Abstract: An electronic, externally controlled ballast has a control oscillator which feeds a fluorescent lamp via an invertor bridge and a resonant circuit. To keep the voltage constant, there are derived from the lamp AC voltage charge packets whose size (and/or phase angle) characterizes the size of the lamp AC voltage. The charge packets are conducted onto a frequency-determining capacitor of the oscillator, which is designed as a sweep oscillator, voltage control thereby being achieved. The ballast provides for reliable operation of gas-discharge lamps. Its design is robust and yet simple, avoids undesired hunting and delivers a good degree of voltage stability.

Abstract: A device and method that inhibits the ability of photographic equipment from obtaining a recognizable picture upon its recording media, of areas of a vehicle equipped with this invention. The leading edge or beginning of the photographic equipment's photoflash is detected by the photoflash detector cicuit group (50). A xenon reply flash (30) is immediately output towards the photographic equipment's general location, for the remainder of the photographs exposure time, rendering sections of the photograph unrecognizable.

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 circuit that forms a square wave pulse train signal wherein each pulse is centered about a zero crossing of a reference sinusoid. A first capacitor is coupled to be charged and discharged at equal rates by a first transconductance amplifier. Upon a first positive zero crossing of the reference sinusoid, the first transconductance amplifier begins charging the first capacitor. Upon the first negative zero crossing, the first transconductance amplifier begins discharging the first capacitor until a first predetermined voltage level is reached. Upon reaching the first predetermined voltage level, the first transconductance amplifier begins charging the first capacitor again. The voltage on the first capacitor is compared by a first comparator to a second predetermined voltage level higher than the first voltage level. The output of the first comparator is a pulse which is centered about a second positive zero voltage crossing of the reference sinusoid.

Abstract: A circuit arrangement according to the invention for operating a discharge lamp (I) comprises a DC/AC converter (II) provided with a series circuit with a first and a second switching element, (1, 1', respectively) between a first and a second input terminal (5, 5', respectively) for connection to a DC voltage source, and with a starting circuit (F) with a first resistive means (R1) between the first input terminal (5) and the control electrode (2) of the first switching element (1). The DC/AC converter is also provided with a second resistive element (R2) which together with the first resistive element (R1) form a voltage divider between the input terminals (5, 5'). The power dissipation in the DC/AC converter is reduced thereby.

Abstract: A circuit arrangement for igniting and operating a discharge lamp is provided withinput terminals for connecting a supply source, and a ground terminal, differential-mode and common-mode filters in which inductance and capacitance are incorporated,output terminals for connecting the discharge lamp, anda switch mode power supply connected to the input terminals and the output terminals by respective voltage conduction branches.The circuit arrangement is characterized in that the input terminals and output terminals are connected both to one another and to the ground terminal by respective capacitive filters, in that a bead is included in one of the voltage conduction branches, and in that further common-mode capacitance is present between the inductance and the switch mode power supply. The requirements formulated in both EN55022 and EN55015 can be complied with in this manner.

Abstract: Power to a self-oscillating inverter ballast is supplied from a DC voltage source through an inductor means having two separate windings on a common magnetic core--with one winding being positioned in each leg of the power supply. The inverter is loaded by way of a parallel-tuned L-C circuit connected across the inverter's output, thereby providing an output voltage thereat. The output voltage consists of sinusoidally-shaped voltage pulses of alternating polarity, with a distinct brief period of discontinuity at or near the cross-over points. A fluorescent lamp is connected by way of a current-limiting capacitor with the inverter's output.

Abstract: In accordance with the present invention, a hybrid sequence start circuit is provided for operating a plurality of instant start lamps. The circuit utilizes two coils, a primary and a secondary, and an electronic switch to start a plurality of series-connected, instant start lamps in sequence. When the circuit is energized, the electronic switch causes open circuit voltage to be applied to a first lamp by placing a low impedance across the other lamps, causing the first lamp to strike. The first lamp then conducts current, causing a starting capacitor in parallel with a second lamp to be charged, eventually, causing the second lamp to strike. The current through the second lamp shunts current away from the switch, and when this current drops below a predefined threshold level, the switch opens, effectively removing both the low impedance and the starting capacitor from the circuit.

Abstract: A laser diode driver chip is disclosed which has a circuit to substantially reduce a ringing on a laser diode driving current generated by the laser diode driver chip. This invention identifies that the ringing on the laser diode driving current is caused by three different resonances which are coupled together. This invention also suggests a model for the sources of these three different resonances and identifies the three main nodes which are common between the sources of resonances. Finally, this invention places a damping circuit between the three main nodes of the laser diode driver to substantially reduce the ringing on the laser diode driving current.

Abstract: A circuit for turning off an indicator light operates in two phases that provide a first rapid discharge phase and a second slow discharge phase. This sequence dims the light in a visual approximation of the exponential dimming that occurs with lights that operate with power supplies that have capacitors that give a slow turn off. The preferred light is an electroluminescent element that will be called a glow-effect capacitor which stores sufficient charge for slow turn off. When a switch associated with the light is opened, an FET turns on to discharge the capacitor rapidly to a selected voltage. This FET is then turned off and other components discharge the capacitor slowly. The switching signal for this FET is formed as a logic function of the switch position (open or closed) and the occurrence of the selected voltage level on the glow-effect capacitor.

Abstract: A fast repetition rate (FRR) flasher suitable for high flash photolysis including kinetic chemical and biological analysis. The flasher includes a power supply, a discharge capacitor operably connected to be charged by the power supply, and a flash lamp for producing a series of flashes in response to discharge of the discharge capacitor. A triggering circuit operably connected to the flash lamp initially ionizes the flash lamp. A current switch is operably connected between the flash lamp and the discharge capacitor. The current switch has at least one insulated gate bipolar transistor for switching current that is operable to initiate a controllable discharge of the discharge capacitor through the flash lamp. Control means connected to the current switch for controlling the rate of discharge of the discharge capacitor thereby to effectively keep the flash lamp in an ionized state between Successive discharges of the discharge capacitor.

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: An electronic ballast for one or more F32T8 or F25T8 or F17T8 fluorescent lamps has a new design tool for efficient transfer of power to the lamp or the lamps. The design tool is constructed from the ballast DC voltage and the commercially available lamp specifications by the manufacturers or from the American National Standards (ANSI). This design tool is shown below: Frequency.times.Capacitance=CONSTANT. ##EQU1## where W=Lamp rating in watts, V.sub.0 =Lamp voltage.V.sub.1 =Electronic Ballast DC voltage,R.sub.0 =Lamp Impedance in ohms,(ANSI C78.1-1991).k=Empirical constant=2.5 to 3.5.

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: The invention relates to a circuit arrangement for operating a discharge lamp. According to the invention the series connection of a PTC thermistor V1 with a bi-directionally acting breakdown voltage component V2 is disposed parallel to the inductance L1 and/or the capacitor C1 in a load circuit which has a discharge lamp H1, an inductance L1 connected in series with the discharge lamp and a capacitor C1 disposed parallel to the discharge lamp H1, wherein the PTC thermistor V1 and the bi-directionally acting breakdown voltage component V2 are thermally coupled. The object of the invention is to provide a simple circuit arrangement for operating a discharge lamp which allows a substantially constant ignition of a discharge lamp.

Abstract: The invention relates to a circuit arrangement for igniting a high-pressure discharge lamp (L), provided with input terminals (C,D) for connection to a commutating supply source with a square-wave supply voltage; a pulse-generating circuit (IV) provided with a voltage-dependent breakdown element (3) and with a voltage-raising network (2) formed by a network of rectifiers and capacitors; a pulse transformer (1); and an electrical connection between a secondary winding (12) of the pulse transformer and lamp connection terminals (E,F). The voltage-raising network (2) is in addition provided with inductors means (21, 22). The result of this is that a strongly increased voltage is available across the breakdown element substantially instantaneously after each commutation of the commutating supply voltage.

Abstract: A first half-bridge inverter is powered from an unfiltered full-wave-rectified ordinary 60 Hz electric utility power line voltage. This first inverter provides at a first inverter output, across which is series-connected a first tuned L-C circuit, a first squarewave voltage of fundamental frequency between about 30 and 33 kHz; which first squarewave voltage is magnitude-modulated at 120 Hz. The first tuned L-C circuit, which is series-resonant at about 30 kHz, is parallel-loaded by a full-wave high-frequency rectifier whose DC output is applied to substantially constant-magnitude DC voltage existing across a pair of energy-storing capacitors. At a constant 30 kHz inverter frequency, the waveshape of the current drawn from the power line is substantially that of a squarewave in phase with the power line voltage, thereby giving rise to a power factor of about 90%.

Abstract: In a power-line-operated current-fed parallel-tuned electronic ballast, power-factor-correction and harmonics-reduction are attained by placing a high-frequency inductor as well as a high-frequeny voltage source in series with the DC output of a bridge rectifier connected with the power line voltage. The DC output is then supplied to a filter capacitor through a high-speed diode, thereby to provide a DC voltage of substantially constant magnitude to the ballast's inverter while at the same time drawing power from the power line with a power factor well over 90% and with a total harmonics content well under 20%. The AC voltage provided from the high-frequency voltage source, which has a peak-to-peak magnitude essentially equal to that of the power line voltage, is represented by a simple auxiliary winding on the ballast's main output transformer.

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: A solid state, bipolar, ignition exciter for gas turbine engines is described for delivering high energy pulses to one or more igniter plugs. A storage capacitor is charged with typically 12 to 20 Joules of stored energy and discharged through a solid state switch and a series-connected ignitor plug. The solid state switch consists of a plurality of silicon controlled rectifiers (SCRs) connected in series, in combination with other components connected in parallel with each SCR. Protection is provided against transients in voltage by means of resistance-capacitance snubber circuits connected in parallel with each SCR. Protection is provided against transients in current by means of inductance connected externally, and in series with, the solid state switch. Protection is provided against damage from reverse voltages by means of a reverse current path through the solid state switch, typically by means of a diode or series-connected diode chain connected in parallel with the SCRs.

Abstract: A ballast circuit arrangement with hot restrike capabilities includes an input transformer having a primary winding receptive of line power and a secondary winding over which an output voltage is made available. A first capacitor coupled across the secondary winding of the input transformer develops a voltage charge thereon. A resistor and a second capacitor are series connected to one another and are parallel coupled across the first capacitor. A starting aid device is coupled to the secondary winding of the input transformer and produces an output voltage of a predetermined magnitude. The output voltage of the starting aid is coupled to a spark gap device having first, second and third electrodes associated therewith. A first spark gap formed between the second and third electrode is first fired by the output voltage of the starting aid which in turn triggers the firing of a second spark gap formed between the first and second electrodes.

Abstract: A low cost multipurpose electronic ballast for ultraviolet transilluminators and crosslinkers for starting and operating four or more ultraviolet lamps simultaneously. The electronic ballast is designed to be capable of operating with input voltages ranging from 85 volts AC to 250 volts AC and input frequencies ranging from 40 Hertz to 400 Hertz. The output to the lamps comes from a group of capacitors which control the current to the lamps. Because the output comes from capacitive ballasts in parallel, alternate sets of capacitors can be switched to alternate sets of lamps allowing the central ballast control to be used with different sets of lamps. By placing another set of capacitors in parallel with the existing output capacitors and making a momentary connection, a momentary power boost can be achieved. This feature also allows a variable intensity control comprised of a number of different size capacitors in series with the parallel group to vary the total current to all the lamps.

Abstract: A novel high frequency LCLC double resonant electronic ballast has been developed for gas discharge lamp applications. The ballast consists of a half-bridge inverter which switches at zero voltage crossing and an LCLC resonant circuit which converts a low ac voltage to a high ac voltage. The LCLC resonant circuit has two LC stages. The first LC stage produces a high voltage before the lamp is ignited. The second LC stage limits lamp current with the circuit inductance after the lamp is ignited. In another embodiment a filament power supply is provided for soft start up and for dimming the lamp. The filament power supply is a secondary of the second resonant inductor.

Abstract: A ballast circuit for fluorescent lamp which comprises an additional D2 located just after the rectifier bridge D1 and before smoothing capacitors C5, C6. The diode D2 is matched to the value of a mylar capacitor C3 connected across the output of the rectifier bridge and the fluorescent lamp load whereby the fluorescent lamp draws current over substantially the whole of the supply voltage waveform to thereby improve the power factor and reduce the current harmonic distortion.

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 fluorescent lamp ballast having improved power factor by providing high frequency signals fed back to the a.c. side of the ballast rectifier. The feedback signal is regulated by limiting or reducing the voltage gain of the feedback signal based on the level of the unregulated feedback signal or rectified signal, respectively.

Abstract: According to the invention there is provided a remote ballast circuit assembly comprising at least one ballast circuit; a housing having a top panel, an optional perforated bottom panel, two lateral side panels and a back panel, the panels defining a housing interior; the interior being divided into an upper chamber and a lower chamber, the upper chamber having exterior vent openings; at least one ballast coil in the ballast circuit disposed in the upper chamber; at least one resonating capacitor connected with the ballast coil disposed in the lower chamber; primary power connecting means for connecting primary power to the ballast circuit; and load connecting means for connecting a load to the ballast circuit. According to a further feature, the remote ballast circuit assembly according to the invention includes a hinged door panel hingedly attached to the housing for providing access to the housing interior.

Abstract: An intermediate voltage or cable marker with a gas filled lamp with reflectively enhanced conspicuity comprising an inner conductive coating in an opaque shell; the shell being mountable on an the intermediate voltage line and having one end of the gas filled lamp electrically connected to the intermediate voltage line or grounded cable and the other end electrically connected to a electrical coil in series with the conductive inner shell coating; the gas filled tube being mounted in a reflective chamber shaped to increase both lateral and vertical conspicuity.

Abstract: To eliminate the necessity for a saturated or air gap inductance to provide feedback circuit for a self-exciting oscillator including two active electronic switches (T1, T2) , for example MOSFETs, an auxiliary winding (HW1, HW2, . . . HW11) is inductively coupled to the resonance inductance (L2) present in the circuit for the discharge lamp (LP) anyway; and a pulse shaping - phase shifting network (R3, C3; R4, C4 . . . ) , devoid of inherent resonance, coupling the auxiliary winding to the active switching elements. The pulse shaping - phase shifting network is formed of a one or multiple-stage RC low-pass circuit, connected serially between the auxiliary winding and the control input, for example the gate, of the active switching element. The RC network can be constructed with variable elements, for example including PTC resistors, a varistor or the like, and may include a current source, protective circuits to protect against voltage peaks including Zener diodes.

Abstract: An adaptor circuit used to enable stable, flicker-free operation of T8-type fluorescent lamps in a lighting fixture which already has a standard two-lamp, series-sequence, 40 watt, rapid-start type ballast installed therein. The adaptor circuit contains an isolation transformer for controlling the voltage supplied by the ballast to the T8-type fluorescent lamps and a frequency selective impedance modifier circuit for controlling the operating current supplied by the ballast to the T8-type fluorescent lamps at preselected frequencies. In one embodiment, the frequency selective impedance modifier circuit substantially eliminates the third harmonic component of the fundamental frequency of the operating current.

Abstract: A ballast circuit for the operation of a discharge lamp includes a bridge rectifier. A capacitive energy storage device and a load circuit are connected in series across the bridge rectifier. A charge circuit provides charge to the capacitive energy storage from the load circuit in a potential so as to add to the potential from the outlet of the bridge rectifier.

Abstract: An amusement device comprising a gas-filled plasma discharge tube; an electrode adjacent an end of the tube for coupling high-frequency, high-voltage energy into the gas in the plasma discharge tube; an ionization energy supply operably connectable to a source of electrcity for producing an adjustable high-frequency, high-voltage energy at an output thereof having an upper limit sufficient to ionize the gas in the plasma discharge tube without a ground return by utilizing the electrical capacity of the surroundings to provide a reactive impedance for plasma tube current to flow into, the electrode being operable connected to the output; and, a control circuit operably connected to the ionization energy supply for adjusting the level of the high-frequency, high-voltage energy at the output between levels causing ionization of the gas in the plasma discharge tube to occur in differing amounts as a function of a changing stimulus connected to an input thereof.

Abstract: A variable capacitor includes a fixed conductive plate and a movable conductive plate with a dielectric disposed between them. A piezoelectric actuator is used to vary the distance between the conductive plates by moving the movable plate with respect to the fixed plate, with capacitance changing in inverse proportion to distance moved. In an electrodeless high intensity discharge lamp ballast, such a variable capacitor is situated in series with the excitation coil of the lamp. When a control voltage is applied to the piezoelectric actuator, the movable plate is moved from a starting position to a running position so as to maintain the ballast load in tune under both starting and running conditions, respectively, resulting in higher efficiency operation.

Abstract: The present invention discloses a means and method for preventing damage to electronic ballasts for high frequency lamps. In normal use lamps assume rectifying characteristics and generate direct current which interferes with the proper functioning of the system. In one aspect of the invention, a capacitor is used to prevent damage caused by this direct current. In another aspect of the invention, the capacitor also reduces the operating voltage of the lamps while preventing damage caused by the direct current. Another aspect of the invention gives added control of the filament voltage before and after the ignition of the lamps. In a further aspect of the invention, a capacitor is connected in series with the primary of the filament transformer to prevent damage caused by a short circuited secondary.

Abstract: Ballast and starting circuits for controlling current and voltage applied to an electrical discharge lamp. The ballast circuits use diodes or other suitable means to divide the AC power into positive and negative currents. The ballast circuits use positive and negative capacitors which are charged by the divided AC line current. In some embodiments the positively charged capacitors are charged during positive portions of alternating current and discharged during negative portions of the alternating current. The negatively charged capacitors are charged during negative portions of the alternating current and discharged during positive portions. Transistors or other appropriate switching means are used to controllably conduct current from the positive and negative capacitors to the lamp in an asynchronous manner. Startup circuits are included for boosting the voltage applied to the lamp either manually or automatically upon startup.

Abstract: An illuminated aerial marker for a high voltage transmission line using a spherical colored opaque capacitor with gas filled lamps electrically connected, exterior to the capacitor with one electrode of the lamps connected to the high voltage source and the other to the conductive area of the capacitor or capacitors. The lamps are spaced and sized to provide illumination with nighttime conspicuity of at least 4,000 feet when the lamps are activated.

Abstract: A portable high pressure sodium lamp lighting system is mounted on a mobile cart, the cart carrying a mobile power supply in the form of a automotive type battery. The portable lighting system employs a standard high pressure sodium luminaire designed to be driven by 115 volt 60 cycle utility generated power. A DC to AC converter is employed which converts the DC battery supply to a 115 volt simulated 60 cycle supply. The AC characteristic is simulated by generating a quasi-square wave form which approximates a 60 cycle characteristic when driving the luminaire.

Abstract: A novel lighting equipment for providing bright illumination with limited surge, including a capacitor connected in parallel with an incandescent lamp, the capacitor having a capacitive reactance lower than the resistance of the filament at ambient temperature; an impedance having a time constant connected between the capacitor and an ac source; and means for rectifying the current from the ac source.

Abstract: A circuit arrangement for operating at a supply voltage V.sub.n a high-pressure sodium discharge lamp (4) having a lamp voltage V.sub.la in conjunction with a current limiter circuit (3) and a first controlled semiconductor switching element (1). The circuit arrangement comprisesa first part of comparing a proportional part of the lamp voltage V.sub.la with a reference voltage V.sub.r anda second part for comparing a proportional part of the supply voltage V.sub.n with the resultant of the first comparison. The circuit arrangement makes it possible to operate the lamp so that the lamp voltage V.sub.la is substantially constant.

Abstract: An electronic ballast circuit is provided for starting, operating and controlling the brightness of one or more fluorescent lamps. The brightness of the lamps is controlled over the full range of brightness from zero to full-rated power. The circuit power factor is controllable, and is preferably operated at a relatively high leading power factor. The circuit includes a capacitive ballast working in conjunction with a gapped transformer so as to provide the high leading power factor while, at the same time, maintaining stable and uniform brightness of the lamps. A power field effect transistor is utilized to function as a current stabilizer in conjunction with the capacitive ballast and gapped transformer. The system incorporates a dimming control circuit for increasing and decreasing the brightness of the lamps.

Abstract: Appliances such as fluorescent lamps and low-voltage DC motors can be operated from household AC without a transformer by employing a current-limiting circuit which is compact, lightweight, reliable, draws less energy, and has fewer power consuming components than do prior devices for driving those applicances. The current-limiting circuit has 4 rectifiers in a bridge circuit and a current-limiting capacitor which should be selected to match the load, a larger capacitor being necessary to supply a larger current. When used to drive a discharge lamp, the current-limiting circuit should also contain an inductive coil in series with the current-limiting capacitor. Otherwise there may be undue flicker. The inductive coil and capacitor together improve the power factor and therefore reduce the current drawn from the line without reducing the lamp output.

Abstract: A compact capacitor discharge and strobe light beacon system is disclosed which is designed to be used in a conventional incandescent aircraft warning light fixture. The system comprises: a step-up transformer; a pulse shaping network for rectifying the output of the transformer to pulsating DC, capacitor means connected to the output of the pulse shaping network, a choke, at least two xenon lamps with terminals and connected across the terminals of an energy storage capacitor through the choke, and a switch which fires the lamps.

Abstract: An improved non-lighting fluorescent lamp substitute to replace one lamp in a two-lamp series connected circuit so that the circuit is completed through the remaining lamp allowing it to light, whereas without the lamp substitute, the circuit is incomplete if one lamp is removed and then the other lamp is unable to light. In one form, the device is wired into a light fixture, while in another form, it looks like a conventional fluorescent lamp and fits into the sockets of the fixture. Either form cuts power consumption substantially in half with a corresponding reduction in light output. The improvement is a triac in the device that limits the magnitude of the effective arc current by phase angle control to the original design current of the lamp and ballast in order to achieve the normally expected life of the lamp and ballast.

Abstract: A switching arrangement suitable for the ignition and operation of at least one high-pressure discharge lamp, which arrangement is provided with a branch comprising a capacitor parallel to the lamp. The capacitor is also connected to a charge voltage source. The branch comprising a capacitor includes a gas-filled breakdown element. During ignition of the lamp current can be supplied from the capacitor to the lamp, while in the operating condition of the lamp the capacitor is switched off.

Abstract: A circuit arrangement for operating at least one gas discharge lamp (5) with a periodically varying lamp current and adapted for connection to an alternating voltage source with a period N. The circuit is provided with a controlled semiconductor switch (3) and a control circuit for switching the controlled semiconductor switch with a switching period S in dependence upon a comparison between an actual signal proportional to the lamp current and a nominal signal derived from a voltage across the switching transistor (3).

Abstract: A fluorescent lamp assembly for operation from a source of AC line voltage. The assembly includes a fluorescent lamp having an arc length not greater than about 120 mm and an envelope which includes at least one constricting portion located therein for constricting the plasma discharge to provide an increase in the lamp voltage. Also included is a lead-type ballasting means which comprises a capacitor in one embodiment connected in series with the lamp.

Abstract: A high intensity discharge metal vapor lamp comprising an arc tube having an inner chamber vented to the arc tube and disposed therein is disclosed. The combination of the arc tube and inner chamber being of a double wall construction confines the arc condition occurring between thermionic electrodes to be within the inner chamber. The inner chamber is operated at an increased wall temperature, relative to a conventional arc tube, while at the same time reducing the typically experienced sodium losses that normally occur for increased wall temperature operation. Ceramic evaporation at elevated temperatures from the inner chamber can be rendered innocuous by deposition on a similar material utilized in the arc tube. The characteristics of the arc tube allows for improved methods of its operation such as a pulsed operation at a relatively high rate of 1 to 20 KHz so as to achieve a relatively high color temperature. If desired, the arc tube may be operated in a d.c.

Abstract: An illuminated aerial marker for a high voltage transmission line using a spherical colored opaque capacitor with neon lamps in series or series/parallel or parallel, exterior to the capacitor with one electrode of the lamps connected to the high voltage source and the other to the conductive area of the capacitor or capacitors.

Abstract: Ballast and starting circuits for controlling current and voltage applied to an electrical dishcarge lamp. The ballast circuits use positive and negative capacitors which are alternately charged and discharged in an asychronous manner. The positively charged capacitors are charged during positive portions of alternating current and discharged during negative portions of the alternating current. The negatively charged capacitors are charged during negative portions of the alternating current and discharged during positive portions. Transistors or other appropriate switching means are used to switch the capacitors to the lamp during discharge thereof. Startup circuits are included for boosting the voltage applied to the lamp either manually or automatically upon startup. A startup regulator circuit is also shown for controlling current flow during periods of high current demand such as during startup.

Abstract: A high-intensity discharge (HID) metal vapor lamp and starting apparatus includes a metal vapor lamp having an outer envelope containing a gas filled arc tube, the fill gas including xenon, the arc tube having a pair of spaced electrodes with a starting aid surrounding the arc tube intermediate the electrodes, a non-linear dielectric element shunting the spaced electrodes and a ballast means and an electrical conductor coupling the spaced electrodes to a base member connected to a low voltage source whereby starting of the metal vapor lamp from a low voltage source is effected.