Abstract: The invention describes an ignitor arrangement (1) for a high-intensity discharge lamp (2), which ignitor arrangement (1) comprises a first pair of input terminals (101, 102) for applying an ignition voltage to the ignitor arrangement (1); a second pair of input terminals (101, 103) for applying an input drive voltage to the ignitor arrangement (1); and a discharge resistor (10) arranged in the interior (100) of the ignitor arrangement (1) and connected across the first input terminal pair (101, 102), which discharge resistor (10) is realized as a temperature-dependent resistor (10). The invention also describes a lamp driver (3) realized to drive a high-intensity discharge lamp (2); a lighting arrangement (4); and a method of driving a high-intensity discharge lamp (2).

Abstract: A bandgap ready circuit for an RFID tag includes a bandgap circuit for providing a bandgap voltage, a first comparator for monitoring first and second voltages in the bandgap circuit and for providing a first logic signal, a second comparator for monitoring third and fourth voltages in the bandgap circuit and for providing a second logic signal, and a logic circuit for combining the first and second logic signals to provide a bandgap ready logic signal.

Abstract: A light source device for a projector device having a discharge lamp with a silica glass discharge vessel containing a pair of opposed electrodes and at least 0.15 mg/mm3 of mercury, a concave reflector which surrounds the discharge lamp and reflects light emitted from the discharge lamp in a given direction, and a power supply device which selectively supplies a first wattage and a lower second wattage, is provided with a reflection heating arrangement which, in operation of the discharge lamp with the lower second wattage, returns at least part of the light emitted by the discharge lamp in the direction of the discharge lamp, and in operation of the discharge lamp at the first, higher wattage returns less light than in operation with the second wattage in the direction of the discharge lamp.

Abstract: The invention relates to a novel ballast device for pre-heating, starting and operating at least one UV emitter, constructed in the form of a gas discharge lamp with two heating coils lying opposite each other in relation to a gas discharge path, whereby four electrical connections are provided in total for each of such gas discharge paths, namely two for each heating coil. According to the invention, switching means are provided for a parallel switching of both of said connectors of a heating coil, dependent upon operating conditions. A capacitive loading of the ballast device is thus avoided by means of the otherwise open connector line for the heating coil and the current feed to the coils is evenly distributed.

Abstract: A lighting device including a temperature sensing device for controlling the operation of the light emitting device. The lighting device includes a housing, a reflector coupled to the housing, a bulb received in the housing, the bulb being connected to a source of electrical power, and a capillary tube thermostat received in the housing. The capillary tube is an elongated metal member having a hollow center filled with a vacuum charged fluid. The fluid is calibrated to open the thermostat between 150.degree. F. and 350.degree. F. The capillary tube thermostat is in electrical communication with the power source and is supported by the housing in thermal communication with the bulb. The thermostat extends along at least a portion of the length of the bulb. The thermostat is also in thermal communication with the reflector, and thus will open the thermostat contacts if an overheat condition is detected at either the bulb or the reflector.

Abstract: A ballast circuit for a gas discharge lamp, of the type having a pair of resistively heated cathodes that are resistively heated both during a cathode pre-heat period prior to lamp turn-on, and during steady state lamp operation, is disclosed. The ballast circuit includes circuitry for providing, on a bus conductor, a d.c. bus voltage with respect to a ground, and a converter, responsive to the d.c. bus voltage, for supplying bidirectional current to a resonant load circuit. The resonant load circuit includes the gas discharge lamp, a resonant capacitor coupled between the lamp cathodes such that its voltage varies with lamp voltage, and a resonant inductor serially coupled to the resonant capacitor and cooperating therewith to set a magnitude, and resonant frequency, of the bidirectional lamp current. Circuitry is provided for powering the resistively heated lamp cathodes, to thereby heat the cathodes.

Abstract: An improved, more energy efficient reactor-type ballasting circuit for fluorescent lamps includes an inductive ballasting coil for directly applying an AC line voltage to the cathodes of a lamp without an intermediate autotransformer and also includes a glow type thermal switch in series with a positive temperature coefficient (PTC) resistor for electrical connection across the cathodes of the lamp to conduct pre-heating current to the lamp cathodes. The PTC resistor will effectively remove the glow switch from the ballast circuit if the switch fails to open after an appropriate time delay.

Abstract: A starting and operating circuit for a super compact fluorescent lamp includes ballast and discharge circuits for applying current to the filaments of the lamp and then apply starting pulses which enable the lamp to commence operation. The circuits include discharge devices and assure operation and proper starting of the lamp under low temperature as well as moderate temperature conditions.

Abstract: A ballast-inverter circuit for a discharge lamp with preheatable electrodes. The lamp is connected to the supply voltage input terminals via a ballast impedance. A triac provides a preheat current path for the lamp electrodes and has a gate electrode connected to an RC timing circuit. A PTC resistor is coupled between one input terminal and the timing circuit to trigger the triac so as to heat up the lamp electrodes and assist the lamp to ignite. The PTC resistor heats up until its resistance is so high that the timing circuit is no longer able to trigger the triac into conduction. The electrode preheat circuit is effectively disconnected from the lamp electrodes when the lamp is in operation.

Abstract: A high pressure metal vapor discharge lamp comprises a light-emitting tube in which a pair of electrodes is enclosed, a starting element including a normally closed-type thermal switch and a resistive member, the starting element generating a pulse by closing and opening switch operations, a connecting element for electrically connecting the starting element to the electrodes, the pulse being applied to the electrodes through the connecting element, and a member including an insulating body provided in vicinity of the thermal switch for causing a conductive portion to be formed on the body, the conductive portion being sufficient to bypass a current supplied to the starting element by repetitions of the switch operations, thereby lowering the pulse voltage.

Abstract: The arrangement of this invention includes circuitry for sequentially lighting a series of lamps, followed by extinguishing them in unison; said circuitry including, in association with each lamp, at least one bi-metallic element for controlling the opening or closing of a switch.

Abstract: For the operation of warm start gas discharge lamps upon employment of an electronic ballast wherein the gas discharge lamp lies parallel to the effective capacitance of a series-resonant circuit and has its heater coils incorporated into this series-resonant circuit. An isolating switch is provided in series with the effective capacitance. This isolating switch interrupts the shunt to the lamp and, thus, the heater coil current as well, as soon as the lamp has ignited. It is assured in this way that the current flowing in the shunt to the lamp which otherwise represents a dissipated power is suppressed. Particular significance is accorded to this method when the effective capacitance of the series-resonant circuit is executed variably during the starting interval phase with the assistance of temperature-dependent resistors or is executed with time delayed electronic switches for the control of the lamp voltage.

Abstract: To provide for reliable ignition of low-pressure discharge lamps, particularly compact fluorescent lamps, operated at high frequency, for example in the order of about 45 kHz, an ignition circuit is connected in parallel to the lamp and serially with the electrodes (16, 17) thereof, which comprises a limiting capacitor (19) and the parallel circuit of a positive temperature coefficient (PTC) resistor (20) and a starting capacitor (18). The two capacitors (18, 19), together with an inductance (13, 14) in the operating circuit of the lamp, and a further capacity formed by a blocking capacitor (15), after preheating of the lamp electrodes by current flowing through the initially cold PTC resistor, will cause voltage rise across the resonance capacitors (18, 19) which will cause ignition of the lamp.

Abstract: A rapid-start fluorescent lamp includes a circuit breaker having a sealed glass bottle, a pair of electrical conductors sealed therein and passing therethrough and a thermally sensitive bimetal switch within the glass bottle with the bimetal switch having a pair of leg portions of unequal length.

Abstract: A rapid-start fluorescent lamp has a thermally-sensitive circuit breaker disposed thereon for disconnecting the electrodes of the lamp from an energizing source at a given range of bulb temperatures and for connecting the electrode to the energizing source at bulb temperatures above and below the given range of bulb temperatures whereby the electrodes are energized during lamp manufacture and until conductivity of the lamp is established.

Abstract: A rapid-start fluorescent lamp includes a pair of spaced electrodes within an envelope with one electrical lead connected to an electrode and the other lead coupled to the electrode by a thermally-sensitive bi-metal strip whereby one end of the bi-metal and one end of a conductor are formed to provide a straight member within a U-shaped member such that the straight U-shaped members are in electrical contact at temperatures above and below a given range of temperatures and electrically disconnected at the given range of temperatures.

Abstract: A ballast circuit for starting and operating a preheat type circular fluorescent lamp, which replaces a multiple wattage incandescent lamp in a three-way incandescent lamp socket, so that the fluorescent lamp can be ignited to function at three different operating wattages. A lamination stacked core structure mounts first and second coils. A passive circuit element, such as positive temperature coefficient resistor also known as a thermistor, is connected in the circuit, which includes a three-way incandescent lamp screw base, for current switching functions to achieve the desired ignition and operating currents for the fluorescent lamp at its different operating wattages.

Abstract: A circuit breaker for a rapid-start fluorescent lamp includes a pair of electrical conductors sealed into a glass bottle, a bimetal switch within the bottle having one end affixed and the other end contacting the pair of electrical conductors and a meltable by-pass element shunting the pair of electrical conductors and formed of a material having a relatively high cold resistivity and a low temperature coefficient of resistance.

Abstract: Apparatus for starting and operating a discharge lamp includes a starting device having bimetals and a rigid conductive member forming a switch, a ballast coupling the switch to an AC source and a discharge lamp and a spark gap each shunting the starting device with the starting device bimetals and rigid conductive device hermetically sealed in a vacuum.

Abstract: A discharge lamp starting device employing a thermal switch which comprises main and auxiliary bimetal electrodes respectively thermally bendable in the same direction, and an auxiliary heater for heating the auxiliary bimetal electrode in addition to a main heater for the main bimetal electrode. The auxiliary heater is energized to heat the auxiliary electrode upon a starting failure specifically when the discharge lamp is to be lighted again immediately after its extinguishment, whereby the auxiliary electrode is forced to bend toward the main electrode and a re-closing of the thermal switch and eventual lamp starting can be accelerated.

Abstract: A multiple fluorescent lamp ballast circuit of the rapid start type in which heating current is supplied to the lamp cathodes. A time delay switch is connected in series with a starting capacitor across one or more of the lamps, to delay lamp starting until the cathodes are sufficiently heated.

Abstract: A high pressure discharge lamp in which the restriking voltage and time are significantly decreased. A pair of electrodes are sealably disposed in a tube containing an appropriate amount of mercury. Means is provided for heating at least one of the electrodes for starting the lamp if it has been recently turned off and the mercury vapor pressure inside the tube is high. The heating means is preferably a filament made of a thermally stable material. One terminal of the filament may be connected to one of the electrodes.

Abstract: A circuit arrangement for starting and operating a discharge lamp by means of an electronic ballast includes a series arrangement of a PTC resistor and an ohmic resistor connected in parallel with an electronic switch of the ballast, with only the PTC resistor being in parallel with a control circuit of the electronic switch. The value of the ohmic resistor is 8 to 12 times the cold resistance of the PTC resistor.

Abstract: A metal vapor discharge lamp comprises main electrodes and an auxiliary electrode in an arc tube to initiate the discharge between the main electrode and the auxiliary electrode at the initiation of the operation and then to result the discharge between the main electrodes by disconnection of the auxiliary electrode by a bimetallic switch means. A second bimetallic switch means which delays the operation from that of the first bimetal, is connected in series to the first bimetallic switch means so as to discharge in a circuit formed in an outer bulb to break a part of the circuit and to prevent a ballast from overheating.

Abstract: A high pressure metal vapor discharge lamp according to the present invention comprises the following first and second starting aid circuits mounted within an outer envelope. The first starting aid circuit includes a starting aid and a first thermal switch, and the second starting aid circuit includes a resistive element and a second thermal switch. These two thermal switches are arranged so that at the time of re-starting after a certain period of stopping, the first thermal switch is reset earlier than the second thermal switch. In this high pressure metal vapor discharge lamp having this specific structure, the starting characteristic is improved, and a high voltage pulse generated by the second starting aid circuit and a ballast is assuredly absorbed by an arc tube and occurrence of dielectric breakdown in the respective elements can be completely prevented.

Abstract: A starting circuit for gas discharge lamps, such as fluorescent lamps, includes a relay coil controllable switch. A rectifier-multiplier has its input connectable to the alternating-current mains via the controllable switch. A polarity-reversing switch is coupled to an output from the rectifier-multiplier for supplying direct-current to electrodes of at least one gas discharge lamp. Devices responsive to energization of the mains effect reversal of the polarity-reversing switch upon each energization of the mains. A time-delay relay responsive to each energization of the mains effects the closing of the relay coil controllable switch subsequent to each polarity-reversing action of the polarity-reversing switch.

Abstract: Method and apparatus for starting high intensity discharge lamps utilizing a spiral line pulse generator to generate high voltage, short duration starting pulses. The spiral line pulse generator includes two conductors and two insulators, each in the form of an elongated sheet, in an alternating arrangement which is rolled together in a spiral configuration having a plurality of turns. A high voltage, short duration pulse is provided upon closure of a low inductance switch coupled between the conductors. The pulse is coupled to the discharge lamp by an elongated conductor located in close proximity to the discharge tube. The spiral line pulse generator can be included within the outer jacket of the light source.

Abstract: An energization circuit for a microwave oven employs a PTC thermistor to eliminate high transient current surges resulting from energization and deenergization of induction elements therein to provide circuit protection both during oven start and operation. The energization circuit comprises first and second parallel circuit portions for energizing a transformer used to energize a magnetron that produces microwave energy, the first circuit portion including a normally open start switch and a current limiting PTC thermistor coupled in series relation and the second circuit portion including a relay operated switch, a relay for operating the relay operated switch, and a relay circuit portion connected to the first circuit portion between the start switch and PTC thermistor for energizing the relay upon closure of the start switch and then through the PTC thermistor upon opening of the start switch.

Abstract: The present invention relates to a lighting unit utilizing an energy efficient arc lamp as the main source of light supplemented by a standby filamentary lamp, the filament serving as a resistive ballast for the arc lamp during normal operation. The lighting unit is designed for functional similarity to an incandescent lamp, the filament providing immediate illumination when the lighting unit is first energized and continuing illumination until the arc lamp itself produces light. In accordance with the invention, if the arc lamp does not start within a predetermined period, the application of starting potentials produced through operation of a solid state switch and a high frequency step-up transformer is discontinued and the lighting unit rendered inactive. Exemplary means includes a positive temperature coefficient thermistor responsive to the temperature rise of the solid state switch.

Abstract: The invention relates to a high-pressure sodium lamp which is provided with a discharge tube having an external auxiliary electrode. The auxiliary electrode is switched off by a bimetallic switch in the operating condition of the lamp.According to the invention the lamp also comprises a glow starter which in the operating condition of the lamp is switched off by means of the same bimetallic switch. This apparatus achieves in a simple manner, a large available voltage for igniting the discharge tube with an operating condition of the lamp in which no disturbance is experienced from any of the ignition auxiliary means.

Abstract: Methods and apparatus for electronically igniting gas discharge lamps, such as hot- or cold-cathode fluorescent lamps, various high-pressure, metal-gas, and halogen-gas lamps.The initial heater current, in the case of hot-cathode lamps, or the initial high voltage across the unignited lamp, in the case of cold-cathode lamps, is used to heat a positive temperature coefficient resistor. The heat generated by this resistor causes a striker mechanism, consisting in essence of a pre-tensioned bi-metal disc or strip, to buckle, the said buckling striking a piezo-electric crystal, thereby inducing a high voltage, which ignites the lamp.Various coupling circuits between the mechanism and the lamp are described.The important features, compared to presently known igniters relate to the flickerless and reliable ignition of the lamp, more reliable igniter structure, and lengthened life time of the lamps.

Abstract: A ballast circuit for controlling the ignition characteristics of a preheat type fluorescent lamp of the type having a transformer with a primary, operating secondary, filament and auxiliary ignition windings, in which there is provided a rectifier having A.C. input terminals, one connected to an end of the operating winding and the other connected to an end of the auxiliary ignition winding by a resistor, and a pair of D.C. output terminals across which is connected a resistive ballast. A starting capacitor is connected to the junction of the resistor and the rectifier A.C. input terminal and applies the auxiliary starting voltage after a time delay. A second capacitor, connected in the lamp running circuit, is charged through a resistor and diode and makes an additional voltage available.

Abstract: A high pressure sodium vapor lamp utilizing an alumina ceramic arc tube within an outer glass envelope is provided with a bi-metal switch which short circuits the arc tube at starting. Current flow through the switch causes it to heat up and open the short circuit, producing a voltage pulse which starts the lamp. The bi-metal is fastened to a pin conductor extending from the metal exhaust tube of the arc tube to the frame. The pin conductor, which receives heat by conduction from the exhaust tube and is also heated by lamp current flow, transmits sufficient heat to the bi-metal to maintain it deflected during normal operation.