Abstract: A photocontroller operates one or more lamps, such as a GU24 compact fluorescent lamp, based on ambient light to provide dusk-to-dawn operation. The photocontroller includes a photosensor for detecting the level of ambient light. The photosensor provides a signal to a photocontrol circuit that controls a switching device to selectively provide power to the lamp based on the level of ambient light detected by the photosensor. A fault detection circuit monitors the level of ambient light and the status of the lamp to determine whether the photocontroller is operating properly. The fault detection circuit determines the status of the lamp based on current flow to the lamp as determined by a current sensor. In addition, the photocontroller can include a processor for performing certain photocontrol and fault monitoring functions.

Abstract: An arc protection circuit is provided for a current-fed, parallel-resonant inverter ballast. The circuit includes a lamp current rate of change sensing circuit coupled with one or more lamps to detect a total lamp current; a ballast shutdown circuit to disable the ballast in response to a disturbance in the detected signal; a startup delay circuit, at least a portion of which defines a first time delay from a predetermined condition during which the ballast can not be disabled by the shutdown circuit; and an automatic restart circuit to enable restarting of the ballast, at least a portion of which defines a second time delay during which the ballast remains disabled, after which the ballast is restarted.

Abstract: An improved LED traffic signal is provided. The LED traffic signal suitably includes a housing with an opening, a printed circuit board coupled to the housing, and a power supply system coupled to the printed circuit board. The power supply system includes a power supply module that receives an AC input voltage from an AC input line and transforms the AC input voltage into a DC voltage with a regulated current to power the LED load, and a synchronized power pulse circuit connected to the power supply that generates a synchronized power pulse representing a power consumption substantially equivalent to that of a halogen or incandescent traffic signal.

Abstract: A battery operated device such as a road stud comprises a micro-controller, a battery, and a light source. The micro-controller is configured to operate the battery to provide a train of power pulses to the light source, and each power pulse has a characteristic pulse period and a characteristic duty cycle comprising an on-cycle and an off-cycle. The micro-controller is turned on during the on-cycle and turned into a power saving or sleep mode during the off cycle. Setting the micro-controller into the power saving or sleep mode during the off cycle of the power pulse means substantial battery power saved to extend the operation time per charging of the battery.

Abstract: Semiconductor light emitting circuits include semiconductor light emitting diodes that are serially connected between a pair of input terminals. Four layer semiconductor devices, such as Shockley diodes and/or thyristors are also provided, a respective one of which is connected across a respective one of the semiconductor light emitting diodes. The four layer semiconductor devices can allow a string of light emitting diodes to continue to be lit if one light emitting diode fails.

Abstract: An LED drive circuit is an LED dive circuit that receives an alternating voltage to drive an LED, and includes a current remove portion that removes a current from a current supply line that supplies an LED drive current to the LED. If an input current to the LED drive circuit is an unnecessary current, the LED does not light because of current removal by the current remove portion. If the input current to the LED drive circuit turns into the LED drive current from the unnecessary current, the current remove portion decreases the amount of current removed.

Abstract: Solid state light source driving and dimming systems are provided that enable a plurality of solid state light source (e.g., LED) driver circuits to be coupled to a single AC voltage source. The driver circuits may include constant current circuitry configured to generate a constant AC current from the AC voltage source, and rectifier circuitry configured to generate a DC current to drive the solid state light source (e.g., LEDs). Dimming control includes shunt circuitry operable with a PWM switch to shunt the AC voltage source during certain portions of a PWM signal and to decouple the shunt circuitry from the AC voltage source during other portions of the PWM signal. Shunting the AC voltage source causes the interruption of the DC current to effectively turn off the LEDs. Decoupling the shunt circuitry may improve overall efficiency of power transfer to the LEDs.

Abstract: An illumination device includes a light source, an AC power source and a balance sensing switch. The AC power source is adapted for supplying an alternating current to the light source. The balance sensing switch is connected between the light source and the AC power source for automatically cutting off an electrical connection between the light source and the AC power source when the illumination device topples down.

Abstract: The present invention provides a LED device with the voltage-limiting unit and the shunt current-limiting resistance wherein a voltage-limiting unit is connected in series with a current-limiting resistance then connected in parallel with two ends of a LED, so that to constitute the light-emitting unit, thereby when plural of the light-emitting units are connected in series (including connected in series and parallel), the current of LED loaded with higher end voltage passing through the voltage-limiting unit is prevented to be overly high when subject to abnormal high voltage.

Abstract: The invention relates to a driver device for a load (11), particularly an LED/OLED unit (12; 20, 22), comprising a shunting switch (30) parallel to the load, a control unit (14, 26) for controlling the shunting switch (30), an energy storage element (40) adapted to supply energy to at least the control unit (14, 26), and a recharge control circuitry (46) arranged in series with the energy storage element (40), the series connection of energy storage element (40) and recharge control circuitry (46) being provided parallel to the shunting switch (30), wherein said control unit (14, 26) is adapted to activate said recharge control circuitry (46) and to switch said shunting switch (30) off, when said energy storage element (40) is to be recharged. The invention also relates to a method of driving a load (11).

Abstract: The lighting control device provides technology that, by means of a simple configuration, enables the disconnection of a light-emitting element to be detected with high accuracy during PWM dimming. The lighting control device for controlling lighting states of a light-emitting element, includes current supply unit for supplying a current, which is obtained by superimposing a bias current of a predetermined value on a pulse-shaped current whose size periodically fluctuates, to said light-emitting element, and a detection unit which detects a conductive state of said light-emitting element.

Abstract: According to one embodiment, a lighting device includes a power supply circuit and a control circuit. The power supply circuit lights a light source. The control circuit determines a threshold based on an output from the power supply circuit to the light source, and controls the power supply circuit to cause a protecting operation to be performed when an output voltage of the power supply circuit deviates from the threshold.

Abstract: Embodiments of a lamp having an internal fuse system are provided herein. In some embodiments, a lamp may include a transparent housing; a filament disposed in the housing, the filament having a main body disposed between a first end and a second end of the filament; a first conductor coupled to the filament at the first end of the filament; a first interceptor bar disposed in the housing and beneath the main body of the filament, wherein the first interceptor bar is coupled to the second end of the filament; a second conductor disposed proximate the first end of the filament and conductively coupled to the second end of the filament via the first interceptor bar, wherein the first interceptor bar is positioned such that an electrical short forms between the first and second conductors when the main body of the filament contacts the first interceptor bar.

Abstract: A low voltage LED Lamp produces variable illumination in response to industry standard lighting dimmers, through the use of an input voltage monitoring circuit which variably controls the current output of an integral driver in response to sensed changes in the input voltage. Input circuitry is employed to provide “ghost” loading in the case of high frequency voltage sources such as that provided by certain electronic ballasts requiring minimum loads to operate. Additionally, the capacitive nature of prior art LED driving circuits is altered, increasing power factor and further helping electronic ballasts run properly. A firmware algorithm adapts to the output voltage capability of the driving transformer, dynamically adjusting the illumination to achieve the best dimming curve suited to each transformer. The circuit employed drives high power LEDs, and the lamp is preferably adapted to fit common MR16 size fixtures. Illumination output equivalent to similar size halogen bulbs is achieved.

Abstract: A light emitting module driver circuit utilized for driving a light emitting module includes a voltage dividing module, a short circuit detection module, and a driving module. A method of performing short circuit protection in the light emitting module driver circuit includes disabling the driving module during a dimming off cycle of the light emitting module driver circuit, enabling the voltage dividing module during the dimming off cycle, dividing a voltage of the light emitting module to generate a divided voltage during the dimming off cycle, and generating a short circuit protection signal according to the divided voltage during the dimming off cycle.

Abstract: The invention relates to an LED lamp (1, 1?, 1?, 1??, 1??) comprising at least one light emitting diode (LED, 2) arranged in a housing (3), and an isolation monitoring device (4) configured to determine a defect of the housing (3) and disconnect said at least one LED (2) from power in case said defect is detected, to enhance the safety of the LED lamp (1, 1?, 1?, 1??, 1??) and reduce the risk of electric shock for a user.

Abstract: A starter stopper for use with a high intensity discharge (HID) lighting source includes a timer and switch. The timer controls the durations of on-time and off-time periods during an energizing period. The starter stopper connects the HID lighting source to power to start the HID lighting source during on-time periods, and disconnects the HID lighting source from the power to start the HID lighting source during off-time periods. A method of starting and stopping an HID lighting source includes initiating an energizing period in response to application of power to a starter stopper, enabling the HID lighting source to be connected to power to start the HID lighting source during on-time periods by the starter stopper, enabling the HID lighting source to be disconnected from the power to start the HID lighting source during off-time periods by the starter stopper, and stopping the energizing period in response to removal of the power to the starter stopper.

Abstract: The invention provides an ignition control device and a killing control device correspond. An ignition control device comprises an ignition circuit module and a killing control device corresponds. The ignition circuit module comprises a killing control device including a killing switch and a timing retard circuit module connected to the ignition circuit module. When the killing control operates, the ignition circuit stops igniting. The invention has following advantages: reasonable structure, low cost, stable control circuit and safe operation and so on.

Abstract: An apparatus and method thereof for igniting and operating a high intensity discharge (HID) lamp during an in service life, and powering down the lamp when an end-of-life (EOL) lamp condition is detected. The apparatus and method defines a series of thresholds of lamp voltage asymmetry, or rectification thresholds, and monitors the lamp rectification from ignition through normal operation. The detection scheme is masked off for a predetermined period of time when the lamp is initially started. Thereafter, the rectification threshold of the lamp voltage asymmetry is gradually reduced over time, until a defined minimum rectification threshold level is reached and maintained. The method continuously monitors the lamp voltage and records whenever the lamp voltage asymmetry is higher than the rectification threshold level at any lamp voltage cycle.

Abstract: A power supply control device for lamp includes a control unit, the control unit receives a forward voltage signal and a reverse voltage signal simultaneously from a zero-crossover sampling circuit and determines if a connected load is an LED lamp, then the control unit turns on a tri-electrode AC switch (TRIAC) after an operating voltage for the LED voltage is reached, thereby outputting the AC power to an outlet for illuminating the LED lamp; since the TRIAC can be turned on with the forward voltage or the reverse voltage, the LED lamp is powered with a stable power supply to prevent the LED lamp from blinking.

Abstract: An automobile LED driving device includes a current setting portion to set multiple reference currents independently from one another for multiple respective current setting resistors connected externally, a current controller to select one of the multiple reference currents based on a control signal provided from outside, and an output transistor to control an output current to an automobile LED connected externally based on the reference current selected by the current controller.

Abstract: A semiconductor component and a method for manufacturing the semiconductor component, wherein the semiconductor component includes one or more transient voltage suppression structures. In an embodiment, the semiconductor component may include an over-voltage detection circuit, an over-current detection circuit, an over-temperature detection circuit, an ESD protection circuit, or combinations of these circuits.

Abstract: A driver (1) for driving a gas discharge lamp (2) comprises:—a current source (3) generating lamp current, having a setpoint input (4) for receiving a setpoint signal;—a controller (10) generating a current setpoint signal (SM);—a controllable noise signal source (20) generating a pseudo random noise signal (SPRNS);—an adder (22) adding the current setpoint signal (SM) from the controller and the pseudo random noise signal (SPRNS) from the noise signal source, and providing the result to the setpoint input of the current source;—measuring means (40) measuring a characteristic lamp response of the lamp in response to the pseudo random noise signal (SPRNS), and providing to the controller a sense signal;—a memory (30) associated with the controller, having stored therein at least one reference signal. The controller compares the measured lamp response with said predetermined reference signal in the memory, and may switch off the lamp.

Abstract: A blackout light bulb has a housing with an Edson screw at one end for screwing into a light fixture socket and a plurality of spaced apart LEDs mounted to its opposite end. A flexible stalk is connected to the housing between the Edison screw and the LEDs and can be bent into a selected shape for positioning a free end of the stalk as desired. A circuit board in the housing has an electronic circuit connected to the Edison screw, to the LEDs and to a photo cell at the free end of the stalk. A rechargeable battery in the housing is connected to the circuit board so that it is charged under certain normal conditions and so that it lights up the LEDs under other blackout conditions.

Abstract: There is provided a lighting control circuit comprising a duty cycle detection circuit, an averaging circuit, a waveform generator and a comparator circuit. The duty cycle detection circuit generates a first periodic waveform having a duty cycle and frequency corresponding to an input waveform duty cycle and frequency. The averaging circuit generates a first signal having a voltage level corresponding to the duty cycle of the first periodic waveform. The waveform generator outputs a second periodic waveform having a frequency different from the input waveform frequency. The comparator circuit compares the second periodic waveform with the first signal to generate an output waveform having a duty cycle corresponding to the input waveform duty cycle and a frequency corresponding to the frequency of the second periodic waveform. Also, there are provided methods.

Abstract: A circuit structure for LCD backlight is disclosed in the present invention. The circuit structure includes an inverter topology, a current balance circuit, and a plurality of loads. The current balance circuit is coupled to the plurality of loads and capable of balancing current of N loads by using N/2?1 balance chokes. The circuit structure may further include a protection circuit which is coupled to the low voltage sides of the plurality of loads. The protection circuit is capable of sensing lamp voltages and providing a feedback signal to a controller. Furthermore, the protection circuit is composed of count-reduced and cost-competitive electronic elements.

Abstract: A photocontroller operates one or more lamps, such as a GU24 compact fluorescent lamp, based on ambient light to provide dusk-to-dawn operation. The photocontroller includes a photosensor for detecting the level of ambient light. The photosensor provides a signal to a photocontrol circuit that controls a switching device to selectively provide power to the lamp based on the level of ambient light detected by the photosensor. A fault detection circuit monitors the level of ambient light and the status of the lamp to determine whether the photocontroller is operating properly. The fault detection circuit determines the status of the lamp based on current flow to the lamp as determined by a current sensor. In addition, the photocontroller can include a processor for performing certain photocontrol and fault monitoring functions.

Abstract: Methods of protecting an electrical device, such as a ballast, from damage due to an inrush current, and devices incorporating such methods, are disclosed. A loss of input power received by the ballast is detected. In response, the ballast is entered into a standby mode. The ballast is able to remain in the standby mode for a standby period of time. The input power is monitored during the standby period of time to measure a start time. Measurement of the start time is triggered by the ballast receiving input power again. The ballast is entered into an active mode when the measured start time exceeds a protection time. The protection time corresponds to an amount of time needed for an inrush current to dissipate following input power again being received by the ballast, protecting the ballast from possible damage due to the inrush current.

Abstract: In an apparatus for driving a CCFL, a first inverter outputs a first alternating current (AC) voltage to one end of the CCFL. A second inverter outputs a second AC voltage having a reversed phase to the first AC voltage to the other end of the CCFL. A first current-voltage converting circuit converts a secondary current of a first transformer in the first inverter to a voltage and outputs the voltage as a first detection voltage. A second current-voltage converting circuit converts a secondary current of a second transformer in the second inverter to a voltage and outputs the voltage as a second detection voltage. A first abnormality detection circuit determines a circuit abnormality when the potential difference between the first and second detection voltages exceeds a predetermined first threshold voltage.

Abstract: An electrodeless lamp protecting device installed between an electrodeless lamp and a power source comprises a substrate having a feedback signal input module, a signal level determination module and a protection signal output module installed on the substrate. A signal of the power source is transmitted from the feedback signal input module to the signal level determination module, and the signal serves as a reference for an output signal of the protection signal output module, such that the electrodeless lamp has an automatic protection function upon the receipt of an abnormal signal.

Abstract: An end of life (EOL) detection circuit for a gas discharge lamp. The circuit includes a comparator for comparing an input voltage to first and second threshold voltages and providing an EOL signal; a sensing circuit for sensing a DC offset in the lamp-voltage during the EOL of the lamp; and a reference voltage setting circuit responsive to the DC offset including a reference diode for setting an adjustable reference voltage as said input voltage to the comparator.

Abstract: An LED light bulb which turns itself permanently off when it reaches the end of its useful life, and more particularly, to a scheme which slightly varies the end-of-life condition from unit to unit.

Abstract: A circuit arrangement for operating an OLED may include a current source to supply the OLED with power; an OLED voltage measuring device configured to provide at its output a signal which is correlated with the voltage dropping across the OLED; an evaluation device configured to provide at its output a first signal if the voltage dropping across the OLED lies above a specifiable threshold value, and to provide a second signal if the voltage dropping across the OLED lies below the specifiable threshold value; an electronic switch having a reference electrode, a working electrode and a control electrode; and at least one ohmic resistor; wherein the series connection of the at least one ohmic resistor and the working electrode-reference electrode section of the electronic switch is connected in parallel with the OLED.

Abstract: The present invention provides, in one embodiment, a gas discharge lamp ballast with an integral shutdown timer. The ballast includes a circuit for receiving AC power, a converter circuit for converting the AC power to DC power and a square wave oscillator powered from the DC power. A resonant circuit powered by the square wave oscillator supplies power to at least one gas discharge lamp. A time-delay circuit disables the square wave oscillator, without interrupting the DC power supplied to the oscillator, upon the passage of a predetermined period of time from power-up of the AC power. The ballast can be realized with only a marginal increase in cost and size of the ballast.

Abstract: The light emitting device has a limiter transistor which is connected to a monitoring element, and an inverter an output terminal of which is connected to a gate electrode of the limiter transistor and an input terminal of which is connected to one electrode of the limiter transistor and the monitoring element. In the case where the monitoring element is short-circuited, the limiter transistor can be turned off by the inverter to correct a defect of the monitoring element.

Abstract: An apparatus is disclosed that is capable of delivering substantially constant power to a luminous load in response to variation in the input voltage and variation in the environment temperature. The apparatus may be further adapted to vary the power supplied to the luminous load in response to changes in the input voltage produced by a dimmer circuit. In other words, during non-dimming applications, the apparatus is able to maintain substantially constant power supplied to the load even though the input voltage and environment temperatures are varying during typical daily operations. Additionally, if the input voltage is changed due to a user controlling a dimmer device to control the brightness of the luminous load, the apparatus is able to control the power delivered to the load in response to the dimmer device.

Abstract: An electronic ballast has control circuitry to provide a pre-heating signal to the filaments of a gas discharge lamp for a predetermined length of time before the lamp is ignited and, further, cease providing the pre-heating signal after the lamp has been ignited.

Abstract: The configurations of an end of lamp life protection circuit for a ballast and a method thereof are provided in the present invention. The proposed circuit includes a voltage-dividing circuit receiving an input voltage and outputting a first and a second divided voltages and a switch apparatus raising the first divided voltage when the second divided voltage is less than a first pre-determined threshold value and turning off the ballast when the first divided voltage is higher than a second pre-determined threshold value.

Abstract: Electronic ballasts, driver apparatus, and methods are provided in which a heating current is generated by the driver to power a resistive heating element of an insulation detector associated with a recessed can fixture using a regulated current source/sink circuit.

Abstract: An LED lamp for outdoor and large space lighting, particularly for streets, warehouses car parks and the like, is adapted for fitting into legacy light fittings designed for sodium bulbs and the like. The LED lamp comprises a plurality of light emitting diodes arranged over a surface of the lamp, is rotatably connected through a rotatable electrical connection to a screw-in adaptor for insertion into a legacy screw-in socket, such that the screw in adaptor is rotatable independently of the lamp, so that the legacy screw in socket can be used even though the light fitting is too small to allow rotation of the LED lamp. Additional embodiments provide for cooling airflow through the light fitting, for temperature control of the LEDs, and for failure protection, to ensure a longest possible lamp lifetime.

Abstract: A semiconductor laser device has a cathode grounded and an anode connected to a collector of a transistor. The transistor has an emitter grounded and a base connected to a first external terminal via a first resistor. A digital transistor has a collector connected to the base of the transistor, an emitter grounded, and a base connected to a second external terminal via a resistor. When a voltage equal to or higher than the predetermined first voltage is applied to the base of the transistor, the transistor is put into a conducting state, and the semiconductor laser device is grounded via the transistor and thereby protected from static electricity and leak current.

Abstract: A ballast circuit for a light emitting diode (LED) based lamp including power factor correction with protective isolation. The circuit includes a transformer with electrically isolated windings and a power factor correction circuit that receives no feedback from a secondary winding side of the transformer. An LED-based lamp assembly and a method of driving an LED-based light source are also provided.

Abstract: A shut-down circuit configured for use with an electronic ballast coupled to a lamp in a control path includes a device for sensing the electrical energy associated with the control path, and a sensing circuit for shutting down the ballast in the event that the energy does not conform to a predetermined condition. The sensed energy may be current indicative of lamp installation or short circuit, or voltage indicative of arcing or open circuit. The device for sensing the electrical energy associated with the control path may be an isolation transformer, or alternative devices such as optical isolators may be employed. The circuitry may further include electronic componentry to disable the sensing circuit during initial energization of the lamp.

Abstract: An apparatus and method thereof for igniting and operating a high intensity discharge (HID) lamp during an in service life, and powering down the lamp when an end-of-life (EOL) lamp condition is detected. The apparatus and method defines a series of thresholds of lamp voltage asymmetry, or rectification thresholds, and monitors the lamp rectification from ignition through normal operation. The detection scheme is masked off for a predetermined period of time when the lamp is initially started. Thereafter, the rectification threshold of the lamp voltage asymmetry is gradually reduced over time, until a defined minimum rectification threshold level is reached and maintained. The method continuously monitors the lamp voltage and records whenever the lamp voltage asymmetry is higher than the rectification threshold level at any lamp voltage cycle.

Abstract: A lamp includes a light source, a power tool battery for providing a DC voltage level, and a base for housing the power tool battery. A stem is coupled to the base and supports the light source. A power inverter converts the DC voltage level to an AC voltage level, and a current sensing circuit operatively coupled to the converter or the inverter senses an over-current condition when the converter or the inverter draws more than a predetermined amount of current. The converter or inverter is disabled if the over-current condition continues for more than a predetermined amount of time so that the light source receives the AC voltage level and is illuminated for the predetermined amount of time before power is removed.

Abstract: A lighting apparatus receives a regulated AC line voltage as an input voltage and comprises a light emitting diode array and a driving circuit. The light emitting diode array is composed of at least one light emitting diode set connected in parallel. The driving circuit has a plurality of outputs corresponding to the light emitting diode sets, and each output has a predetermined value for controlling the brightness of the light emitting diode set. Each light emitting diode set is conducted automatically and in sequence for a fixed time interval based on the output of the driving circuit and the amplitude of the regulated AC line voltage, and is turned off based on the predetermined signal of the driving circuit.

Abstract: A limited current circuit of this invention comprising: a transformer that raises an alternating current (AC) power supplied from the digital inverter to an AC voltage of a high voltage to light a lamp; a voltage/current detection unit that detects at least one of the current and voltage supplied to the lamp; an A/D converter that converts the detected voltage/current value of analog to a digital value; and a microcontroller unit (MCU) that induces an LCC check point after the start of a striking process, compares at least one of the output current value and voltage value from the transformer with a preset reference value on the basis of an output signal of the A/D converter and then shuts down the inverter when the output current value or voltage value is determined to be abnormal, wherein the reference value comprises at least one of the current value and voltage value measured at the LCC check point when an object having noninductive resistance is not contacted to the inverter.

Abstract: An illumination device includes a light source, an AC power source and a balance sensing switch. The AC power source is adapted for supplying an alternating current to the light source. The balance sensing switch is connected between the light source and the AC power source for automatically cutting off an electrical connection between the light source and the AC power source when the illumination device topples down.

Abstract: A PWM dimming circuit for a LED load including a LED load connected to the main LED drive circuit, a current loop configured to measure output current from the LED load, a current loop regulation circuit connected to the current loop, a main control circuit configured to receive a signal from the current loop when the LED load produces an output current, and a PWM dimming controller configured to provide a signal to control the current loop regulation circuit and to make the current loop operate in a closed-loop mode when the LED load produces the output current and to provide a shutdown signal to the main control circuit when the LED load does not produce the output current. When the output current is detected, the main control circuit controls the main LED drive circuit to set its output current at a predetermined load current.

Abstract: An LED device with simultaneous open and short detection function includes a plurality of LED strings, a voltage converter, a current driving unit, a loop control unit, an open detector, a short detector and a voltage detector. The open detector and the short detector are utilized for detecting LED open and LED short for the plurality of LED strings, respectively. The voltage detector is coupled to the open detector, the short detector and the voltage converter, and is utilized for generating a reset signal to the short detector according to an output voltage of the voltage converter when the LED open occurs on the plurality of LED strings, so as to initiate the LED short detection for the plurality of LED strings again.