Abstract: A dimmer circuit provides AC power to an inductive lighting load in series with the dimmer circuit. A bidirectional semiconductor switch has a control electrode with a control signal for determining the power provided to the load. The switch in normal operation is controlled to block voltage in first and second half-cycles of the AC voltage. In a failure mode it can block the AC voltage in only one half-cycle. A controller for the switch determines the failure mode of the switch occurs which can cause an asymmetry between the half-cycles and thus a DC voltage component. A power supply supplies power to the controller from across the dimmer circuit. The controller drives the switch into substantially full conduction during most of the half-cycle which the switch is able to control; and drive the switch into non-conduction for a period of time during that same half-cycle so as to reduce the DC voltage component to prevent excessive transformer heating.

Abstract: A portable power converter comprising input means to receive low voltage DC input, voltage converter means for converting the low voltage DC input into high DC voltage output, the voltage converter means in electrical communication with the input means, output means for operably supplying the high DC voltage to an appliance. The output means is in electrical communication with the converter includes a housing adapted to receive at least one of the input means, the voltage converter means and the output means. Preferably, the portable power converter also includes processing means for controlling some of the functions of the device such as shutting it down when power falls below preselected threshold. The device may also include a remote control which may be manually activated or in an alternative embodiment activated by external environment stimuli.

Abstract: Switching of parallel capacitors in an HID bi-level lighting control system is accomplished through use of transient voltage suppression across an electronic relay for discharge of residual charge from a switched capacitor when combined peak voltage exceeds clamping voltage, thereby allowing maximum switch voltage rating to be lower than is possible through the use of conventional switching methods and circuitry. The invention contemplates method and apparatus permitting capacitive switching at voltage levels higher than are possible in conventional capacitive switching arrangements including capacitive switching arrangements used in lighting control systems.

Abstract: Circuit arrangement for operating discharge lamps (LP), having the following features: A power factor correction device (PFC) provides an intermediate circuit voltage; an inverter (INV), which draws its power from the intermediate circuit voltage, outputs power to discharge lamps (LP). According to the invention, an oscillation of the power factor correction device (PFC) only takes place when it is started, by means of a starting device (TRG), by an oscillation of the inverter (INV). This provides cost-effective control of the sequences in the circuit arrangement.

Abstract: A method and apparatus are provided for reducing the stable lamp standby power to the order of 5% of nominal full power in order to reduce the effects of heat from the lamp on a substrate during production downtime. In particular, a power controller changes the operating voltage and current of the lamp, and controls the temperature of the lamp in order to maintain stable lamp operation at the changed voltage and current.

Abstract: A bidirectional switch, including a first bidirectional switch between two power terminals of the switch, a low-voltage storage element between a first power terminal and a control terminal of the switch, and a control stage adapted to cause, upon each halfwave beginning of an A.C. supply voltage applied between the power terminals and when the switch is on, the charge of the storage element with a biasing depending on the sign of the halfwave.

Abstract: An incandescent lamp 12 and a MOSFET 14 are connected in series with a power supply. A capacitor 164 is interposed between the gate G of the MOSFET 14 and a reference potential. Electric charges are gradually stored in the capacitor 164, thereby gradually increasing the voltage level of the control signal to be supplied to the gate G.

Abstract: A driving circuit for powering an electroluminescent display using energy recovered from a varying panel capacitance of the display. The driving circuit comprises a source of electrical energy; and a resonant circuit using the panel capacitance for receiving the electrical energy and in response generating a sinusoidal voltage to power the display at a resonance frequency which is substantially synchronized to a scanning frequency of the display. The resonant circuit uses a step down transformer to reduce the effective panel capacitance of the display in order to reduce its effect on the resonance frequency.

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: A 0-10V dimming interface protection circuit generating an indication that line voltage is applied across first and second leads of the dimming interface controlling light output by a lamp, includes a first device for limiting current serially connected between a line voltage source and the first lead of the dimming interface, a second device connected across the first and second leads for detecting application of line voltage to the dimming interface and for generating a control signal, and a third device for switching, operated in response to the control signal, for causing an increase in resistance of the first device to thereby limit current to the dimmer interface and limit light output by the lamp. According to one aspect of the invention, the protection circuit also includes a fourth device for preventing spurious operation of the second device.

Abstract: One of the objectives of the present invention are to provide smaller, lighter and less expensive structure in a starting device for discharge lamp for car use so as to prevent breakage due to vibrations etc. And another objective is to obtain the high efficient device having a reduced conductor loss. A starting device for discharge lamp comprising; a socket equipped with a high voltage electrode and a grounding electrode for mounting the discharge lamp and a starting parts equipped with a starting transformer, which has a bobbin, a core having a through hole a primary and secondary coils wound around the bobbin where a high voltage leading wire of the secondary coil is connected to a high voltage terminal of the socket via the through hole of the core.

Abstract: A combination electronic ballast designed to operate a metal halide lamp and a high-pressure sodium gas discharge lamp is disclosed. The ballast includes a primary and secondary coil coupled to a magnetic core. The primary is adapted to be connected to an ac power source and the secondary is adapted to be connected to a metal halide lamp and a high-pressure sodium lamp. The primary and secondary coils are connected together using a capacitance circuit including two capacitors and a switch. The capacitance circuit is designed to connect both of the capacitors between the primary and secondary coil when a high pressure sodium lamp is connected to the ballast and to connect only one of the capacitors in parallel when a metal halide lamp is connected to the ballast. In an alternative embodiment, the primary is adapted to be connected to one of four different ac power sources.

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: 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 ballast circuit for energizing a lamp includes an inductive element coupled to an input terminal and a capacitive element coupled to the inductive element in parallel with the lamp. In one embodiment, the capacitive element includes a plurality of capacitors each of which is coupled in series with a switch to control the total capacitance provided by the capacitors. By controlling the total capacitance, the intensity of light emitted by the lamp can be selected. In another embodiment, a switching element is coupled across one of the capacitors for providing a selected capacitance to the circuit for controlling the lamp light intensity. In a further embodiment, a transformer has a first winding coupled in series with the capacitive element with the inductive impedance of the first winding being controlled via a second transformer winding coupled to a control circuit.

Abstract: An open circuit failure monitoring apparatus for controlled electrical resistance heaters is disclosed. The heater failure monitoring apparatus allows controlled electrical resistance heaters to be continuously monitored for open circuit failures without applying an operational current flow through the heater, regardless of the operational status of the heater and without significant power consumption during periods when the heater is not operated. The failure monitoring apparatus includes a reactive current limiting element, such as a capacitor, and a current monitoring circuit. The capacitor is connected in parallel with the contact switch used to control line voltage applied to the resistive load. The reactance of the capacitor provides a small but continuous test current capable of being detected by the current sensing component, but not large enough to consume significant power.

Abstract: A lighting control system for discharge lamps which comprises a ballast for supplying energy from a power source to a lamp. First and second capacitors and a first control relay and contact set control the supply of energy from the ballast to the lamp to switch the lamp between dimmed and normal wattage operational modes. A second control relay and contact set connects a single output control wire to neutral when a predetermined condition is sensed or a switch is thrown. The first control relay, which is connected at one end to the lamp ballast, is energized when the other end thereof is connected to neutral via the second control relay. The first control relay in turn closes the normally open contact set, which is connected to one of the capacitors, to increase the energy provided to the lamp. In accordance with one embodiment the first capacitor and the contact set of the first control relay are connected in series, and together are connected parallel to the second capacitor.

Abstract: A pulse generator for a stable output pulse voltage obtains a high voltage pulse with a charge accumulated in a capacitor and discharged at a discharge gap made ON, wherein a pulse energy source and a trigger source for conduction of the discharge gap are separately provided, so that the discharge gap will be conducted by a boosting action of the trigger source when a predetermined value is reached by a voltage of the pulse energy source.

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 zero current crossing capacitive switching scheme for controlling the switching of a capacitor into and out of an HID lead ballast circuit at a time when a current through the capacitor is at or near zero. The capacitor switching enabling bi-level operation of an HID lamp such that the HID lamp operates at full power mode or in a reduced power mode. The zero current crossing is achieved by delaying the capacitor switching, a duration equal to about 5.degree. to 10.degree. lag from the zero volt crossing. The device can be used in a method of controlling a plurality of HID lamps using an isolated class 2 wiring scheme. Potential damage to the HID lamp caused by aborted lamp ignitions is also disclosed. The method includes suppressing off input signals during the warm up period.

Abstract: A discharge lamp operating circuit is connected to a source of alternating current (AC) voltage, and has a discharge lamp and a semi-resonant circuit connected to the source of alternating current voltage and in series with the lamp. A starting circuit for initiating operation of said discharge lamp is also connected in the circuit. The lamp switching maintains the series semi-resonant circuit in oscillation and the series semi-resonant circuit maintains the lamp in operation after operation has been initiated by the starting circuit. Highly efficient energy transfer between inductive and capacitive components of the system result in low loss and high power factor. A variable capacitance circuit is provided to allow use of the discharge lamp operating circuit with different line voltages, and to allow dimming.

Abstract: An arrangement for switchably operating one or more gas discharge lamps, such a compact or circline fluorescent lamps, with a single ballast commonly used with a linear fluorescent lamp. One or more capacitors is either in parallel or in series with the gas discharge lamp. When engaged by a switch, the capacitor either shunts or reduces the current to the gas discharge lamp in a manner which allows appropriate starting voltage, appropriate operating current and a plurality of illumination levels of the gas discharge lamp.

Abstract: A discharge vessel with a ceramic wall is filled with inert gas and metal and is ignited and operated by an electronic circuit including a half bridge converter with an LC circuit which, when the lamp is not ignited, enters an oscillation state near a resonance frequency which lies near the third harmonic of the switching frequency of the half bridge converter. The vessel encloses a cylindrical discharge space of diameter D and length L, wherein L.ltoreq.D.ltoreq.1.2 L.

Abstract: A method for improving electrical and light producing efficiency in two terminal, direct current, low voltage incandescent lamp dimming wherein a small inductance in series with the power source, lamp, and two terminal controller boosts the voltage supplied to the timing circuitry. Accordingly, the voltage level of the controlling signal applied to the insulated gate of the field effect transistor is increased as well, improving electrical efficiency and allowing for efficient use with a wide range of supply voltage, from 18 volts or more down to as low as one volt. Also a technique is provided whereby, even though using only two terminals, lamp intensity is regulated over a wide range of supply voltage excursions, improving light producing efficiency in incandescent lamps. Also, this same technique proportionally reduces current demand when the supply voltage exceeds that of the lamp, affording increased energy extraction efficiency from batteries.

Abstract: A circuit arrangement for operating a high pressure discharge lamp having a full bridge commutator network. A capacitor across each of four commutator switches forms a tuned circuit together with a ballast coil for soft switching. To counteract the core material of the ballast coil from vibrating audibly during lamp operation about no more than 15% of the commutation cycle elapses between turning off the first of the four commutator swithes and turning on the last of the four commutator switches.

Abstract: In a gas discharge device having a gas discharge channel, which comprises two gas discharge electrodes and a gas discharge volume lying between said electrodes, having an energy storage circuit connected by a switching device to the gas discharge electrodes for producing a current surge flowing between a first output terminal and a second output terminal for operating a gas discharge, and having an ignition device for separate ignition of the gas discharge, in order to improve said device in such a way that it operates better and more reliably, it is proposed that the switching device comprises a voltage divider lying between the output terminals and comprising a first and a second impedance, that the gas discharge electrodes are connected in parallel to the first impedance and a spark gap is connected in parallel to the second impedance, that the first impedance is so dimensioned that, in the absence of a gas discharge, a voltage lying below the breakdown voltage of the gas discharge electrodes is applied to

Abstract: A discharge lamp operating circuit is connected to a source of alternating current (AC) voltage, and has a discharge lamp and a semi-resonant circuit connected to the source of alternating current voltage and in series with the lamp. A starting circuit for initiating operation of said discharge lamp is also connected in the circuit. The lamp switching maintains the series semi-resonant circuit in oscillation and the series semi-resonant circuit maintains the lamp in operation after operation has been initiated by the starting circuit. Highly efficient energy transfer between inductive and capacitive components of the system result in low loss and high power factor.

Abstract: An apparatus for retrofitting an HID light fixture is described in several embodiments. The apparatus is coupled in series with the secondary winding and the HID lamp of the HID light fixture. A first retrofit capacitor replaces the light fixture capacitor of the HID light fixture. A switching device is coupled in series with a second retrofit capacitor and couples the first and second retrofit capacitors in parallel in response to a normal power mode control input so that the HID lamp provides normal intensity lighting at normal power. The switching device uncouples the first and second retrofit capacitors from being in parallel in response to a low power mode control input so that the HID lamp provides low intensity lighting at low power.

Abstract: An apparatus for dimming a discharge lamp is provided which comprises an electromagnetic regulator. The electromagnetic regulator has a primary winding connected to an AC power supply, a secondary winding connected to the lamp, and a tertiary winding. A capacitor is selectively connected to a tap on the tertiary winding via a switching device for dimming purposes.

Abstract: In an electronic flash apparatus having a flash tube (2) which is disposed inside a reflector (3), having a storage capacitor (5) which can be discharged via the flash tube having a d.c. voltage converter (7) which is fed by a d.c. voltage source, preferably a battery (6), and by means of which the storage capacitor (5) can be recharged to its operating voltage following each discharge, and having a control circuit (8) which switches the d.c. voltage converter (7) on or off as a function of the voltage at the storage capacitor (5), overheating of the reflector (3) and/or its front elements (4) is prevented by a protective circuit (12) which influences the flash light emission in such a way that the temperature of the reflector (3) and/or its front elements (4) does not exceed a predetermined maximum value.

Abstract: A FIFO memory (4) provides serial to parallel and parallel to serial data conversion. A read frame buffer (40) and a write frame buffer (30) are coupled with a RAM array (22). Serial input data is stored temporarily into the write frame (30) of fixed width, n bits wide. Then, the entire n bit wide frame of stored serial input data is written into RAM array (22) at once in parallel. Data read in parallel from RAM array (22) is stored temporarily into the read frame (40) and thereafter provided serially to the FIFO output (53). By converting serial input to parallel input, overall chip size is reduced by reducing the number of pointers required because it is not necessary to address the RAM (22) individually when serially writing data into it. The read frame (40) coupled to the write frame (30) and to the serial input data. This allows data written into the FIFO to be immediately available and allows the read frame (40) to receive backfilled data from the write frame (30).

Abstract: A switching power supply 38 for use in a switched anode, field emission flat panel display includes energy recovery modules 48.sub.R, 48.sub.G and 48.sub.B for recovering energy from each anode electrode 50.sub.R, 50.sub.G and 50.sub.B of the display as the voltage on the anode V.sub.A is switched from a high level to a low level, and for restoring this energy to the anode as the voltage is returned from the low level back to the high level. Each energy recovery module 48 includes a capacitor 62 for storing charge and an inductor 60 for storing energy. During the deactivation period of each anode electrode 50, dc source 40 is uncoupled from anode electrode 50 and energy is transferred from the anode electrode 50 to inductor 60, and subsequently from inductor 60 to storage capacitor 62. During the re-activation period, energy transfers from storage capacitor 62 to inductor 60 and anode electrode 50, and subsequently from inductor 60 to anode electrode 50.

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: An electronic ballast for powering at least two rapid start, parallel connected fluorescent lamps. Associated with each lamp is a serially connected choke and capacitor combination. A train of pulses of alternating polarity having a fundamental frequency, which is generated by an inverter, is applied to each serially connected combination. Each combination is characterized by a resonant frequency which is other than an odd harmonic of and at least two times and preferably .sqroot. 5 times greater than the fundamental frequency. Reduction in filament heating, following lamp ignition, is provided through the addition of voltages applied to each filament which are substantially out of phase with each other.

Abstract: A two terminal pulse width modulated incandescent lamp dimmer using low frequency pulse repetition rate provides increased illuminating efficiency by compensating both for light producing inefficiency of a tungsten filament at dimmed level settings, and for internal resistance of a direct current power source. A preferred embodiment of the dimmer is designed for 3.5 to 9.0 volt operation.

Abstract: An EL lamp is driven by a flyback inverter having an inductor connected in series with a first transistor which switches on and off at a high frequency. The junction of the inductor and transistor is connected through a switching diode to an output terminal for connection to an EL lamp. A discharge path, including a second transistor, is coupled to the lamp for removing accumulated charge. The second transistor switches on and off at a low frequency for periodically discharging the electrical charge accumulated on the EL lamp. In accordance with one aspect of the invention, several diodes are connected in series with the switching diode to block waste current during discharge of the EL lamp. In accordance with another aspect of the invention, the switching diode is temporarily by-passed to provide the discharge path for the lamp. In accordance with either aspect of the invention, the inverter can produce alternating current through the lamp by adding a capacitor in series with the lamp.

Abstract: A gas discharge lamp power ballast or power supply having simplified power factor correction, simplified automatic short circuit/overload protection and output open circuit voltage regulation. The gas discharge power ballast or power supply includes self-oscillating converter circuitry to which simplified power factor correction is provided via simple passive circuitry that includes a split winding from the power transformer in conjunction with an input storage capacitor and a current limiting resistor. The short circuit/overload protection is implemented, without elaborate current sensing circuitry, by utilizing the drive winding of the power transformer. In a shorted or overloaded state, a capacitor interacting with oscillator circuitry, controls oscillator cycling to reduce current flow and protect the circuitry against the overload at the output. Output open circuit voltage regulation and power regulation are also implemented in a simplified manner without the need for significant additional circuitry.

Abstract: A lamp driving circuit having a series inductor and capacitor (L-C) in which the lamp load is connected in parallel with the capacitor. During pre-ignition of the lamp load, the driving signal supplied by a half-bridge oscillator includes a fundamental frequency and a third harmonic of the fundamental frequency. The resonant frequency of the series connected L-C circuit is at least .sqroot.5 times greater than the fundamental frequency but less than the third harmonic of the driving signal.

Abstract: The resolution .DELTA.C of a binary capacitance ladder having a plurality of N branches is precisely determined by appropriately selecting the value of a fixed capacitor in each branch relative to the parasitic capacitance of a corresponding series-connected switch. The capacitance of each respective branch varies by 2.sup.n-1 .DELTA.C, where n is the number of the branch, adjacent branches being numbered sequentially. The total capacitance is variable between C.sub.Total and C.sub.Total -(2.sup.N -1).DELTA.C in steps of .DELTA.C, where C.sub.Total is the sum of the capacitances in the ladder with all switches closed, and C.sub.Total -(2.sup.N -1).DELTA.C is the capacitance of the ladder with all switches open. For any particular branch of the ladder, the switch capacitance may be further controlled by adding a fixed capacitance in parallel with the respective switch. Such a variable capacitance is useful as a tuning capacitor in an electrodeless HID lamp ballast.

Abstract: A lighting fixture has a lamp and a housing for a lamp ballast. In the new fixture for providing bilevel illumination, the housing also contains a control device comprised of a dual capacitor and a "random crossing" relay connected to the capacitor. A single electrical control wire is attached to the relay and extends from the housing to a control module for remotely controlling the level of illumination consumed by the fixture. In a system employing one or more of the new fixtures, the level of illumination provided by each fixture is controlled by applying a signal to the control wire and switching the relay independently of the instantaneous value of the voltage across the relay terminals. A new method for providing two levels of power to the fixtures (and, thus, two levels of illumination) is also disclosed.

Abstract: Disclosed is a ballast circuit arrangement for a gas discharge lamp, which includes a ballast transformer arrangement receptive of an input power signal, having a winding and a serially connected ballast capacitor, and providing an output, ballast voltage that alternates in polarity during successive half cycles. A bypass capacitor is coupled to the winding of the ballast transformer for being charged by the ballast voltage. A voltage for driving the lamp exists on the bypass capacitor. The inventive arrangement includes 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 hot restrike starting circuit is provided, comprising a starting capacitor coupled across the bypass capacitor, and a circuit for discharging the starting capacitor including a primary winding of the pulse transformer and a serially connected current switch.

Abstract: A light-emitting element drive circuit for a camera comprises a diode and a light-emitting element connected in series with each other between a power source and ground, a first switching element switchable between on and off states for driving the light-emitting element, second and third switching elements connected in series with each other between the power source and ground, and a capacitor connected between a junction point of the diode and light-emitting element and a junction point of the second and third switching elements. The second and third switching elements also constitute switching elements of a drive circuit for driving a DC motor, whereby the light-emitting element can be driven with a voltage which is approximately twice as high as the power source voltage. Since the light-emitting element is driven by a capacitor charge/discharge operation instead of using a boosted power source, the consumption of current is reduced and the light-emitting period is shortened.

Abstract: A built-in igniter type high pressure sodium lamp includes an igniter connected in parallel with an arc tube 1 for a high pressure sodium lamp and composed of a series circuit of a thermally-activated bimetal switch 2 and a nonlinear capacitor 3. The high pressure sodium lamp is so constructed that a heating resistor 11 which can heat the nonlinear capacitor 3 to the Curie point temperature when the igniter operates is connected in parallel with and located close to the nonlinear capacitor 3.

Abstract: This is an emergency lighting system that provides an emergency driving voltage to drive at least one lamp when the AC power input to the lamp is detected as absent. A rechargeable battery pack and recharging circuit are contained in a first modular housing, and driving circuitry is contained in a second modular housing. An easily accessible, manually-operable service switch disables the provision of battery power to the driving circuitry (when the switch is in the open state), thereby allowing substantial reduction in installation time and cost. A test switch is included to emulate power failures. A transmitter and receiver mechanism allow a user to remotely disable the provision of battery power to the driving circuitry, thereby offering battery power conservation, if the emeregency lamplight is not needed. Likewise, a photo-sensing mechanism disables the provision of battery power to the driving circuitry, if there is sufficient ambient light.

Abstract: The Lamp (La) is connected in series with first reactive impedances (C1, . To generate pulses, one or more second reactive impedances (C3, L3; C3-L2) are located as energy storage elements in series with one or more switch elements (S3, VTh1, VD1) to at least one of the first reactive impedances (C1, L1) and also in series with the high-pressure gas discharge lamp.

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: A starting capacitor disconnect scheme for a fluorescent lamp system in which each starting capacitor shunts one or more series connected fluorescent lamps until all of the fluorescent lamps are ignited. Following ignition of all fluorescent lamps, each starting capacitor is effectively removed from the ballast. Preconditioning of the fluorescent lamp filaments can be limited to the period of time that one or more lamp loads are shunted by the starting capacitor.

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

Abstract: A bi-level control system includes a plurality of slave units, each for connection to a respective ballast and HID lamp of a plurality of HID lighting fixtures, and a common control unit. Each slave unit includes a switched capacitor and a slave relay which has one input connectable to a common line of an AC power supply branch circuit powering the fixtures and another input adapted for receiving a line voltage signal. The control unit includes an output connected to the control inputs of each of the slave units by a single control line and switchably connected to line voltage. Dimming of the HID lamp is accomplished by switching line voltage to the output of the control unit which causes the slave relay to switch the slave capacitor into circuit with the HID lamp and ballast. Use of a single control line connecting each of the slave units to the control unit greatly reduces wiring over known systems.