Abstract: The present application discloses a method and apparatus for providing an isolated set point from an input signal. The set point can control the amount of power applied to a lamp via a lamp ballast. An AC output signal from the ballast powers a dimming circuit. The AC signal is coupled across an isolation transformer and subsequently converted into a DC signal. This DC signal is loaded by a variable resistor, which creates a voltage differential across the resistor. This voltage differential is then seen across DC input terminals of the ballast, and it is across the DC input terminals that the set point is created. By varying the value of the resistor, the ballast set point is varied ultimately changing the power that is applied to the lamp by the ballast.

Abstract: An apparatus for driving a backlight includes a controller for driving a lamp; a limiter for preventing the controller from driving the lamp during a contact condition of the lamp; and means for disabling the limiter during a first time of the controller, wherein the controller drives the lamp from a zero condition to the contact condition during the first time of the controller.

Abstract: A method for controlling striations in a lamp powered by an electronic ballast includes the steps of generating an asymmetric lamp current using an unbalanced circuit component in the electronic ballast and supplying that current to the lamp. The unbalanced circuit component may be an unbalanced output transformer or an unbalanced DC choke. The output transformer is unbalanced by offsetting the number of turns on each side of the tap on the primary winding of the transformer. In a similar manner, the DC choke is unbalanced by offsetting the number of turns in each winding of the choke.

Abstract: An illuminator includes a primary power supply and a secondary supply. The first power supply includes a primary wire. The secondary power supply includes two energy-recycling units each comprising a magnetically conductive annular core made of iron powder and a secondary wire wound around the magnetically conductive annular core. The primary wire is wound around the energy-recycling units. A first illumination unit is connected to the primary wire. A second illumination unit is connected to the secondary wires. A first pulse modulator is connected to the primary wire and the first illumination unit. A second pulse modulator is connected to the primary wire and the second illumination unit. An oscillator is connected to the primary wire and the first pulse modulator.

Abstract: A discharge-lamp lighting apparatus includes first and second cold cathode fluorescent lamps (CCFLs) and first and second transformers. The second transformer has a primary winding connected in parallel to one of primary and secondary windings of the first transformer, a first secondary winding, and a second secondary winding. Each of the first and second secondary windings of the second transformer is connected to the secondary winding of the first transformer with polarities being set so that a voltage of each secondary winding of the second transformer becomes additive to a voltage of the secondary winding of the first transformer. The first CCFL is connected in parallel to a series circuit that includes the secondary winding of the first transformer and the first secondary winding of the second transformer.

Abstract: A circuit arrangement for operating a low-pressure gas discharge lamp with a first and a second filament, between which a gas discharge can be formed, is provided. The circuit arrangement may include a device for generating an electrical potential which varies over time at a node, which is connected to the first filament via a first inductive element, and a half-circuit, which includes a switch, the first filament being electrically connected to the second filament when the switch of the half-circuit is closed, wherein a second inductive element is provided in the half-circuit.

Abstract: An apparatus for driving a backlight includes a controller for driving a lamp; a limiter for preventing the controller from driving the lamp during a contact condition of the lamp; and means for disabling the limiter during a first time of the controller, wherein the controller drives the lamp from a zero condition to the contact condition during the first time of the controller.

Abstract: An electronic ballast circuit having at least two distinct switching cycles also includes an anti-striation feature. More particularly the electronic ballast includes an input section configured to receive an input from a power source. A resonant section receives the signals from the input section in order to generate a resonant signal. An anti-striation component is connected within the electronic ballast circuit to affect operation of the resonant section, which results in an affected resonant signal. A switching arrangement is configured to receive the affected resonant signal from the resonant section and anti-striation component, and is further configured to generate an asymmetric output signal due to the affects of the anti-resonant component, wherein the anti-striation component causes parameters of the resonant section of the electronic ballast circuit to be different for different switching cycles of the electronic ballast circuit.

Abstract: An electronic ballast for driving a gas discharge lamp comprises an inverter circuit that operates in a partially self-oscillating manner. The inverter circuit comprises a push-pull converter having a main transformer having a primary winding for producing a high-frequency AC voltage, semiconductor switches electrically coupled to the primary winding of the main transformer for conducting current through the primary winding on an alternate basis, and gate drive circuits for controlling the semiconductor switches on a cycle-by-cycle basis. The drive circuits control (e.g., turn on) the semiconductor switches in response to first control signals derived from the main transformer, and control (e.g., turn off) the semiconductor switches in response to second control signals received from a control circuit. The control circuit controls the semiconductor switches in response to a peak value of an integral of an inverter current flowing through the inverter circuit.

Abstract: In a constant current switching power supply, the current flowing through the load, is feedback-controlled based on the deviation of the detection value (Id) from the target value (Ir), multiplied by a proportional gain (PG), the value of the gain is set to a predetermined value immediately after the load switching element (5) is turned on, and is thereafter gradually reduced with elapse of time. When the current to the load (4) is supplied by a PWM controlled switching circuit (1), the PWM signal is determined based on a product of the deviation and a proportional gain. It is possible to shorten the rise time of a pulsative load current in a situation where the current is relatively large.

Abstract: An LED lighting apparatus can be configured to supply a number of LEDs connected in series with a requisite voltage and power even if an amount of forward voltage of the LEDs connected in series is larger than a supply voltage of a battery. The LED lighting apparatus can include a boosting circuit and an inverted boosting circuit. LEDs can be connected between outputs of the boosting circuit and the inverted boosting circuit. The LED lighting apparatus can also include a current detection circuit configured to detect an LED current, and can include a dual PWM control IC configured to control the boosting circuit and the inverted boosting circuit in accordance with the LED current detected by the current detection circuit so as to keep the LED current substantially constant. The LED lighting apparatus can include a shutdown circuit to stop supplying a power supply when a load that includes the LEDs is in a circuit that is either opened or shorted.

Abstract: A lamp driving circuit (110) for driving a gas discharge lamp (11) is described, comprising current generating means (M1, M2, D1, D2, L, C, C1, C2) for generating a lamp current in discontinuous mode or critical discontinuous mode, and a controller (12) for controlling the operation of the current generating means. In an embodiment, the current generating means have HBCF topology. A zero-crossings detector (120) detects zero-crossings of the lamp current, and generates a detection pulse for each detected zero-crossing. A signal processor (130) monitors the detection pulses from the zero-crossings detector (120), and generates a lamp current inhibit signal if the detection pulses are absent during at least a predetermined time interval. The controller, in response to the lamp current inhibit signal, switches off the lamp current generating means.

Abstract: A high-voltage discharge lamp lighting device provides a starting pulse voltage sufficient to turn on a high-voltage discharge lamp having terminal wire connections of variable length. A power conversion circuit is coupled to a commercial AC power source input and rectifies the AC input into a predetermined DC voltage output. A charging capacitor is coupled to the power conversion circuit. A full bridge circuit is coupled to the power conversion circuit and the charging capacitor and provides a rectangular wave AC output signal to a transformer primary winding circuit of at least a capacitor, a single switching element and a primary winding of a transformer. A low pulse voltage is induced in the primary winding and a transformer secondary winding is connected on one end to the high-voltage discharge lamp, wherein the low pulse voltage is stepped up to a high pulse voltage and applied to the high-voltage discharge lamp.

Abstract: Relative comparison is made between a voltage applied to the whole of the first through eighth LEDs and a voltage applied to the first LED by a comparator. When the voltage applied to the whole of the LEDs has relatively dropped with respect to the voltage applied to part of the LEDs, the comparator outputs a Low Level signal, assumes an abnormality that accompanies a short-circuit fault in any one of the LEDs and causes a ninth LED to illuminate. Meanwhile, relative comparison is made between a voltage applied to the whole of the first through eighth LEDs and a voltage applied to the first LED by another comparator. When the voltage applied to the whole of the LEDs has relatively dropped with respect to the voltage applied to part of the LEDs, the comparator outputs a Low Level signal, assumes an abnormality that accompanies a short-circuit fault in the first LED and causes a ninth LED to illuminate.

Abstract: An inverter for driving light source is disclosed. The inverter includes a pulse control unit for producing a conduction period signal, a power switch unit driven by the conduction period signal and a power conversion unit for outputting a driving power, wherein a waveform modulation unit is further connected between the power switch unit and the power conversion unit, and the waveform modulation unit obtains the input power from the power switch unit and converts thereof into a modulation power, wherein the modulation power includes a positive edge modulation period with gradually rising voltage peak and a negative edge modulation period with gradually falling voltage peak, with the positive edge modulation period has a duration longer than that of the negative edge modulation period, and the modulation power is transmitted to the power conversion unit for being further converted into the driving power.

Abstract: A lamp assembly includes a lamp and a lamp driving device. The lamp includes a body and first and second electrodes. The body converts invisible ray generated by a discharge into visible ray, and the electrodes are disposed on the body. The lamp driving device provides the first and second electrodes with first and second driving voltages, respectively, to generate the discharge. The first driving voltage is less than a first critical voltage at which a corona discharge occurs at the first and second electrodes. When the first electrode is electrically connected to a ground, the first critical voltage may be about 1,200 volts. When the second driving voltage has an inverted phase with respect to the first driving voltage, the first critical voltage is about 2,400 volts. An ozone gas may not be generated at the first and second electrodes to prevent the damage of the electrodes.

Abstract: A lamp lighting apparatus comprises a glass tube, electrodes provided in an axis direction of the glass tube, and an inverter circuit which apply a high voltage of an alternating current to the electrodes. The inverter circuit includes an inverter control circuit which outputs a switching element operating signal, a switching element circuit which converts a direct current voltage into an alternating voltage by ON/OFF controlling the switching element according to the switching element operating signal, and a boosting transformer which boosts the alternating voltage from the switching circuit. In the lighting apparatus, a frequency of the switching element operating signal is higher than that in a steady state operating period, during at least part of period from a beginning of lighting according to the burst light control until the lamp emits light entirely, approximately in the axis direction of the lamp.

Abstract: A light source driving device is for driving a plurality of light sources of a light source module (12), and comprises an inverter circuit (11), a current sampling circuit (13) and a PWM controller (14). The inverter circuit converts a received DC signal to an electrical signal adapted for driving the light sources. The current sampling circuit for sampling current flowing through the inverter circuit, comprises an impedance detecting component (Z11) and an amplifying circuit (132), the impedance detecting component detects the current from the inverter circuit, the amplifying circuit is connected to the impedance detecting component for amplifying the current signal. The PWM controller is connected to the current sampling circuit for receiving the amplified current signal output from the current sampling circuit, and generating a control signal to the inverter circuit to control output thereof.

Abstract: A voltage detection circuit includes a voltage obtaining circuit for transforming an AC signal into a voltage signal, an over-voltage detection circuit connected to the voltage obtaining circuit, and an under-voltage detection circuit connected to the voltage obtaining circuit. The over-voltage detection circuit is for determining whether the AC signal is over-voltage, and generating an over-voltage signal if the voltage signal is over-voltage. The over-voltage detection circuit includes a first transistor. The first transistor includes a first control electrode electrically connected to the voltage obtaining circuit, a first electrode, and a second electrode. The under-voltage detection circuit is for determining whether the AC signal is under-voltage, and generating an under-voltage signal if the voltage signal is under-voltage. The under-voltage detection circuit includes a second transistor.

Abstract: A fluorescent lamp driving circuit is provided. The fluorescent lamp driving circuit collects a pulse-width-modulation and a MOS switch in a single package. The pulse-width-modulation for driving multiple lamps only needs two pins to achieve feedback control and protection control. Thereby the pins required by the pulse-width-modulation are decreased substantially, and the electronic elements needed for feedback and protection control are also reduced, and the overall circuit design is simplified.

Abstract: The present invention provides a low-cost ballast circuit for fluorescent lamps. A resonant circuit has a transformer to operate the fluorescent lamp. The fluorescent lamp is connected in series with a first winding of the transformer. A first transistor and a second transistor are coupled to switch the resonant circuit. A second winding and a third winding of the transformer are used for generating control signals in response to a switching current of the resonant circuit. Furthermore, the present invention achieves soft operation for the first transistor and the second transistor.

Abstract: An inductively powered gas discharge lamp assembly having a secondary circuit with starter circuitry that provides pre-heating when power is supplied to the secondary circuit at a pre-heat frequency and that provides normal operation when power is supplied to the secondary circuit at an operating frequency. In one embodiment, the starter circuitry includes a pre-heat capacitor connected between the lamp electrodes and an operating capacitor located between the secondary coil and the lamp. The pre-heat capacitor is selected so that the electrical flow path through the pre-heat capacitor has a lesser impedance than the electrical flow path through the gas of the lamp when power is applied to the secondary circuit at the pre-heat frequency, and so that the electrical flow path through the pre-heat capacitor has a greater impedance than the electrical flow path through the gas when power is applied the operating frequency.

Abstract: The present invention provides a power supply circuit for providing power for a plurality of external electrode fluorescent lamps (EEFLs) connected in parallel, comprising a controllable voltage regulator for receiving an input power signal and for providing a regulated voltage signal, an output inverter and a resonant circuit connected to receive the regulated voltage signal and for providing a resonant frequency signal, a voltage transformation stage for receiving the resonant frequency signal for transforming the resonant frequency signal to a power voltage signal capable of driving a plurality of EEFLs connected in parallel, wherein the controllable voltage regulator is connected to receive the resonant frequency signal and is responsive thereto to keep the resonant frequency signal within an acceptable operating voltage range to power the EEFLs independently of the number of EEFLs connected to receive the power voltage signal.

Abstract: An apparatus and method are provided for suppressing the input current inrush for a voltage converter in a pre-charge stage. The voltage converter comprises a power input for receiving an input current, a power output for supplying an output voltage for a load, and an output capacitor connected to the power output. In a pre-charge stage, a current limiting device is connected between the power input and the output capacitor to limit the input current to flow therethrough, and a variable current limiting control circuit provides a control signal to the current limiting device to determine a variable maximum value for the input current.

Abstract: The invention provides a circuit system for driving a high-intensity discharging lamp, comprising a boosting circuit, an ignition coil circuit and a clamp circuit. The boosting circuit includes a first transformer and a first switch, in which the primary of the first transformer receives an input power, the secondary of the first transformer produces a boosting DC voltage, and the first switch is connected to the first transformer to control turning-on and turning-off of the first transformer. The ignition coil circuit is connected to the boosting circuit for converting the boosting DC voltage into a switching AC voltage to drive a load. The clamp circuit is connected to the boosting circuit and the ignition coil circuit for directing energy, reflected from the secondary of the first transformer to the primary of the first transformer, to the secondary of the first transformer as the first switch is turned off.

Abstract: An inverter has an inductor, a capacitor, a switching device, a driving circuit and a transformer. A first terminal of the capacitor is connected to the inductor, and the switching device is connected between the first terminal of the capacitor and a ground terminal. The driving circuit is connected to the switching device, wherein the driving circuit is arranged to control the switching device to turn on or turn off; and a primary side of the transformer is connected between a second terminal of the capacitor and the ground terminal.

Abstract: The present invention discloses a front-stage voltage-adjustment inverter, which comprises: a front-stage voltage-adjustment unit, a duty cycle modulation unit, a half-bridge driving unit and a transformer unit. The front-stage voltage-adjustment unit receives an input power, a dimming signal and a feedback signal. The front-stage voltage-adjustment unit varies the voltage of the input power according to the dimming signal and performs a feedback adjustment according to the feedback signal. In the present invention, the cycle signal generated by the duty cycle modulation unit does not vary with the dimming signal and feedback signal. Thus, the half-bridge driving unit can work in a zero-voltage switching state constantly and drive the transformer unit to output a driving power. Thereby, the present invention can decrease the switching loss and increase the service lives of loads and electronic elements.

Abstract: A solid state light illuminator includes a solid state lighting element, a primary coil, and a secondary coil. The secondary coil and the solid state lighting element cooperatively form a circuit. The secondary coil couples electromagnetically with the primary coil. The primary coil is adapted for electrically connecting to an AC power source to generate an alternating magnetic field. The alternating magnetic field generates an induced electromotive force in the secondary coil to apply an electrical current to the solid state lighting element.

Abstract: An electronic ballast circuit having at least two distinct switching cycles also includes an anti-striation feature. More particularly the electronic ballast includes an input section configured to receive an input from a power source. A resonant section receives the signals from the input section in order to generate a resonant signal. An anti-striation component is connected within the electronic ballast circuit to affect operation of the resonant section, which results in an affected resonant signal. A switching arrangement is configured to receive the affected resonant signal from the resonant section and anti-striation component, and is further configured to generate an asymmetric output signal due to the affects of the anti-resonant component, wherein the anti-striation component causes parameters of the resonant section of the electronic ballast circuit to be different for different switching cycles of the electronic ballast circuit.

Abstract: A cold-cathode tube lighting device uniformly lights multiple cold-cathode tubes using a common power source, and the cold-cathode tube lighting device is effectively downsized by using ballast capacitors. A substrate is divided into blocks as many as the cold-cathode tubes. Each of the blocks includes two conductor layers each including two foils. A first foil of a first conductor layer is connected to a common low-impedance power supply. Between the two conductor layers, first ballast capacitors are formed in areas where the first foils are overlapped, second ballast capacitors are formed in areas where the first and second foils are overlapped, and the third ballast capacitors are formed in areas where the second foils are overlapped. Second foils are connected to first electrodes of the cold-cathode tubes.

Abstract: A fluorescent lamp assembly includes a fluorescent lamp ballast capable of detecting at least one of a plurality of input signals and generating an output signal. The output signal is associated with a power level that is based on the at least one detected input signal. The fluorescent lamp assembly also includes a fluorescent lamp capable of receiving the output signal and generating light. An intensity of the light is based on the power level associated with the output signal.

Abstract: A backlight assembly with a light source unit, includes: a drive signal generator which generates a switching drive signal on the basis of a predetermined drive frequency and a feedback power fed back from the light source unit; a switching unit which outputs a power to the light source unit in response to the switching drive signal; and a controller which decreases the drive frequency if the feedback power is higher than a predetermined critical value.

Abstract: A power supply and methods are provided. In one implementation, the power supply includes a switching circuit and a converter. The switching circuit includes a first transistor and a second transistor, and the converter includes a capacitor and an inductor. The switching circuit alternately switches an input voltage to the converter. The power supply further includes a controller operable to adjust a switching frequency of the first transistor and the second transistor to substantially match a resonant frequency of the capacitor and the inductor.

Abstract: The present invention provides an electronic ballast for a high intensity discharge lamp such as a metal halide lamp. The ballast includes an inverter and a resonant circuit with an ignition capacitor between the resonant circuit and the lamp. The ignition capacitor serves to provide the necessary start-up energy and also serves to provide a low impedance discharge path. A single ignition capacitor may be sufficient, but if a long cable is used to connect the lamp to the ballast, then two ignition capacitors in parallel at opposite ends of the cable may be used. The ballast further provides means for monitoring and controlling lamp power by monitoring a nominally constant dc link voltage, and means for detecting short-circuit and open circuit conditions. A retrial mechanism is provided in the event of the lamp failing to ignite that includes a temporary disabling of the inverter in order to keep the rms lamp voltage low.

Abstract: There is provided a discharge lamp lighting apparatus including a dimmer circuit which is provided with a control means to dynamically adjust screen brightness according to an input signal, and a control means to adjust screen brightness based on a user's operation. The dimmer circuit includes: an amplitude adjusting circuit to superpose a first dimming control signal composed of a DC voltage onto a second dimming control signal composed of a pulse width modulation signal; an integration circuit to integrate an output of the amplitude adjusting circuit; and a comparison circuit to compare an output of the integration circuit with a triangular wave having a predetermined frequency thereby generating a dimming signal, wherein a burst dimming mode is performed according to the dimming signal.

Abstract: A backlight driving and control circuit with an isolated power factor correction structure includes a power stage for providing a power supply; a driver stage having a first power factor correction unit for correcting the power factor of the power supply and outputting DC power; an inverter for converting a middle-voltage DC power into a high-voltage power output and driving the operation of a backlight light emitting component; and a control/dimming stage having a second power factor correction unit, a DC transformer unit, and an AD board installed at a secondary winding of the DC transformer unit and grounded jointly with the inverter. With the invention, the power factor correction unit can be electrically isolated from the power stage, and the AD board can directly control/dim the inverter of the driver stage to change the operating status of the backlight light emitting component.

Abstract: A ballast control circuit for driving at least one gas discharge lamp in accordance with an embodiment of the present application includes a high side driver operable to provide a high side driving signal to a high side switch of a half bridge controlled by the ballast control circuit, wherein the high side driving signal indicates a preferred duty cycle for the high side switch, a low side driver operable to provide a low side driving signal to a low side switch of the half bridge, wherein the low side driving signal indicates a preferred duty cycle for the low side switch and a dead time control circuit operable to provide a dead time signal that indicates a dead time during which both the high side and low side switches are turned OFF, wherein the dead time is set based on a value of an external dead time resistor.

Abstract: An improved driving circuit for piezoelectric lamps includes a power switch unit and at least one piezoelectric transformer. The power switch unit is connected to a power source. ON/OFF of the power switch unit controls power amount transmitted to the piezoelectric transformer. The piezoelectric transformer transforms the power and drives at least one load. Operation of the power switch unit is controlled by a duty cycle signal generated by a pulse modulation unit. The pulse modulation unit is connected to a buffer unit which generates a time series at start time to suppress instant output of the piezoelectric transformer, thereby to improve the problem of voltage surge at the start time happened to the conventional piezoelectric transformers.

Abstract: A power supply system is provided for a multiple lamp LCD panel. In one aspect, the power supply includes a plurality of transformers for driving a plurality of respective CCFLs. The primary sides of each transformer are coupled in series to thereby reduce the stress on each transformer. For LCD panels that include longer CCFLs, a power supply is provided that includes a plurality of transformers for driving a plurality of respective CCFLs. The primary sides of each transformer are coupled in series and each lamp is coupled to two secondary sides of the transformers, thereby reducing the problems associated with longer CCFL tubes. In any of the embodiments, the power supply can be adapted to convert a high voltage DC signal to high voltage AC used to power the lamps.

Abstract: A backlight inverter to light a plurality of CCFLs is provided which supplies a stable clamp current without influence of the CCFL temperature, and which stabilizes the LCD surface brightness immediately from the start of lighting the CCFLs, and a method of driving the backlight inverter is also provided. In a backlight inverter including a plurality of inverter transformers and adapted to light a plurality of CCFLs, two primary windings of each of the inverter transformers are connected in series to each other, and a resonant circuit is formed of a leakage inductance and capacitances at the secondary side of each of the inverter transformers, wherein the inverter transformers are operated at a frequency which is lower than an intermediate frequency between the series resonance frequency and the parallel resonance frequency of the resonant circuit, and which is higher than a frequency at which the phase characteristic curve has its peak.

Abstract: In a two stage inverter providing power to a load, a first stage component is operable to receive a first voltage input and a first control input to generate a first voltage output, which is higher than the first voltage input. The first control input is indicative of the power provided to the load. The first voltage output varies in response to a change in the first voltage input by a predefined function. A second stage component of the inverter is operable to receive the first voltage output and a second control input to generate the power as an output. The second control input is indicative of the power provided to the load. A controller component of the inverter is operable to receive a feedback input indicative of the power required by the load and generates the first and second control inputs.

Abstract: The present invention discloses a primary-side driving backlight circuit for LCD panel. The primary-side driving backlight circuit employs a single isolation device to achieve isolation request for safety for the secondary side. The PWM controller on the secondary-side of a transformer generates a control signal according to a feedback signal. The control signal is transmitted by the isolation device to a High/Low side driver. The High/Low side driver has a High Output and a Low Output, which drives power switches at high side and low side respectively, in order to control the power of an input source transmitting into the transformer and further control the voltage and current of cold cathode lamp(s) of a backlight circuit.

Abstract: The configurations of a dielectric barrier discharge lamp (DBDL) system and the driving method thereof are provided in the present invention. The proposed DBDL system includes a driver circuit receiving a DC input voltage and generating an AC output voltage, including a transformer having a primary winding and a secondary winding, a dielectric barrier discharge lamp coupled to the secondary winding and a burst mode dimming circuit including a first switch. In which, the first switch is turned on when the first switch is starting such that the first switch and the primary winding forms a conducting path so as to apply a driving high voltage to the DBDEL and turn off the first switch after the DBDL is breaking through by the driving high voltage such that a driving normal voltage is applied to the DBDL.

Abstract: A voltage control apparatus (10) for an HID lamp includes a voltage control transformer circuit (20), and is connected between supply mains (22) and a high intensity discharge (HID) lamp. The HID lamp is started at full line voltage, and after a sufficient operating interval ensuring that the lamp has achieved a sustaining temperature, the operating voltage applied to the lamp is reduced, effecting a considerable savings in energy use, with little or only an acceptably small decrease in light output from the lamp. Further, the voltage control apparatus include a circuit portion responsive to voltage transients on the AC line, and which effects restarting of the HID lamp in the event a voltage transient occurs which is sufficiently long (i.e., about 1/2 cycle) as to extinguish the HID lamp.

Abstract: A nightlight including a light emitting diode (LED) is provided. The nightlight includes a switch that is operative to control the flow of power to the LED. The nightlight also includes a driver circuit that is configured to convert alternating current to direct current, where the direct current provides power to the LED. The nightlight also includes a housing coupled to the nightlight that contains the driver and is configured to fit within a single-gang junction box. The switch includes an LED that is powered by the driver circuit, where the LED is illuminated without regard to the position of the switch.

Abstract: Methods and apparatus for providing and controlling power to at least some types of loads. In one example, a controlled predetermined power is provided to a load without requiring any feedback information from the load (i.e., without monitoring a load voltage and/or load current). In another example, a “feed-forward” power driver for an LED-based light source combines the functionality of a DC-DC converter and a light source controller, and is configured to control the intensity of light generated by the light source based on modulating the average power delivered to the light source in a given time period, without monitoring and/or regulating the voltage or current provided to the light source. In various examples, significantly streamlined circuits having fewer components, higher overall power efficiencies, and smaller space requirements are realized.

Abstract: A control circuit controls a driving circuit of a discharge lamp. The driving circuit comprises a half bridge and a clock generator that determines the switching frequency of the half bridge. The control circuit comprises a regulator that regulates the value of the switching frequency when the value of the voltage across the lamp exceeds a threshold value.

Abstract: A power supply includes a light source, a signal converting unit converting an externally supplied AC voltage into a DC voltage, a DC-DC converting unit converting a magnitude of the DC voltage, and a light source protecting unit. The light source protecting unit outputs the DC voltage of a predetermined range as a light source driving voltage to supply a stabilized source driving voltage to the light source and suspending an application of the light source driving voltage to the light source when a magnitude of the light source driving voltage is larger than a predetermined value, based on an externally supplied control signal.

Abstract: A hybrid power supply system including piezoelectric and ferrite transformers for driving a discharge lamp is provided. Specifically, the hybrid power supply system includes a rectifier/filter, a piezoelectric inverter, and a ferrite converter. The rectifier/filter has an input terminal connected to an external AC voltage to convert the external AC voltage to a DC voltage. The piezoelectric inverter is connected to the rectifier/filter to step up and convert the DC voltage to an AC voltage for driving the discharge lamp. The ferrite transformer is connected to the rectifier/filter to step down the DC voltage to a rated DC voltage for driving discharge lamp circuits other than the discharge lamp. The piezoelectric inverter and the ferrite converter are integrated by connecting a primary side of the piezoelectric step-up transformer and a primary side of the ferrite step-down transformer in series or in parallel with an output terminal of switching circuits.

Abstract: Circuit with a switch-off device for the operation of light sources The invention relates to a circuit with a switch-off device for the operation of light sources (Lp), have the following features: a self-commutated half-bridge inverter having a series circuit of an upper electronic switch and a lower electronic switch (T1, T2), which are joined at a half-bridge midpoint (M) and are connected between a supply voltage (+) and a ground potential, a start capacitor (C3) which is joined via a trigger element (DIAC) to a control electrode of the lower electronic switch (T2), and a switch-off device having an input (E) and an output, which are configured and connected so that they discharge the start capacitor (C3) if a switch-off signal is applied to the input (E). The switch-off device contains a time delay.