Abstract: This is an electron emission with a semiconductor substrate having a p-type semiconductor layer whose impurity concentration falls within a concentration range for causing an avalanche breakdown in a least a portion of a surface of the semiconductor layer. A Schottky electrode is connected to the semiconductor layer. There are a means for applying a reverse bias voltage between the Schottky electrode and the p-type semiconductor layer to cause the Schotty electrode to emit electrons, and a lead electrode, formed at a proper position, for externally guiding the emitted electrons. At least a portion of the Schottky electrode is formed of a thin film of a material selected from metals of Group 1A, Group 2A, Group 3A, and lanthanoids, metal silicides of Group 1A, Group 2A, Group Group 3A, and lanthanoids, and metal borides of Group 1A, Group 2A, Group 3A, and lanthanoids, and metal carbides of Group 4A. A film thickness of the Schotty electrode is set to be not more than 100 .ANG..

Abstract: A voice decoding apparatus of an adaptive PCM coding system in which an auxiliary controller is provided between a controller and a prediction coefficient holder. The controller receives a voice activity detection flag b separated from a received demodulated signal a and, at the time of transition from the voice-active duration to the voice-nonactive duration and vice versa, outputs a reset signal d and a signal e indicating whether the voice activity detection flag is voice-active or voice-nonactive. The prediction coefficient holder extracts, from an ADPCM decoder for decoding a coded signal c, a prediction coefficient g, calculates and stores its average value for each frame and updates the old value with the new one and, at the time of transition from the voice-nonactive duration to the voice-active duration, outputs an immediately stored value h.

Abstract: A circuit for igniting and operating a discharge lamp includes a DC-AC converter provided with a first branch coupled to a DC voltage source and including at least one switching element for generating an alternating current at a frequency f. A load branch is coupled to the first branch and includes inductive means, capacitive means, and an inductor for coupling the lamp to the load branch. A control circuit switches the switching element at the frequency f and includes a resonant circuit of a further inductor and a further capacitor. An ignition voltage limiter includes a second branch coupled to the resonant circuit and comprising a series arrangement of a frequency-dependent impedance and a semiconductor element of variable impedance as a function of its control electrode potential. A third branch is coupled to the load branch and to the control electrode of the semiconductor element for influencing the potential of the control electrode dependent upon the lamp voltage.

Abstract: In a fluorescent lamp ballast, a source of high-frequency voltage is applied directly across a series-resonant L-C circuit. The fluorescent lamp is connected in parallel with the capacitor of the L-C circuit and a voltage-limiting means is operative to prevent the series-resonant L-C circuit from overloading the voltage source during any period when the lamp is not effective in providing circuit loading. When power is initially applied to the series-resonant L-C circuit, a control means provides a short circuit across the capacitor; and, by way of a first current transformer, the resulting short circuit current is used for pre-heating the fluorescent lamp cathodes. After about 1.5 second, the control means provides for removal of the short circuit for a period of about 25 milli-seconds, thereby permitting the voltage across the capacitor to grow to a magnitude sufficient to ignite and operate the lamp.

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

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

Abstract: The load circuits for the different lamps of a 2-lamp ballast are selected to have sufficiently different resonant frequencies so that the luminous fluxes of the two are different when the ballast operating frequency is at one of the resonant frequencies. The ballast is operated at a frequency between those two resonant frequencies. The circuit may include a device for measuring the ratio between the luminous fluxes of the two lamps, and the frequency control circuit is then responsive to that ratio.

Abstract: A DC/AC convert circuit for operating a discharge lamp includes a branch A having ends suitable for connection to a DC voltage source and comprising a series circuit of two switching elements for generating a periodic voltage by being conducting and non-conducting alternately at a frequency f, each switching element being shunted by a diode. A control circuit is coupled to control electrodes of the switching elements for rendering the switching elements conducting and non-conducting alternately at the frequency f. A load branch B shunts one of the switching elements and comprises an inductor. The discharge lamp is coupled to the load branch B. The power consumed by the discharge lamp is adjusted by adjusting the value of the difference Tt-Td, in which Tt is a time interval during which one of the switching elements is conducting during a half cycle of the periodic voltage, and Td is the time interval during which a diode is conducting during the same half cycle of the periodic voltage.

Abstract: To insure high power factor for the operating circuit of a low-pressure discharge lamp, especially of miniature fluorescent lamps, a high-frequency active rectifier bridge (D1-D4) is provided which interrupts charging of a smoothing capacitor (C2), which smoothing capacitor supplies an inverter circuit (WR) in the switching rhythm of the inverter. A storage choke or inductance (L1), a negative feedback capacitor (CG) and an auxiliary capacitor (CS) are coupled to the high-frequency rectifier bridge (D1-D4) which, together with the inductance insure an approximately sinusoidal current being taken from a power network, with a power factor of 0.98 or higher. Preferably, the circuit includes voltage dividers (R8, R9, R11; R15, R16, R17) which are coupled to a voltage sensitive trigger circuit (DI, TH) to turn OFF alternate switching of transistors (T1, T2) of the inverter (WR) in case excess supply voltage or operating voltages of the lamp are sensed.

Abstract: The present invention features a gas discharge lamp electronic ballast that uses a frequency-dependent control circuit. The lamps are all energized by means of a single electronic ballast, including an electronically regulated power supply, a power oscillator/driver circuit, an output coupling circuit and a feedback circuit that provides frequency-to-voltage conversion for controlling the output voltage of the power supply. In this way, constant lamp current is maintained, regardless of the number of lamps connected. Since the remaining lamps are operated at their specified, correct lamp current, lamp life is preserved. Another feature of the circuit is its ability to dim the lamp output continuously over a limited range to reduce energy usable in circumstances in which full lamp illumination is not required. Such dimming can be controlled by a suitable external control signal such as from a potentiometer, switch, light monitoring device or a motion detector.

Abstract: In an electronic ballast, a half-bridge inverter is powered from a DC voltage and provides a nominal 30 kHz square-wave-like inverter output voltage. The inverter output voltage is applied to a series-resonant LC circuit. Parallel-connected across the tank capacitor of this LC circuit are plural series-combinations, each consisting of an instant-start fluorescent lamp series-connected with a current-limiting capacitor. The magnitude of the high-frequency voltage present across the tank capacitor is controlled by controlling the frequency of the inverter output voltage. Prior to lamp ignition, the magnitude of the high-frequency voltage is controlled to a relatively high level, such as to provide for sufficiently forceful lamp ignition. After the lamps have fully ignited, to enhance overall efficiency, the magnitude of the high-frequency voltage is reduced to a relatively low level. This low level is too low to provide for lamp ignition but sufficiently high to permit proper lamp operation.

Abstract: A transformer-less electronic ballast for a gas-discharge lighting system having a power amplifier, with an input, driving a gas-discharge lamp in combination with reactive elements to form a resonant load. The lighting system includes a resistor for sensing current flowing in the resonant load, a comparator having an output coupled to the input of the power amplifier, a non-inverting input coupled to the resistor, and an inverting input coupled to the output of a ramp generator, polarity of the ramp signal being dependent on the output of the comparator. The comparator generates a first signal that is amplified by the power amplifier and applied to the load. The ramp generator generates a ramp signal in response to the first signal. The first signal is asserted by the comparator when the sensed current flowing in the load differs from the ramp signal.

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

Abstract: The electronic reactor for discharge lamps (L) comprises a bridge rectifier (5) connected to an alternating voltage source (3); a half-bridge with two controlled switching means (11, 13) made alternately conducting to connect the said lamp (L) and the said bridge rectifier (5); a resonant load circuit (17) connected to the said half-bridge (11, 13); and a smoothing capacitor (29) connected in parallel with the half-bridge (11, 13). An auxiliary resonant circuit (33) is provided to reduce the crest factor and correct the power factor between the output (19) of the half-bridge (11, 13) and the positive pole (5A) of the bridge rectifier (5).

Abstract: In an electronic ballast, a series-resonance-loaded half-bridge inverter is powered from a DC voltage and provides an AC voltage at an AC rail across which are connected plural lamp-ballast series-combinations, with each lamp-ballast series-combination consisting of a current-limiting capacitor series-connected with an instant-start fluorescent lamp. The DC voltage, which is obtained via a pre-converter, is controlled so as to maintain a predetermined magnitude even during the lamp ignition process. The 35 kHz AC voltage is generated by the half-bridge inverter powering a series-tuned L-C circuit near its natural resonance frequency. The AC rail is connected across the tank-capacitor of the L-C circuit. Except for being reduced so as to maintain total lamp current below a predetermined level on a sustained basis, the magnitude of the AC voltage is controlled to a given level in response to an AC control action applied to an AC control input.

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: Briefly, to reduce switching stresses, employed is a high-frequency AC power source (110) and a current-limiting (ballasting) network (116). The network ( 116 ) includes a high-frequency trap ( 120 ) and an impedance transforming network (122), which is coupled to the AC power source (110) by the trap (120) and which is for connection to a load that includes at least one gaseous discharge (fluorescent) lamp or other non-linear or negative-resistance load (102). The trap, which has the parallel resonant combination of an inductor ( 130 ) and a capacitor ( 132 ), is resonant at a frequency chosen such that the switching-circuit transistor(s) (210, or 230 and 232, or 250 and 252, or 270 and 272, or 708) of the AC power source (110) switch at times when the level of the current (charge flowing) therein and/or the voltage developed there across is zero, preferably, at a frequency slightly higher than a harmonic frequency of the high-frequency AC power source ( 110 ).

Abstract: A circuit arrangement for preheating electrodes of a discharge lamp connected in series with a ballast by means of a supply voltage of alternating polarity. The circuit arrangement is provided with a switching element (S) which shunts the lamp and which is operated by means of a control signal. A circuit portion (II) adjusts both the phase and the frequency of the control signal in dependence on whether the ballast is inductive or capacitive. The electrodes of the lamp are preheated in a short period both for an inductive ballast and for a capacitive ballast.

Abstract: A lamp driving circuit having a series inductor and capacitor (L-C) in which the lamp load is connected in parallel with the capacitor. During pre-ignition of the lamp load, the driving signal supplied by a half-bridge oscillator includes a fundamental frequency and a third harmonic of the fundamental frequency. The resonant frequency of the series connected L-C circuit is at least .sqroot.5 times greater than the fundamental frequency but less than the third harmonic of the driving signal.

Abstract: To operate a low-pressure discharge lamp, typically a fluorescent lamp, from a low voltage source of, for example, between 5 and 24 V, two diodes (D1, D2) polarized to provide for current passage towards the lamp are connected between the output of a blocking oscillator and the lamp (L). At least one diode (D2) provides for preheating the lamp electrode. The other diode (D1) prevents immediate starting of the lamp; it is integrated in the circuit between the secondary winding (N2) of the blocking oscillator transformer (TR) and one lamp electrode (E1). The first diode (D2) is connected between the primary winding (N1) and the other terminal of the secondary winding (N2), and also to the other lamp electrode (E2). An additional capacitor (C4) connected, effectively, across the lamp (L) improves the starting of the lamp. The circuit is readily adaptable for association with a recharging circuit (FIG. 3) for recharging a rechargeable battery to supply the lamp.

Abstract: According to this invention, there is provided a method for starting a gas-conducting lamp, by which a gas-conducting lamp is started directly by a high-voltage without pre-heating of filament. Such a high-voltage is realized by an inductor-capator resonant circuit (LC resonant circuit) or a tap of an inductor. According to this invention, there is also provided a gas-conducting lamp for carring-out the abovementioned method. The method according to this invention is simple and effective and is adapted to the use of a gas-conducting lamp without filament or that with filament which has been broken or has failed.

Abstract: A power line-operated electronic converter is adapted to deliver a relatively constant magnitude high frequency signal to a load (113) and is operable to draw a substantially sinusoidal current from the AC voltage source (101). The converter has DC input terminals (V+, V-) having a capacitor (108) connected therebetween, rectifying bridge (103) and boosting rectifiers (D5,D6) coupled to the DC input terminals, a resonant oscillator circuit coupled to the DC input terminals and to the transistor inverter (106) employing two integrated and synchronized resonant circuits having two resonant capacitors (114,112) and one common resonant inductor (110) wherein one circuit is used to operate the load and the other to provide boosted pulsating DC voltage to be naturally added and integrated with the rectified voltage of the AC voltage source.

Abstract: A plasma source for generating a plasma in a chamber in conjunction with a radio frequency generator is described. The plasma source comprises a coil spiral, at least one insulator and at least one capacitor. The coil spiral conducts the radio frequency wave from the radio frequency generator and induces a plasma in the chamber. It comprises at least two segments. Each insulator and capacitor couple two adjacent segments of the coil spiral together.

Abstract: Power is provided to a fluorescent lamp by connecting a source of alternating electrical current, consisting of a series of alternately positive and negative current pulses, to the lamp and shaping the current pulses such that the absolute value of the current increases as a function of time within each pulse.

Abstract: An electronic ballast draws current from the power line with power factor over 90% and total harmonic distortion under 20%, and powers two series-connected 48"/T-12 fluorescent lamps with a 30 kHz current having crest-factor better than 1.7. The ballast includes a power-factor-correcting up-converter and a half-bridge inverter providing a 30 kHz squarewave voltage across a series-resonant high-Q L-C circuit. When the L-C circuit is not loaded, the magnitude of the 30 kHz voltage developing across its tank capacitor is clamped by non-dissipative means to a peak-to-peak magnitude equal to the magnitude of the inverter's DC supply voltage. The ballast output voltage consists of the sum of two components: (i) the 30 kHz voltage across the tank capacitor, and (ii) a 30 kHz voltage obtained from an auxiliary winding on the tank inductor. The ballast output voltage is non-pulsing and is provided at a pair of ballast output terminals across which are series-connected the two 48"/T-12 fluorescent lamps.

Abstract: In a fluorescent lamp ballast, a high-frequency AC voltage is applied directly across a tuned L-C circuit. The fluorescent lamp is connected in parallel with the capacitor of the L-C circuit and a voltage-limiting means prevents the series-resonating L-C circuit from overloading the source of AC voltage during any period when the lamp is not effective in providing circuit loading. When power is initially applied to the L-C circuit, a control means provides a short circuit across the capacitor; and, by way of a first current transformer, the resulting short circuit current is used for pre-heating the fluorescent lamp cathodes. After about 1.5 second, the control means provides for removal of the short circuit for a period of about 25 milli-seconds, thereby permitting the voltage across the capacitor to grow to a magnitude sufficient to ignite and operate the lamp, while at the same time removing the cathode voltage.

Abstract: The invention relates to a DC power supply utilizing DC to AC to DC conversion with pulse to pulse current mode IC controlled PWM modulation at an above-sonic repetition rate (e.g., 30 Khz) in a degenerative feedback loop to achieve output regulation.The powder supply, which includes a step-down transformer and a choke input LC filter, is designed for energizing a short-arc, lamp and provides glow to arc transition energization, regulated run energization, and igniter controls. Output regulation may be either of current or power and is based on using a current emulating the current flowing into the filter choke or using both the emulating current and a voltage sensed in a separate secondary winding of the transformer. A novel ramp generating circuit which preserves loop sensitivity at high power loads and a novel method of powering the controlling IC are also disclosed.

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

Abstract: An electronic ballast circuit for discharge lamps, comprising a boosting transformer for applying a high voltage as a discharging voltage to the discharging lamps, the high voltage being induced in a main secondary winding of the transformer according to forward and reverse currents flowing through a primary winding of the transformer, a charging section for charging a voltage from an input power source terminal, first and second switching sections for repeatedly performing switching operations contrary to each other, a resonance section for allowing the forward current to flow through the primary winding of the boosting transformer when the first switching section conducts and allowing the reverse current to flow through the primary winding of the boosting transformer when the second switching section conducts, and a plurality of condensers, each connected between the secondary winding of the boosting transformer and a filament of a corresponding one of the discharge lamps, the condensers limiting amounts of

Abstract: A circuit for igniting and operating a discharge lamp includes a DC-AC converter provided with a first branch coupled to a DC voltage source and including at least one switching element for generating an alternating current at a frequency f. A load branch is coupled to the first branch A and includes inductive means (L), capacitive means, and an inductor for coupling the lamp to the load branch. A control circuit switches the switching element at the frequency f and includes a resonant circuit of a further inductor and a further capacitor. An ignition voltage limiter includes a second branch coupled to the resonant circuit and comprising a series arrangement of a frequency-dependent impedance and a semiconductor element of varible impedance as a function of its control electrodes potential at its control. A third branch is coupled to the load branch and to the control electrode of the semiconductor element for influencing the potential of the control electrode dependent upon the lamp voltage.

Abstract: An efficient ballast for Mini-fluorescent lamps, includes an inductor, in communication with a power source and constructed as transformer with only primary winding, a fluorescent lamp in series with the inductor, and a capacitor in series with the fluorescent lamp, and optionally may include a resistor in parallel with the coil, and a switch interposed between the capacitor and power source. The value of the capacitance may change based upon the degree of change in the supply voltage.

Abstract: A lead ballast circuit with power regulation for a gas discharge lamp includes an input pair of conductors for receiving an a.c. supply voltage, the magnitude of which voltage fluctuates within a known range. Further included is an output pair of conductors for supplying a driving voltage to the lamp. A lead inductor having a magnetic core and a lead capacitance serially connected to the lead inductor between an input, and an output, conductor are included. The inductive impedance of the lead inductor is less than the capacitive impedance of the lead capacitance whereby the aggregate impedance of the serially connected inductor and capacitance is capacitive rather than inductive. The lead ballast circuit also includes a power factor-correcting inductor connected across the input conductor pair, and having a magnetic core that shares a leg in common with the magnetic core of the lead inductor.

Abstract: An electronic high frequency supply, such as a lamp ballast, having a full-wave rectifier, a storage capacitor charged to a voltage greater than the peak of the rectifier output, and an isolating diode between the rectifier and the storage capacitor. An inverter is connected to the storage capacitor, and has a high frequency inductive load circuit connected between the inverter output and a junction between the isolating diode and the bridge rectifier. A capacitor, connected to the junction in parallel with a series circuit formed by the isolating diode and storage capacitor, forms a high frequency resonance circuit with the inductive load circuit. Current is drawn from the rectifier only as a series of pulses at the inverter frequency. To minimize variation in the high frequency load current, the inverter frequency is varied linearly with but oppositely to the instantaneous value of the rectifier output voltage.

Abstract: An inverter-type electronic fluorescent lamp ballast normally powers a fluorescent lamp by way of a series-excited parallel-loaded resonant L-C circuit. During the lamp starting phase, as well as whenever the lamp is inoperative or not connected, inverter frequency is automatically increased substantially beyond resonance, thereby preventing circuit self-destruction which would otherwise probably result whenever an inverter is used for series-exciting an unloaded resonant L-C circuit.

Abstract: The Lamp (La) is connected in series with first reactive impedances (C1, . To generate pulses, one or more second reactive impedances (C3, L3; C3-L2) are located as energy storage elements in series with one or more switch elements (S3, VTh1, VD1) to at least one of the first reactive impedances (C1, L1) and also in series with the high-pressure gas discharge lamp.

Abstract: In a high frequency plasma power supply comprising a final stage push-pull amplifier 2 with each phase having a parallel combination of at least two FETs, an output transformer 5 having the connection of the phase outputs of the push-pull amplifier 2 to the opposite terminals of a primary winding with a neutral tap, and a low pass filler 6 allowing passage of substantially the fundamental frequency component from the secondary winding output of the output transformer 5, the high frequency power passing through the low pass filter being supplied between the electrodes of a plasma chamber 10 through an impedance matching circuit 9 having an impedance adjusting mechanism,the dc voltage Vds to be applied between the drain and source of each FET of each phase of the push-pull amplifier is adjusted to not more than about 30% of the dc absolute rated value and the turn ratio of the output transformer is 1:4, thereby supplying the power having the level necessary for plasma reaction.

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 circuit is disclosed to implement an energy saving electronic ballast (1A) for driving a fluorescent lamp or tube (2). The circuit is characterized by a high power factor, low harmonic distortion and minimized radio frequency interference. The circuit includes a unique DC power supply (4) comprising a high pass filter (8), which receives an AC input signal, a diode bridge rectifier (6) and a high speed diode rectifier (D2) which cooperates with the bridge rectifier to provide the power supply with first and second rectification stages. A current regulating capacitor (C4) for driving the fluorescent lamp or tube is connected to the DC power supply between the first and second rectification stages. A trigger and high frequency oscillator are provided after the second rectification stage of the power supply to provide the DC current necessary to operate the ballast circuit.

Abstract: A power-line-operated frequency-converting power supply provides a 30 kHz current-limited AC voltage at an output receptacle. A neon lamp is connected across the secondary winding of a gapped ferrite-type leakage transformer, the primary winding of which is connected with the output receptacle by way of a light-weight cord, thereby permitting the lamp-transformer combination to be located remotely from the power supply. The secondary winding is arranged to have a well defined inductance; which inductance is tuned to resonate at 30 Khz by way of a parallel-connected tuning capacitor. Tightly coupled with the secondary winding is a control winding with which is connected a protection circuit operative to place an auxiliary capacitor across the control winding in case the neon lamp fails to ignite within a few milli-seconds, thereby detuning the secondary winding enough to protect the power supply and the leakage transformer from sustained overload.

Abstract: A power supply circuit for a gas discharge lamp is disclosed. The power supply circuit includes a circuit for providing a d.c. bus voltage on a bus conductor, and a resonant lamp circuit. The resonant lamp circuit includes a gas discharge lamp, a first resonant impedance in series with the gas discharge lamp, and a second resonant impedance substantially in parallel with the gas discharge lamp. The resonant load circuit operates at a resonant frequency determined by the values of the first and second resonant impedances. Further included is a series half-bridge converter for impressing across the resonant load circuit a bidirectional voltage, and thereby inducing a bidirectional current in the resonant load circuit.

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

Abstract: An electrical power controller includes a boost converter, an invertor and an output section. The boost converter includes a control circuit which charges a capacitance from an inductance in accordance with a stream of pulses having a variable duty cycle. A feedback circuit responsive to the power consumed by a load provides an error signal for varying the duty cycle of the pulses. In the invertor, a pair of switches sample the charge on the capacitor to create an AC signal which is introduced to the output section. The sampling frequency in the boost converter is related to the sampling frequency in the invertor by an integer.

Abstract: The present invention offers improvement of performance and efficiency of a compact fluorescent lamp by means of a series tuned LRC ballasting circuit. The resonant voltage rise in the circuit is utilized to increase the cyclic crest voltage necessary for lamp ionization. After ionization occurs, lamp current and power are clamped and regulated by the lower Q factor of the tuned circuit. The LRC circuit provides a square wave of voltage across the lamp with considerable reduction in noise and RF ringing. Since it is a tuned circuit, it operates at approximately unity power factor, at lower temperature, and with a net equivalent impedance that provides for maximum illumination, lamp life and efficiency.

Abstract: A ballast arrangement is disclosed for use in powering fluorescent and other gas discharge lamps. The ballast arrangement provides both full current and low current outputs for multiple sets of lamps so that dual lamps can be powered simultaneously, at the same or different output levels.

Abstract: A lighting system using a 120 volt AC power source and including within a single enclosure a low wattage fluorescent lamp and a low wattage incandescent lamp. The fluorescent lamp provides an efficient light source operating at a low voltage and low wattage, but providing a relatively bright light. The incandescent lamp may be used to provide a more traditional night light having a lower light output than that which is produced by the flourescent lamp. Either the fluorescent lamp or the incandescent lamp is selected by a switch. To obtain the low voltage required by the incandescent lamp, a resistor is placed in parallel with a capacitor to provide a small voltage drop, e.g., from 120 volts to 115 volts. In this configuration, due to the charging and discharging of the capacitor as the current alternates and discharges through the resistance of the incandescent lamp, a relatively low voltage and current pass through the incandescent lamp.

Abstract: In one aspect of the present invention a capacitor is placed in series with the ballast and the lamp. The capacitor lowers the impedance during lamp starting and is shorted out when final arc conditions of the lamp are reached. Method and device for improvement of lumen maintenance of high intensity discharge lamps through minimizing the wall blackening during lamp starting is disclosed. Reducing the electrode material sputtering during the thermionic arc phase of the lamp starting process was achieved by decreasing the cathode fall voltage. The cathode fall voltage in these lamps was decreased by increasing the current flowing through during the starting phase. The increase of starting current was achieved by increasing the open circuit voltage or by decreasing ballast impedance.

Abstract: A power regulating ballast for gaseous discharge lamps operated from a source of high-frequency power incorporates a method in an apparatus which utilizes a distributed capacitance in combination with an inductor and includes a current feedback derived from charges in the current flow through the lamp.

Abstract: An operating circuit arrangement for a discharge lamp has a chopper circuit and an inverter circuit. The inverter circuit generates a high frequency voltage to start and operate the discharge lamp. The chopper circuit supplies a d.c. voltage to the inverter circuit. The circuit arrangement has a chopper control circuit and an inverter control circuit which are coupled to the chopper circuit so that the operation of each control circuit responds to the chopper circuit. In order to perform a soft starting operation in which the inverter circuit generates a given high frequency voltage to start and operate the discharge lamp prior to the generation of a given level of d.c. voltage generated by said chopper circuit, an inverter control circuit coupled to the inverter circuit is provided.

Abstract: A bi-level control system includes a plurality of slave units, each for connection to a respective ballast and HID lamp of a plurality of HID lighting fixtures, and a common control unit. Each slave unit includes a switched capacitor and a slave relay which has one input connectable to a common line of an AC power supply branch circuit powering the fixtures and another input adapted for receiving a line voltage signal. The control unit includes an output connected to the control inputs of each of the slave units by a single control line and switchably connected to line voltage. Dimming of the HID lamp is accomplished by switching line voltage to the output of the control unit which causes the slave relay to switch the slave capacitor into circuit with the HID lamp and ballast. Use of a single control line connecting each of the slave units to the control unit greatly reduces wiring over known systems.