Abstract: A lamp driver circuit is presented herein for driving a lamp circuit with an AC squarewave voltage at a relatively high frequency. The driver circuit includes a self-oscillating half-bridge circuit having a pair of input terminals connected across a DC voltage supply, which may be obtained from rectifying an AC voltage signal, and a pair of output terminals connected across a lamp circuit including a lamp, either a resistive lamp or a gaseous discharge lamp, to be energized. The circuit also includes a pair of capacitors connected together in series across the input terminals and having a junction therebetween connected to a first one of the output terminals. The bridge circuit also includes first and second switching transistors connected together in series across the input terminals.

Abstract: An apparatus is provided for driving a discharge lamp, the discharge lamp having first and second electrodes, each of the first and second electrodes having first and second terminals. The apparatus includes a switching circuit coupled to the first terminals of the first and second electrodes of the discharge lamp for supplying a high frequency signal to the discharge lamp for igniting the discharge lamp. A starting circuit is provided connected to the second terminals of the first and second electrodes of the discharge lamp and including an inductor and capacitor connected in parallel across the discharge lamp. Alternately, a thermister is provided between parallel connected conductor and capacitor and one of the second terminals of the first electrode of the discharge lamp. Furthermore, circuitry is provided which is connected between the switching circuit and the thermister for deactivating the switching circuit when the thermister is heated to a specified temperature.

Abstract: Apparatus for starting and operating a high pressure discharge lamp includes a pair of input terms for connection to a high frequency inverter. A step-up transformer couples the input terminals to a pair of output terminals for connection of the discharge lamp. A switching arrangement including a voltage-multiplier circuit, is coupled to the primary winding of the transformer and includes a first branch comprising a first capacitor and a diode and a second branch comprising a diode. Between the first capacitor and the diode of the first branch is connected a third branch comprising a semiconductor switch such as a SIDAC. The first branch is connected through the transformer coil to a first supply source connection point. The second branch is connected to a tap point of the coil. The first and the second branch are connected via a common impedance including second capacitor and an inductor to a second supply source connection point.

Abstract: An ignition circuit for fluorescent lamp includes a transformer having coreless windings connected in parallel with a fluorescent lamp with the coreless windings having inductive reactance matched with a capacitive reactance or internal resistance of the fluorescent lamp for forming a harmonic oscillation of a multivibrator in order for stably igniting the fluorescent lamp for saving electric energy.

Abstract: A controller operates in pre-ignition and ignition phases to obtain stable and reliable control of operation of a half-bridge DC-AC converter in a frequency range which is offset from a resonant frequency of an output circuit which includes a transformer and capacitors and which couples the converter to a fluorescent lamp load. The converter is supplied with a DC voltage from a switched-mode DC-DC supply of a pre-conditioner circuit which responds to a full-wave rectified AC voltage and which is supplied with pulse-width modulated gating pulses from the controller, preferably at a frequency which is the same as that of the converter. The controller monitors signals from the output circuit and pre-conditioner circuits and exercises control to reliable starting and highly efficient lamp operation and to obtain an in-phase proportional relationship of input voltage and current waveforms.

Abstract: The inventive power supply converts the low-frequency alternating current source into high-voltage direct current. An induction windings network series connected to the fluorescent tube provides a feedback signal to a pair of bridging transistors which then respectively alternates to be on or off to output a high-frequency, high-voltage signal for the tube to use. The network is connected so that the inductors provide the feedback signal, the signal having a resonant frequency suitable for activating the tube. The light emitted in accordance with this invention is continuous, due to the inventive feedback, in comparison to the light emitted by a fluorescent tube utilizing a transformer and a starter.

Abstract: In a method or combination, a DC voltage supply, a converter including a series or a parallel resonant circuit for converting the DC voltage to a sinusoidal current, and a load including at least one fluorescent lamp responsive to the sinusoidal current to effect excitation of the lamp.

Abstract: In a power-line-operated inverter-type fluorescent lamp ballast with a high-Q parallel-loaded resonant L-C circuit series-connected across the inverter's output, subject invention provides for means to prevent the destructive overload that may occur during the lamp starting period or if the lamp is removed or somehow fails to operate. In this ballast, the unfiltered pulsed DC output of a full-wave power-line-supplied rectifier means is applied to a pair of inverters: an auxiliary inverter for pre-conditioning the fluorescent lamp, and a main inverter for powering the lamp. The auxiliary inverter starts operating immediately upon application of power from the power line, and therefore immediately starts the process of pre-conditioning. The main inverter, however, is not started until after the lamp has completed its conditioning, at which time the lamp will adequately load the series-resonant L-C circuit and thereby prevent destructive overload.

Abstract: A ballast circuit for a fluorescent light bulb of the type having an elongated envelope with an electrode at each end. The ballast circuit includes a square wave generator which generates a square wave in excess of 10,000 hertz. The output from the square wave generator is used to modulate a voltage from a power source having a voltage in the range of 400-800 volts so that the modulated voltage has a frequency equal to the square wave frequency. The resulting modulated voltage is then electrically connected to the electrodes of the fluorescent lamp which illuminates the lamp.

Abstract: A fluorescent lamp supply includes a self-resonant converter for developing high voltage AC for application to the fluorescent lamp. The on-time of the converter is controlled by a pulse width modulator circuit comprising dual comparators, with one comparator being operated as a low frequency oscillator and the other comparator being used to disable the converter by operating a gate transistor. A reference potential is applied to a potentiometer for controlling the output comparator conduction threshold and for varying the width of the pulses of the pulse width modulator. Variation of the reference potential changes the brightness of the fluorescent lamp. The pulse width modulator duty cycle is inversely proportional to changes in the DC source voltage for maintaining constant lamp brightness with changes in the DC source voltage.

Abstract: A starting aid with an autotransformer arranged in a parallel manner with respect to a gaseous discharge lamp is disclosed. The parallel arrangement lowers the current carrying capabilities necessary for the starting aid to handle relative to a serial arrangement. The parallel arranged starting aid by appropriate selection of its component values provides for the application of the starting aid to various sources of alternating current used for the excitation of a variety of types of gaseous discharge lamps.

Abstract: An improved ballast circuit for fluorescent lamps includes an electronic bilateral triggering device and a capacitor connected in series combination across the secondary winding output terminals of a ballasting transformer and in shunt with the fluorescent lamps. The triggering device and the capacitor operate to produce high frequency oscillations superimposed on the high AC voltage applied across the lamp cathodes to improve the capacitive coupling between the lamps and their mounting fixture during starting. The triggering device becomes nonconductive to effectively remove itself and the capacitor from the starting circuit while the lamps are lit.

Abstract: An improved ballast (10) that operates an ionic conduction lamp (40) such as a conventional phosphor coated fluorescent lamp. The ballast (10) comprises an ac/dc converter that converts an a-c power signal to a d-c power signal that drives a transistor tuned-collector oscillator (30). The oscillator is comprised of a high-frequency wave-shape generator (32) that in combination with a resonant tank circuit (36) produces a high-frequency signal that is equivalent to the resonant ionic frequency of the phosphor. When the lamp (40) is subjected to the high frequency, the phosphor is excited which causes a molecular movement that allows the lamp (40) to fluoresce and emit a fluorescent light. By using this lighting technique, the hot cathode of the lamp, which normally produces a thermionic emission, is used only as a frequency radiator. Therefore, if the cathode were to open, it would have no effect on the operation of the lamp. Thus, the useful life of the lamp is greatly increased.

Abstract: A two-lead starter circuit for a gaseous discharge lamp is composed of only four components, namely a capacitor, a bilateral voltage-sensitive switch, a pulse transformer and a resistor. These components are connected in a series-parallel circuit arrangement which is both more economical and more reliable than prior-art two-lead starter circuits.

Abstract: A method of and a device for the operation of a high-pressure discharger lamp provided with a discharge vessel (3) which accommodates an ionizable filling and two electrodes (4, 5), between which electrodes in the operating condition the discharge takes place. The lamp is operated from a supply source which supplies a power of periodically alternating value. According to the invention, for each power frequency .nu..sub.i (i=1,2, . . .) the relation .nu..sub.i .gtoreq.60 .nu..sub.1 is satisfied, where .nu..sub.1 is the lowest frequency at which in the operating condition of the lamp standing pressure waves can occur in the discharge vessel (3). Thus, it is possible to operate the lamp so as to be free from arc instabilities due to standing pressure waves.

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.

Abstract: There is disclosed a device and process for starting up a fluorescent discharge lamp in which a high-frequency pulse is generated having narrow voltage peaks above the voltage required to start electric discharge and broad valleys, applied to the elements of the lamp to effect start up of fluorescence and, after start-up, the voltage automatically goes back to maintenance voltage having broad peaks at the maintenance voltage and relatively narrow valleys. The automatic cutback is effected by the load introduced by the electric discharge and the feedback from the emitter of the transistor used to generate the pulse. A capacitor is serially-connected in the lamp circuit to inhibit the flow of DC current therein.

Abstract: To suppress introduction of harmonics into the power supply network of a high-frequency operated fluorescent lamp, an input capacitor (C2) connected across a direct current supply (P1, P2) for a transistor push-pull high-frequency circuit--operating at between 25-50 kHz--has a pair of serially connected diodes (D4, D5) connected thereto. The junction point (M2) of the diodes is connected via a coupling capacity (C7) to a common junction (M1) of the push-pull connected transistors (T1, T2). The power line circuit has a line choke (L2, L2') connected, either in advance or behind a rectifier (G1) supplying direct current to the transistor push-pull circuit. The circuit effectively suppresses harmonics, particularly the third harmonic, without introducing additional losses in the circuit, especially if a further capacitor (C8) is connected in the resonance circuit of the fluorescent lamp and to the diode junction (M2) between the two diodes (D4, D5).

Abstract: In a rapid restrike starter embodying the invention, a starting circuit applies a series of high voltage pulses, each of approximately the same magnitude through a transformer in series with the ballast and the high intensity discharge lamp to be started, a voltage triggered switch such as a sidac is used to turn the starting circuit on at a predetermined voltage, a second voltage triggered switch connected in series with the first acts in conjunction with a circuit comprised of capacitors and resistors to cause a series of resonant symmetric pulses each approximately the same magnitude as the initial pulse, the use of this oscillating pulse provides restrike performance at approximately two-thirds the pulse voltage otherwise required which improves long term reliability by decreasing the likelihood of socket arcing and insulation breakdown.

Abstract: A circuit for operating a discharge lamp at a low frequency AC voltage while repetitively interrupting at a high frequency the voltage component to be applied to the lamp. The circuit includes at least one switching transistor for repetitively interrupting the voltage to be applied to the lamp at the high frequency, for example, 40 KHz so as to allow the use of a light and less bulky inductor as the current limiting conductor to be connected in series with the lamp. A bridge inverter is provided to have at least one pair of switching transistors for alternately reversing a DC voltage to apply the resulting AC voltage to the lamp at the low frequency, for example, 100 Hz low enough to stably operate the lamp without suffering from acoustic resonance. The high frequency component is bypassed through a bypass capacitor connected in parallel with the lamp.

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: A fluorescent lamp operating circuit includes a high frequency electronic ballast circuit for providing a controlled output to a fluorescent lamp load. A control signal is detected from the power line carrier which includes binary data indicative of the illumination level desired. The control signal comprises a multi-bit binary signal which is detected by the control circuit and used to control the frequency of the power supply circuit so that the fluorescent light illumination level may be dimmed over a wide range.

Abstract: Starting and operating apparatus for high intensity discharge lamps includes first and second pairs of terminals formed for connection to an AC source and a discharge lamp respectively, a series connect ballast means and inductor connected to one of said first pair and one of said second pair of terminals a bilateral switch shunted by a capacitor and in series with an AC impedance coupled to the inductor and to the other one of said first and second pair of terminals whereby relatively wide high voltage, high frequency pulse potentials for starting the discharge lamps are provided.

Abstract: The operation of the starting circuit is only allowed for a predetermined time period in response to a control signal which is generated either following the application of the alternating voltage to the input terminals of the lamp circuit at the beginning of a working period of the lighting installation including said lamp, or a predetermined delay after interruption of said alternating voltage due to a short power interruption. The operation of the starting circuit is not allowed if the lamp extinguishes due to an increase of its voltage, thus avoiding attempts to re-start a defective lamp.

Abstract: A fluorescent lamp driver employs a saturable reactor switch for producing a high-frequency, substantially symmetrical drive signal for igniting and driving a fluorescent lamp. The drive signal is applied to the filaments of a fluorescent lamp using a resonant drive circuit whose components are series resonant near the frequency of the substantially symmetrical drive signal. Before ignition, the resonant drive circuit applies substantially the entire drive signal voltage in series with the filaments as well as across the fluorescent lamp. Thus, the filaments are heated to release electrons which ionize the inert gas to initiate a gas discharge in the lamp. The high-frequency drive signal thenceforth maintains the gas discharge without permitting time for the ionized gas to recombine between half cycles of energization.

Abstract: A dimmer for fluorescent lights utilizes a standard A.C. phase control at normal line A.C. frequencies to control the line power to the standard fluorescent light ballast and thereby control the illumination level of the light. During the "off" time of the A.C. line signal, a high frequency signal is applied to the ballast which supplies additional power through the ballast to the filament of the light but is substantially blocked by the ballast from the discharge portion of the light so does not substantially affect the illuminating output of the light.

Abstract: An arrangement including a frequency converter (4) and a discharge lamp (10) connected thereto wherein the frequency converter (4) is of a type whose output frequency is at least 80 kHz, while the lamp is a low-pressure sodium vapor discharge lamp. This lamp supply system provides a high luminous efficacy for the lamp.

Abstract: A lighting circuit for an electric discharge lamp according to the present invention is constructed in such a way that a switching device is provided at an output terminal of a high frequency inverter which produces a substantially sinusoidal output voltage, and that, by controlling this switching device, an output to the low pressure electric discharge lamp is stopped at the rising part of the abovementioned output voltage in its half cycle, while the output is supplied to the low pressure electric discharge lamp at the voltage level in the vicinity of the maximum instantaneous value thereof. By use of the high frequency inverter of a smaller capacity and less radio noise than those in the conventional device, the operating efficiency of the low pressure electric discharge lamp can be increased.

Abstract: A DC/AC converter provided with two transistors (11 and 20) alternately conductive to supply current to an inductively stabilized discharge lamp (16, 15) to be connected to the converter. The lamp is connected in series with a primary winding (12) of a current transformer. A secondary winding (30, 31) of the transformer is connected to a timing circuit (32 to 35; 32' to 35') of a control device of the transistors. The timing circuit is provided with voltage-dependent elements, i.e. Zener diodes (35, 35'). The combination of the current transformer and the Zener diodes causes the frequency of the converter, during starting of the lamp, to be larger than during the operating condition of the lamp. This insures that the lamp electrodes are properly heated before the lamp ignites.

Abstract: The above and other objects, advantages and capabilities are achieved in one aspect of this invention by a drive scheme for a plurality, that is, for N, where N-2, flourescent lamps. The drive circuit comprises (N+1) pairs of output terminals, each comprising associated first and second individual terminals. An output transformer is coupled at one end to the (0,1).sup.1 terminal and at another end to the (0,1).sup.N+1 terminal. N impedance elements, typically capacitors, are coupled across associated pairs of lamp filaments in a fashion whereby each impedance element is coupled at one end to the second terminal of one pair and at another end to the second terminal of the succeeding pair. To wit: The first impedance element is coupled between the second terminal of the first pair, and the N.sup.th element is coupled between the second terminal of the N.sup.th pair and the second terminal of the (N+1).sup.th pair.

Abstract: A device for starting and operating gas discharge tubes including a DC-to-AC inverter which generates a low voltage or a high voltage at an output thereof in response to first or second input signals, respectively. The output of the inverter is connected to a gas discharge tube and sensing means generates a signal proportional to the current flow through the tube. Suitable means provides a trigger or synchronizing signal to a driver. The driver, responsive to the sensed output signal and the trigger or synchronizing signal, generates a drive signal synchronized with the trigger or synchronizing signal and having a duration inversely related to the magnitude of the current flowing through the gas discharge tube. A high voltage switch applies a second input signal to the inverter in response to the drive signal to provide a decreasing high voltage duration during successive cycles of the inverter as the tube begins to conduct current.

Abstract: A thyristor/capacitor inverter bridge energizes the lamp circuit with a high frequency oscillating voltage derived from full-wave rectified line voltage. Lamp current is regulated by a commutation circuit which is synchronized with zero crossings of the thyristor current. When power is first applied, an initialization circuit initiates a time delay to permit lamp warm up and then enables the high frequency inverter to begin energizing the lamp load. A re-strike circuit generates pulses coupled to the commutation circuit to re-start it when the rectified line voltage falls below that which is necessary to sustain oscillation of the inverter. Fault detection circuits are included for detecting faults such as loss of primary power, thyristor over-voltage, and thyristor over-current for taking corrective action, such as inhibiting the inverter and commencing a new initialization sequence.

Abstract: An electronic ballast for energizing fluorescent lamps comprising a converter including a rectifier and a filter for converting an alternating source voltage into a direct current voltage, a network including first and second switching transistors, a tank circuit having a primary winding of a transformer, a secondary winding of the transformer for providing feedback of a portion of the voltage developed across the tank circuits and a bias circuit coupled between the opposite ends of the secondary winding and the emitters of the transistor for alternatively applying bias to the transistors, the network serving to convert a direct current voltage into an amplified sinusoidal voltage having a high frequency, and fluorescent lamps connected in a series configuration coupled across the primary winding.

Abstract: A high frequency fluorescent lamp circuit for operating two or more fluorescent lamps connected in electrical series. A capacitor is connected between one end of the series-connected lamps and electrical ground and/or an electrically conductive fixture for holding the lamps. This causes the lamps to start more reliably and at a lower starting voltage.

Abstract: A discharge lamp lighting device comprises a serial connection of an inductive ballast and a discharge lamp connected across an A.C. power source, and a switching circuit connected substantially in parallel to the discharge lamp and operable to carry out two consecutive ON/OFF operations in the beginning of each half cycle of the A.C. power source while the discharge lamp is in its lit condition. The switching circuit preferably comprises a full-wave rectifier connected substantially in parallel to the discharge lamp, a switching element connected between the output terminals of the rectifier, and a control circuit for controlling the ON/OFF operation of the switching element.

Abstract: A stabilized dimming circuit for an electronic ballast system. The dimming circuit includes a transformer having a variable inductance primary included as a part of a feedback loop comprising a push-pull inverter and an output transformer for supplying a drive signal to a lamp filament. As the inductance of the primary is varied (decreased), the amount of feedback applied to the inverter is varied (increased) and the lamp brightness dimmed accordingly. The secondary of the dimming transformer is included in a loop that is completed by a secondary winding of the output transformer and a lamp filament. Because the voltage induced in the secondary of the dimming transformer is held relatively constant, the voltage applied to the filament is stabilized in spite of varations in the amount of power supplied to the lamp.

Abstract: In order to effect stabilized dimming of a fluorescent lamp, that is, in order to vary the power level supplied the lamp while maintaining a substantially constant filament voltage, a first, variable, inductance is included as an element of oscillator (inverter) feedback loop. The voltage across the variable inductance is clamped and coupled to a second inductance so that a voltage appears across the second inductance in proportion to the voltage appearing across the variable inductance. The voltage appearing across the second inductance is applied to the lamp filament so as to constitute a dominant component of the lamp filament voltage.

Abstract: An electronic ballast employs an electronic inverter which drives a main power transformer across the output of which terminations are connected for a plurality of fluorescent lamps. A high impedance capacitor is connected in parallel across at least one and less than all of the fluorescent lamps. An auxiliary transformer is interposed between the output of the main power transformer and the cathode elements of the fluorescent lamps. Upon start-up, the high impedance capacitor initially creates a bypass around lamps with which it is connected in parallel to thereby apply the entire high voltage output of the power transformer to start the remaining lamps. Once these lamps are started the voltage drop thereacross is reduced to allow the high voltage output to bypass the high impedance capacitor and start the lamps connected in parallel therewith. The auxiliary transformer provides good magnetic coupling and low voltage to the cathode elements of the fluorescent lamps.

Abstract: Method for heating and igniting as well as controlling or regulating the light flux of low-pressure gas-discharge lamps, including a ballast having an inverter for generating an ac voltage at inverter output terminals from a dc voltage generated from an ac supply network by rectifiers, the ac voltage having a frequency higher than line frequency, the ballast including an L-C circuit having a capacitor and a first choke connected between one of the inverter output terminals and a lamp, the lamp being in turn connected to another of the inverter output terminals, a second choke shunted across the lamp, the charge of the capacitor being constantly reversed by the inverter with controllable frequency, which comprises changing the inverter frequency in accordance with the desired light flux with constant ac voltage amplitude at the outputs of the inverter, tuning the frequency, voltage, capacitor, first choke and second choke to each other, circulating substantially the required heating current through heating coi

Abstract: At least one high intensity discharge lamp is utilized in the growing of plants within a growth chamber. The lamp is connected to a power supply that provides pulses of alternating polarity to the lamp through a ballast which first provides a relatively high inductance and which after lamp current has reached a certain level provides a matched T-configured impedance network. Initially, a microprocessor, there being one for each lamp ballast (or one for a group of lamps), closes a switch to connect the lamp to the power supply through a step-up transformer, the secondary winding of which during start-up contributes to the high impedance condition during the early stage of lamp operation and which is thereafter part of the T-network. When the lamp is ionized, both the lamp current and the lamp voltage are sensed.

Abstract: A discharge lamp lighting circuit system comprises a discharge lamp, an intermittent oscillation circuit, and an arrangement for controlling the energy supplied for lighting the discharge lamp with a high power factor. The intermittent oscillation circuit is energized by a low frequency a.c. power supply, i.e. a commercial alternating current power supply, for intermittently generating a high frequency high voltage in each half cycle of the alternating current of the low frequency a.c. power supply. By supplying the low frequency alternating current voltage and the intermittent high frequency high voltage to the lamp the discharge lamp is reignited in each half cycle of the a.c. of the low frequency alternating current power supply and the lit state of the discharge lamp is sustained by the low frequency alternating current voltage.

Abstract: In a high pressure discharge lamp apparatus comprising a discharge tube and a current limiting device connected in series, an over-current protecting semiconductor switching device such as a triac (TC) is further connected in series to said discharge tube,the triac (TC) being controlled of its firing angle responding to an output of a current detection circuit which detects a change of the lamp current through a change of the lamp voltage, anda pulse generator is further connected in parallel to the discharge tube and gives reignition pulse thereto at least during the zero-current period in each cycle of the lamp current.

Abstract: A parallel circuit of a capacitor and a switching element is connected to a hot cathode discharge lamp lighting device using a high frequency and high voltage generating means for permitting the flow of current into the filaments of the hot cathode type discharge lamp only at the lamp starting time. The switching element of the parallel circuit is a current controlled resistance element, such as a switching semiconductor, having a break-over voltage V.sub.BO lower than the capacitor terminal voltage during the initial ignition period and higher than the capacitor terminal voltage during the reignition or operation period, whereby the filament current to the discharge lamp may be used for preheating of the filament in the initial ignition period. The filament current may be stopped or reduced by turning off of the switching element by raising the terminal voltage of the capacitor in the reignition period during normal operation.

Abstract: A discharge lamp starting device such as for a fluorescent lamp in which a nonlinear capacitor is connected in parallel with a discharge lamp with a Zener diode connected in series with the nonlinear capacitor. A semiconductor switching device, such as a diode thyristor, is connected in parallel with the discharge lamp. Due to the presence of the Zener diode, the semiconductor switching device can have a wide range of threshold voltage so that the cost of the device is low.

Abstract: A converter circuit for addition to the existing lamp operating circuitry of a high pressure mercury lamp consisting of an existing series ballast inductor and a power factor connecting capacitor connected across the input terminals of the existing lamp operating circuit includes inductance arranged to be connected to the ballast inductor so as to adjust the resultant series inductance to a value suitable for a sodium lamp, and an igniter portion coupled to the converter inductance. The igniter portion operates to apply ignition voltage to the sodium lamp during at least part of the time that the converter circuit is supplied with power. Protective circuitry is coupled to the converter inductance to block or limit high frequency voltage pulses which could otherwise reach the ballast inductor.

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: Starting and operating circuit for gaseous discharge lamps has device for quickly re-starting extinguished lamps while still hot. Circuit comprises a source of alternating current, an inductive regulator ballast having its input connected to the alternating current source, and a gaseous discharge lamp connected to the output of the ballast, a sine wave oscillator circuit having its input connected to the current supply and having its output connected to a transformer connected in series between the ballast and the lamp for stepping up and applying voltage to a lamp, the oscillator circuit comprising a transistor switch and an oscillator transformer connected to the step-up transformer for producing a high voltage, high frequency sine wave for starting and re-starting the discharge lamp. The operation of the oscillator circuit is improved by a turn-off circuit comprising series-connected diode and inductor connected to the transistor and the oscillator transformer.

Abstract: A circuit for starting and operating a low-voltage fluorescent lamp from a 120 volt AC supply. The circuit includes a choke type ballast connected in series with the lamp and inductively coupled to a pulse train generator comprising an RC energy storage circuit connected across the line and a voltage sensitive transistorized relaxation oscillator having a divider network for sensing lamp voltage. In a preferred embodiment the circuit is employed in a preheat mode of operation in combination with an electronic starter circuit comprising a PTC resistor, silicon diode and SCR series connected across the lamp.

Abstract: Disclosed is an arc discharge lamp starting device which comprises a starting aid circuit connected in parallel to an arc tube and disposed within an outer envelope. This starting aid circuit comprises a thermal switch, a heater and a resistor. This thermal switch includes contact rods having a high melting point and a small work function and a bimetal plate.In this arc discharge lamp starting device, since the time of duration of the chattering phenomenon caused between the contact rods is very long, the arc discharge lamp can be started assuredly by this starting device.

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.