Abstract: A device for driving a directly heated cathode of a cathode ray tube eliminating a delay due to inductance of a transformer. A transformer that produces the heater-heating signal voltage applied to the cathode includes a secondary coil divided into first and second coils. The voltage induced in the first coil is used for the heater-heating voltage and the signal induced in the second coil is synchronized with the voltage induced in the first coil and used as a bias voltage for turning on and off a switching element in synchronization with the heater-heating voltage. The switching element turns on only when the heater-heating signal voltage is applied to a control terminal of the switching element.

Abstract: In a microwave generator apparatus including a magnetron having a filament and an anode and generating a microwave, a filament power source supplies a filament power to the filament of the magnetron, and an anode power source applies an anode voltage between the filament and the anode of the magnetron. Then a parasitic oscillation detecting circuit detects a parasitic oscillation voltage superimposed on the microwave generated by the magnetron, and a filament power controller, in response to the parasitic oscillation voltage detected by the parasitic oscillation detecting circuit, controls the filament power source to control the filament power so that the parasitic oscillation voltage is made smaller.

Abstract: A circuit arrangement for alternatingly, at a frequency f, establishing and extinguishing a discharge in each of a plurality of discharge paths, each of which is associated with a first electrode situated at a first end of the discharge path and with a second electrode situated at a second end of the discharge path. Operating voltages are generated from a supply voltage during operation and are present across respective discharge paths and are periodic at the frequency f. The same operating voltage is present across each discharge path. During operation each discharge path is associated with an auxiliary electrode situated alongside the discharge path and the circuit arrangement further comprises respective switching devices for connecting and disconnecting each of the auxiliary electrodes at the frequency f to a terminal of the circuit arrangement to establish an ignition voltage during a part of each period between one of the electrodes and the auxiliary electrode associated with the same discharge path.

Abstract: A filament-heater power supply includes a combination forward and flyback power converter for supplying electronically variable, isolated voltages to dimmable discharge lamp filaments while supplying a fixed dc output voltage to a ballast control circuit. Hence, only a single ballast power supply is needed. The control circuit controls the level of filament voltage to operate the lamp filaments at an optimum temperature, even during dimming operation, thereby substantially extending lamp life. The filament-heater power supply provides a high degree of isolation among filament voltages while regulating and tracking the voltage across each filament. The filament-heater power supply can preheat the filaments to aid lamp starting, thereby extending the useful life of the lamp, and is also structured to sense when a lamp is not present in a fixture so that high voltage starting pulses are not applied to the terminals of an empty fixture.

Abstract: A circuit for use in providing high voltage power to a neon bulb positioned on the vehicle utilizing the vehicle DC battery as the power source. The circuit includes an invertor, a transformer, and a rectifier. The invertor receives low voltage DC from the vehicle battery, converts the low voltage DC to a low voltage AC drive voltage, and delivers the AC drive voltage to the transformer primary for conversion to a high voltage AC at the transformer secondary. The rectifier receives the high voltage AC from the transformer secondary, converts the high voltage AC to high voltage DC, and delivers the high voltage DC to the neon bulb. Since the power delivered to the neon tube is DC there is less need to shield the tube with respect to electro magnetic emissions and parasitic losses in the wire runs between the battery and the neon tube are significantly reduced.

Abstract: A fluorescent lamp controller for an original-document exposing apparatus includes a detection circuit for detecting the quantity of light emitted by a fluorescent lamp, an actuator for applying between filaments of the fluorescent lamp a voltage having a duty that is determined in accordance with the quantity of light detected, and a preheating circuit for preheating each of the filaments of the fluorescent lamp by applying a preheating voltage. According to the present invention, the actuator applies, between the filaments of the fluorescent lamp, a voltage having a duty which is smaller than the full duty regardless of a result of the quantity of light detected in a predetermined period at a start of turning the fluorescent lamp on, and the preheating circuit applies the preheating voltage to each of the filaments of the fluorescent lamp simultaneously with the application of the turning on voltage.

Abstract: There is provided a ballast for at least one gas discharge lamp havingan inverter which has two switches (S1, S2) in series, connected to a d.c. voltage source and switched with complementary timings, and a load circuit connected in parallel with one of the two switches (S1, S2) which load circuit includes a series resonant circuit (L1, C1) and the lamp (LA). Additionally there is provided a heating circuit (T, S3,R1) for current supply of the lamp coils, likewise connected to the inverter, which heating circuit includes a further periodically switchable switch (S3) for control of the heating current, whereby the heating circuit is likewise connected in parallel to one of the two switches of the inverter.

Abstract: The present invention is to provide a gas discharge tube which is properly lighted to improve the reproducibility of a satisfactory light emission state. The gas discharge tube includes an envelop for accommodating a hot cathode for emitting thermoelectrons, an anode for receiving the thermoelectrons, a focusing electrode having a focusing opening for converging paths of the thermoelectrons, and a discharge shielding member supporting the focusing electrode and the anode, the discharge shielding member further supporting a cathode box for surrounding the hot cathode while being electrically insulated from the focusing electrode. Since a lighting device for the gas discharge tube sets the focusing electrode to a zero or negative potential while an electric field is generated between the hot cathode and the anode, the lighting device will be certainly turned on.

Abstract: A solar lamp drive circuit is arranged to delay start-up while a current is supplied to the lamp filament to warm up the filament. During operation, the back e.m.f. induced in the lamp is sampled, and, if operating conditions deteriorate, the current to the filament is reapplied automatically and the power supply to the lamp increased.

Abstract: A gas discharge tube includes a light-emitting section in an envelope sealing a gas therein, positioned at distal ends of lead pins while spaced from an inner side wall of the envelope. The light-emitting section includes a hot cathode, an anode, a focusing electrode, and a discharge shielding member having a front surface which faces the hot cathode. The front surface of the discharge shielding member is defined by a first surface being in direct contact with the focusing electrode, for defining a position of the focusing electrode, a second surface continued from the first surface, for defining a distance between the focusing electrode and the anode, and a third surface continued from the second surface and being in direct contact with the anode, for defining a position of the anode.

Abstract: An apparatus for operating a fluorescent lamp having first and second power source circuits, the second power source circuit including a high frequency transformer having two or more outputs for supplying pre-heating electric currents to filaments, the second power source circuit being arranged to be controllable individually from the first power source circuit for supplying a tube electric current to turn on a fluorescent lamp so that the electric power level for pre-heating the filaments is switched between a state where a light adjustment is performed by turning on/off a tube electric current at high frequency and a state where the fluorescent lamp is turned off in a standby mode.

Abstract: A ballast circuit for driving a gas discharge having a source of pulsating and rectified AC (20), an energy storage circuit (30), a switch (40) that can have one end connected to an energy storage inductor and an opposite end that can be connected to circuit common; a control circuit (50) for opening and closing the switch (40) at a rate that is a function of at least a DC control current, a resonant circuit (60) that is coupled to the energy storage circuit (30) for energizing the gas discharge lamp.

Abstract: In a device to control a fluorescent tube supplied from a DC source by an accumulating converter, a rectifying bridge 17 is mounted opposite to the secondary 13, between the preheating electrodes 2, 3 of the tube, and supplies an auxiliary transistor 16. An energizing synchronizer 14 supplied by the rectifying bridge 17 receives at one input 24 the control signal of the primary transistor 5 from the modulator 4, and controls the blocking of the auxiliary transistor 16 in synchronism with the blocking of the primary transistor 5.

Abstract: A new fluorescent device including an electronic fluorescent starter, a phase leading capacitor, a ballast, a bridge rectifier, a fluorescent lamp, a brightness compensation circuit, and a control circuit, the electronic fluorescent starter consisting of a master switch circuit, an ignition circuit and a time control circuit, wherein the electronic fluorescent starter matches with the ballast to turn on the fluorescent lamp; the control circuit turns the electronic fluorescent starter to the open circuit state when the fluorescent lamp is turned on; the brightness compensation circuit improves the intensity of light from the fluorescent lamp.

Abstract: Driver circuit for discharge lamps. The driver circuit contains an inverter driving a lamp circuit with a discharge lamp and the current in the lamp circuit is measured as a voltage U.sub.ILC over a resistor, with a control circuit comprising a strike detector that determines if the lamp did strike during a start-up phase of the driver, and if not, the inverter is switched off, with the control circuit going into a monitoring state where it operates the inverter for short periods at regular intervals, and during each such period, the voltage U.sub.ILC is monitored to detect a removal or an insertion of a lamp, so that, once the lamp has been replaced, a new start-up phase begins.

Abstract: The present invention provides a method of lighting a hot-cathode type low-pressure rare gas discharge lamp without flicker. The method has the steps of operating, as a hot cathode, at least one of electrodes provided at both ends of a glass valve in a stable discharge state, and emitting light from a fluorescent material with the ultraviolet rays generated by the discharge of low-pressure rare gas sealed in the glass valve, or directly with visible light. The hot cathode is heated at least during lighting. In the method, the temperature of the hot cathode relative to the lamp current flowing between the electrodes is set within a region to prevent flicker in the discharge lamp.

Abstract: For triggering a discharge lamp powered by a d.c. source and having electrodes disposed in the lamp bulb, a power supply circuit is proposed having a triggering device where, after the start of heating of a cathode (which cathode is in the form of a heated cathode), the triggering device switches a triggering pulse to a discharge path of the lamp, which discharge path is formed by the two electrodes, and initiates a triggering phase, such that the triggering pulse at least partly overlaps in time with the heating phase of the cathode. In this way, reliable triggering of deuterium discharge lamps and hydrogen discharge lamps is possible, particularly in the case of a deuterium lamp having a relatively small opening, e.g. on the order of 0.3 mm.

Abstract: In an electrical circuit for feeding a fluorescent lamp, a serial resonant circuit is comprised of a first coil of a feedback-transformer, a resonant inductor, a coupling condenser, a first lamp cathode, a resonant condenser, and a first coil of an isolating transformer, this serial resonant circuit being connected between the output of an inverted rectifier, connected to a voltage supply source and one terminal of said voltage supply source, with a second coil of the isolating transformer being connected in parallel with the second lamp cathode. If the coils of the isolating transformer have the same number of loops, this connection of the second lamp cathode ensures that the same heating current will flow through both lamp cathodes, so that these will be heated equally. The parallel circuit of the second lamp cathode with the second coil of the isolating transformer is connected through a resistance with a terminal of the supply voltage.

Abstract: For preserving and, thus, for extending the useful life of a picture tube of a picture tube screen device having a waiting state function. The filament current of the picture tube in the waiting state of the picture tube screen device is reduced by at least a slight percentage of an original filament current. Also, the picture tube is supplied with another video signal, in addition to an original video signal, that generates a beam current in the picture tube having a white image level that is at least a slight percentage of an original white image level generated by the original video signal.

Abstract: A fluorescent lamp starter circuit includes a relay which forms a first circuit loop to detect the input voltage and to switch the relay from the normally-closed position to the normally-open position once the input voltage reaches the threshold level. The switching of the relay to the normally-open position opens the first circuit loop and closes a second circuit loop constituted partly by the relay to allow current to flow through and heat up the electrodes of the fluorescent lamp. After a certain time period, the relay, which is controlled by the discharging of a capacitor, is switched back to the normally-closed position to open the second circuit loop. The electrodes of the fluorescent lamp, after having been heated, begins to emit electrons and this lowers down the impedance that it represents so that the voltage across the first circuit loop is not sufficient to actuate the relay so as to maintain the relay at the normally-closed position.

Abstract: A control device and methods of making and operating the same are provided, the control device comprising a microcomputer unit, a vacuum fluorescent display unit having a filament unit, a power supply unit for being interconnected to a high voltage alternating current power supply that has a certain frequency, and a circuit operatively interconnecting the units together, the power supply unit comprising a transformerless capacitor arrangement for creating a low voltage direct current from the power source to power the microcomputer unit, the circuit comprising an oscillator unit that receives the direct current and pulses the same through the filament unit at a frequency that is greater than the certain frequency and that causes the filament unit to heat to an operating temperature thereof.

Abstract: An energy efficient and cost effective electronic ballast circuit which lights a fluorescent tube but which avoids excessive voltages or pulsing of the tube. The starter circuit preheats the filaments for a time sufficient to ensure quick ignition upon application of an appropriate voltage, then ceases the flow of current after the tube is lighted to avoid wasting energy.

Abstract: The present invention relates to a gas discharge lamp lighting system in which a voltage source is provided for supplying an a.c. voltage across the lamp electrodes and, further, a source of stored d.c. voltage which is gated to the electrodes in synchronism with and additive to the a.c. voltage, in order to provide a resultant voltage across the electrodes of a magnitude sufficient to light the lamp.

Abstract: A fluorescent lamp starter which includes: a series circuit to be connected to a power source for supplying an AC voltage, including a ballast and a fluorescent lamp equipped with electrodes; a transistor having a collector and an emitter connected through a diode between the electrodes on an opposite side of the fluorescent lamp in which the power source is not connected; a control voltage supply means having a resistance means and a capacitor, which are operated by a voltage between the collector and the emitter of the transistor; and a transistor base control means for switching the transistor by a total voltage of a part of a voltage generated in the resistance means of the control voltage supply means and a voltage generated in the capacitor thereof.

Abstract: An improved ion source is provided with multiple filaments and wiring for selectively connecting various combinations of filaments to a current source. In one embodiment an additional filament is a spare filament which is connected to the current source when the primary filament burns out. This decreases down time due to filament replacement. In another embodiment, an additional filament operates simultaneously with a primary filament to provide a more homogenous electron cloud and to increase filament life.

Abstract: In a circuit for operating a fluorescent lamp with controllable luminance, with the fluorescent lamp comprising a discharge path and heater coils, the discharge path is connected through a transformer to a controllable alternating current source. The current through the heater coils is preferably controllable in such fashion that the sum of the current through the discharge path and through the heater coils remains essentially constant.

Abstract: A simple and compact magnetic ballast for powering a wide range of fluorescent lamp load Wattage such as 14 Watt to 60 Watt without need for modification to the ballast unit. Arc current to the lamp load is supplied through a saturable reactor including a power winding on a magnetic core. Arc current delivered to the lamp load is a function of magnetic saturation of the core determined by a control current through a control winding on the core. In one application, multiple fluorescent lighting fixtures of different wattages illuminating the interior of an aircraft cabin are each powered by essentially identical ballast units for easier installation and maintenance of the cabin lighting.

Abstract: Two methods are disclosed for providing a warm-up or pre-heat period for a gas-discharge lighting system, such as a fluorescent light. One method provides current to the lamp for a predetermined period of time to heat the filaments therein without significant ionization of the lamp. The second method provides current to the lamp to heat the filaments without significant ionization of the lamp until the voltage across the filament reaches a predetermined voltage. After the lamp is pre-heated, the current is increased to ionize the lamp.

Abstract: A low component count and lightweight ballast usable with fluorescent lamp loads of widely different wattage has first and second inductors and first and second capacitors connected in a bridge circuit and can provide current regulation within a few percent for lamp loads between 14 Watt and at least 40 Watt. The two inductors can be wound on a single toroidal core for maximum compactness.

Abstract: A control device and methods of making and operating the same are provided, the control device comprising a microcomputer unit, a vacuum fluorescent display unit having a filament unit, a power supply unit for being interconnected to a high voltage alternating current power supply that has a certain frequency, and a circuit operatively interconnecting the units together, the power supply unit comprising a transformerless capacitor arrangement for creating a low voltage direct current from the power source to power the microcomputer unit, the circuit comprising an oscillator unit that receives the direct current and pulses the same through the filament unit at a frequency that is greater than the certain frequency and that causes the filament unit to heat to an operating temperature thereof.

Abstract: A display device having a display tube including a cold cathode, for example a PN emitter (PNE), has the terminals of the PN emitter (PNE) coupled between first terminals of a first (CR1) and a second (CR2) current mirror. The first current repeater (CR1) is connected to an output of an amplifier (AMP) whose feedback input (FI) is connected to second terminals of the first (CR1) and second (CR2) current mirrors.

Abstract: A circuit for lighting a fluorescent lamp. The present invention takes into account the fastidious characteristics of the fluorescent lamp, and during the momentary lighting of the fluorescent lamp. In order to reduce the temperature fluctuations, a separate pre-heating power is supplied. The circuit includes: a first resonance circuit consisting of a first capacitor connected to the opposite ends of the fluorescent lamp, a resonance inductor, a second capacitor, a first switch and a DC power source, serially connected; a second resonance circuit consisting of a second switch, a first capacitor, a resonance inductor, a third capacitor and a DC power source, serially connected; a switch control circuit for activating the first and second switches in an alternate manner. Before the lighting of the fluorescent lamp, the first and second resonance circuits are put to a resonance state, while, after the lighting of the fluorescent lamp, the resonance is eliminated.

Abstract: A circuit, having a split primary transformer, for controlling the warm-up, ignition and normal operating stages of a fluorescent tube initially applies in phase voltages to opposite sides of the split primary transformer during a warm-up stage; during an ignition stage and during the normal tube operation, out of phase voltage waveforms are applied to opposite sides of the split primary of the transformer.

Abstract: A cathode that uses the tunneling effect of electrons through a layer of insulation consisting of alpha alumina in combination with a circuit to provide a pulsed current caused by a current interrupter within a frequency range of one to ten KHz.

Abstract: An arc suppressor is provided for an electron gun of the type used e.g. in semiconductor lithography equipment. The arc suppressor prevents damaging emission properties of the electron gun either due to variation of the cathode work function or any damage to the emitter apex. The arc suppressor includes a resistance and an inductor in series with each electrode lead providing voltage or current to the various electrodes of the electron gun. The inductance is provided by a ferrite toroid which contains a plurality of holes in addition to the main central hole. The leads for each electrode are wrapped around the toroid through the various holes, with one hole being provided for each lead. Thus advantageously each lead is isolated magnetically from the others, reducing the transformer and capacitive effects that couple one lead to another.

Abstract: A driving circuit for one or more gas discharge lamps (102, 104, 106) having heatable filaments (102A&B, 104A&B, 106A&B) includes: a self-oscillating, series-resonant oscillator (196, 198, 178, 180) for producing a high-frequency output voltage for application to the lamps via an output-coupling transformer (212); a resistive-capacitive divider (190, 192) for starting-up the oscillator after a first delay; a voltage boost IC (144) for causing the oscillator to produce a boosted output voltage when the voltage boost IC is activated and an unboosted output voltage when the voltage boost IC is unactivated; and a resistive-capacitive divider (170, 172) for starting-up the voltage boost IC after a second delay.

Abstract: A CRT display system is described wherein a measure of the beam current generated within the CRT is derived and the voltage across the cathode heater modified as a function of this measure. In this way the optimum voltage across the heater coils is maintained, thus preventing "cathode stripping" at times of peak beam currents, and optimizing the CRT's working lifetime.

Abstract: In an electron beam generator where the heating current for the cathode is transformed by an insulating transformer 7 disposed on the high-voltage insulator 4 of the beam head, the primary winding of this insulating transformer 7 being connected to ground potential, and where a single-pole high-voltage connection 2 and a single-pole high-voltage cable 2 connect the beam head 3 to a high-voltage generator 1, the high-voltage cable 2, at its terminal ends, has a protective resistor 10 corresponding to the surge impedance of the high-voltage cable 2 in order to reduce the damages to insulating and component parts.

Abstract: A charging method within a glass tube using a direct current of low voltage is provided in order to obtain a small fluorescent lamp with a light emission of high luminance. Two distinct discharges are achieved through use of one negative electrode. The filament-like negative electrode is arranged at a short spaced relation to a positive electrode at one end of the glass tube and upon application of the direct current voltage becomes the preliminary discharge. A second positive electrode is positioned at the opposite end of the glass tube and has a greater-spaced relation to the negative electrode resulting in the second discharge.

Abstract: Circuits for increasing the efficiency of fluorescent tubes by openings one side of all of the filament circuits of the tubes in response to flow of plasma current. The circuits may be employed in conjunction with the circuits of Lucetta U.S. Pat. No. 3,954,316. It should be noted that solid state relays could also be employed so that filament current, although not completely terminated, would be substantially terminated and filament losses would be inconsequential.

Abstract: An improvement for a vacuum tube or a plasma tube comprises a cathode loop formed of a material suitable for induction heating. A support structure mounted inside the vacuum tube supports the cathode loop at a cathode position. A power supply mounted outside the vacuum tube includes an induction coil wrapped around the tube near the cathode position and generates an alternating electromagnetic field at the cathode position to induce heat in the cathode loop so that electrons are released into the vacuum tube. Finally, a DC bias is applied to the cathode through the support structure. The improved plasma tube with an induction heated cathode is particularly useful for an ion laser gain medium.

Abstract: A dimming system, which provides a time-varying current from a power source between the electrodes of a gas discharge lamp, simultaneously provides high-frequency, low-level current between the electrodes to sustain an electric discharge in the lamp when the time varying current alone is insufficient. The system provides reduced starting stress in the lamp and, therefore, longer lamp life by delaying the formation of an arc discharge, during start-up, until the electrodes have been heated. The system can be used with standard magnetic ballasts to provide full-range dimming of gas discharge lamps from 3 to 100 percent light output with minimal striations, lamp drop out, and flicker.

Abstract: A gas discharge tube comprises an indirectly heated cathode structure including a hot cathode into which a heater is incorporated. During discharging, the heater is supplied with a discharge current so as to generate Joule heat which is used as a heat source for the hot cathode. To this end, in a drive circuit in which the heater is preheated with a heater power source to initiate the discharging and to light up the discharge tube, followed by supply of discharging power from a discharging maintaining power source, a preheating switch is inserted between the heater and heater power source, and is opened at a start of the discharging and kept opened thereafter.

Abstract: An electron tube device comprising an electron tube having a line cathode, and an electric power source for supplying power pulses to the line cathode. The electron tube device comprises determination means for determining, during a power pulse, the value of a physical quantity which depends on the temperature of the line cathode, comparison means for comparing the value with a reference value and for supplying a control signal, and termination means to end the power pulse in dependence on the control signal. Consequently, the temperature of the line cathode is more stable.

Abstract: A negative glow discharge lamp including an anode and an indirectly-heated cathode disposed within a phosphor-coated envelope. The cathode includes a heater filament surrounded by a metallic cylinder which is coated with an emissive material. The differential resistance of the heater filament is sufficient to internally ballast the flow discharge lamp.

Abstract: A brake lamp apparatus causes a neon discharge lamp to light up instantly even when the vehicle key is not inserted into the key hole of the vehicle e.g., when the vehicle is being parked. A neon discharge lamp utilized in the apparatus is pre-heated but cathodes thereof to instantly light up in hot cathode discharge mode upon depression of a brake pedal when a generator drivingly connected with an engine is operating, whereas the hot cathodes of the lamp are not pre-heated but the lamp can still light up instantly in cold cathode discharge mode upon depression of the brake pedal when the generator is operating. Even if the filament coils of the lamp become cut off suddenly while the vehicle is running, the lamp can still light up, being shifted to in cold cathode discharge method, thereby overcoming a drawback that the brake lamp goes off suddenly due to a filament cut-off during running on a road.

Abstract: An electric discharge lamp having two distinct electrode pairs, each pair including a "large" anode, is provided to eliminate the voltage drop between the positive column and the electrodes. A diode is wired in series with each electrode to prevent electron emission from the enlarged anodes. The combination results in a lamp with higher efficacy.

Abstract: The present invention discloses a cross-field amplifier having an anode and cathode with a pair of permanent magnets which create a magnetic field perpendicular to an electric field created between the anode and cathode. An electric bias circuit is connected between the cathode and a power supply that normally supplies energy to an oxygen source within the amplifier. This bias circuit supplies a negative DC voltage to the cathode. After the amplifier is turned off, the DC bias holds electrons within the interaction area between the cathode and anode for supplying the electrons needed to quickly restart the amplifier.

Abstract: A cathode drive circuit couples a video drive signal from a cathode output amplifier to the cathode of a cathode ray tube along a first matched transmission line. Any signal energy not absorbed by the cathode is coupled along a second matched transmission line to a power dissipating load. The use of matched transmission lines avoids reflections in the system and eliminates attendant signal degradation. The power dissipating load can be located at any distance remote from both the cathode output amplifier and the cathode so as to minimize heat dissipation problems.

Abstract: A discharge lamp operating circuit includes at least a discharge lamp, a condenser and four switches. The condenser is charged and discharged through the discharge lamp by the turn-on and turn-off of the switches so that an AC current is caused to flow through the discharge lamp to operate the discharge lamp. A time required for the complete charging and discharging of the condenser is selected to be longer than a time scheduled for the charging and discharging of the condenser in one period. A switching frequency f.sub.0 at the time of heating of the discharge lamp and a switching frequency f at the time of operating of the discharge lamp has a relation of 2.ltoreq.f/f.sub.0 .ltoreq.10.