Abstract: A non-blinking direct current fluorescent lamp circuit includes a switch, a bridge rectifier, a voltage regulation circuit, a filter capacitor, an ignition circuit, a contact points converter, a ballasting circuit, and a pole exchange circuit. The switch is a common switch or a contact switch circuit. Thus, the non-blinking direct current fluorescent lamp circuit does not produce electromagnetic radiation, has a steady illuminance, can be started at one time, has a higher working efficiency, can save the energy, can be worked safely, has a higher reliability, and has a longer lifetime.

Abstract: A DC/AC converter circuit structure for driving a plurality of cold cathode fluorescent lamps is described. A common-mode choke is used between the cold cathode fluorescent lamps. The common-mode choke balances the currents respectively flowing through the cold cathode fluorescent lamps.

Abstract: A flickering mode control system, for operating a high intensity discharge lamp at a flickering mode, comprises an output power controllable transformer and a flickering control unit. The flickering control unit outputs a power modulation signal to a switch the output power controllable transformer for determining a power of a direct current signal output from the output power controllable transformer. In a relatively dim state of the flickering mode, the high intensity discharge lamp has a low enough illumination, resulting in that it looks like the high intensity discharge lamp is completely extinguished. Actually, the high intensity discharge lamp still remains illuminated even in the relatively dim state of the flickering mode. Therefore, the flickering mode is realized without the use of a hot restike ignitor, thereby increasing a lifetime of the high intensity discharge lamp and its operation safety.

Abstract: A method an apparatus for efficiently driving a low-voltage device from a wide-range input supply uses and inductor and a diode coupled in parallel to provide a high-efficiency energy storage circuit. The parallel diode/inductor circuit is coupled to a switch for intermittently supplying a current to maintain a level of energy storage in the circuit. The switch is coupled to a control circuit for controlling the switch. The external device be a relay and the inductor may be a coil of the relay. The external device may be one or more LEDs connected in series and the diode may be the series LED circuit. The control circuit may include a fault-tolerant synchronization input for connection to multiple driver circuits, whereby audible noise produced by beat frequencies between the relays is eliminated.

Abstract: An illumination system of the invention comprises: a first illumination unit comprising a pair of power supply contacts for connection to a commercial AC power source, a light source connected between the pair of power supply contacts, a control circuit connected in series to the light source to control electric current flowing through the light source, and a connection cord connected to the light source; and a second illumination unit comprising a light source and a connection cord connected to the light source, wherein the connection cord of the first illumination unit and the connection cord of the second illumination unit are connected to each other so that the light source of the first illumination unit and the light source of the second illumination unit are connected in parallel to each other.

Abstract: A ballast includes a rectangular wave generating circuit that generates a rectangular wave signal; a driving signal generating circuit supplied with the rectangular wave signal and a dimmer signal of a PWM waveform of a frequency lower than that of the rectangular wave signal and outputting a driving signal of an output obtained by extracting the rectangular wave signal for a period corresponding to “on” period of the dimmer signal; a pulse transformer which is supplied with a rectangular wave voltage based on the driving signal, step up the rectangular wave voltage and applying it to a discharge lamp. A rectangular wave reset circuit is provided so as to reset the generation of the rectangular wave signal at a rising of the dimmer signal. The driving signal generating circuit extracts the rectangular wave signal for a period starting from when the dimmer signal is turned on, until a time at which the dimmer signal and the rectangular wave signal are both off.

Abstract: A method an apparatus for efficiently driving a low-voltage device from a wide-range input supply uses and inductor and a diode coupled in parallel to provide a high-efficiency energy storage circuit. The parallel diode/inductor circuit is coupled to a switch for intermittently supplying a current to maintain a level of energy storage in the circuit. The switch is coupled to a control circuit for controlling the switch. The external device be a relay and the inductor may be a coil of the relay. The external device may be one or more LEDs connected in series and the diode may be the series LED circuit. The control circuit may include a fault-tolerant synchronization input for connection to multiple driver circuits, whereby audible noise produced by beat frequencies between the relays is eliminated.

Abstract: A method is disclosed for stabilization of the radiation output of a gas discharge-coupled radiation source in pulsed operation, particularly of an EUV source based on a gas discharge. The object of the disclosed invention is to find a novel possibility for stabilizing the radiation output of a gas discharge-coupled radiation source in pulsed operation which allows the pulse energy to be regulated on the basis of pulse energy fluctuations of the radiation emission detected through measurements without requiring regular calibration measurements of the E(U) curve in the stationary operating regime with continuous pulse sequences.

Abstract: A power supply circuit for a cold-cathode fluorescent lamp (CCFL). The power supply circuit converts a DC voltage to a high AC voltage for driving the CCFL. The power supply circuit includes: a switch; a switch control circuit for controlling the switch; a transformer for stepping up the voltage; an energy-preserving unit coupled to the transformer and the DC voltage output circuit; a first diode coupled to the transformer, the energy-preserving unit, and the switch; and a decoupling capacitor coupled to the transformer for outputting the high AC voltage.

Abstract: Timing of zero voltage in zero-voltage detector for detecting zero voltage of a commercial power supply 1 is predicted and input from the zero-voltage detector 6 is received only for a given time before and after the predicted timing, whereby overvoltage and overcurrent caused by a zero point shift can be prevented. Thus, it is provided a magnetron drive power supply which is excellent in stability for change in the power supply environment such as noise or instantaneous power interruption.

Abstract: A capacitor C1 and a switch element SG are provided in the primary side of a transformer TT in a start-up circuit 5. Charge stored in the capacitor C1 is discharged when the switch element SG is turned on. A capacitor C2 and a rectifying element D2 are inserted between the output of a DC-AC converting circuit 4 and ground. The capacitor C2 is charged by a current flowing in the forward direction of a rectifying element D2. A capacitor C3 and a rectifying element D3 are inserted between a node between the secondary winding T2 of a transformer T and a rectifying element D1, which form a DC-DC converting circuit 3, and a node on a line connecting the second capacitor C2 and the rectifying element D2. The capacitor C3 is charged by a current flowing in the direction as defined by the third rectifying element D3. A node between the capacitor C3 and the rectifying element D3 is connected to a voltage supplying line to the capacitor C1 of the start-up circuit 5, whereby its charge is stored.

Abstract: Disclosed is an energy-saving dimming apparatus connected to a power source and a load, and adapted to control a luminance of the load. The dimming apparatus includes a first switching unit connected to a power supply line, a second switching unit connected between the first switching unit and a ground line, a microprocessor for generating a square-wave pulse having a duty cycle according to a luminance control command, a switch driver for generating switching control signals respectively adapted to perform alternate ON/OFF controls for the switching units in accordance with the square-wave pulse inputted thereto, and a low-pass filter for removing ripple components contained in a voltage applied to the load via the first switching unit.

Abstract: A gas-discharge lamp lighting apparatus includes: a power conditioning unit regulating power supplied from a power source, and outputting voltages with mutually different levels from two output terminals; a switching circuit unit coupled between the output terminals of the power conditioning unit and including at least one switching element; and a pulse transformer generating a high-voltage pulse, placed in a circuit connecting the output terminals of the switching circuit unit and a gas-discharge lamp. A first terminal of a primary winding of the pulse transformer is connected to a first output terminal of the power conditioning unit via a first output terminal of the switching circuit unit, and a second terminal of the primary winding is directly connected to a second output terminal of the power conditioning unit.

Abstract: The present invention is a high frequency, high efficiency start and quick restart system including a lamp. It includes hook ups for connecting and applying a power input to circuitry; a switch for switching a lamp on and off, and is connected to control power; auto-ranging voltage control circuitry; and a three stage power factor correction microchip controller. The microchip controller is a Bi-CMOS microchip. There is also a feedback current sensor; a power factor correction regulator; bulb status feedback; a bulb voltage controller; a conditioning filter; a half-bridge; a DC output inverter; and, output and connection for, as well as, a sodium discharge lamp.

Abstract: A (vibration) stopper protection circuit of an electronic ballast for fluorescent lamps. The electronic ballast has an inverter to convert a direct current source into a square-wave source, and to provide the square-wave source to multiple lamp tubes. The stopper protection circuit has several harmonic oscillating capacitors, a sampling transformer, a protection signal processing circuit and a stopper circuit. The sampling transformer samples a normal sampling signal and an error sampling signal when the lamp tubes are normal or out of order, respectively. The protection signal processing circuit outputs an error signal while receiving the error signal. While receiving the error signal, the stopper circuit outputs a stop signal to the inverter, so that the inverter stops operating.

Abstract: A brightness-regulating voltage-transforming circuit includes a pulse-width modulator (PWM); a transformer connected at a secondary side to a high-pressure discharge lamp; a voltage-transforming circuit having two transistors connected at bases to outputs of the PWM for the latter to control working frequencies thereof; and a brightness control circuit including a transistor connected at a collector to a middle tap of the transformer and at a base to the PWM for the PWM to control the lamp brightness, and a diode connected at an end to a juncture of a primary side of the transformer and an end of a buffer inductance, and at another end to a voltage source. When the transistor of the brightness control circuit is cut out, energy stored in the buffer inductance is regenerated and sent to the voltage source via the diode, enabling the lamp to have reduced noise interference and increased working efficiency.

Abstract: In an electronic ballast for operating a discharge lamp at a high frequency, a single feedback and a double pump feedback are implemented in a combined way. The resulting electronic ballast combines the advantageous of a simple topology with favorable properties with respect to power factor, THD, efficacy, crest factor of the lamp current and EMI restrain.

Abstract: A light-emitting element drive circuit is provided whereby level variation of the drive current can be suppressed. This circuit is provided with a detection circuit 4 that detects the DC current component I6′ of high-frequency current I4 (I5) flowing through a second current mirror circuit 2, and an adjustment circuit 5 that subtracts the DC current component I6′ detected by the detection circuit 4 from the DC current I1 (I7) flowing through line 1B of first current mirror circuit 1. Thus, level variation of the drive current IL′ which represents the superposition of the DC and high-frequency can be suppressed.

Abstract: A ballast circuit with an ignitor circuit for starting serially connected HID lamps is provided. The ballast circuit comprises an electromagnetic ballast arrangement for driving the lamps and an ignitor circuit for starting the lamps. In an embodiment of the invention, the ignitor circuit comprises a voltage-breakover device, a first capacitor, a resister, a pulse autotransformer, and a second capacitor. A pulse autotransformer is associated with each subsequent lamp after a first lamp of the serially connected lamps.

Abstract: An arrangement in connection with a discharge lamp, the arrangement comprising an electronic ballast for igniting and burning the discharge lamp, and a voltage control device arranged to modify supply voltage of the ballast. The voltage control device is further arranged to include a power control signal in the supply voltage. The arrangement further comprises a power filter and a control filter for separating the power control signal from the supply voltage, the ballast being responsive to the power control signal in order to control the level of light of a fluorescent tube.

Abstract: An electronic ballast for discharge lamps with electrode filaments. The ballast contains a frequency-selective device, which suppresses an auxiliary heating current in the electrode filaments during operation of the lamp. Heating of the electrode filaments is possible only within a narrow frequency band.

Abstract: A discharge lamp lighting apparatus has a DC power supply, generating a direct current voltage, an inverter circuit, switching the direct current voltage at a high frequency, and including one bipolar transistor, which is turned on by a feedback signal of the high frequency voltage and turned off by an off-switching signal of a control circuit, and a resonance circuit resonated by the switching operations, a discharge lamp, operated by the high frequency voltage, and the control circuit, provided with a timer regulating operation modes of the discharge lamp, and an oscillator generating the off-switching signal according to each operation mode of the discharge lamp.

Abstract: This invention relates to dimmable electronic ballasts for particular use with fluorescent lamps.

Abstract: An electronic ballast with lamp run-up current regulation. In one aspect, the electronic ballast comprises an input stage coupled to an AC source, the input stage converting an AC voltage to a direct current bus voltage, an output stage having inputs coupled to the bus voltage and outputs connected to a lamp, the output stage providing (i) power to the lamp so as to produce a lamp voltage and lamp current in a steady state mode of operation, and (ii) a lamp run-up current to the lamp during a run-up phase of the operation of the lamp, and a current regulation circuit for regulating the lamp run-up current so that the lamp run-up current exceeds a steady state lamp current value, and increases if either the bus voltage increases or the lamp voltage decreases. The output circuit comprises a main high-frequency switching inductor through which an inductor current flows wherein the lamp current is based upon the inductor current.

Abstract: A kind of energy-saving fluorescent luminaire complying to Energy Star criteria, consisting of electronic ballast and pre-heat form fluo bulb. Each filament is parallel connected with a voltage-stabilizer, and said ballast has a high position trigger circuitry for increasing the peak voltage of oscillation output. When the filament is un-broken, said ballast started the bulb per traditional pre-heating form through the thermal resistor. When the filament is broken, since the starting capacitor can still be charged, the bulb can be started by higher voltage of the cold cathode form. And the resonant circuitry formed by choke and the starting capacitor raises said peak voltage 2 or 3 times thus to excite and start the bulb. Therefore, no matter the filament is broken or not, the coating on the filament can be completely used out. This in return will elongate the lamp-life to 2 or 3 times as ever.

Abstract: An electronic ballast comprises a direct current power supply configured to provide a direct current voltage, an inverter circuit for converting the direct current voltage to a high-frequency alternating current and a load circuit. The inverter circuit includes a switching element and a resonance circuit, and is connected in parallel to the direct current power supply. The resonance circuit includes a resonance inductor, a resonance capacitor, and a first winding of an electrical insulating transformer having first and second windings.

Abstract: A description is given of an operating method for a discharge lamp with dielectrically impeded discharges and also a corresponding ballast and illumination system. The invention is directed at withdrawing the external lamp voltage across the discharge lamp in order to produce a back ignition in the lamp by virtue of an internal counterpolarization. The back ignition improves the efficiency of the lamp operation and makes it possible to construct a very small, lightweight ballast.

Abstract: A discharge lamp lighting apparatus includes a discharge lamp having a pair of electrodes, at least one electrode being placed on an outer surface of a discharge vessel containing an inert gas-dominated discharge agent, a high frequency generator having an output transformer and a switching apparatus, a high frequency operation detector for detecting a high frequency and outputting a high frequency operation detection signal, a controlling responsive to the high frequency operation detection signal for performing a feedback control to the switching apparatus to make the high frequency operation detection signal a first level and protecting the apparatus when the high frequency operation detection signal is changed to a second level, and a no-load detector for forcefully changing the high frequency operation detection signal supplied to the controller to the second level when detected the nonleaded state.

Abstract: This invention relates to circuits for operation over a range of voltages, more particularly for a vehicle lamp circuit that provides lighting over a range of voltages. The invention provides a circuit that allows the operation of an LED array lamp over a range of voltage. This is achieved by making use of three-terminal adjustable regulators. One of the three-terminal regulators is configured as a voltage regulator. It regulates the voltage by a connection to a voltage divider. A second three-terminal regulator is connected to the voltage regulator. The second regulator is configured to be a current regulator with the current set by one resistor. This circuit can be further modified with additional adjustable three-terminal regulators to increase in functionality.

Abstract: The invention relates to a supply coupling of a fluorescent lamp used for supervising the operation and condition of a lamp circuit, particularly a supply coupling in connection with an electronic coupling device wherein the power required by the lamp circuit is supplied to the coupling by a transformer. The supply coupling comprises a supply transformer (T1), a resonance circuit comprising the secondary coil (N2) of the transformer (T1) and a capacitor (C1) connected in parallel with the secondary coil, and a fluorescent tube (Lamp 1) connected in parallel with the resonance circuit and comprising fluorescent cathodes (F1, F2).

Abstract: A discharge lamp which eliminates the large line noise that forms in discharge lamps during startup while preventing heat loss in the transformer by providing a pair of opposed electrodes for the main discharge and an auxiliary electrode arranged such that it does not come into contact with the discharge space for the main discharge, a feed circuit for supplying the discharge current to the electrodes for the main discharge, and a starter circuit which produces a high voltage between one of the electrodes for the main discharge and the auxiliary electrode. The high voltage generating part of the starter circuit which includes at least a high voltage transformer that is separated from the feed circuit while the discharge lamp and the high voltage generating part are formed as an integral unit.

Abstract: A method of color mixing a very high frequency operated HID lamp which effectuates power modulation to the HID lamp at a frequency of the second longitudinal acoustic mode by modulating the duty cycle of a half bridge configured resonant inverter. The duty cycle is modulated with a modulation frequency which is substantially one-half the frequency of the second longitudinal acoustic mode of the HID lamp. In operation, exciting the second longitudinal acoustic mode of the HID lamp with the half bridge configured resonant inverter operated with a modulated duty cycle achieves color mixing along a vertical axis of the HID lamp.

Abstract: A lamp stand with multi-stage light modulation includes plural resistors annularly arranged to form a circular space. The resistors have terminals soldered on the outer walls of U-shaped contact blades, with an empty position terminal provided in the circular space. A light-modulating controller extends in the lamp stand, having a rotor formed with plural slopes on an outer wall for rotor copper strips to rest thereon. A trigger diode is connected to the gate of a triac AC switch and a capacitor is connected to the trigger diode and the paralleled terminals of the resistors and to the main terminals of the triac AC switch. The light-modulating controller is rotated to let the rotor copper strips contact the contact strips of the resistors to turn on power and charge the capacitor. Different resistance values change the breakdown speed of the DIAC and control the gate of the TRIAC to change the voltage effective value of the lamp, thus reaching a goal of light modulating.

Abstract: An inverter is powered from a DC voltage whose instantaneous absolute magnitude is equal to that of the AC power line voltage except for being prevented from falling below a level equal to half the peak of the power line voltage. The inverter's output is loaded via a series-tuned high-Q LC circuit. Two fluorescent lamps are loading the secondary winding of a transformer whose primary winding is connected across the capacitor of the LC circuit. The magnitude of the voltage present across the capacitor is normally limited by the loading of the fluorescent lamps. However, with the lamps removed, if not expressly prevented from doing so, the magnitude of the voltage across the capacitor will increase to a destructive level due to Q-multiplication.

Abstract: A lamp ballast system includes a frequency inverter unit having a driver circuit connected to a voltage multiplying unit so as to receive a voltage-multiplied direct current output therefrom, an oscillator circuit connected to and driven by the driver circuit so as to generate a high-frequency oscillating current output, and a converter circuit connected to the oscillator circuit and operable so as to convert the oscillating current output into a stable high voltage, high frequency alternating current output. A phase correction unit interconnects the converter circuit and the lamp load, and includes at least one set of a transformer and a capacitor that are connected in series.

Abstract: A discharge lamp operating apparatus includes a DC power circuit portion for outputting a DC voltage; an inverter circuit including a switching element provided with a control terminal for converting an output from the DC power circuit portion to an AC voltage; a control terminal driving circuit for controlling the switching element provided with a control terminal to be on or off; and a resonant load circuit including a discharge lamp, a first inductor and a first capacitor. The control terminal driving circuit includes a drive winding mutually coupled to the first inductor; a series circuit of a voltage clamp element and an impedance element, the series circuit being connected to at least one end of the drive winding, and the control terminal driving circuit is configured to control the switching element provided with a control terminal to be on or off by a voltage generated at the drive winding.

Abstract: A discharge-lamp illumination circuit has a DC power supply circuit, a DC-AC conversion circuit, and a control circuit for controlling a voltage from the DC power supply circuit. The DC power supply circuit has a transformer and a first switching element connected in series with a primary coil of the transformer. The activation/deactivation of the first switching element is controlled by the control signal from the control circuit. The transformer is equipped with secondary coils equal in number with the discharge lamps. Each secondary coil is equipped with a second switching element whose activation or deactivation is controlled by a signal from the control circuit. The secondary coils provide different voltages by means of control of the second switching elements.

Abstract: A method and a system for controlling a RBG based LED luminary which tracks the tristimulus values of both feedback and reference whereby the forward currents driving the LED luminary are adjusted in accordance with the errors between the feed tristimulus values and the reference tristimulus values until the errors are zero.

Abstract: It is provided a magnetron drive power supply wherein a series connection body of first and second semiconductor switch elements that can be brought into reverse conduction and a series connection body of first and second diodes are connected in parallel, first and second capacitors are connected in parallel to the first and second diodes, a series circuit of a commercial power supply and a primary winding of a high-voltage transformer is connected between a connection point of the first and second semiconductor switch elements that can be brought into reverse conduction and a connection point of the first and second diodes, and output of a secondary winding of the high-voltage transformer energizes a magnetron through a high-voltage rectification circuit.

Abstract: A light source device for use in image readout devices capable of light emission in which a dielectric barrier discharge fluorescent lamp is synchronized with an external synchronization signal without attendant fluctuation in optical power. A phase comparator compares the oscillation signal phase of a variable frequency oscillator divided by a frequency divider with an external synchronization signal. The phase comparator controls the oscillation frequency of a variable frequency oscillator as a function of the phase difference. Consequently, the oscillation phase of the variable frequency oscillator is phase locked by the external synchronization signal. The oscillation signal of the variable frequency oscillator is input to the gate signal generation circuit, and the switch devices of an inverter circuit are opened and closed by the output of a gate signal generation circuit.

Abstract: The invention concerns a circuit arrangement for igniting and operating an electrodeless gas discharge lamp by means of a high operating frequency drive voltage, comprising a half-bridge commutator having two switching elements each having an emitter electrode and a control electrode. The said switching elements are alternately switched to a conducting state by means of a resonant control circuit, which is coupled to an oscillator via a transformer. The said resonant control circuit comprises capacitor means forming part of said oscillator and a driver stage driven by an oscillator, the driver being of the class-E type. A DC supply voltage is supplied to the driver via a current-limiting circuit.

Abstract: The invention improves an operating method, already described in the prior application 198 39 329.6, for a silent discharge lamp L, in which, using the forward transformer principle, a voltage pulse effecting a forward ignition is impressed from a primary circuit P via a transformer T into a secondary circuit S containing the silent discharge lamp L, and the secondary circuit S thereafter executes a half wave which, as a consequence of the polarization, leads to a back ignition in the discharge lamp L. The improvement consists essentially in that an inductance of the transformer T which governs a transformer current is temporally varied.

Abstract: The present invention is directed to accurately sensing and regulating lamp current, and thus lamp output, over a range of lamp outputs, down to and below 10% of total lamp output. Exemplary embodiments can be used with a single set of power elements to drive multiple lamps in either an isolated or a non-isolated condition.

Abstract: A push-pull inverter is supplied from an inductively current-limited DC voltage source by way of a center-tap on a transformer having significant inductance. This transformer inductance is parallel-coupled with a capacitance means. The inverter is made to self-oscillate through positive feedback provided by way of a saturable current transformer. The inverter frequency is determined by the saturation time of this current transformer, which saturation time is designed to be somewhat longer than the half-cycle period of the natural resonance frequency of the transformer inductance combined with the capacitance means. By controlling the length of this saturation time, the magnitude of the current provided to the fluorescent lamp is controlled, thereby permitting control of the light output in response to changes in the magnitude of the power line voltage.

Abstract: A ballast circuit for supplying AC voltage and current to a gas discharge lamp, mounted in a troffer having a ground connection, upon the application of DC voltage and current. The circuit comprises: a transformer including a first and a second primary winding; first and second transistors, each having base, collector and emitter terminals, wherein the base terminal of each transistor is coupled to a drive terminal of the second primary winding; a constant current flow network coupled to the drive terminal so as to maintain the circuit in an oscillating mode; the first primary winding configured to be coupled across the lamp such that a capacitance at a first end of the lamp relative to the transformer is equal to a capacitance at a second end of the lamp relative to the transformer; and a current supply source coupled to the troffer ground connection. The circuit is configured such that a net current induced via the lamp and the current supply source into the troffer is substantially equal to zero.

Abstract: The invention relates to a device (1, 14, 17) comprising: a terminal (2) for connection of the device to a power source; a rectifier (3) connected to the terminal; a half-bridge circuit (4) connected to the rectifier in order to generate an a.c. switching voltage, and having a half-bridge point (5); a control circuit (6) for controlling the half-bridge circuit; a power supply (7) for deriving a supply voltage for the control circuit from the switching AC voltage supplierd by the half-bridge circuit, said supply comprising a charging capacitor (10) connected to said half-bridge point; and a load circuit (8) connected to the half-bridge point, wherein the charging capacitor is connected to the half-bridge point through an impedance (13, 16).

Abstract: A circuit arrangement and control thereof for igniting a high intensity discharge (HID) lamp, for reducing the variation of the resonant ignition voltage under the parasitic capacitive loading condition, and for increased circuit stability. The high frequency ignition voltage is only applied to the lamp during an ignition phase. The variation of the magnitude of the resonant ignition voltage with respect to the parasitic capacitance at the lamp leads is minimized by inserting a damping resistor in series with the ignition resonant capacitor. In a normal operation after ignition, the charge and/or discharge current of the ignition resonant capacitor is bypassed through a bypass device instead of flowing through a current sense resistor, so that only a chopper current flows through a sensor by paralleling a relatively high impedance resistor with the sensor.

Abstract: In an electronic ballast, a half-bridge inverter is powered from a DC voltage and provides a 40 kHz squarewave inverter output voltage. The DC voltage is obtained via a pre-converter with a control input operative to permit control of the magnitude of the DC voltage. The 40 kHz squarewave inverter output voltage is applied across a series-resonant L-C circuit, thereby establishing a 40 kHz sinusoidal voltage across the L-C circuit's tank capacitor. By controlling the symmetry of the squarewave voltage, the magnitude of the 40 kHz sinusoidal voltage is regulated to be appropriate to instant-starting a gas discharge lamp. Each of several instant-start fluorescent lamps is series-connected with a capacitor, such as to form several lamp-capacitor series-combinations, each of which is connected across the tank capacitor, thereby to be properly ignited and powered from the magnitude-controlled 40 kHz sinusoidal voltage.

Abstract: A capacitively coupled fluorescent lamp package having a capacitively coupled fluorescent lamp having cylindrical ceramic tubes is disclosed. The lamp package further includes an electronic driver or inverter circuit for driving the lamp and supply nodes for receiving a supply voltage. The inverter circuit is a conventional inverter circuit, such as, for example, current-fed push-pull, voltage-fed push-pull, active clamped Flyback, and voltage-fed half-bridge inverter circuits, used in conventional CCFLs. A ballast circuit may be connected to the inverter circuit for properly ballasting the lamp.

Abstract: A driver for an EL lamp includes a voltage boost circuit and an H-bridge output having an AC diagonal and a DC diagonal. An EL lamp is coupled across the AC diagonal. A current path is coupled in series with the DC diagonal and limits current through the EL lamp. The current path is either internal or external to the semiconductor device implementing the driver.