Abstract: A power converter for an LED lighting device includes a primary side circuit, a secondary side circuit, a detecting circuit, a load-dependent circuit, and a feedback circuit. The feedback circuit generates a feedback signal according to a detected signal which the detecting circuit generates according to a second node of the secondary side circuit. The primary side circuit adjusts a duty cycle according to the feedback signal. The secondary side circuit outputs a first output voltage at a first node of the secondary side circuit and outputs a second output voltage at a third node of the secondary side circuit, according to the duty cycle of the primary side circuit. The load-dependent circuit receives the second output voltage and controls an electrical strength between the first node and the second node of the secondary side circuit according to the first output voltage.

Abstract: A single non-thermal atmospheric plasma generation device is used to detect and analyze vital fields of a living subject to determine the presence of a condition, such as an illness or injury, and responsively modify characteristics of the plasma to treat, heal, or alleviate the condition. The device includes a capacitance dielectric discharge array of plasma emitters, and a controller having a power supply, a transformer, and circuit components for driving the transformer at a resonant frequency of the plasma emitters to cause the plurality of plasma emitters to ionize surrounding air and produce the non-thermal plasma. The resonant frequency is around 60 GHz and harmonics thereof. A receiver of the device recovers frequency mixing products from the plasma, which are extracted by signal processing circuitry; signals in the VHF and UHF bands are extracted and analyzed to determine whether signatures of particular vital fields are present.

Abstract: Provided are a TRIAC dimmer detection circuit, chip and method, and an LED driving chip and system. A bus voltage reflecting signal is received, and a TRIAC dimmer detection signal is generated according to the bus voltage reflecting signal, a first reference voltage and a second reference voltage, the dimmer detection signal being used to detect whether a dimmer exists and to determine the type of the dimmer. The TRIAC dimmer detection circuit, chip and method, and the LED driving chip and system consistent with the present invention can detect whether a TRIAC dimmer is contained in an LED illuminating system, so as to determine a working state of a bleeder, thereby reducing the power consumption of the entire LED illuminating system and improving the efficiency thereof.

Abstract: A charge pump that can be configured to operate in a first mode and a second mode is disclosed. The charge pump can comprise a charging capacitor coupled to a first node and configured to transfer a first DC voltage to the first node. The charge pump can also comprise a first output node and a second output node coupled to the first node. During the first mode, the first output node can be configured to output a second DC voltage based on the first DC voltage, and the second output node can be configured to output a third DC voltage based on the first DC voltage. During the second mode, the first output node can be configured to output the second DC voltage, and the second output node can be configured to output an AC voltage, the AC voltage being offset by the third DC voltage.

Abstract: An LED driver may use a DIAC oscillator circuit to controls a semiconductor switch in a switching circuit. The DIAC oscillator circuit uses rectified line power and so it does not require a separate power source. An LED driver may uses a zero crossing circuit to provide low level dimming. The zero crossing circuit includes a linear circuit or a constant current circuit that keeps a TRIAC dimmer on and stable during low current levels.

Abstract: A discharge lamp lighting device according to the invention can reliably light a discharge lamp, and at the same time, prevent output of unnecessary high-voltage pulses with a simple circuit configuration. The discharge lamp lighting device includes a capacitor charged with a current from a direct-current power supply, a transformer adapted to output a starting pulse between electrodes of the discharge lamp in accordance with a discharge current flowing from the capacitor, a discharge control circuit adapted to switch ON/OFF the discharge current from the capacitor to the transformer, and a timing generation section adapted to switch the discharge control circuit to ON after a voltage between both ends of the capacitor has reached a reference voltage. The timing generation section can operate in accordance with a plurality of reference voltages.

Abstract: A method of controlling an ignition circuit to output an excitation voltage is disclosed. The ignition circuit is used to excite a discharge lamp and includes a transformer and a switch element which is connected to a primary winding of the transformer. The method of controlling the ignition circuit comprises steps of: (a) receiving a control signal which is set in accordance with a waveform characteristic of a predetermined excitation voltage to control an impedance of the switch element; (b) controlling a primary current in the primary winding or a primary voltage across the primary winding of the transformer by controlling the impedance of the switch element; and (c) generating the excitation voltage by the secondary winding of the transformer in accordance with the primary current or the primary voltage so as to excite the discharge lamp.

Abstract: A current driver circuit for regulating a light emitting diode (LED) is disclosed. An example driver circuit uses one input node of the driver circuit for controlling both maximum brightness and dimming of an LED coupled to an output node of the driver circuit. The driver circuit supplies a reference voltage (VREF) to its input node. A microcontroller is coupled through a resistor or other resistive component to the input node of the driver circuit and provides the input current, where the input current is adjustable by the resistor value. The driver circuit is configured to drive multiple times the input current from its output node. By adjusting the resistor value the output current of the LED is adjusted. The microcontroller is configured to provide pulse width modulation (PWM). By reducing the duty cycle of the PWM waveform the dimming of the LED can be controlled.

Abstract: There are provided a power supply device switching power input to a primary side to supply the power to a predetermined load connected to a secondary side electrically insulated from the primary side and a control circuit thereof. The control circuit generates a predetermined PWM signal to apply the PWM signal to a dimming switch connected to an end of the load and controls a switching frequency of the primary side, based on a control voltage generated according to a feedback signal according to the power supplied to the load and the PWM signal, and the control voltage maintains a constant difference between a minimum voltage level and a maximum voltage level regardless of a duty of the PWM signal.

Abstract: There is provided a power supply apparatus supplying a power to an electronic device, especially, a light emitting diode, capable of stably supplying power to different loads with simple circuit configuration, and maintaining the balance of the current supplied to light emitting diodes.

Abstract: There are provided a power supply apparatus switching a power input to a primary side to supply the power to a predetermined load connected to a secondary side electrically insulated from the primary side and a control circuit thereof, the control circuit generating a predetermined PWM signal to apply the generated PWM signal to a dimming switch connected to an end of the load and controlling a switching frequency of the primary side based on a control voltage generated according to a feedback signal depending on the power supplied to the load and the PWM signal, wherein a voltage variation amount of the control voltage may be constantly maintained regardless of a duty of the PWM signal.

Abstract: Provided is a compact ignition coil apparatus that can realize reliable insulation breakdown and spark discharge with high discharge current. A high-frequency discharge ignition coil apparatus includes: a capacitor 116 connected to a high-voltage terminal, for preventing passage of high voltage; and an inductor 117 connected to the capacitor 116 and forming, together with the capacitor 116, a band pass filter that allows only a predetermined frequency component to pass. High-frequency current is supplied from outside to the inductor 117. The high-frequency discharge ignition coil apparatus further includes a current level detection device 115 for detecting the level of current flowing in the inductor 117. The current level detection device 115 is placed in one package, together with a primary coil 111, a secondary coil 112, a capacitor 116, and an inductor 117.

Abstract: A communication system with SSL light bulb assemblies comprises a first and a second transceiver. The first transceiver comprises a magnet, and the second transceiver comprises a switched-mode power converter which comprises an inductor element with an inductor core material having a magnetic field dependent permeability. The magnet and the inductor core material of the inductor element are magnetically coupled. The first transceiver is configured to modulate a magnetic field generated by the magnet to generate a modulated downstream magnetic field indicative of downstream data, and the second transceiver is configured to extract the downstream data from a measurement signal from the power converter. The measurement signal is dependent on an inductor value of the inductor element.

Abstract: The present invention relates to a controlling circuit and controlling method for an LED driver implemented as a flyback topology. The controlling circuit may be at a primary side of a transformer of the LED driver, and include a sampling circuit, an on time sensing circuit of an output diode, a regulating signal generator, and a PWM controller. The sampling circuit may generate a sampling signal indicating output current by sampling at the primary transformer side. The on time sensing circuit can detect an on time of the output diode. The regulating signal generator can generate a regulating signal by regulating the sampling signal, a voltage reference, and the on time of the output diode. The PWM controller may generate a controlling signal to control operation of a switching device of the LED driver to maintain a substantially constant output current in accordance with the regulating signal.

Abstract: A light-emitting-element lighting circuit for dimming a light emitting element having a diode characteristic by a PWM dimming signal is provided. The lighting circuit includes a dimming signal conversion unit configured to generate the PWM dimming signal having a duty ratio corresponding to an emission level specified by an input dimming signal. The lighting circuit further includes a minimum current generating circuit configured to flow a minimum current during an OFF period of the PWM dimming signal generated by the dimming signal conversion unit such that a voltage greater than a threshold voltage designed to allow the light emitting element to emit a light is applied to the light emitting element, and the light emitting element emits a light of a brightness equal to or less than a lowest emission level specified by the dimming signal.

Abstract: An ignition apparatus has an ignition transformer that has a primary winding and a secondary winding. The transformer has a first primary winding connection for connection to a first supply voltage potential and a second primary winding connection for connection to a second supply voltage potential via a controllable switching element. Accordingly a first capacitor is connected up between the first primary winding connection and the second supply voltage potential and a second capacitor is connected up between the second primary winding connection and the second supply voltage potential.

Abstract: This invention provides an integrated power supply for a controller of an electronic ballast for a fluorescent lamp. The integrated power supply couples output power from the electronic ballast and uses the coupled power to provide power to the controller. In one embodiment, the electronic ballast may include a rectifier for converting an alternating current input voltage into a direct current output voltage, and a circuit including a combined power factor correction (PFC) stage and an inverter, wherein the PFC stage and the inverter share a switch. Also provided is a controller for an electronic ballast. The controller may include a voltage mode or current mode duty ratio controller that controls a duty ratio of a switch of the ballast. The controller and the ballast allow dimming of the fluorescent lamp while maintaining a high power factor.

Abstract: A method for starting a high-pressure discharge lamp by means of a starter, having a starting capacitor, a starting switch and a starting transformer, wherein the method comprises the following temporally successive steps: charging the starting capacitor to a predetermined voltage; closing the starting switch; and opening the starting switch before the current through the starting switch reaches zero for the first time in terms of its fundamental component.

Abstract: A light emitting diode (LED) driver circuit is provided. The LED driver circuit includes an LED the LED; a power unit which provides a current to the LED through an inductor; a dimming switch which is connected to the LED and bypasses the current provided to the LED; an input unit which receives brightness information of the LED; a logic unit which calculates reference currents for each driving mode according to the received brightness information; a current control unit which controls the power unit to provide the current based on the driving mode and the calculated reference currents to the inductor; and a switch control unit which switches the dimming switch on if the driving mode of the LED driver circuit is switched to the dimming mode.

Abstract: A display device with wireless power supply from power transmission means is disclosed in the disclosure. The display device comprises a display module, a system controlling module and a wireless power receiving module. The system controlling module is electrically connected to the display module. The wireless power receiving module is electrically connected to the system controlling module. The wireless power receiving module comprises a plurality of near-field coil units. The near-field coil units have individual receiving frequencies and individual output powers. The near-field coil units are configured to resonate with a transmission coil of the power transmission means. According to a transmission frequency on the transmission coil, the near-field coil unit with corresponding receiving frequency generates an electricity supply with a certain output power to the system controlling module. In addition, a wireless power transmission system is also disclosed herein.

Abstract: A dimming angle sense circuit according to an exemplary embodiment of the present invention generates a source current that depends on an auxiliary voltage corresponding to an input voltage during a turn-on period of a power switch for a period during which an input is generated according to a dimming angle. The dimming angle sense circuit generates a dimming sense voltage by mirroring the source current, and generates a sampling voltage by sampling a dimming sense voltage for every turn-on period of a power switch. The dimming angle sense circuit generates a dimming signal by supplying a dimming current to a dimming resistor and a dimming capacitor according to a result of comparison between the sampling voltage and a reference voltage.

Abstract: A control circuit of a light-emitting element comprises a rectifying unit (30), a switching element (38), a transformer (48) having a first winding (L1) which generates a magnetic field using a current controlled by switching of the switching element (38), a second winding (L2) which is magnetically coupled to the first winding (L1) and which generates a current flowing to an LED (102), and a third winding (L3) which is magnetically coupled to the first winding (L1) and which generates a voltage (Sfbk), and an averaging capacitor (32) which averages a voltage derived by superposing a voltage (Srec) rectified by the rectifying unit (30) and the voltage (Sfbk), and a voltage averaged by the averaging capacitor (32) is applied to the first winding (L1), so that light is emitted from the LED (102).

Abstract: A pulse controller performs a control to apply at least one high-energy first pulse P1 between a pair of electrodes in a first interval T1 to thereby promote a discharge breakdown between the pair of electrodes, and performs a control to apply at least two second pulses P2, which are lower in energy than the first pulse P1, between the pair of electrodes in a second interval T2 after the discharge breakdown has occurred between the pair of electrodes, to thereby maintain the discharge breakdown between the pair of electrodes.

Abstract: An electronic ballast for a light emitting load is provided, and includes a transformer module, a resonance module, a high-frequency push-pull inverter and a driving controller module. The high-frequency push-pull inverter includes a first switch component and a second switch component. The driving controller module is used for generating and providing an asymmetric driving waveform to the first switch component and the second switch component. The asymmetric driving waveform includes a first discharging waveform portion for discharging and turning off the first switch component, and also a second discharging waveform portion for discharging and turning off the second switch component. The first and second discharging waveform portions are different in current amplitudes and time spans.

Abstract: An isolated flyback converter for an LED driver may include: (1) A snubber circuit configured to be connected to the primary side of a transformer. (2) A switching unit configured to have a source terminal and a drain terminal and configured to be turned on or off. (3) A control unit configured to detect a first input signal proportional to a fluctuation in the power supply voltage, detect a second input signal when the switching unit is turned off, generate a signal inversely proportional to the maximum value of the first input signal and multiply the generated signal to the second input signal, and control a peak current of the switching unit to be proportional to the multiplication result of the signal inversely proportional to the maximum value of the first input signal and the second input signal such that a secondary-side current of the transformer is maintained constant.

Abstract: The present invention discloses a primary-side controlled switch-mode power supply controller for driving LED with constant current and method thereof as well as an apparatus for controlling switch-mode power supply having the switch-mode power supply controller. The switch-mode power supply controller includes an input dimming phase detection circuit, a multiplier, a turn-on signal control circuit, a zero-crossing detection circuit, a comparator, a trigger and a driving circuit. The circuit controls to drive LED with constant current by means of a primary-side controlled method. The circuit realizes the triac dimming function, ensures a constant output current regardless of a high voltage or a low voltage, and obtains a high power factor. The direct use of the isolation transformer improves the safety of the circuit, and simplifies the peripheral circuit, thereby reducing the cost of the circuit and minimizing the size of the PCB layout, which is favorable in minimizing the product.

Abstract: A discharge lamp lighting device according to the invention can reliably light a discharge lamp, and at the same time, prevent output of unnecessary high-voltage pulses with a simple circuit configuration. The discharge lamp lighting device includes a capacitor charged with a current from a direct-current power supply, a transformer adapted to output a starting pulse between electrodes of the discharge lamp in accordance with a discharge current flowing from the capacitor, a discharge control circuit adapted to switch ON/OFF the discharge current from the capacitor to the transformer, and a timing generation section adapted to switch the discharge control circuit to ON after a voltage between both ends of the capacitor has reached a reference voltage. The timing generation section can operate in accordance with a plurality of reference voltages.

Abstract: The invention discloses a driving circuit structure for driving light-emitting loads. The driving circuit structure may include a power supplying device, a signal processing device and an impedance balancing device and a dimming control unit. The power supplying device is used for supplying an alternating current power supply. The signal processing device is used for converting the alternating current power supply into a direct current power supply, so as to drive the light-emitting loads. The impedance balancing device is used for balancing an alternating current magnitude of the alternating current power supply, so as to stabilize a direct current magnitude of the direct current power supply for driving the light-emitting loads. The dimming control unit is capable of controlling output luminance of the light-emitting loads.

Abstract: A circuit for powering a light source includes a filter, a transformer, and a controller. The filter receives an input voltage and filters the input voltage to provide a regulated voltage. The transformer converts the regulated voltage to an output voltage to power the light source. The controller generates a driving signal to alternately operate the switch between a first state and a second state. The controller corrects a power factor of the circuit by controlling time durations of the first state and the second state, such that an input current decreases to a predetermined level during the second state and increases from the predetermined level to a peak level proportional to the input voltage during the first state. The controller controls the ratio of time in the first state to time in the second state to adjust an output current flowing through the light source to a target level.

Abstract: The present invention relates to a controlling circuit and controlling method for an LED driver implemented as a flyback topology. The controlling circuit may be at a primary side of a transformer of the LED driver, and include a sampling circuit, an on time sensing circuit of an output diode, a regulating signal generator, and a PWM controller. The sampling circuit may generate a sampling signal indicating output current by sampling at the primary transformer side. The on time sensing circuit can detect an on time of the output diode. The regulating signal generator can generate a regulating signal by regulating the sampling signal, a voltage reference, and the on time of the output diode. The PWM controller may generate a controlling signal to control operation of a switching device of the LED driver to maintain a substantially constant output current in accordance with the regulating signal.

Abstract: A circuit for driving a light-emitting diode (LED) light source includes a converter, a saw-tooth signal generator, and a controller. The converter includes a switch which is controlled by a driving signal. The converter provides a sense signal indicating the current through said LED light source. The saw-tooth signal generator generates a saw-tooth signal based on the driving signal. The controller generates the driving signal based on signals including the saw-tooth signal and the first sense signal to adjust the current through the LED light source to a target level and to correct a power factor of the driving circuit by controlling an average current of the input current to be substantially in phase with said input voltage.

Abstract: A method is provided for operating at least one LED by a switched-mode regulator circuit to which a DC or a rectified AC voltage is supplied and which provides a supply voltage for at least one LED by a coil and a switch clocked by a control/regulation unit. When the switch is activated, power is temporarily stored in the coil and is discharged through a diode and through at least one LED when the switch is deactivated and the current flows through the LED through a first power storage element which is coupled to a second power storage element. The first power storage element just reaches its maximum capability of storing power due to the current flowing through the LED. A rising current is supplied to the second power storage element such that the time can be detected when the first power storage element recovers its capability of storing power.

Abstract: A method of controlling an ignition circuit to output an excitation voltage is disclosed. The ignition circuit is used to excite a discharge lamp and includes a transformer and a switch element which is connected to a primary winding of the transformer. The method of controlling the ignition circuit comprises steps of: (a) receiving a control signal which is set in accordance with a waveform characteristic of a predetermined excitation voltage to control an impedance of the switch element; (b) controlling a primary current in the primary winding or a primary voltage across the primary winding of the transformer by controlling the impedance of the switch element; and (c) generating the excitation voltage by the secondary winding of the transformer in accordance with the primary current or the primary voltage so as to excite the discharge lamp.

Abstract: A circuit arrangement (10) for operation of a high-pressure discharge lamp having a commutation device (K), which has an input (E1, E2) for coupling to a DC voltage source and has an output (A1, A2) for coupling to the high-pressure discharge lamp (EL). A control apparatus (12) is configured to commutate the polarity with which the voltage (UZW), which is applied to the input (E1, E2) of the commutation device (K), is coupled to the output (A1, A2) of the commutation device (K). A synchronization apparatus (14) is configured to provide a synchronization signal (Sy) at its output (A1, A2). A timer apparatus (16) is configured to produce a commutation initiation signal (KA) at its output (A1, A2), which commutation initiation signal (KA) is synchronized with a predeterminable operating frequency of the high-pressure discharge lamp (EL).

Abstract: A discharge lamp lighting circuit includes a DC/DC converter which generates from an input voltage a drive voltage to be applied to a discharge lamp of a driven object. A first drive voltage generating path has one end to which the input voltage is applied, and at the other end of which is an output capacitor on an output side of the DC/DC converter. A second drive voltage generating path has one end to which the input voltage is applied, and at the other end of which is the output capacitor. The second drive voltage generating path is different from the first drive voltage generating path. A control circuit controls ON/OFF of the first drive voltage generating path. The discharge lamp lighting circuit is arranged so that the voltage of the output capacitor when the first drive voltage generating path is in an ON-state becomes higher than the voltage of the output capacitor when the first drive voltage generating path is not so.

Abstract: Provided is an LED driver circuit, to be connected to an AC power supply via a phase-control dimmer, for driving an LED load, including: a switching power supply part including a switching element and a switching current detection part; an LED current detection part; a first control part for controlling and switching the switching element so that a switching current has a desired current value based on a detection signal of the switching current detection part; a second control part for controlling and switching the switching element so that an LED current has a desired current value based on a detection signal of the LED current detection part; and a switch part for switching between control performed by the first control part when the phase-control dimmer is set to high brightness dimming and control performed by the second control part when the phase-control dimmer is set to low brightness dimming.

Abstract: The present invention discloses a control apparatus, which not only accepts multiple dimming control signals, but also combines the signals in analog manner. By means of this, an inevitable analog to digital converter in a conventional voltage multiple dimming control apparatus can be saved without hurting the performance of generation of pulse width modulation signals. Compared with the conventional arts, the present invention further exhibits reduction in view of chip size and power consumption.

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: The present invention provides a dimming circuit for controlling the luminance of a light source and the method for controlling luminance. The dimming circuit comprises an inverter circuit and a driving circuit. The inverter circuit is electrically coupled to a light source to be controlled, to convert a direct current (DC) power input into an alternating current (AC) power. The inverter circuit comprises a transformer, a capacitor connected in parallel to the transformer, a plurality of switches located at both ends of the capacitor, and an oscillating circuit electrically connected to both ends of the transformer. The driving circuit is electrically connected to the inverter circuit, for regulating the AC voltage to control the time period that the light source is turned on.

Abstract: The present invention uses the mutually series connected resistive, or inductive, or capacitive impedance to divide the voltage of bi-directional power source, thereby using the divided power of the impedance component to drive the bi-directional conducting light emitting diode in parallel connection at the two ends of the impedance.

Abstract: A dielectric barrier discharge lamp (14) has an inside electrode (142) in a tube axis direction within the airtight container (141), which has ultraviolet transmission properties and a long tube shape, and an outside electrode (143) having a semicircular shape arranged outside of the airtight container (141) in close contact with it. Besides, an excimer-forming gas is sealed in the airtight container (141). AC voltage supplied from the power source (11) is converted into DC voltage through a converter (12) and outputted. A high-frequency wave is generated by an inverter (13) based on the DC voltage supplied from the converter (12), and a dielectric barrier discharge is induced in the dielectric barrier discharge lamp (14) to irradiate ultraviolet rays. The converter (12) is configured by connecting in series the outputs of DC power sources (121), (122).

Abstract: An automotive lighting assembly receiving light from a power source and for producing light. The automotive lighting assembly includes a first lighting circuit which is operatively connected to the power source for emitting light as a function of electric current. A second lighting circuit is operatively connected to the power source independently from the first lighting circuit. The second lighting circuit emits light as a function of the electric current. The automotive lighting assembly also includes a controller which is electrically connected between the power source and the first and second lighting circuits for independently operating the first and second lighting sources to emit a chosen amount of light in a chosen direction.

Abstract: A starting circuit arrangement for starting at least one discharge lamp by applying an electrical starting voltage pulse to the discharge lamp, the starting circuit arrangement has: at least one source circuit arrangement for providing an electrical primary voltage pulse, at least one starting circuit for providing the starting voltage pulse, and at least one inductive coupling element for inductively coupling-in the primary voltage pulse into the starting circuit for the purpose of generating the starting voltage pulse. The inductive coupling element has a transformation ratio for a voltage transformation which is selected from the range of from 1/25 to 1/400. A method for starting a discharge lamp by applying a starting voltage pulse using the starting circuit arrangement is also disclosed.

Abstract: A capacitor 42 (C1) of a first bootstrap circuit 4 for maintaining the ON state of a first switching device 61, one of the two switching devices disposed on a higher potential side of first DC voltage V1, is not only charged with second DC voltage V2, but also supplied with a charging current from third DC voltage V3 on a secondary winding n2 side of a transformer 22, and maintains the ON state of the first switching device 61 for a long time with the charge of both of them. This makes it possible to fix the polarity of the voltage to be applied to the discharge lamp 8 to the single side polarity closer to the DC output operation.

Abstract: An LED driver circuit may include dimming circuitry. In particular, the LED driver circuit may include a switching converter, an LED and a switch. The LED may be electrically connected to the switching converter and the switch may be connected in parallel with the LED. The switching converter and/or the switch may be configured to be controlled to achieve dimming of the LED. Current may be supplied to the LED and the switch may be turned on and off to dim the LED. The switching converter coupled to the LED may include a switching element in series with an inductor and the LED. In such case, the switching element may be turned on to supply current to the LED and the inductor, and the switch may be turned on and off to dim the LED.

Abstract: A circuit arrangement is provided, which may include an input; an output; an inverter, configured to provide an AC supply voltage from a DC supply voltage; a control device configured to drive the inverter, the control device being configured to initiate a preheating phase once a preheating criterion has been met; a resonant circuit having a resonant inductor and having a resonant capacitor; and a transformer configured to preheat electrodes of a gas discharge lamp; wherein the primary winding of the transformer is connected in series with the resonant capacitor and is connected directly to the reference potential of the control device, and an electrical switch is coupled in parallel with the primary winding of the transformer, which switch has a control connection, which is coupled to the control device being configured to transfer the electrical switch into its electrically conducting switching state once the starting criterion has been met.

Abstract: An electronic ballast includes a step-up converter, which includes a storage inductor, a diode, an intermediate circuit condenser and a switch element. According to the invention, a current passing through the storage inductor is used in the form of an indicator of turnon and turnoff times of the step-up converter oscillates in a self-exciting manner.

Abstract: A circuit arrangement (1, 1?, 1?) for driving a high-pressure gas discharge lamp (2) is described, which has a first terminal (x1) for a first voltage potential, a second terminal (x2) for a second voltage potential, and a third terminal (x4) for applying a third voltage potential for igniting the high-pressure gas discharge lamp (2).

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 capacitor 42 (C1) of a first bootstrap circuit 4 for maintaining the ON state of a first switching device 61, one of the two switching devices disposed on a higher potential side of first DC voltage V1, is not only charged with second DC voltage V2, but also supplied with a charging current from third DC voltage V3 on a secondary winding n2 side of a transformer 22, and maintains the ON state of the first switching device 61 for a long time with the charge of both of them. This makes it possible to fix the polarity of the voltage to be applied to the discharge lamp 8 to the single side polarity closer to the DC output operation.