage, hot restrike starting pulse across the lamp. A bypass capacitor is coupled to the ballast transformer for being charged by the ballast voltage. A hot restrike starting circuit for pulsing a primary winding of the pulse transformer comprises a serially connected starting capacitor and resistor coupled across the bypass capacitor; and a circuit for discharging the starting capacitor including, in serial circuit, the primary winding of the pulse transformer and a current switch having a control electrode responsive to a control signal.

Abstract: The present invention is concerned with a power supply circuit for discharge lamps, especially those intended for vehicle headlamps. It also relates to a headlamp having a power supply circuit. The latter has a half wave bridge structure, the discharge lamp being connected to the midpoint of the bridge. A primary of a transformer works as a quasi-resonant wave generator under the switching effect of a quasi-resonant interrupter, which is controlled by a control circuit for controlling the electrical state of the discharge lamp. In addition, starting of the lamp is effected by a second transformer, the primary of which is connected to a spark gap having a suitably chosen triggering voltage.

Abstract: According to this invention, there is provided a method for starting a gas-conducting lamp, by which a gas-conducting lamp is started directly by a high-voltage without pre-heating of filament. Such a high-voltage is realized by an inductor-capator resonant circuit (LC resonant circuit) or a tap of an inductor. According to this invention, there is also provided a gas-conducting lamp for carring-out the abovementioned method. The method according to this invention is simple and effective and is adapted to the use of a gas-conducting lamp without filament or that with filament which has been broken or has failed.

Abstract: Disclosed is an electronic ballast circuit for a high pressure gas discharge lamp with a reduced parts-count starting circuit. The circuit comprises an arrangement for supplying d.c. voltage from a d.c. source, and a main inductor for receiving energy from the d.c. source and supplying the energy to the lamp. The main inductor has a plurality of windings. A first winding of the inductor is coupled to receive energy from the d.c. source. Further included is a current-switching arrangement conductive during periodic first part cycles for transferring energy from the d.c. source to the main inductor, and non-conductive during periodic second part cycles. A first part cycle is followed by a second part cycle in successive periods of switching operation of the current-switching arrangement. The first winding of the main inductor has impressed across it substantially the d.c. source voltage during the first part cycles, and reflects substantially the lamp voltage during the second part cycles.

Abstract: The invention relates to a high-pressure discharge lamp (2) provided with a discharge vessel (3) and an outer envelope (30) which encloses a space (6). The lamp is provided with an igniter circuit (10) which comprises a voltage-dependent capacitor (8) and a fuse (7). According to the invention, the voltage-dependent capacitor and the fuse (7) are integrated so as to form a single component (18).

Abstract: A ballast circuit for a fluorescent lamp including a magnetic choke electrically connected between the lamp and a power supply and an electronic starter circuit electrically coupled across said lamp, which ballast circuit is configured to provide a power factor of at least 90%. To this end, for certain lamps a power factor correcting capacitance is electrically connected across the power supply. For other lamps, a power factor correcting resistance is coupled between the ballasting capacitance and inductor so that the inductor and ballasting capacitance close to resonance.

Abstract: A circuit arrangement for operating a gas-discharge lamp is proposed, in which the high voltage for starting the gas-discharge lamp is generated by means of the energy stored in a transformer or capacitor. In order to obtain a steep rise in voltage of the starting voltage, the starting voltage is provided to the gas-discharge lamp via a voltage-controlled switch. A break-over diode, which has very short switching times, is proposed as the voltage-controlled switch. The starting circuit is switched off after starting. This circuit arrangement is also particularly suitable for starting gas-discharge lamps which are warm from operation. In consequence, it is particularly suitable for motor vehicle headlights.

Abstract: An electronic starter for fluorescent lamps includes a hybrid solid state switch energized by a line and filtering unit connected in series with a pulse restrictor. The inputs of the hybrid solid state switch and the line and filtering unit are connected to a terminal. Also included in the starter is a pulse generator connected to the output of the hybrid solid state switch, the output of the pulse generator being connected to another terminal. The starter is connectable through such terminals to a power source, is parallel to the bridged terminals of a fluorescent lamp, and in series to the ballast of the lamp.

Abstract: The invention relates to a high-pressure discharge lamp (2) provided with a discharge vessel (3) with a ceramic wall (3a) and provided with a bimetal element (11) which rests against the discharge vessel wall in the cold state of the lamp, and which is removed from the discharge vessel wall during lamp operation. The discharge vessel is surrounded by an outer bulb (30) with intervening space (6), in which space a solid-state getter (15) is provided. According to the invention, the solid-state getter is provided on the bimetal element.

Abstract: A hot restart circuit includes a storage capacitor and SCR connected across a tapped portion of a ballast with a breakdown device to start the SCR. A charging circuit for the storage capacitor includes a diode, pumping capacitor and choke in series from the ballast tap to the AC line and a further diode interconnecting the capacitors. The pumping capacitor increases the charge on the storage capacitor in a step-wise fashion until the breakdown voltage is reached, whereupon starting pulses are applied to the lamp.

Abstract: An ignition scheme for a high intensity discharge ballast. The ballast includes a down converter for producing a varying level of current during the glow stage of the lamp. The level of current available at the time of lamp ignition is equal to or greater than any other level of current produced during at least takeover of the lamp. The need for building up the level of current during at least takeover is eliminated thereby minimizing the need for re-ignition of the lamp.

Abstract: A starting circuit is used in combination with a high intensity discharge lamp having electrodes. An inductor is in series with the electrodes of the lamp, and a first switching transistor is arranged in series with a diode and a load resistor. The first switching transistor, diode, and resistor are arranged in shunt with the electrodes of the lamp and in series with the inductor for charging the inductor when the first switching transistor is switched ON. The energy stored in the inductor is discharged as a voltage pulse across the lamp when the first switching transistor is switched OFF. A first bias circuit turns the first switching transistor ON at a first voltage level from an AC power source. A second switching transistor turns the first transistor OFF at a second voltage level. A second bias circuit turns the second switching transistor ON at the second voltage.

Abstract: An electronic ballast circuit for a discharge lamp, comprising a plurality of transistors connected in series across a DC power line, a driving circuit for alternately turning on/off the transistors and a first LC series resonance circuit connected to an output of the driving circuit, the first LC series resonance circuit having a coil and a plurality of condensers. According to the invention, the electronic ballast circuit comprises a damping circuit connected across the coil for absorbing an instantaneously excessive preheating current or a high voltage pulse. The electronic ballast circuit also comprises a plurality of impulse voltage absorbing devices connected at their one sides to an output side of the coil and at their other sides to a high frequency zero potential point of the DC power line for absorbing a contact high voltage pulse generated across the discharge lamp.

Abstract: A ballast circuit system provides for efficient starting and operation of high voltage discharge lamps using a common 120 volt AC power source. As a result of this improved ballast circuit system, the necessary high voltage is generated from a normal 120 volt AC in such a way that there is low power loss. The system efficiency allows for use of plastic fixtures and small size packaging of the discharge lamp.

Abstract: A quick start ultraviolet emission unit with an elongated, electrode-type, mercury-filled, arc lamp having spaced end electrodes connected to an electrical power supply that connects to an alternating current power source and to each end electrode of the arc lamp for powering the lamp with an alternating current having a sinusoidal cycle, the unit includes a pulse generating, circuit means connected to said power supply for generating a high current, high voltage, electrical pulse added to the alternating current to the lamp during start-up and restart and a trigger circuit connected to the pulse generating circuit for triggering generated high current, high voltage electrical pulses at the peak potential in the sinusoidal cycle of the alternating current form the power supply.

Abstract: A low DC input, low wattage, high efficacy metal halide arc discharge lamp apparatus is provided which has a simplified control system including a regulated power supply, a forty kilohertz oscillator and driver for powering the bulb a main power transformer connected to the metal halide bulb; a starting and filtering inductive/capacitive network connected to the secondary of said main power transformer for start up and running the arc discharge bulb, and a power output sensing and emergency shutdown control circuit for safety shutdown of the system should a failure occur in the lamp or associated circuitry that could cause undesired sparking. An automatic mechanism for compensating for aging of the discharge bulb is also provided.

Abstract: An improved fluorescent ballast circuit for 277 volt commercial application is disclosed utilizing a resonant circuit mechanism to generate high open circuit voltage (OCV) during lamp starting. The result is an energy efficient effective lighting system for commercial buildings.

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 high-pressure discharge lamp has an outer bulb which surrounds a discharge vessel with intervening space. The lamp is provided with an ignition circuit which comprises a SIDAC. According to the invention, the SIDAC is mounted in a gas-filled, hermetically closed glass capsule in the outer bulb.

Abstract: A high-pressure metal vapor discharge lamp comprises: an arc tube, which is shunted by a series circuit of a thermal switch and a nonlinear ceramic capacitor, a pyroelectric current bypassing resistor connected in parallel to the nonlinear ceramic capacitor, and a lamp outer bulb incorporating the arc tube, the thermal switch, the nonlinear ceramic capacitor and the resistor. Because of this construction, the nonlinear ceramic capacitor is prevented from early deterioration, thus lengthening the service life of the discharge lamp.

Abstract: A projection type image display apparatus uses an optical modulation image display device as a light valve. Notwithstanding the use of a metal vapor discharge lamp which has a long re-starting period of time as a light source, the apparatus can display images instantaneously by igniting the discharge lamp for a prescribed period of time after switching off and then on again a main power source of the apparatus. Also, the projection type image display apparatus does not generate audio noise at the time of starting the discharge lamp. Furthermore, even in case of adding an instantaneous re-ignition circuit, the frequency of use of such instantaneous re-ignition circuit can be suppressed to an utmost extent, and the useless igniting period of time of the discharge lamp can be curtailed.

Abstract: A transformer (10) which forms part of a lamp ignition switching device has at least its primary winding (12) composed of a foil. Moreover, the transformer has an air core. In this way a satisfactory coupling, which is also maintained at high temperatures, is obtained between the primary (12) and the secondary (11) winding. This switching device is very suitable to be built in a lamp and to ignite the lamp at a high temperature.

Abstract: The invention disclosed here is an anti-cycling device for high-pressure sodium lamps. A current sensor continually monitors lamp current and outputs a low voltage signal to an amplifier. When lamp current increases, indicating a starting or recycling condition, the sensor's voltage output correspondingly increases, and the amplifier responds by amplifying such output and transmitting it to a second amplifier. The latter acts as a voltage comparator and compares the first amplifier's output with a threshold level. Each time the first amplifier's output exceeds the threshold, the second amplifier outputs a trigger signal. Such signal is counted over time, and if the number of counts reaches a certain number, the counter outputs a malfunction signal to a relay that cuts off power to the lamp. An easy-to-see LED simultaneously illuminates to indicate the cycling condition and the need for lamp maintenance.

Abstract: A switchmode DC to AC converter, and particularly a master-slave half-bridge converter. The slave half-bridge power converter is controlled by a lower power self-oscillating half-bridge master converter. More particularly, the invention pertains to a high frequency ballast for gas discharge devices, especially, for high pressure sodium lamps, completed by a high voltage ignition apparatus.

Abstract: A circuit arrangement for igniting a high-pressure discharge lamp (6), in which ignition voltages are generated by means of discharges from two capacitors (10, 14) through a primary winding (12) of a transformer. During this, the lamp (6) is connected to a secondary winding (4) of this transformer. One capacitor (14) is charged to a higher voltage than the other capacitor (10), the two capacitors being discharged alternately through breakdown elements (11, 15) associated with the capacitors (10, 14, respectively). An ignition pulse with a low peak value for igniting the lamp (6) in the cold state is then followed by an ignition pulse with a high peak value for igniting the lamp (6) if it should be in the hot state.

Abstract: An ignitor circuit for a discharge lamp is controlled by a timer to shut-off ignition pulses after a predetermined time if the lamp does not ignite. The timer is controlled by the application of power to the input line. Means in the lamp housing allow the timer to be manually reset during a hot relamping operation.