Abstract: A capacitor structure comprises a single sheet of spirally-wound conductive material having an insulative layer disposed on one side. In contrast to previously-employed capacitor structures, the structure of the present invention includes only a single conductive sheet of material not a plurality of conductive plates or layers. In particular, the present invention is readily employable in magnetic circuits, particularly those employing magnetic core material. In these circuits, the capacitor is installed without the requirement of external leads and is readily integrated with the core structure. The instant capacitor structure is also particularly useful in constructing multi-stage LC filter circuits.

Abstract: An HPS starting aid for providing pulses to an HPS lamp via a ballast tap connection, the aid employing a capacitive voltage divider connected to the power distribution line for charging purposes. There is no power resistor so that the pulse width and amplitude is not dependent on voltage amplitude fluctuations of the line voltage. A voltage breakdown device and a timing RC network determine the pulse positioning of the starting pulse. The size of the capacitors in the capacitive voltage divider and the number of turns on the ballast tap winding determine the pulse width and amplitude.

Abstract: A multi-legged transformer core is employed to integrate into a single structure the discrete magnetic components required to form a multiple stage inductor-capacitor filter. The device may be employed in low pass filters used with inverters to remove high order harmonic frequency signals. The filter of the present invention is particularly useful in discharge lamp ballast circuits.

Abstract: A circuit for starting and operating fluorescent lamps from an a-c power source, comprising reactive ballast means connected to ballast the lamps and having a non-linear characteristic for producing harmonics of the power source frequency, and a capacitor and a cathode heating transformer connected in series and connected to receive power from said ballast means and resonant in a frequency range including two or more of said harmonics. A switch may be connected in series with the capacitor and cathode heating transformer for opening the cathode heating circuit when the lamps are operating, to conserve electrical energy.

Abstract: A switching system for delivering pulses of power from a source (10) to a load (20) using a storage capacitor (C3) charged through a rectifier (D1, D2), and maintained charged to a reference voltage level by a transistor switch (Q1) and voltage comparator (12). A thyristor (22) is triggered to discharge the storage capacitor through a saturable reactor (18) and fractional turn saturable transformer (16) having a secondary to primary turn ratio N of n:l/n=n.sup.2. The saturable reactor (18) functions as a "soaker" while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor (C4) charges, and then switches to a low impedance state to dump the charge of the storage capacitor (C3) into the load through the coupling capacitor (C4).

Abstract: A low cost high frequency electronic dimming ballast for gas discharge lamps is disclosed which eliminates the need for external primary inductance or choke coils by employing leakage inductance of the transformer. The system is usable with either fluorescent or high intensity discharge lamps and alternate embodiments employ the push-pull or half-bridge inverters. Necessary leakage inductance and tuning capacitance are both located on the secondary of the transformer. Special auxiliary windings or capacitors are used to maintain necessary filament heating voltage during dimming of fluorescent lamps. A clamping circuit or auxiliary tuned circuit may be provided to prevent component damage due to over-voltage and over-current if a lamp is removed during operation of the system.

Abstract: An improved electrical circuit for selectively controlling the power to a gaseous discharge lamp. One use for such circuit and lamp is in an ink-curing process for objects printed with multiple-colored ink wherein areas of the object are printed and cured in a multiple-step operation.

Abstract: A high efficiency controlled direct current source for operating high pressure mercury or metal halide lamps for use as substitutes for ordinary incandescent lamps. The circuit includes a voltage sensitive circuit for pulsed starting of the arc discharge lamp as well as for the activation of an auxiliary incandescent filament during the warm-up or hot restart of the arc.

Abstract: Starting and operating circuit for gaseous discharge lamps has device for quickly re-starting extinguished lamps while still hot. Circuit comprises a source of alternating current, an inductive regulator ballast having its input connected to the alternating current source, and a gaseous discharge lamp connected to the output of the ballast, a sine wave oscillator circuit having its input connected to the current supply and having its output connected to a transformer connected in series between the ballast and the lamp for stepping up and applying voltage to a lamp, and a positive temperature coefficient resistor (PTCR) connected between the alternating current source and the oscillator circuit for reducing power to the oscillator circuit when the lamp is inoperative or absent.

Abstract: This discharge lamp lighting device for copying machines is used, for example, for lighting a discharge lamp for electrostatic copying machines of a type in which is reflected light from objects to be copied as irradiated sequentially with a moving light source is recorded on a rotary electrostatic drum. In this lighting device, the lamp current flowed to the discharge lamp is made substantially to be of a rectangular wave form and the substantial non-light emitting section is removed or reduced in the light output wave form of the discharge lamp, whereby an excellent copying result is made to be obtained particularly in such copying machine in which the light irradiation is momentary as referred to in the above.

Abstract: A periodic current generator is connected with a long power supply line through a first transformer. The lamp of the traffic light is connected to the long line through a second transformer. First and second safety capacitors with four terminals each are respectively arranged in series on the long line with the first and second transformers. A DC current is generated by a detector when the lamp is operating. The detector is connected to one of the capacitors and the DC current passes through the long line to the second capacitor across which the coil of a relay is connected. The relay is actuated by the DC current and sends information concerning the status of the lamp to a central control station.

Abstract: A low cost, high frequency, solid-state dimmable fluorescent ballast is disclosed which utilizes a resonant bridge inverter to provide high frequency sinusoidal power to the lamps. One embodiment of the invention includes auxiliary windings connected to the filaments of the lamps to be powered which utilize the inductance of the resonant bridge inductor coil to maintain the voltage across the filaments during dimming. A clamping circuit or auxiliary tuned circuit may be provided to prevent damage due to an over-voltage and over-current condition upon removal of a lamp during operation of the system. In an alternative embodiment, the auxiliary windings, are replaced by capacitors across each of the lamps to be powered. This also eliminates the need for the clamping circuit. If desired, a current splitting capacitance system may be used. Pulse width modulation of the inverter drive or variable AC or DC power supply input may be used to accomplish dimming.

Abstract: A lamp operating circuit comprising a DC power source, an inverter including step-up transformer inductance windings and a controlled transistor switch connected across the output of the DC source, and a high frequency oscillator coupled to the transistor switch for operating the same at predetermined intervals. A low wattage HID lamp is connected across the inverter through a ballast capacitor series connected to one terminal of the lamp and a ballast inductance coupled in series with the other lamp terminal. The ballast inductance and ballast capacitor are selected to resonate sinusoidally at a frequency having a half period coinciding with the on-time of the transistor.

Abstract: A circuit for starting and ballasting a compact high-intensity arc discharge lamp. A filament connected in series with the arc lamp provides illumination during arc start-up and functions as a ballast during normal arc operation. An oscillatory starting circuit includes a transformer and a frequency-controlling ringing circuit, and applies starting voltage to the arc lamp until an operating arc is established. The circuit includes capacitor means for isolating the starting transformer from the operating path of the arc lamp, and further includes a voltage-doubling starting circuit and also a "keep-alive" feature which prevents the arc from extinguishing during power fluctuations.

Abstract: Starting and operating circuit for gaseous discharge lamps has device for quickly re-starting extinguished lamps while still hot. Circuit comprises ballast reactor, pulse transformer having a magnetic core formed with an air gap, charging capacitor and voltage sensitive switch device connected to the pulse transformer to form a series discharge loop with a portion of the transformer, and a storage capacitor connected at the output of the ballast reactor having sufficiently high capacitance to provide, in combination with the pulse transformer, for hot re-start of the lamp.

Abstract: A dc to ac inverter for operating a gaseous discharge lamp through pre-ignition, arc stabilization, warm-up and final run states is disclosed. The arrangement comprises a transformer and a pair of transistors connected for alternate conduction in a self-oscillating configuration in which turn off occurs at a predetermined flux level in each conduction period. The flux limit is used to preclude excess current drain during warm-up when the lamp resistance is at a minimum. A capacitor is provided, resonant at a harmonic of the inverter output waveform for producing the enhanced output voltage required for pre-ignition. The capacitor also helps to maintain a higher harmonic content during warm-up, enhancing the effective ballasting reactance during that period in relation to that during final run operation. A shift of the oscillating frequency of the inverter from pre-ignition to final run operation further enhances inverter operation.

Abstract: A constant current transformer for gas-discharge tubes consisting of an aluminum can containing an iron core made of grain-oriented magnetic sheet material in split-tape core form with electrically isolated primary and secondary windings. The core has gaps on opposite sides with non-magnetic spacers. Stray field yokes are provided adjacent the gaps. A series-resonance capacitor is included in the can. The active parts fit tightly against the can, which serves to carry away heat losses. The parts are impregnated in the can using an epoxy resin in an overpressure centrifuging process. The primary and secondary windings may be connected outside the transformer in a voltage-adding arrangement in series with a load. Two or more transformers may be connected with their primaries in parallel and their secondaries in parallel with a load so that their currents are added, or with their secondaries in series with a load to add their voltages. An inductance may be connected in series with the series-resonance capacitor.

Abstract: The magnetic core of a lamp ballast is bifilar wound from inherently thin amorphous metal strip and utilizes the laminations of the magnetic circuit as the plates of a capacitor. The outer yoke of the core encases the coils and is edge-wound from amorphous metal ribbon alternated with insulation to also be the power factor capacitor. The inner core is accordion-pleated or spirally wound and is electrically connected to be the starting capacitor. Cutaways in the inner core cause saturation and shape the lamp current waveform.

Abstract: A power circuit for a discharge lamp, in particular a flash lamp serving as light source in an optical analysis apparatus which comprises an electric power source outputting a d.c. voltage and capable of reabsorbing electrical energy, which also comprises an energy transferring circuit inserted between the electric power source and a first capacitor connected to the lamp, the capacitor being charged via the energy transferring circuit and adapted to store the energy required for each discharge across the lamp, the energy transferring circuit comprising a first current path comprising the primary winding of an autotransformer and adapted to transfer current from the electric power source to the first capacitor until the voltage across it reaches a predetermined value, and a second current path comprising a second capacitor for storing part of the surplus or non-used energy stored in the autotransformer during the charging of the first capacitor.

Abstract: Circuit for providing low ripple DC power supply from a single-phase AC source without the use of a filter capacitor. The circuit comprises a high leakage reactance transformer with a primary winding and two secondary windings arranged with the secondary windings on opposite sides of the primary winding, a leading current circuit connected to one secondary winding and a lagging current circuit connected to the other secondary winding, and a three-phase full wave rectifier bridge connected to the leading and lagging current circuits to provide a low ripple DC power output. The DC power supply circuit is used with a pulse generating circuit to provide pulsed operation of a gaseous discharge lamp such as a high pressure sodium vapor lamp, and produces desirable relationship of lamp watts to lamp volts for improved lamp life and uniformity of illumination.

Abstract: A power supply and firing control circuit for a strobe lamp has a capacitor means for providing electrical power to the power electrodes of the strobe lamp for discharge through the strobe lamp. A transformer has a pair of secondary windings, one of which is connected to each of the power electrodes of the strobe lamp in series with the capacitor means. The firing pulses provided by the secondary windings of the transformer are of opposite electrical polarity. The absolute voltage differential between any portion of the circuit and ground potential will be minimized and energy losses thereby reduced. Additionally, the circuit provides substantial improvement in ionization effectiveness, thereby permitting the secondary turns of the transformer to be reduced in number and the transformer size and weight reduced correspondingly.

Abstract: A spark ignition circuit comprising a first capacitor arranged to be charged from a mains power supply through rectifying means and discharged through the primary of a transformer to produce sparking across a spark gap in the secondary circuit of the transformer in response to the operation of a triggerable switching means under the control of a timing circuit connected across the first capacitor and including a second capacitor, the charge voltage of which when it exceeds a predetermined level causes an arc discharge device to break down and the triggerable switching means to be triggered. When the triggerable switching device conducts, the first capacitor will be discharged. The circuit will continue to produce sparks at a rate determined by the timing circuit until such time as gas in the vicinity of a spark gap is ignited. Flame sensing and re-ignition facilities may also be provided. Examples of suitable arc-discharge devices are also disclosed.

Abstract: A device which is designed to save electrical energy expended by a regular rapid start fluorescent lighting fixture having a plurality of lamps, or tubes, and a conventional ballast. The device comprises the combination of a step-up transformer, a resistor and two capacitors, all of which are mounted externally of the ballast. The device is wired in series with the ballast and one of the lamps to allow normal ballast voltages to be delivered to the lamp circuit, thereby eliminating any detrimental effects to the lamps or ballast. At the same time, the current to the lamps and consequent consumption of power by the lamps is substantially reduced to save electrical energy while providing a reduced, but uniform level of illumination.

Abstract: A system for operating gas discharge lamps at high frequency from a high voltage supply, typically 115 V AC with a 160 watt, 25,000 Hz output. The system provides efficient conversion, having the capability of driving any number of lamps up to maximum wattage, inherent open-cirucit and short circuit protection, and higher efficacy from the lamps. Filament power may or may not be used. Filament power is not necessary under conditions when the lamps are forced into a glow discharge to charge each cycle through the use of a tuned resonant circuit. An unsaturated inverter provides fast cut-off times. Dimming capabilities may be provided.

Abstract: A sinusoidal wave oscillator ballast circuit includes a tuned oscillator coupled to a DC rectifier means coupled by a power factor correction circuit to an AC potential source. The oscillator is coupled to an inductor means including a first and second transformer means with the secondary winding of the first transformer means coupled to the oscillator, the primary of the first transformer means in series connection with a capacitor and the primary winding of the second transformer means to form a resonant circuit, a first secondary winding of the second transformer means coupled to a lamp circuit to form a load circuit shunting the capacitor of the resonant circuit and a second secondary winding of the second transformer means having opposite ends connected by clamping diodes to the DC rectifier means. Means for compensating for "storage time" of the transistor of the oscillator and for conditioning the line to transients and radio frequency interference (RFI) are also provided.

Abstract: A device for starting and operating a discharge lamp, in particular a low pressure sodium vapor lamp. The device comprises two input terminals connected by means of a coil and the primary winding of an auto-transformer with the lamp connected in series with a capacitor between the ends of the transformer secondary winding. In the operating condition of the lamp the core of the transformer becomes saturated. The lamp is shunted by an electronic starter which assists, in the operating condition of the lamp, in the restart of the lamp during each half cycle of the AC electric supply.

Abstract: A variable frequency ac source drives a gas discharge lamp connected as a damping element in an otherwise high Q L-C circuit. Commutation of the ac source voltage is initiated as the instantaneous current drawn from the source equals a predetermined reference current level. Prior to lamp ignition the ac source drives the L-C circuit at resonance causing a voltage buildup which initiates an ignition. After ignition the source limits lamp current to provide a ballasting function.

Abstract: Method and apparatus for start and hot restart of a high pressure arc discharge lamp includes the application of an AC ionizing potential to the lamp, the ionizing potential characterized by a period such that the electron density of the fill material of the lamp is increased on each half cycle of said potential until the lamp is started. The invention is disclosed in an integrated ballast, and in an addition to an existing conventional ballast.This application is a continuation-in-part of Ser. No. 506,116, filed Sept. 16, 1974, and now abandoned.

Abstract: Circuit operating from a direct current source applies DC pulses to a high pressure sodium vapor lamp to improve the color properties of the lamp. The circuit includes a controlled thyristor switch in series with the lamp, an RC timing circuit for periodically turning on the switch at predetermined intervals, and an LC circuit for turning the switch off. An inductor comprising the primary winding of a transformer in series with a diode across the capacitor of the LC circuit provides for discharge of the capacitor to enable subsequent re-charging thereof, so as to produce the desired pulsed operation of the circuit, and the transformer secondary winding in series with a diode clamps the voltage of the primary winding. The disclosed arrangement prevents excessive voltage across the controlled switch and provides for the control of lamp wattage with respect to changes in lamp voltage.

Abstract: A fluorescent lamp ballast circuit includes a tuned oscillator coupled to a pulsed DC potential source and to a transformer having a first winding directly connected to the oscillator and in series connection with a capacitor to form a series resonant circuit. A second winding of the transformer inductively couples the first winding of the transformer to the oscillator, a third winding inductively couples a load across the capacitor of the series resonant circuit, and a fourth winding is inductively coupled to the first winding of the transformer and clamps the DC potential source to a given potential level. Also, protection for open circuits, short circuits, and temperature change due to changed ambient conditions or increased current flow is provided.

Abstract: An improved energy conversion apparatus for use in charging energy storage capacitors for energizing flash lamp devices. A transformer has a primary winding coupled to a low voltage DC source and transistor switches and a secondary winding coupled to a chargeable capacitor. The transistor switches are turned on or off in response to current signals in the primary and secondary windings. A detection circuit senses the energy stored in the capacitor and supplies signals to the transistor switches to maintain energy stored in the capacitor at a predetermined level.

Abstract: An inverter circuit suitable for use as a fluorescent lamp inverter ballast is disclosed. The inverter has the capability of starting the fluorescent lamp through regenerative feed-back techniques made possible by the amplification characteristic of the inverter switching transistor. Good efficiency at high frequency is provided by minimizing the transistor switching losses through use of resonant storage techniques and an unique feed-back system. Further, the normal energy lost in the feed-back circuit is eliminated by combining the resonant load means and the feed-back means into a single structure.

Abstract: Starting and operating ballast circuit for gaseous discharge lamp. Ballast winding comprises a pair of series connected coils each having a portion with a selected number of turns thereof connected in a high voltage starting circuit including a discharge capacitor and a voltage sensitive switch and forming a series discharge loop with the coil portions to provide high voltage, high frequency starting pulses on the lamp.

Abstract: The visibility of warning lights employing flash tubes is enhanced by control circuitry which generates closely spaced trigger pulse pairs for energizing the tubes to thereby produce double flashes. Noticeability of the warning light may be enhanced by addition thereto of a noise maker which operates off the same power supply that provides a high voltage for operating the flash tube or tubes.

Abstract: A starting circuit for high intensity discharge lamps supplied from an alternating current line through a ballast inductance, and in some cases a pulse transformer inductance, includes a surge voltage protector (SVP) or like voltage responsive, current switching gas breakdown device connected intermediate the end of the inductance, a capacitor connected to the lamp end of the inductance, the SVP and capacitor being connected in parallel with each other and in series with a resistance across the lamp so that upon breakdown of the device in each half AC cycle the capacitor discharges applying a voltage surge to the lamp stepped up through the inductance. The charge on the capacitor follows the ignition voltage required to start or reignite the lamp as the ignition voltage varies during the life of the lamp.

Abstract: A ballast circuit for providing constant power to a high intensity discharge lamp, the ballast including a transformer having two cores separated by a gap, one core being at least partially closed and the other, having an air gap. A primary coil winds around a portion of each core and secondary coils wind around another portion of each core. The secondary coils and a capacitor are in series with the lamp to regulate the current and voltage applied to the lamp.

Abstract: The disclosure relates to a ballast unit for gas discharge lamps, particularly fluorescent lamps, by which a substantially constant burning current is supplied to the lamp. The ballast unit includes a transformer mounted on a core having a defined air gap. The transformer is provided with a leakage inductance having a value resulting in a voltage drop of between approximately 15 and 30 percent of an input voltage applied thereto. One or more capacitors are connected in series with the transformer output supply to the lamp. The one or more capacitors provide a capacitance in series with the lamp substantially equal to the ratio of the burning current to the angular frequency of the input voltage multiplied by the secondary no-load voltage supplied to the secondary circuit.

Abstract: A lighting system for gaseous-discharge lamps for applying high voltage pulses to ignite the lamp and for discontinuing the application of high voltage pulses when the lamp is operating. The system includes ballast facilities having an inductive portion, and a control circuit which is responsive to a voltage induced in the inductive portion when the gaseous-discharge lamp operates. When the control circuit is operative, the pulsing portion of the system is disabled. The system is arranged so that the components of the control and pulsing circuits are not subjected to the application of high voltage pulses at any time.