Abstract: A driver assembly (100) for a lighting unit (230) comprises a control unit (110). The lighting unit (230) comprises a plurality of strands (240, 250, 260), wherein each strand comprises a series circuit (242, 252, 262) of light-emitting diodes and a current source (243, 253, 263) with a first and a second terminal (246, 256, 266), and wherein the series circuit (242, 252, 262) of diodes is connected between a supply voltage input (231) of the lighting unit (230) and the first terminal of the current source (243, 253, 263) and the second terminal (246, 256, 266) of the current source is connected to a reference potential terminal via a resistor (245, 255, 265).

Abstract: A light emitting diode luminance system includes a first power source, a voltage divider, a first switch, a clamping device, a plurality of current sources and a feedback circuit. The voltage divider is coupled to the first voltage source. The first switch is coupled to the voltage divider and a ground. The clamping device includes a plurality of transistors each coupled to a respective set of light emitting diodes and the voltage divider. The plurality of current sources is coupled to the plurality of transistors respectively. The feedback circuit is coupled to the plurality of transistors and the plurality sets of light emitting diodes.

Abstract: A light emitting module includes a plurality of light emitting device packages configured to be sequentially turned on or off according to the level of external drive voltage and connected to one another in series. Each of the plurality of light emitting device packages includes a light emitting cell having at least one light emitting device, and an on/off controller configured to control to turn the light emitting cell on or off.

Abstract: A feedback circuit for a power converter (e.g., a non-isolated converter) is disclosed. The feedback circuit may include a sense circuit coupled to receive an output current of the converter. A sense voltage may be generated across the sense circuit and a voltage-to-current converter may be used to convert the sensed voltage into a feedback signal representative of the output current. The voltage-to-current converter may include a variable shunt regulator, resistor, and transistor. A voltage across the shunt regulator may change in response to a change in voltage across the sense circuit, and the feedback signal may change in response to a change in the voltage across the shunt regulator. A controller may be coupled to receive the feedback signal from the feedback circuit and may control switching of a power switch to regulate the output current based at least in part on the feedback signal.

Abstract: A light-emitting device control method is provided. The light-emitting device control method comprises the steps outlined below. A light-emitting module of a light-emitting device having light-emitting unit string each having light-emitting units connected in series is operated. One end of each light-emitting unit strings receives a same DC voltage. A voltage drop value across each current control units connected in series to at least one of the light-emitting unit strings is retrieved to further determine whether the light-emitting unit of each of the light-emitting unit strings malfunctions. When x light-emitting units of a specific string malfunction and x is larger than or equal to a malfunction threshold value p, the x malfunctioned light-emitting units are shorted and (x?p+1) light-emitting units in each of the light-emitting unit strings other than the specific string are shorted. The DC voltage received by each of the light-emitting units is decreased.

Abstract: Disclosed are electronic control gears for LED light engines able to improve power factor by way of gearing up or down the LED current and the AC input current in response to and in synchronization with the AC input voltage. Moreover, the disclosed electronic control gears could further reduce flicker phenomenon and total harmonic distortion when used in collocation with disclosed valley fillers, filling the LED current valleys only during the dead time, and in conjunction with disclosed dummy loads, ramping up or down the AC input current only during the dead time.

Abstract: A load driving apparatus relating to light-emitting-diodes (LEDs) is provided. In the invention, a compensation voltage on a compensation pin (CMP) of a control chip would not be changed in response to (or with) the variation (i.e. enabling and disabling) of a pulse-width-modulation (PWM) signal for dimming. In other words, the compensation voltage on the compensation pin (CMP) of the control chip would be maintained in unchanging regardless of whether the PWM signal for dimming is enabled or disabled. Therefore, an LED string at the current switching transient does not have the generation of over-shoot current.

Abstract: Conditioning circuits are provided for driving two or more LED groups using a rectified AC input voltage. The conditioning circuits uses analog circuitry to gradually and selectively activate the LED groups based on an instantaneous value of the rectified input voltage. The circuit includes a first series interconnection of a first LED group, a first transistor, and a first resistor, and a second series interconnection of a second LED group, a second transistor, and a second resistor. In one example, the second series interconnection is connected between a drain terminal and a source terminal of the first transistor, while in another example, the second series interconnection is connected between an anode of the first LED group and a source terminal of the first transistor. The first and second LED groups are selectively activated by the rectified voltage applied across the first series interconnection.

Abstract: Provided is a LED lighting system, including a lighting device driver having a power converter for converting an input voltage into a first DC voltage and outputting a first current having a substantially constant current value; and a LED lighting device assembly connected to the lighting device driver through two contacts. The LED lighting device assembly includes a plurality of light-emitting diode lighting devices having a plurality of lighting device connection bases and a plurality of LED units. The lighting device connection bases are connected in series with each other to allow the LED lighting devices to be connected in series with each other, and the lamp voltage is applied across the positive terminal and the negative terminal of the lighting device connection base and is generated by dividing the first DC voltage, thereby allowing the lamp currents outputted by the lighting device connection bases are substantially equal.

Abstract: An LED constant current driving apparatus includes a power supply module; an LED module comprising one or more LEDs connected in serial, the LED module that is luminous by the power supplied by the power supply module; a current detection module connected to an output terminal of the LED module, to detect a current flowing to the LED module; an error amplification module configured to compare the current signal detected by the current detection module to a first preset signal and to amplify and output an error signal base on the result of the comparison; and a plurality of sequential driving control modules connected to the one or more LEDs provided in the LED module in serial, to compare the error signal amplified and outputted by the error amplification module to a second preset reference and to control luminosity and off driving of each LED of the LED module.

Abstract: A protection circuit of a DC-DC converter is disclosed. An input terminal of the DC-DC converter receives an input voltage and an output terminal of the DC-DC converter provides an output voltage. The DC-DC converter includes an output stage between the input terminal and the output terminal The protection circuit includes a current sensor, a comparator, a determining circuit, and a protection control circuit. The current sensor provides a sensing signal. The comparator compares a default over-voltage with the sensing signal to provide an over-current control signal. The determining circuit provides a determining control signal. The protection control circuit determines whether to enable a short protection according to the over-current control signal and the determining control signal.

Abstract: Electrical and mechanical connection for a series connected LED lamp to an appropriate electrical circuit. The circuit contains additional series connected light producing elements. To enable continuous operation of all the other light producing elements in the series circuit, the socket contains a device to bypass the series current to the remaining circuit elements in the case of a defective lamp or connection. Operation of the bypass device is controlled within the socket with operational parameters controlled either from within the socket or in conjunction with an external element in the lamp. The operation of the bypass circuit is latching, once operating the bypass will continue to operate until reset preventing unwanted flicker in the case of intermittent connections. The method of resetting the bypass circuit may be either manual or automatic. The socket bypass may contain a time delay to allow internal bypass circuits included within the lamp to operate before the socket bypass activates.

Abstract: A LED light source comprises a first rectifier (DB1) having input terminals coupled to an AC voltage source and output terminals connected by a first series arrangement comprising N LED loads and further comprises circuitry (I1, I2, I3, CC) for making the LED loads one by one carry a current when the momentary value of the AC voltage increases and one by one stop carrying a current when the momentary value of the AC voltage decreases. The LED light source also comprises a second rectifier (DB2) having input terminals coupled to the AC voltage source via a reactive element and LED1 LED2 LED3 output terminals connected by a second series arrangement comprising M LED loads and further comprises circuitry (I4) for making the LED loads one by one carry a current when the momentary value of the AC voltage present at the input terminals of the second rectifier increases and one by one stop carrying a current when the momentary value of the AC voltage decreases.

Abstract: An object of the present invention is to provide an organic EL element lighting device whereby surge current can be reduced at start-up while controlling start-up variation, along with a lighting fixture using the same. Provided are a current supply part for supplying lighting current to a light source formed of one or more organic EL elements and connected between output terminals of the current supply part, a current detection part for detecting the lighting current, a target setting part for setting a target value of the lighting current, and a control part for performing feedback control of the lighting current by controlling the current supply part so that the detected value of the current detection part matches the target value of the lighting current. The target setting part has a sweep period during which the target value is gradually increased at start-up of the light source.

Abstract: There is provided a light emitting diode (LED) driving apparatus configured such that a waveform of current input to an LED follows a sine wave, the LED driving apparatus including, a switching unit switching an LED unit having a plurality of LEDs receiving rectified power and emitting light, a driving control unit controlling the switching of the switching unit according to a voltage level of the rectified power, a current limiting unit limiting current flowing in the LED unit, and an adjusting unit adjusting current limitation of the current limiting unit according to the voltage level of the rectified power.

Abstract: A Light Emitting Diode (LED) light includes a bridge rectifier configured to be powered by an alternating current power source and to produce a rectified output. Control circuitry couples to the bridge rectifier and is configured to produce a shunt signal when the rectified output is less than a threshold voltage. A series connected Light Emitting Diode (LED) string includes a first group of LEDs and a second group of LEDs. A switch couples to a first side of the second group of LEDs and is controlled by the shunt signal to deactivate the second group of LEDs. The control circuitry may include a ratio metric series resistor string configured to sense a proportion of the rectified output and an inverter configured to generate the shunt signal based on the proportion of the rectified output.

Abstract: Driver circuit of light sources, particularly of the LED type, comprising a first and at least a second group of light sources, each connected to a common power supply terminal, a first and at least a second regulation circuit, each suitable for regulating the current absorbed by a respective group of light sources, at least one actuation circuit operatively connected to a respective second regulation circuit, and a serial connection circuit, suitable for connecting in series at least a first and a second group of light sources, when the voltage downstream of the first group of light sources is greater than or equal to the voltage upstream of the second group of light sources.

Abstract: There is provided a light emitting diode driving device capable of preventing a number of switches from being turned on simultaneously when a plurality of light emitting diodes are respectively driven using a plurality of switches, the light emitting diode driving device, including: a light emitting diode unit having a plurality of light emitting diodes connected to one another in series and emitting light through receiving rectified power; and a driving unit having a plurality of drivers driving the plurality of light emitting diodes of the light emitting diode unit, respectively, wherein each of the plurality of drivers selects a maximum voltage from among a plurality of detection voltages with respect to current flowing in at least one light emitting diode corresponding thereto and compares the maximum voltage with a preset reference voltage to thereby drive the corresponding light emitting diode.

Abstract: A light-emitting diode (LED) lamp includes a number of different color LEDs that can be turned on and off in different combinations using an external switch operable by a user. A user or a controller can adjust the color temperature of light output by the lamp. The color temperature change may be a user preference and can compensate for decreased phosphor efficiency over time.

Abstract: A lighting device and a method of controlling a light emitted thereby are disclosed. A lighting device including light emitting units configured of a plurality of light emitting diodes connected with each other in series according to the present invention may include a rectifier unit configured to rectify an alternation current voltage to supply the rectified voltage to each of the light emitting units, a control unit configured to control on and off of each light emitting unit according to the input voltage and light emitting units configured to be on and off based on the control of the control unit, wherein a first light emitting unit and a second light emitting unit are connected with each other in series, and the first light emitting unit and a third light emitting unit are connected with each other in parallel.

Abstract: An LED with an internal bypass transistor, particularly suited for use in a series wired LED string to keep the string lit in the event of a failure of an LED. In one embodiment, the collector and/or base of the bypass transistor is used as one terminal of the shunt and the emitter is used as the opposite terminal. The preferred embodiment is to use the collector and emitter terminals only with the base terminal open.

Abstract: A lamp is provided with a full-wave rectifier for convert AC to DC; a SPD electrically connected to the full-wave rectifier for protecting the lamp from voltage spikes; series connected LEDs electrically connected to the SPD; a microprocessor electrically connected to the SPD; series connected MOSFET start circuits electrically to the microprocessor, the MOSFET start circuits configured to switch electronic signals; and resistors each electrically interconnected the LED and the MOSFET start circuit. In response to a normal DC supplied from the SPD, the microprocessor creates a PWM signal to activate the MOSFET start circuits which in turn initiate operations of the LEDs via the resistors respectively. In response to an abnormal DC having voltage spikes supplied from the SPD, the microprocessor deactivates the MOSFET start circuits which in turn direct the DC through the resistors rather than supply the DC to the LEDs via the resistors respectively.

Abstract: Apparatus and associated methods involve operation of an LED light engine in which a relative intensities of selected wavelengths shift as a function of electrical excitation. In an illustrative example, current may be selectively and automatically diverted substantially away from at least one of a number of LEDs arranged in a series circuit until the current or its associated periodic excitation voltage reaches a predetermined threshold level. The diversion current may be smoothly reduced in transition as the excitation current or voltage rises substantially above the predetermined threshold level. A color temperature of the light output may be substantially changed as a predetermined function of the excitation voltage. For example, some embodiments may substantially increase or decrease a color temperature output by a solid state light engine in response to dimming the AC voltage excitation (e.g., by phase-cutting or amplitude modulation).

Abstract: A lighting device (10) includes a voltage converter (2) for generating a predetermined DC voltage, a detector (4) for obtaining a detection voltage corresponding to a predetermined DC voltage applied across a light source (20), a controller (3) for controlling the voltage converter (2) so that a current flowing through the light source (20) is constant, and a determination unit (5) for determining whether the detection voltage is a preset first reference voltage or higher. The first reference voltage is set higher by a specified voltage than the detection voltage, and is set to vary more slowly than the detection voltage. The controller (3) stops an operation of the voltage converter (2) when the detection voltage is determined to be the first reference voltage or higher through the determination unit (5).

Abstract: This invention relates to control circuits for LED systems with a feedback loop to regulate a drive voltage. A controller for the system is proposed comprising a plurality of LED circuits and a controllable power source. The controller comprises a control unit configured to cause regulation of the drive voltage based on a determination of a plurality of feedback voltages and a fault condition detecting means. At least one of the LED circuits is determined as having a fault condition if the respective feedback voltage is below a fault threshold. In response to a detected fault condition, a test voltage is applied to a cathode of the fault circuit to confirm the presence of a fault condition.

Abstract: The subject matter disclosed herein relates to a system for controlling strings of lights. This system can include a host controller, one or more strings of lights, and an effects modulator. Each string of light can include at least one LED light. The effects modulator can be operatively connected to the host controller and to the strings of light. The effects modulator can include a microcontroller and an inverter. The inverter can include a high side driver circuit and one or more low side driver circuits operatively connected to the high side driver circuit. Each low side driver circuit can be operatively connected to one of the strings of light. The microcontroller can be configured to receive one or more control signals from the host controller and control the strings of light via the inverter in accordance with the control signals. Related apparatus, methods, and techniques are also described.

Abstract: Disclosed is an LED lighting apparatus equipped with a high-efficiency power supply, capable of representing high power efficiency even in a low-power LED lighting apparatus by recycling a surplus voltage to charge a condenser, which supplies power to the controller, with the surplus voltage if the surplus voltage is generated from an LED acting as a load after a rectified voltage supplied to the LED has been consumed in the LED according to a design value.

Abstract: A load driving apparatus related to light emitting diodes (LED) is provided. The load driving apparatus includes a power conversion circuit, a complex function circuit, and a control chip. The power conversion circuit receives a DC input voltage and provides a DC output voltage to at least one LED string in response to a gate pulse-width-modulation (PWM) signal. The complex function circuit is serially connected with the LED string and provides a short-protection mechanism. The control chip is coupled to the power conversion circuit and the complex function circuit. The control chip generates the gate PWM signal to control the operation of the power conversion circuit, and when the LED string is short-circuited, the control chip controls the complex function circuit to activate the short-protection mechanism, so as to protect the load driving apparatus from being damaged.

Abstract: A light emitting diode (LED) backlight driving circuit includes an LED lightbar, and a constant current chip that controls current flowing through the LED lightbar. The LED backlight driving circuit further includes a comparison module that receives an output voltage of the LED lightbar. When the output voltage of the LED lightbar is greater than the preset reference voltage, the comparison module controls the constant current chip to switch off the current of the LED lightbar.

Abstract: Apparatus and method are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). A representative apparatus comprises: a plurality of LEDs couplable to form a plurality of segments of LEDs; a current sensor; and a controller to monitor a current level through an overall series LED current path, and to provide for first or second segments of LEDs to be in or out of the overall series LED current path at different current levels. The controller is configured to, in a first light emitting diode configuration, cause first and second segments of LEDs to be parallel to one another and in the overall series LED current path. The controller is further configured to, in a second light emitting diode configuration, cause first and second segments of light emitting diodes to be coupled in series and in the overall series light emitting diode current path.

Abstract: The present disclosure provides a light emitting diode driving circuit, comprising: a power conversion module having an input end, a control end and an output end, wherein the input end receives a voltage, the control end controls the regulation of the duty cycle signal therein according to a received control signal, and the output end outputs a DC voltage having a constant current and a variable voltage value; an overcurrent protection circuit having a switch module and a first resistor connected in series, wherein the overcurrent protection circuit and a LED load connected in series with each other are connected to the power conversion module, so as to turn off the electrical channel between the LED load and the power conversion module when overcurrent occurs; and an overvoltage protection circuit for outputting the control signal when overvoltage occurs and thereby protecting the LED load.

Abstract: A LED device with a voltage-limiting unit and a shunt current-limiting resistance where the voltage-limiting unit is connected in series with the current-limiting resistance then connected in parallel with two ends of a LED, so as 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 high when subject to abnormal high voltage.

Abstract: The present teachings provide a device and method of regulating current flow across an array of emitting diodes (LEDs) for the purpose of illumination. The device has a power supply (vext) connected to an LED array. The LED array is connected to a current foldback element, a current limitation element, a current sensing element, and a current switch. Current through the array of light emitting diodes achieves an upper current level, the current sensing element signals activation of the current limitation element, said current limitation element maintains current through the array of light emitting diodes at approximately the upper control limit.

Abstract: A solid state lighting apparatus can include a Light Emitting Diode (LED) string that includes a plurality of light emitting diode (LED) segments that are coupled in series with one another wherein a ratio of respective numbers of LEDs in each of the segments is about equal to a ratio of respective average powers for each of the respective segments. Other configurations are also disclosed.

Abstract: An apparatus, method and system are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). A representative apparatus comprises: a plurality of LEDs coupled in series to form a plurality of segments of LEDs; first and second current regulators; a current sensor; and a controller to monitor a current level through a series LED current path, and to provide for first or second segments of LEDs to be in or out of the series LED current path at different current levels. A voltage regulator is also utilized to provide a voltage during a zero-crossing interval of the AC voltage. In a representative embodiment, first and second segments of LEDs are both in the series LED current path regulated at a lower current level compared to when only the first segment of LEDs is in the series LED current path.

Abstract: A light-emitting diode (LED) lighting driver is provided, which includes a bridge rectifier, multiple LED sections, multiple shunt regulators, a weighted current mirror array, a mean power integrator, and a reference generator. The bridge rectifier provides a rectified sinusoidal voltage. The LED sections are coupled in series and coupled to the rectified sinusoidal voltage. Each shunt regulators regulates a shunt current flowing out from the LED sections according to a current reference value. The weighted current mirror array provides a plurality of copy currents. Each copy currents tracks the conduction time of one shunt regulator and also tracks the instantaneous output power of the LED sections. The mean power integrator provides a mean power value by integrating the copy currents. The reference generator provides the current reference values. Each current reference values is directly proportional to the difference between a mean power reference value and the mean power value.

Abstract: An LED driver controls current through an LED string. The LED driver generates a boosted PWM signal to drive a PWM transistor in the LED current path such that the PWM transistor maintains a substantially constant VGS, thus minimizing turn-on impedance of the PWM transistor. A current mirror circuit controls peak LED current when the PWM transistor is on. A trimming circuit includes a set of programmable switches to couple or decouple trimming transistor from the LED current path, and allowing for fine calibration of the LED current. By maintaining a low resistance and compensating for current mismatch in the LED current path, the LED driver provides efficient power performance and robustness that is particularly beneficial in high current applications.

Abstract: Apparatus and associated methods involve operation of an LED light engine in which a relative intensities of selected wavelengths shift as a function of electrical excitation. In an illustrative example, current may be selectively and automatically diverted substantially away from at least one of a number of LEDs arranged in a series circuit until the current or its associated periodic excitation voltage reaches a predetermined threshold level. The diversion current may be smoothly reduced in transition as the excitation current or voltage rises substantially above the predetermined threshold level. A color temperature of the light output may be substantially changed as a predetermined function of the excitation voltage. For example, some embodiments may substantially increase or decrease a color temperature output by a solid state light engine in response to dimming the AC voltage excitation (e.g., by phase-cutting or amplitude modulation).

Abstract: An apparatus includes an input node, a light-emitting diode (LED) string to receive a current from the input node, a voltage divider to output a control voltage, and a switch to receive the control voltage. The switch coupled to the LED string controls the current through the LED string according to the control voltage.

Abstract: An analog electronic circuit for driving a string of LEDs including input terminals for accepting connection to AC voltage, a current regulation circuit operatively coupled to receive an AC voltage from the input terminals and to provide an output for connection to drive the string of LEDs. Included is a current regulation circuit configured to limit the current flow through the string of LEDs on a half-cycle basis to a predetermined value. Also disclosed is an over voltage circuit configured to switch off electrical connection between the AC voltage and the string of LEDs upon the AC reaching a predetermined high voltage value on a half-cycle basis.

Abstract: The invention discloses an LED backlight driving circuit, an LCD device and a driving circuit. The LED backlight driving circuit includes a power supply module, an LED lightbar coupled with an output terminal of the power supply module, a dimming module coupled with the output terminal of the LED lightbar, and the LED backlight driving circuit further includes a transfer switch. A first input terminal of the transfer switch is coupled to the output terminal of the LED lightbar, and a second input terminal of the transfer switch is coupled to a feedback voltage. The output terminal of the transfer switch is coupled to the power supply module. The transfer switch is switched to the first input terminal when the dimming module is ON, and the transfer switch is switched to the second input terminal when the dimming module is OFF. Therefore, the LEDs of the invention can operate normally within the short dimming cycle.

Abstract: A light emitting diode luminance system includes a first power source, a voltage divider, a first switch, a clamping device, a plurality of current sources and a feedback circuit. The voltage divider is coupled to the first voltage source. The first switch is coupled to the voltage divider and a ground. The clamping device includes a plurality of transistors each coupled to a respective set of light emitting diodes and the voltage divider. The plurality of current sources is coupled to the plurality of transistors respectively. The feedback circuit is coupled to the plurality of transistors and the plurality sets of light emitting diodes.

Abstract: The disclosure regards to drivers and driving methods for a LED string consisting of LEDs. The LED string and a current switch are coupled in series between a power line and a ground line. The power line is powered to regulate a signal representing a current passing through the LED string. An enable signal capable of switching the current switch is provided. Whether a predetermined event occurs is detected. When the predetermined event occurs, the enable signal is clamped to have a predetermined logic value, the current switch thereby being kept either open or short.

Abstract: There are provided a light source apparatus and a vehicle headlight using the same. The light source apparatus includes a light emitting device array unit, a first detection unit, a driving unit, a second detection unit, and an interruption unit. A uniform quantity of light can be maintained and damage can be prevented.

Abstract: An intelligent power control system connects with a LED power adaptor and a LED light string and drives the LED light string to emit light. The intelligent power control system comprises a sensing-modulating-setting (SMS) unit and a digital power control unit. The SMS unit detects an infrared signal and generates a plurality of brightness-selection signals. The digital power control unit connects with the SMS unit and regulates the output power thereof according to the infrared signal and the brightness-selection signal of the SMS unit to modulate the brightness of the light emitted by the LED light string. The intelligent power control system can stepwise modulate the brightness of the LED light string to reduce power consumption without using any expensive sensor.

Abstract: A PFC LED driver capable of reducing current ripple, comprising: a current source unit, having a control terminal coupled to a control voltage, which is a ratio of a full-wave rectified line input voltage, a first channel terminal coupled to a power line, and a second channel terminal used to generate an output current according to the control voltage; and at least one LED load unit, being in series with the current source unit, wherein each of the at least one LED load unit comprises: a first load, including a first parallel combination of an LED module and a capacitor, wherein the LED module has at least one light emitting diode; a diode, being in a first series combination with the first load; and a switch, being in a second parallel combination with the second series combination.

Abstract: Aspects of the disclosure provide a circuit that includes a driver circuit and a current limiter circuit. The driver circuit is configured to drive a load with an output current when the load is coupled with the driver circuit. The current limiter circuit is configured to turn on a path to deplete a portion of the output current from the driver circuit in order to prevent a load current flowing through the load from exceeding a current limit.

Abstract: Disclosed is an LED protection circuit using a one-shot vibrator. The LED protection circuit includes an LED module; an LED load-open detection circuit for detecting a voltage applied to the LED module to vary a reference potential; a latch circuit for maintaining a latch state according to the reference potential of the LED load-open detection circuit; a current limit circuit for receiving an output signal from the latch circuit to output a first signal; an LED load connection detection circuit for varying the reference potential through the first signal to output a second signal; a trigger input circuit connected to the LED load connection detection circuit for outputting a third signal using the second signal; and a one-shot vibrator for outputting a fourth signal of a square waveform during a predetermined time when the third signal is input.

Abstract: An LED fluorescent lamp includes: an LED array having a plurality of LEDs connected in series; a first connection pin and a third connection pin connected to one side of the LED array; a second connection pin and a fourth connection pin connected to the other side of the LED array; at least one pair of capacitors connected to the LED array; and a short-circuit means for connecting at least one of the first connection pin and the third connection pin, and the second connection pin and the fourth connection pin, wherein the capacitors include: a first capacitor having one end connected to the first connection pin and the other end connected to one side of the LED array; a third capacitor having one end connected to the third connection pin and the other end connected to the one side of the LED array; a second capacitor having one end connected to the second connection pin and the other end connected to the other side of the LED array; and a fourth capacitor having one end connected to the fourth connection pin

Abstract: A light unit includes a bulb having a light source with lead wires and a separator, a switch member that includes a support member and a pair of spring terminals, and a socket having two or more conductive terminals and adapted to receive the bulb and the switch member. The switch member is adapted to cause the pair of spring terminals to contact one another to form an electrical short circuit across the pair of conductive terminals and the light source when the bulb is completely or partially removed from the socket. The lead wires form an electrical connection across the conductive terminals and the separator breaks contact between the pair of spring terminals when the bulb is seated in the socket.