Abstract: The present invention refers to a detector device for detecting a status of at least a first electronic element of an automotive lighting device. This detector device comprises a status detection unit configured to detect a status of the at least first electronic element and to generate a reference signal which depends at least on the status of the first electronic element. It also comprises a comparison signal generator configured to generate a comparison signal and a comparison unit configured to generate a pulse-width modulation signal by comparing the reference signal with the comparison signal.

Abstract: An AC power supply for connection to at least one electrode of an electrodynamic screen includes a DC-to-DC converter electrically coupled to a source of DC voltage including an output. The system includes a DC-to-AC converter electrically coupled to the output of the DC-to-DC converter, including a two-terminal passive element electrically coupled in series with a first transistor including a control terminal electrically coupled to a periodic voltage signal configured to switch the first transistor between an on/off state. The system includes an AC output including an AC voltage configured to change periodically. The system includes a regulator circuit configured to sample the AC output voltage and detect when the AC output voltage reaches a predetermined voltage. The regulator circuit is configured to electrically couple the power supply to the source of DC voltage when the output voltage is less than the predetermined voltage.

Abstract: A method includes determining a first voltage that is in a high-side path of a circuit, the path including a high-side switch connected between a first potential connection of the circuit and a first connection of a load of the circuit; determining a second voltage that is in a low-side path of the circuit, the path including a low-side switch connected between a second potential connection of the circuit and a second connection of the load; responsive to a determination that one of the voltages exceeds a threshold for at least a duration of a predefined time interval, checking whether the other voltage currently exceeds the threshold; and determining that there is a short circuit across the load or in whichever of the paths has the voltage that exceeded the threshold for the duration, respectively, if the result of the check is positive or negative.

Abstract: Systems and methods for suppressing and mitigating harmonic distortion in a circuit are disclosed. In one example, a disclosed circuit includes a radio frequency (RF) oscillator and a power amplifier. The RF oscillator is configured to generate an RF signal. The power amplifier is configured to generate an amplified RF signal based on the RF signal. The power amplifier includes a transformer including a primary winding and a secondary winding, and a feedback capacitor electrically coupled to the primary winding and the secondary winding.

Abstract: A controller includes a first sensing pin receiving a first sensing signal indicating a level of an input voltage of a resonant converter, a second sensing pin receiving a second sensing signal indicating a level of an input current of the resonant converter, a feedback pin receiving a feedback signal indicating a level of an output voltage of the resonant converter, and a first driving pin and a second driving pin controlling a high side switch and a low side switch of the resonant converter, respectively. The controller generates a compensated signal based on the first sensing signal, compares the compensated signal with a peak value of the second sensing signal to generate a first comparison result, compares the feedback signal with a threshold to generate a second comparison result, and controls the high side low side switches based on the first and the second comparison results.

Abstract: An instrument for coagulation and dissection of biological tissue including a tool with coagulation electrodes and at least one cutting electrode. The electrodes are actuated via an operating circuit including an evaluation circuit, to which an external apparatus delivers an evaluation signal with first and second half-waves having opposite polarities. During at least one first half-wave, the evaluation circuit checks whether a first switch or a second switch are actuated on the instrument. Depending on the evaluation result, a triggering signal is transmitted to a switching unit. Depending on the triggering signal, the switching unit is switched into a first or second switching state. In the second switching state, no voltage suitable for dissection and no current suitable for dissection, respectively, is applied to the cutting electrode. In the first switching state, a voltage suitable for dissection or a current suitable for dissection is applied to the cutting electrode.

Abstract: The present invention relates to an organic light emitting diode display device which minimizes a temperature increase of an organic light emitting panel in consideration of an input image and an external environment, the organic light emitting diode display device comprising: an organic light emitting panel; a power supply unit for supplying a current to the organic light emitting panel; a control unit for performing an automatic current limit for controlling the maximum value of the current supplied to the organic light emitting panel to be less than or equal to the current limit value; and a temperature sensor for sensing the temperature of the organic light emitting panel, wherein the control unit may change the current limit value according to the present temperature of the organic light emitting panel.

Abstract: A constant current LED driver, for controlling a current flowing through a LED, comprising: an adjusting circuit, configured to generate a first current and a first adjusting signal; a feedback circuit, controlled by an output signal, to generate a feedback voltage according to the first current; an operation amplifier, configured to generate the output signal according to the LED voltage and the feedback voltage; and an edge adjusting circuit, configured to adjust a first type of edges or a second type of edges of the first adjusting signal to generate a second adjusting signal, wherein the LED is controlled by the second adjusting signal. The above-mentioned constant current LED driver can be used as a current control circuit for controlling a current flowing through a target device.

Abstract: An LED driver that is operable with two different types of power source originally designed for a high-intensity discharge lamp. The LED driver directs current of an input power provided by the power source down a first current path if it is determined that the power source comprises a functional ignitor. The LED driver directs current of an input power provided by the power source down a second current path if it is determined that the 5 power source does not comprise a functional ignitor.

Abstract: A method for controlling a power conversion device for converting power from a power supply by controlling an input to a resonance circuit comprising a resonance coil and a resonance capacitor, with a switching element, the method comprising simultaneously changing a switching frequency and a time ratio of the switching element so that the switching element satisfies a condition of zero-voltage switching when an output power of the power conversion device is changed.

Abstract: A charging energy control system includes an implantable medical device (IMD) and an external charger for effectuating wireless power transfer. The IMD receives charging energy to recharge a battery during an ON period and rejects the charging energy during an OFF period. A series switch is disposed between the IMD's coil and rectifier circuitry that is controlled by voltage regulation circuitry operative to generate a clamp control signal configured to detune the coil in the OFF state.

Abstract: A controller controls a first inverter drive circuit and a second inverter drive circuit. The first inverter drive circuit drives a load having a load current larger than the second inverter drive circuit. The first inverter drive circuit includes a control ground terminal and a drive ground terminal which are isolated from each other. The ground terminal of the second inverter drive circuit is connected to the ground of the controller. The control ground terminal of the first inverter drive circuit is connected to the ground of the controller. The drive ground terminal of the first inverter drive circuit is connected to the negative side of the first inverter circuit.

Abstract: The present invention relates to a drive device for an illuminating load, an illumination device, a lighting system and a method for controlling the lighting system, wherein the drive device is connected between the illuminating load and a power adapter device for power supply, wherein the drive device comprises a control unit, wherein the control unit is configured to adjust the impedance of the drive device according to an electric output signal measured from the illuminating load so as to accordingly adjust the output voltage of the power adapter device and thereby to adjust the electric output signal for the illuminating load.

Abstract: Light output from an LED light source is increased or reduced in response to adjustment of a triac-based dimmer having a triac holding current to maintain conduction of the dimmer. An LED controller to control the light output includes a voltage-controlled impedance to provide an adaptive holding current that causes a triac current of the dimmer to be greater than the triac holding current, particularly when the dimmer is adjusted for significantly low light output (e.g., less than 5%, 2%, or 1% of full power light output). The adaptive holding current also allows for smooth increase of the light output starting from low light output, without perceivable flicker or shimmer. In one example, the voltage-controlled impedance is a resistive-like impedance that is placed on a secondary side of a transformer providing power to the LED light source. In another example, the voltage-controlled impedance is not pulse width modulated.

Abstract: In a control circuit of a switching power supply device, a switching cycle generating unit controls a switching cycle in keeping with a signal of an error voltage detected on a secondary side to stabilize an output voltage at a target value. A load current for overload protection is estimated based on a value produced by integrating a resonant current at an integrator and averaging at an averaging calculation unit. Here, although the switching cycle is correlated to the ratio of input/output voltages, the switching cycle is negatively correlated to the input voltage because the output voltage is controlled so as to be constant. A correction calculating unit uses a signal that decides the switching cycle as information corresponding to the input voltage, which eliminates the need to detect the input voltage.

Abstract: A projector panel includes pixel display, a display controller, and a pattern generator. The pattern generator is operative to output pixel data indicative of at least one application specific predetermined pattern. In a particular embodiment, the projector panel is a liquid-crystal-on-silicon panel. In another particular embodiment, the projector panel is adapted for selective use in either structured light projection systems or conventional video projection systems.

Abstract: A lighting system includes a controller that is configured to provide thermal management for the lighting system by distributing excess energy in the lighting system through multiple power dissipation circuits. In at least one embodiment, the lighting system is a phase cut compatible, dimmable lighting system having one or more light sources selected from a group consisting of at least one light emitting diode and at least one compact fluorescent lamp. In at least one embodiment, the controller is configured to control the plurality of power dissipation circuits in accordance with a thermal management strategy to dissipate the excess energy in the phase cut compatible, dimmable lighting system. The particular thermal management strategy is a matter of design choice. The power distribution circuits include two of more of: a controlled switch path power dissipation circuit, a controlled link path power dissipation circuit, and a controlled flyback path power dissipation circuit.

Abstract: Provided are a piezoelectric element drive circuit and state detection method, and an image recording device which realize state detection of a piezoelectric element inexpensively and with a suppressed circuit scale in a drive circuit for rapidly driving a large-capacity load that uses negative voltage drive. An output potential (VOUT) of a boost unit (BST) is detected in a state in which VS_AMP supplied to an amplification unit (AMP) is set to a voltage lower than a maximum rating of a transistor (FET1) by SW1, supply of VS_FET to the boost unit (BST) is blocked by SW2, and an individual electrode (28) of a piezoactuator (30) is pulled down to VS_FET via a resistor (R6).

Abstract: A cable modem is provided in a premises. The cable modem is operated in a first mode with a first upstream passband. At least one fusible link in the cable modem is caused to be blown, which in turn causes the cable modem to upgrade to a second mode with a second upstream passband, greater than the first upstream passband, without use of any switch.

Abstract: A control circuit is configured to compare an input voltage measured through an input voltage detection circuit with a first threshold which is lower than a rated voltage of an external DC power supply and with a second threshold which is lower than the first threshold. The control circuit is configured, when detecting that a duration time in which the input voltage is kept lower than the first threshold reaches a predetermined holding period, to stop operating a switching device. The control circuit is configured, after detecting that the input voltage is lower than the second threshold, to more shorten a maximum ON time than that during a normal operation or lengthen an OFF time of the switching device than a maximum OFF time during the normal operation.

Abstract: Apparatus and methods for detecting lamp failure in a rapid thermal processing (RTP) tool are provided. Lamp failure detection systems are provided that can accommodate DC and/or AC voltages. The systems sample voltage signals along a circuit path formed by at least two serially connected lamps, calculate a voltage drop across the first lamp of the at least two serially connected lamps based on the sampled voltage signals, and determine whether a lamp failure has occurred based on a relationship between the voltage drop across the first lamp and a total voltage applied to the circuit path.

Abstract: An LED array switching apparatus, comprises: a plurality of LED segments D1 to Dn connected in series, each LED segment having a forward voltage; a voltage supply coupled to the plurality of LED segments; and a plurality of constant current sources G1 to Gn, coupled to outputs of LED segments D1 to Dn, respectively. Each of the constant current sources is switchable between a current regulating state and an open state such that as the voltage of the voltage supply increases, LED segments are switched on and lit to form a higher forward voltage LED string, and as the voltage of the voltage supply decreases, segments are switched off and removed from the LED string starting with the most recently lit segment.

Abstract: A power source includes a rectifying unit configured to full-wave rectify an AC voltage to be input, a first and second converter configured to convert the voltage rectified by the rectifying unit, a zero cross detection unit configured to detect a zero cross of the AC voltage, a voltage detection unit configured to detect the AC voltage, a first capacitance element connected across a potential after being subjected to rectification by the rectifying unit and a ground, a first discharging resistor configured to discharge electric charges charged in the first capacitance element, a first switch unit configured to cut off a current flowing to the first discharging resistor and a stopping unit configured, in a case where the AC voltage is detected by the voltage detection unit and the detected voltage is smaller than a threshold value, to stop the operation of the second converter.

Abstract: Anti-arcing circuits are described herein that are configured to prevent or substantially mitigate arcing when a power adapter is connected/disconnected from a client device. The anti-arcing circuit restricts power supplied when a connection of a connector of a power adapter to the adapter interface is not fully established. The anti-arcing circuit is further configured to detect when a connection is made and remove the restriction to supply power for operations of the client device. In one approach, the anti-arcing circuit includes two different paths and components associated with a detection mode and operational mode respectively. In the detection mode, power supply is suppressed and a current pulse may be sent to determine if a connection is established. If current is detected, a switch is made to operational mode and power for normal device operations is supplied.

Abstract: Control unit decreases power to be supplied to high-pressure discharge lamp when an output voltage or an output current for high-pressure discharge lamp measured by measurement unit is in an abnormal range. Drive unit driving switching element includes capacitor that supplies, to a control electrode of switching element disposed on high potential side, electric charge necessary for turning on switching element disposed on high potential side when switching element disposed on low potential side is turned off. When high-pressure discharge lamp is started up, a discharge lamp lighting device starts to charge capacitor before DC/DC converter is started to operate, and control unit has a determination period for determining presence/absence of an abnormality based on a measured value acquired by measurement unit in a state in which DC/DC converter and DC/AC inverter are operated after completion of charging of capacitor.

Abstract: An electronic ballast and startup method including an electronic ballast operably connected to a lamp having a lamp filament, the electronic ballast having a timer (110) generating an inverter control signal (112) and a preheat control signal (114); a converter (120) receiving AC power and generating DC power (122); a self-oscillating inverter (130) receiving DC power (122) and being operable to provide lamp power (132) to the lamp, the self-oscillating inverter (130) being responsive to the inverter control signal (112); and a filament preheater (140) receiving DC power (122) and being operable to provide filament power (142) to the lamp filament, the filament preheater (140) being responsive to the preheat control signal (114). When AC power is initially applied, preheat control signal (114) directs the filament preheater (140) to provide filament power (142), and inverter control signal (112) directs the self-oscillating inverter (130) not to provide lamp power (132).

Abstract: An electronic ballast for driving a gas discharge lamp includes an EMI filter, a bridge rectifier coupled to a DC bus without a conventional electrolytic capacitor, a passive valley fill circuit built as a network having 4 charge/discharge energy storage capacitors and 9 diodes (4C9C), and a resonant DC to AC high frequency inverter for powering gas discharge lamp. The 4C9D circuit divides the rectified peak voltage by four and the low output voltage of the circuit is used to provide continuous lamp operation. The result is a ballast having substantially improved power factor, total harmonic distortion, and current crest factor. The electronic ballast is provided with a dimming capability from a TRIAC based wall dimmer.

Abstract: A compact fluorescent lamp (CFL) ballast driver includes first, second and neutral AC voltage terminals, a full wave rectifier between the first AC voltage terminal and the neutral AC input terminal, and a separate branch between the second AC voltage terminal and the neutral AC input terminal. A resonator circuit includes at least two inductors and provides its output voltage to a CFL lamp. The driver includes a first state detector circuit to monitor the first AC voltage terminal, and a second state detector circuit to monitor the second AC voltage terminal. The first and second state detector circuits activate respective first and second switches. The first switch shunts one inductor of the resonator circuit, and the second switch shunts another inductor of the resonator circuit. The driver can be housed in a CFL having a capper, a three-way lamp base adjacent to the capper and an arc tube.

Abstract: A light adjusting device for adjusting the luminance of a light source is provided. The light adjusting device comprises a rectifier module, a first switch element, a second switch element and a control module. The rectifier module receives an AC signal from a first power node and a second power node, and rectifies the AC signal to output a driving signal to the light source. The first switch element is coupled to the first power node. The second switch element is coupled to the second power node. The control module outputs a control signal to the first and second switch elements to control the conduction states of the first and second switch elements. When the first and second switch elements are turned on, the driving signal provided to the light source is interrupted.

Abstract: An illumination apparatus includes: a series circuit of a thyristor and at least one load circuit connected across an AC power source; a current control circuit for adjusting an input current to be maintained at a predetermined level during a part or the whole of an ON period of the thyristor; and a short circuit for short-circuiting input ports of the load circuit to have a predetermined resistance during a part of the ON period of the thyristor and a part or the whole of an OFF period of the thyristor. The current control circuit and the short circuit are connected in parallel to the load circuit.

Abstract: The present invention provides a protection circuit with low energy-consumption and a driving circuit thereof. The protection circuit includes a detection circuit and a switch circuit. The switch circuit is disposed between a power supply circuit and a peripheral step-down shunt. The detection circuit and the switch circuit are connected for controlling. The switch circuit includes a PNP triode or a P MOS transistor connected between the power supply circuit and the peripheral step-down shunt. A base of the PNP triode or the P MOS transistor is connected to a drain of another N MOS transistor through a resistor, and a gate of the N MOS transistor is connected to a status pin of the detection circuit. The present invention solves drawbacks of existent input voltage after the circuit entering a protection state causing unnecessary energy-consumption in peripheral small-signal circuit and voltage-dividing resistors.

Abstract: An illumination system includes a lighting apparatus having a solid-state light emitting element as a light source; and a dimmer including a bidirectional switching element having a self-sustaining function and connected to a serial circuit of the lighting apparatus and an external power source. The dimmer varies a conduction angle of the bidirectional switching element by controlling a phase of an AC voltage of the external power source, wherein the lighting apparatus performs dimming of the light source based on the conduction angle of the bidirectional switching element, and the dimmer continues to apply driving current to the bidirectional switching element during a first period, which is a part of a second period, the bidirectional switching element being allowed to conduct throughout the second period.

Abstract: An Alternating-current-Direct-current (AC-DC dual-use) Light Emitting Diode (LED) driving circuit includes an input power circuit, a buck-boost converter, and a Pulse Width Modulation (PWM) signal controller. The buck-boost converter, including a switching transistor and a feedback resistor, receives a current signal output from the input power circuit, and drives an LED with a driving signal. The PWM signal controller outputs a PWM signal according to the driving signal, so as to sequentially turn on and turn off the switching transistor. One end of the feedback resistor is coupled to the LED, and a floating ground terminal of the PWM signal controller is coupled to the switching transistor and the other end of the feedback resistor. Therefore, the AC-DC dual-use LED driving circuit is capable of dynamically adjusting the duty ratio of the PWM signal without connecting an external photocoupler.

Abstract: An LED constant-current drive circuit includes a BUCK circuit consisting of a transformer T1, a diode D9, a capacitor C5 and a field effect transistor Q1; a voltage limiting circuit consisting of a resistor R1, a diode D8, a capacitor C1, a resistor R3, a triode Q2, a zener diode DZ1 and a diode D10; and a current limiting circuit consisting of a resistor R4, a triode Q3, a triode Q4 and a resistor R2. When the transistor Q1 is turned on, a current flows through a primary side of the transformer T1 and an LED load, and then flows through the transistor Q1 and the resistor R2, and then flows back to a negative electrode of a power supply. When the transistor Q1 is turned off, the current flows through the primary side of the transformer T1, the LED load and the diode D9, thus forming a loop.

Abstract: A circuit for driving a light emitting diode (LED) comprises: an alternating voltage power supply, comprising a triac dimmer having a firing angle and output terminals that provide power to the LED; a zero crossing detector that detects a polarity change of the alternating voltage provided by the alternating voltage power supply and provides a zero crossing output signal indicative of the zero crossing; a timer triggered by the zero crossing output signal that generates a timer output signal during a time period of the timer; and LED power circuitry that reduces current to the light emitting diode based upon timing characteristics of the timer output signal.

Abstract: An LED bulb is described, comprising LEDs within a shell and a driver circuit to operate the LEDs at a plurality of brightness levels. The driver circuit comprises first and second inputs to receive AC, a neutral input, a converter circuit, first and second rectifier circuits, a detector circuit, and a processing circuit. The first rectifier circuit is connected to the first and neutral inputs and rectifies the AC received. The second rectifier circuit is connected to the second and neutral inputs and rectifies the AC received. The detector circuit is connected to the first and second rectifier circuits. The processing circuit has a first and a second processor input, and is connected to the detector circuit. The processing circuit produces a chop signal with a duty cycle based on whether the first or second input is hot. The converter circuit powers the LEDs based on the chop signal.

Abstract: A solid-state light-emitting element drive device includes a switching regulator and a control circuit. The switching regulator includes a series circuit of a switching element and an inductor, a regenerative element configured to allow a regenerative current to flow therethrough from the inductor when the switching element is turned off, and output terminals configured so that a solid-state light-emitting element is connected therebetween. The control circuit is configured to control a switching operation of the switching element of the switching regulator. The control circuit is configured to suppress an output power of the switching regulator if a parameter obtained from at least one of an ON-period and an OFF-period of the switching element is out of a prescribed range.

Abstract: A direction indication lamp control device includes: a current control element including an end which outputs a drive current having a magnitude corresponding to amplitude of a pulse signal; a current clamp unit which limits the drive current to a current upper limit value; a voltage clamp unit which limits a reference voltage to a voltage upper limit value; and a wire disconnection detection unit which outputs a wire disconnection detection signal in a case where the drive current corresponding to the pulse wave of the pulse signal is equal to or less than a wire disconnection detection value, or in a case where the reference voltage is equal to the voltage upper limit value. The current upper limit value is smaller than the drive current flowing through a direction indication lamp when the reference voltage is the voltage upper limit value.

Abstract: The invention discloses an illumination control circuit and an illumination control method. The illumination control method includes modulating an alternating current input signal and accordingly generating a dimming signal, which includes several waveform pulses each with an adjustable conduction angles; continuously sampling the waveform pulses of the dimming signal and forming an average waveform pulse from the sampled waveform pulses; extracting the average waveform pulse, which has an average conduction angle corresponding to the conduction angles of the waveform pulses; performing an integration on the sampled average waveform pulse and accordingly generating a current-controlling signal; and driving an illumination lamp according to the current-controlling signal.

Abstract: A driver circuit for driving an LED includes a rectifier circuit to receive AC voltage and to convert the AC voltage to DC voltage. The driver circuit further includes a filter circuit for filtering the DC voltage. The driver circuit further includes a detection circuit for determining a change in the filtered DC voltage over a predetermined time interval. The driver circuit further includes a dampening circuit for dampening the filtered DC voltage responsive to the detection circuit determining that the change in filtered DC voltage over the predetermined time interval exceeds a predetermined threshold.

Abstract: A power supply has a TRIAC dimmer, and an AC-DC converter connected to the TRIAC dimmer. The AC-DC converter has a power switch, a bleed switch, and a controller. The controller turns off the bleed switch in a first time duration and turns on the bleed switch in a second time duration. Magnitude of a current of the power switch in the first time duration is larger than magnitude of a current of the power switch in the second time duration. Magnitude of a current of the bleed switch in a third time duration within the second time duration is smaller than magnitude of a current of the bleed switch in a fourth time duration within the second time duration.

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: Various embodiments of a dimmable power supply are disclosed herein. For example, some embodiments provide a dimmable power supply including an input current path, a switch in the input current path, an energy storage device connected to the input current path, a load output connected to the energy storage device, and a timer-based variable pulse generator connected to a control input of the switch. The timer-based variable pulse generator is adapted to generate a stream of pulses having a variable on-time and off-time. The dimmable power supply is adapted to vary the on-time and off-time to control a current at the load output.

Abstract: Various embodiments of the invention provide power factor correction in solid state lighting applications. In certain embodiments, an LED driver for an LED array is controlled for power factor correction by a control circuit block. The control circuit block comprises electronic circuitry that enables the input current to the LED driver to be measured and controlled. This control circuit block comprises at least one switching device that enables an alternating form of current at a particular frequency to be applied to the LED array regardless of whether the main power source is a DC or AC power source.

Abstract: A ballast including a latching circuit is provided. The ballast includes an inverter circuit for providing an oscillating voltage signal to energize a lamp set, a control circuit for controlling operation of the inverter circuit, and a voltage supply circuit for providing a supply voltage to the control circuit. The ballast also includes a fault detection circuit for detecting a fault condition and a latching circuit connected to the fault detection circuit. The latching circuit is configured to drain the supply voltage and thereby disable the control circuit so that operation of the inverter circuit is discontinued during a fault condition.

Abstract: Provided is an LED driving circuit (4), including: an impedance detecting section (7) for detecting an impedance value of a phase-control type dimmer (2); and an impedance adjusting section (6) for adjusting an impedance of the LED driving circuit (4) based on the impedance value detected by the impedance detecting section (7).

Abstract: A temperature control method for light emitting diode (LED) is disclosed, and the method comprises the following steps: acquiring the present temperature of the LED during the light emission of the LED; obtaining a driving electric current corresponding to the present temperature based on the present temperature of the LED; and driving the LED based on the driving electric current. This invention further discloses a temperature control device for the LED and a liquid crystal display.

Abstract: A circuit for connecting to a dimmer, the circuit configured to receive an input signal from the dimmer. The circuit comprises a first load and a switch. The switch is operable to automatically engage the first load at a predetermined time from a zero-crossing of the input signal and automatically disengage the first load at other times.

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: An apparatus and method provides a driver circuit that provides for power factor correction (PFC) to a load, such as a solid-state lighting (SSL) device, such as, for example, a light emitting diode (LED) or an array or cluster of LEDs. A programmable reference is provided in the circuit to operate in a fixed frequency peak current mode control (FFPCMC) or in a fixed frequency average current mode control (FFACMC). A driver circuit is employed to operate the SSL device using power derived from a main power source which may be DC or AC. In a FFPCMC embodiment, a programmable power reference is programmed to be a fixed DC voltage. In a FFACMC embodiment, source input current to the circuit can be programmed to be proportional to the rectified AC voltage after a bridge rectifier.