Abstract: A high frequency and high voltage generating circuit for a discharge lamp lighting device controls its initial output at the starting time of a discharge lamp to prevent applying a high voltage to the discharge lamp in the "cold cathode" state. The circuit comprises in combination an oscillation circuit having an oscillation capacitor, a non-linear inductor and a thyristor, and an initial output limiter for delaying the output supply until the lamp filament is sufficiently preheated for preventing sputtering and for extending the operational life of the discharge lamp. The output control is formed as a bias circuit for the nonlinear inductor and includes a thermistor with a negative or a positive temperature coefficient.

Abstract: A solid state ballast circuit for a discharge lamp includes a transistor oscillator with a current amplifier connected to a transformer one secondary winding of which is connected to the lamp and another secondary winding of which is coupled to the amplifier input. An inductive choke coil is connected in the power circuit of the amplifier so that when the lamp burns out or is removed the operating frequency increase resulting from the decrease in load circuit capacitance results in an increase in impedance of the choke, drastically reducing current flow through the amplifier power circuit to prevent transistor damage or RF interference radiation. The current amplifier disclosed is a two-stage emitter follower circuit.

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 discharge lamp is ignited in every half cycle in its operating system including a discharge lamp operating circuit provided with a low frequency alternating current power source, a single winding type current limiter. The discharge lamp is connected to the power source through the current limiter and a series circuit including a high voltage output generator is connected in parallel to the discharge lamp. The high voltage output generator operates during the lamp operation for reigniting the discharge lamp. The voltage of the low frequency alternating current power source is set to less than the required reignition voltage of the discharge lamp during its operation, whereby the lamp current stabilizer size is minimized. Further, a filament preheating circuit is arranged to use current derived from the high voltage generator. The filament preheating circuit is combined with this operating circuit and so is a time delay for assuring a stable operation.

Abstract: A circuit for operating an electric discharge lamp from an a.c. supply wherein a burst of high voltage pulses for starting the lamp is generated during each cycle or half cycle of the supply by rapidly turning on and off an electronic switch, e.g. a triac, connected between a tapping point on a ballast inductance and an input terminal of the circuit.

Abstract: A cycling cut-off arrangement and method of protecting from burn-out a ballast-starter of a luminaire having a power source normally connected to the ballast-starter, and a high pressure sodium lamp across which the ballast-starter supplies voltage of predetermined magnitude to operate the lamp, in the event of a cycling malfunction wherein the lamp is extinguished and the ballast-starter applies a voltage of greater magnitude than the predetermined magnitude across the extinguished lamp. The voltage across the lamp is detected, and a current signal is generated when the voltage magnitude across the lamp reaches a threshold magnitude which is greater than said predetermined magnitude. In response to the generation of the current signal, the power source is disabled from the ballast-starter to protect the latter from damage.

Abstract: An integral fluorescent lamp-ballast unit comprises a fluorescent lamp fastened to an end cap at one end and a housing at the other end. An elongated support member extends between the end cap and the housing, is fastened to both, and serves as a backing for the lamp. The ballast comprises a choke and a preheat starter which are disposed in the end cap and/or housing.

Abstract: Discharge lamps are connected to a commerical alternating current power supply through an impedance for blocking high frequency signals and an impedance compensating for the negative resistance of the discharge lamps. The discharge lamps are also connected to the commercial alternating current power supply through a rectifier and oscillator circuit, a voltage signal is generated including the commercial alternating current voltage superposed on a high-frequency, high-voltage signal from the oscillator. This voltage signal is applied to the discharge lamps to energize the same and maintain the lamps in a lighted condition.

Abstract: High efficiency push-pull inverters minimize undesirable energy losses usually resulting from simultaneous conduction and imperfect switching of the transistor switching means. In each of the disclosed circuits, a saturable inductor and a diode are connected in parallel and across the base-emitter junction of each transistor. Voltage on the base of each transistor causes its associated saturable inductor to saturate, and the saturated inductor then terminates the flow of base current and provides a path for rapid evacuation of the charge carriers stored in the transistor base-emitter junction in order to render the transistor rapidly non-conductive. Each diode provides a drain path for current continuing to flow through its associated saturable inductor after junction evacuation. A novel triggering means initiates oscillation of the inverters.

Abstract: A light control device for a high frequency lighted fluorescent lamp includes a high frequency variable voltage power source. A first impedance element (a capacitor and inductor in series) is provided between the terminals of the lamp on the side opposite to the power source. A second impedance element (an inductor) is connected between the power source and the terminals of the lamp, and a third impedance element (a capacitor) is connected across the lamp on the power source side. A constant power source circuit supplies, upon starting of the lamp, constant power to the first impedance element to thereby apply substantially constant cathode pre-heating current and starting voltage and applies, during the lighting of the lamp, substantially constant cathode heating current. The control circuit is capable of pre-set light control. The light control device suppresses beat interference and fluorescent lamp noises due to the electric field radiated from the lamp. Rapid and instant starting is enabled.

Abstract: A bimetal switch circuit, which consists of the series combination of a bimetal switch and a fixed resistance, is connected in parallel with a discharge lamp which is connected across an AC power source through an inductive ballast. The bimetal switch has a heating filament which is closed at the normal temperature and opened when heated to high temperatures by the heating filament. The total resistance value R.sub.o (in ohm) of the bimetal switch circuit at the normal temperature is set so as to establish the relation V.sub.s /R.sub.o .ltoreq. 1 with the effective voltage V.sub.s (in volts) of the AC power source. Under such a condition, when the bimetal switch having been once opened at the starting of the discharge lamp is closed again, high-frequency high-voltage pulses are generated across both terminals of the bimetal switch circuit, and the discharge lamp is easily and stably lit up by the high-frequency pulse voltages.

Abstract: A pulse generator comprising an induction element, and a nonlinear condenser whose dielectric material portion is made of ferroelectric ceramics represented by a general formula of (Pb.sub.1-x-y, Ba.sub.x, Sr.sub.y)(Ti.sub.z, Zr.sub.1-z)O.sub.3.

Abstract: It is the purpose of the present discharge lamp lighting system to provide reignition energy to a discharge lamp in each half cycle of the a.c. power source. The discharge lamp is connected to a conventional a.c. power source through ballast means and an oscillation booster circuit, which provides an intermittent oscillation output for the reignition operation of the discharge lamp. The operation period of the intermittent oscillation output is so controlled that the reignition operation period is included in each half cycle of the discharge lamp current. The lamp voltage and source voltage are established to agree as much as possible with each other for minimizing the terminal voltage of the ballast means, whereby a compact and economical device with a small inductance ballast means is achieved.

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: Apparatus is disclosed which may be utilized as an energizing circuit for the ignition of fluorescent lamps and other gas discharge luminescent devices. The circuit directs energizing signals to gaseous discharge tubes at a voltage sufficient to intitiate ionization of the gases therein. The signals are characterized by having a predetermined frequency in the range from about 20 kilohertz to 10 megahertz. Thereafter, the circuit lowers the voltage and current of the signal delivered to the tubes to a level sufficient to maintain gas ionization. Significant power savings are realized over conventional ballast circuits with the apparatus of the present invention.

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: A circuit for operating an electric discharge lamp comprises an inductor in series with the lamp, a capacitor in parallel with the lamp, and a transistorized inverter circuit connected in series with the inductor and the lamp. The operating frequency of the inverter increases with increasing load. A harmonic of the inverter output frequency is initially established at the resonant frequency of the inductor and capacitor to produce a high open circuit lamp starting voltage. Upon establishment of an electrical discharge in the lamp, the inverter frequency increases to provide efficient, stable lamp operation.

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: A device for starting a discharge lamp by means of a transistor starter provided with an auxiliary transistor for stopping the starting procedure if the lamp fails to ignite.A zener diode is included in the control circuit of the auxiliary transistor, a capacitor is connected in parallel across the lamp, and a self-inductor is included in the connection from the lamp to the main transistor. The auxiliary transistor has a second function in that, by the action of the zener diode, the auxiliary transistor delays the conduction of the main transistor so that a large rise of the voltage between the lamp electrodes is produced, which provides a more reliable ignition of the lamp within a large temperature range.

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: A circuit for operating an electric discharge lamp wherein a change in the mode of operation of the circuit is effected in response to a change of phase of a voltage or current in the circuit which occurs during operation e.g. when the lamp strikes or as the lamp runs up to full current.

Abstract: A voltage regulating transformer is disclosed which includes a magnetic core and a primary winding connectable to an alternating current source for inducing an alternating magnetic flux in the magnetic core. The secondary winding comprises a plurality of paired sectioned windings responsive to the magnetic flux in the magnetic core. Each pair of the plurality of paired sectioned windings has a first and a second foil with a dielectric interposed between the first and the second foils thus creating a plurality of capacitors. One pair of the plurality of paired sectioned windings has a different number of turns than the other of the plurality of paired sectioned windings creating a potential imbalance upon interconnection of the paired sectioned windings.

Abstract: An electric discharge lamp lighting circuit in which a discharge lamp is lighted by a circuit comprising a semiconductor switching circuit in which the cathode of a first thyristor is connected to the gate of a second thyristor and the first and second thyristors are commonly connected at the respective anodes, an integration circuit consisting of a capacitor and a resistor and connected between the gate of the first thyristor and the cathode of the second thyristor, a resistor connected between the integration circuit and the anode of the first thyristor, and a resistor connected between the gate and cathode of the second thyristor.

Abstract: Circuits are disclosed for starting and operating a high pressure sodium vapor lamp in combination with another gaseous discharge lamp of low voltage breakdown characteristics. The sodium vapor lamp is connected in series with a ballast induction coil, while the low voltage breakdown lamp, a portion of the ballast coil at its input side, and a capacitor are connected in a series discharge loop to produce high frequency, high voltage pulses for starting the sodium vapor lamp, and providing for operation of both lamps. A ballast capacitor is connected in series with the low voltage lamp to provide a lead ballast circuit therefor.