Abstract: A scan-type display apparatus includes an LED array and a scan driver. The LED array has a common anode configuration, and includes multiple scan lines, multiple data lines and multiple LEDs. The scan driver includes multiple scan driving circuits. Each scan driving circuit includes a voltage generator and a detector. The voltage generator has an output terminal that is connected to the scan line corresponding to the scan driving circuit, and is configured to output one of an input voltage and a clamp voltage at the output terminal of the voltage generator. The detector is connected to the output terminal of the voltage generator, and generates a detection signal that indicates whether any one of the LEDs connected to the scan line corresponding to the scan driving circuit is short circuited based on a voltage at the output terminal of the voltage generator and a detection timing signal.

Abstract: An electronic device includes a substrate, an array circuit, a first distribution terminal, a second distribution terminal, a first power input terminal, a first wire and a second wire. The first distribution terminal and the second distribution terminal are disposed on a side surface of the substrate and are electrically connected to the array circuit. The first power input terminal, the first wire and the second wire are disposed on a bottom surface of the substrate. A first end of the first power input terminal is electrically connected to the first distribution terminals through the first wire. A second end of the first power input terminal opposite to the first end is electrically connected to the second distribution terminals through the second wire. A minimum distance between the first end and the first distribution terminal is less than a minimum distance between the second end and the first distribution terminal.

Abstract: A display substrate includes: a pixel circuit including: a switching transistor connected between a first terminal of a compensation capacitor and a data line; and a pixel transistor connected between a second terminal of the compensation capacitor and a first voltage line, the pixel transistor to receive a test voltage; and a test transistor including: a test gate terminal to receive a test signal; a test source terminal electrically connected to the first voltage line; and a test drain terminal electrically connected to the data line.

Abstract: The disclosure provides a display panel and a spliced display device. The display panel includes a substrate, an array circuit, and a power supply circuit. The substrate includes a top surface, a bottom surface, and a side surface located between the top surface and the bottom surface. The array circuit is disposed on the top surface. Power is supplied to the array circuit through the power supply circuit. The power supply circuit has a power input terminal. The power input terminal corresponds to at least two distribution terminals. The at least two distribution terminals are disposed on the side surface and distribute the power to different portions of the array circuit.

Abstract: An open circuit detection method and an LED display device are provided, relating to the technical field of LED display, wherein the open circuit detection method includes: supplying an open-circuit detection voltage to any row line to be detected among a plurality of row lines in the LED display device, and pulling down electric potentials of row lines other than the row line to be detected among the plurality of row lines to a first preset value, wherein the first preset value is smaller than an ON-voltage of each of the LED lamp beads and greater than 0; detecting whether the respective column lines include a column line having an electric potential lower than a second preset value, wherein if yes, it is determined that the LED display device has an LED lamp bead in an open circuit state.

Abstract: A portion of a source electrode exposed by an opening in a passivation film is used as a portion of a source pad. A first portion of the source pad includes a plating film formed by a material that is harder than a material of the source electrode. During screening, a probe needle that is a metal contact contacts the plating film that is on the first portion of the source pad. A second portion of the source pad has a layer structure different from that of the first portion of the source pad and in a second direction parallel to the front surface of the semiconductor chip, is disposed adjacently to and electrically connected to the first portion of the source pad. A bonding wire is wire bonded to the second portion of the source pad after an inspection process of the semiconductor chip.

Abstract: Systems and methods for testing a light emitting display unit having a plurality of light emitting elements are disclosed. Embodiments include a system with a test module, the test module including a plurality of light detection elements. Each of the plurality of light detection elements may generate a signal upon detection of light emitted from a light emitting element. The test module may also include a circuit. The circuit may receive input signals from the plurality of light detection elements, process the input signals based on a pre-determined function of the circuit, and generate an aggregate output signal based on the processing of the input signals. The circuit may also process the input signals based on discrete implementation of a combinational logic. The circuit may further receive instructions determining the combinational logic to be implemented.

Abstract: The present disclosure provides a display substrate, a repairing method, and a display device, the display substrate includes a plurality of driving circuits, each of which is configured to drive a display element in each of at least one sub-pixel to display, an output terminal of each driving circuit is coupled to the display element in the sub-pixel driven by the driving circuit through a branch having a switching element, the display substrate further includes: at least one repair line, which is configured to be associated with at least two driving circuits and initially decoupled from an output terminal of at least one of the at least two driving circuits, and the repair line is couplable to the output terminals of the at least two driving circuits with which the repair line is associated in response to a failure of one of the at least two driving circuits.

Abstract: A display device includes: a display panel including a plurality of pixels configured to receive pixel driving currents; a current sensor configured to measure an entire driving current diverged into the pixel driving currents; and a temperature sensor configured to measure an ambient temperature of the display panel, wherein the display panel includes a degradation compensator configured to generate output grayscale values for the pixels based on the entire driving current, the ambient temperature, and input grayscale values for the pixels.

Abstract: The application relates to an active-matrix organic light emitting diode (AMOLED) panel cell testing circuit and a method for repairing data lines via the AMOLED panel cell testing circuit. The application not only can achieve a screen detecting function of the cell testing circuit, but also achieve to repair the circuit and to improve panel yield.

Abstract: An aging system includes panel groups each including display panels, an auxiliary board including the panel groups disposed thereon, and an aging device for supplying aging signals to the display panels through line boards to perform aging on the display panels, where the aging device supplies switch signals respectively to the display panels through the line boards, where each of the display panels includes a switch unit for supplying the aging signal to a pixel unit according to the switch signal.

Abstract: A detecting apparatus and method, repairing apparatus and method, and repairing system of AMOLED display device are provided. The detecting apparatus includes: an illuminating device for sequentially illuminating a plurality of detection regions of a screen of the AMOLED display device, the screen being divided into the plurality of detection regions, each of the detection regions including at least one light-emitting unit; a current detecting device for acquiring a detection current which is a sum of driving currents of the light-emitting unit in the detection region being illuminated; and a judging device for judging whether the detection region corresponding to the detection current is a defective region according to the detection current. The apparatus can detect luminance uniformity of the AMOLED display device. The detection efficiency is high, the detection standard is unified and the detection accuracy is high.

Abstract: The present disclosure relates to a method for detecting a defect of a sensing transistor disposed in each sub pixel of an organic light emitting display device and extracting a coordinate of a sub pixel in which a defective sensing transistor is disposed. A defect detecting data voltage is applied to a data line after initializing a reference voltage line and a voltage of the reference voltage line is sensed during an interval in which the scan transistor is turned on and the sensing transistor is turned off to determine whether the sensing transistor is defective.

Abstract: A circuit comprises a CLVS, a LEA coupled to the CLVS, and a peak detector coupled to the CLVS and the LEA, wherein the peak detector is a switch-based peak detector. A method comprises closing a first switch for a period of time to provide a current to an actuator, opening the first switch after the period, measuring, after the opening, a voltage associated with the actuator, and determining, based on the measuring and using an ADC, whether a diode is present in the actuator and coupled with a correct polarity, is missing, or is present in the actuator and coupled with an incorrect polarity.

Abstract: A driving circuit includes a first driver, a switching circuit and a second driver. The first driver receives an input signal and an inverted input signal, and generates a driving signal. The switching circuit receives the driving signal and a first mode signal. Moreover, an output signal is outputted from an output terminal. The second driver is connected with the output terminal.

Abstract: Embodiments of the invention are directed to using a DC multimeter configured for checking device amperage. A DC voltmeter is electrically-connected in series with the DC multimeter. A linear circuit is electrically connected in series between the DC multimeter and the DC voltmeter. A device under test is electrically-connected between positive and negative terminals of the DC voltmeter.

Abstract: Embodiments of the invention are directed to using a DC multimeter configured for checking device amperage. A DC voltmeter is electrically-connected in series with the DC multimeter. A linear circuit is electrically connected in series between the DC multimeter and the DC voltmeter. A device under test is electrically-connected between positive and negative terminals of the DC voltmeter.

Abstract: A level conversion circuit includes: first P-ch and N-ch transistors and second P-ch and N-ch transistors respectively connected in series between first and second power sources; third and fourth P-ch transistors respectively connected between the gates of the second and first P-ch transistors and the drain of the first and second P-ch transistors; and fifth and sixth P-ch transistors respectively connected between the gates of the second and first P-ch transistors and a third power source, wherein differential input signals are applied to the gates of the first and second N-ch transistors, a bias voltage is applied to the gates of the third and fourth P-ch transistors, the gate of the fifth and sixth P-ch transistors are respectively connected to connection nodes of the first P-ch and N-ch transistors the second P-ch and N-ch transistors.

Abstract: A display device includes a plurality of first direction pixel lines. Each of the first direction pixel lines includes a plurality of pixels. Each of the plurality of first direction pixel lines is extended in a first direction. The plurality of first direction pixel lines are spaced apart from each other. A plurality of second direction conductive lines intersects the plurality of first direction pixel lines. The plurality of second direction conductive lines is connected to the first direction pixel lines. The plurality of second direction conductive lines transmits a scan signal.

Abstract: A lighting device with improved optical performance and efficiency is provided. The lighting device includes a source of energy, a light source, a reflector and a holder. The reflector has a first open end, a second end, and a parabolic profile extending between the first open end and second end. The focus of the parabolic profile is located outside of the profile. The reflector may also be movable relative to the light source. The lighting device may include a circuit that delivers a pulsed or thermally compensated pulsed current to the light source. The light device may also include a heat sink housing.

Abstract: An organic light emitting display device includes a display unit including pixels coupled to scan lines and data lines, first and second power lines coupled to the pixels, a DC-DC converter configured to output first and second power sources to the pixels via the first and second power lines, respectively, and a short-circuit-sensing circuit configured to detect whether a short-circuit between the first and second power lines occurs, and configured to control an operation of the DC-DC converter when the short-circuit is detected, wherein voltage levels of the first and second power sources are configured to be changed in a frame period, the frame period including a reverse voltage application period in which the voltage level of the second power source is higher than that of the first power source.

Abstract: A sign-monitoring system includes at least one electronic sign and a controller comprising a processor and memory. The electronic sign includes a pixel array, the pixel array including a plurality of pixels. The electronic sign further includes an embedded controller coupled to the at least one electronic sign. The embedded controller develops diagnostic information for the at least one electronic sign, the diagnostic information including information related to a number of malfunctioning pixels in the plurality of pixels. The controller is communicably coupled to the embedded controller and receives at least a portion of the diagnostic information from the embedded controller. In addition, the controller assesses the at least a portion of the diagnostic information to develop health information. The assessment involves evaluating the information related to the number of malfunctioning pixels.

Abstract: An imaging system and use thereof for large-area monitoring with very high temporal resolution are provided. In one aspect, an imaging system includes a camera equipped with curved optics having a field of view of from about 0.01 miles to about 1.5 miles; and interchangeable light filters positioned in front of the camera configured to change one or more of an intensity and an amplitude of light captured by the imaging system. The curved optics may include a hemispherical mirror configured to reflect an image of objects in front of the mirror, and the camera may be positioned facing a reflective surface of the hemispherical mirror so as to capture the image reflected in the hemispherical mirror. Alternatively, the curved optics may include a fisheye lens mounted to the camera. An imaging network of the present imaging systems and a method for use thereof for thermal monitoring are also provided.

Abstract: An apparatus for testing light emitting diodes (LEDs) comprising a chamber which is configured to heat or cool LEDs inside the chamber by ambient heating or cooling of the LEDs and an optical sensing unit configured to sense light emitted by the LEDs while the LEDs are inside the chamber. A method for testing LEDs is also described.

Abstract: A current measurement unit measuring power supply currents each consumed in a plurality of circuit blocks of which at least one of the circuit blocks includes a processor, and outputting the measurement result as the power supply current values. A selection unit selecting at least one of the power supply current values according to selection information. A trace buffer sequentially holding the power supply current values being selected by the selection unit together with execution information of the processor, and sequentially outputting the held information. By selecting the power supply current values of the circuit blocks required for debugging according to the selection information, the number of external terminals of a semiconductor integrated circuit required for the debugging which includes tracing the power supply current values may be reduced. As a result, a chip size of the semiconductor integrated circuit with a debug function may be reduced.

Abstract: An integrated circuit within an integrated circuit package, including a configuration module and a timing module. The configuration module configures the integrated circuit using a configure operation performed via N pins of the integrated circuit package, where N is an integer greater than 1. The timing module is configured to control on/off timing of (N*M) light emitting diodes arranged in N columns and M rows connected to the N pins and M pins of the integrated circuit, respectively, where M is an integer greater than 1. During a first period, the configure operation utilizes the N pins. During a second period, the N*M light emitting diodes receive data from the M pins and refresh signals from the N pins. The second period is different than the first period.

Abstract: Disclosed herein is a method of detecting an LED failure in a series-connected string of LEDs using a parameter indicative of a voltage difference between a voltage across the string at a predetermined relatively high current and a voltage across the string at a predetermined relatively low current. The disclosure extends to controllers configured to detect an LED failure in a string of LEDs, to LED lighting units comprising such controllers, and to lighting subsystems, for instance automobile lighting subsystems.

Abstract: The present invention provides a method for measuring the interface state density by a conductance technique. In particular, the method comprises: biasing a MOS capacitor structure to be measured in an accumulation region, measuring the MOS capacitor structure under a fixed bias voltage and at predetermined scanning frequencies in the accumulation region by using a Gp-G model, and calculating the values of the series resistor at respective predetermined scanning frequencies to obtain a series resistor model; obtaining an accurate model in an inversion region from the series resistor model varying with the predetermined scanning frequencies obtained in the accumulation region and obtaining the measurement results of interface state according to the accurate model.

Abstract: A system and method are provided for mimicking a bioluminescent signal from an animal or an insect, such as a firefly. A first version includes a controller, an electrical energy battery, a solar energy collector and a light emitting device. The solar energy collector receives sunlight and converts the sunlight to electrical energy that is stored in the battery. The electrical energy battery provides electrical energy to the light emitting device under management by the controller, and may comprise two or more battery cells or circuits. A time sequence for energizing the light emitting device may be applied to cause the light emitting device to mimic a bioluminescent lighting pattern generally exhibited by a selected species of insect or animal. A light emitting diode may be used with a voltage source and a voltmeter to detect the approximate intensity of light of an ambient environment surrounding the device.

Abstract: A photodetector array includes a plurality of photodetector cells such as avalanche photodiodes and readout circuits. An array self-tester tests a dark count or other performance characteristic of the cells. The test is performed in connection with the manufacture of the array or following the installation of the array in a detection system.

Abstract: An anode driver chip and a cathode driver chip attached to an OLED device by means of anisotropic glue. The fine structure of the attachment means requires inspection to determine any resulting open and short conditions. The anode driver circuits comprise an output current detection that allows open circuit testing of the contact between the OLED device and the anode driver chip. The cathode driver circuits comprise a voltage detection circuit that allows both open and short circuit detection between cathode driver pads.

Abstract: The present invention provides an LED chip testing device that measures characteristics of an LED chip. The LED chip testing device includes: a rotation member that supports the LED chip and rotates the LED chip to a testing position where the characteristics of the LED chip are tested; and a tester installed next to the rotation member and serving to measure the characteristics of the LED chip at the testing position.

Abstract: A short detection circuit includes a voltage divider circuit, for generating, according to a bottom voltage of one or more light-emitting diode strings, a divided voltage less than the bottom voltage. Additionally, the short detection circuit includes a voltage clamp circuit, coupled to the voltage divider circuit, for clamping the divided voltage, and a comparator, coupled to the voltage divider circuit, for comparing the divided voltage and a reference voltage, to decide whether a short circuit occurs in the one or more light-emitting diode strings according to a result of the comparison.

Abstract: A fault detecting circuit in a string of LEDs D1-Dc containing comparing operational amplifiers IC1/IC2 connected to a current source is divided into sections, D1-Da, D2-Db, and D3-Dc, wherein the common between the Da cathode and the D2 anode is connected to the noninverting input of IC1, while the common between the Db cathode and the D3 anode is connected to the noninverting input of IC2, and to the string D1-Db is connected in parallel to a divider comprising R1/R2, while the string comprising D2-Dc is connected in parallel to a divider comprising R3/R4, and the common of R1/R2 is connected to the inverting input of IC1 and the common of R3/R4 is connected to the inverting input of IC2, while the outputs of IC1/IC2 are connected to the bases of corresponding transistors T1/T2, whose emitters are connected to ground and collectors are connected to the voltage source and also to the output terminal.

Abstract: An inspection system is provided, which applies a forward or reverse voltage on a light-emitting device and measures a current thereof respectively before and after temperature rise, and determines whether the device fails according to the fact whether a current difference before and after the temperature rise is larger than a failure current determination value. Alternatively, the inspection system adopts a current applying device to apply a forward and reverse current on a light-emitting device and measures a voltage difference thereof respectively before and after temperature rise, and determines whether the device fails according to the fact whether a difference of the voltage differences before and after the temperature rise is larger than a failure voltage determination value. Alternatively, the inspection system adopts a predetermined inspecting step and a rapid inspecting step respectively to determine whether a light-emitting device fails.

Abstract: Provided is a low-cost and high-efficient system for measuring reliability of an electronic device. According to the present invention, a single input power source for applying power to an input terminal of a plurality of electronic device samples and a single output power source for applying power to an output terminal of the plurality of electronic device samples are provided. Further, an input switch having first switches of which the number corresponds to the number of the plurality of electronic device samples, the input switch being installed between the input power source and the input terminal so that the first switches are selectively switched to apply input power; and an output switch having second switches of which the number corresponds to the number of the plurality of electronic device samples, the output switch being installed between the output power source and the output terminal so that the second switches are selectively switched to apply output power are provided.

Abstract: In a testing method for an LD, an LD die is held. Then, electric current increasing with a fixed increment and having a sequence of current values is supplied to the LD die to drive the LD die to emit light and a sequence of voltage values across the LD die and corresponding to the sequence of current values, respectively, is metered. A sequence of power values corresponding to the sequence of current values, respectively, is also metered. Next, an electro-optical property of the LD die is determined according to the sequence of current values, the sequence of voltage values, and the sequence of power values. Finally, if the LD die is determined to be qualified based upon the electro-optical property of the LD die, the LD die is packaged into the LD.

Abstract: A plurality of diode/resistor devices are formed within an integrated circuit structure using manufacturing equipment operatively connected to a computerized machine. Each of the diode/resistor devices comprises a diode device and a resistor device integrated into a single structure. The resistance of each of the diode/resistor devices is measured during testing of the integrated circuit structure using testing equipment operatively connected to the computerized machine. The current through each of the diode/resistor devices is also measured during testing of the integrated circuit structure using the testing equipment. Then, response curves for the resistance and the current are computed as a function of variations of characteristics of transistor devices within the integrated circuit structure and/or variations of manufacturing processes of the transistor devices within the integrated circuit structure.

Abstract: An aspect of the present invention relates to a method of evaluating metal contamination in a semiconductor sample by DLTS method, which includes obtaining a first DLTS spectrum by measuring a DLTS signal while varying a temperature, the DLTS signal being generated by alternatively and cyclically applying to a semiconductor junction on a semiconductor sample a reverse voltage VR to form a depletion layer and a weak voltage V1 to trap carriers in the depletion layer; obtaining a second DLTS spectrum by measuring a DLTS signal while varying a temperature, the DLTS signal is being generated by cyclically applying the VR to the semiconductor junction; obtaining a differential spectrum of the first DLTS spectrum with a correction-use spectrum in the form of the second DLTS spectrum or a spectrum that is obtained by approximating the second DLTS spectrum as a straight line or as a curve.

Abstract: A mother substrate including a plurality of organic light emitting display panels that include pixel circuits having a simple structure, is designed so that a sheet unit test may be performed while preventing or reducing brightness variation during sheet unit test, and a sheet unit test method for the mother substrate. The mother substrate also includes first and second wiring line groups and a compensating unit. The compensating unit is coupled to a coupling line for coupling a wiring line from among the first and second wiring line groups for transmitting a sheet unit test signal to the panels. The compensating unit is also for subtracting a voltage corresponding to a threshold voltage of a driving transistor included in a pixel of the panels from the sheet unit test signal before transmitting the sheet unit test signal to the panels.

Abstract: A testing device includes a laser source, a current testing device, and a processor. The processor includes a user interface, a control unit, a calculation unit, and a data generation unit. The user interface receives user inputs to determine control parameters. The control unit controls the laser source to emit a laser beam on a photoelectric conversion die according to the control parameters. The laser beam has an optical output power value P. The control unit also controls the current testing device to measure a current value I output by the photoelectric conversion die after the laser beam irradiating on the photoelectric conversion die. The calculation unit calculates a photoelectric conversion efficiency F according to the formula: F=P/I. The data generation unit processes the photoelectric conversion efficiency F which indicates the electro-optical property of the photoelectric conversion die.

Abstract: A LED light source measuring instrument includes a shell portion and a test portion. The shell portion supports the test portion. The test portion includes a carrier plate for carrying a LED light source, and provides automatic electrical connections to a bottom surface of an SMT LED light source. The test portion further includes a flexible tube and a vacuum pump, at least one air hole set in the test portion, the flexible tube connecting with the air hole and the vacuum pump, the vacuum provided by the vacuum pump holding the LED light source firmly to the under test zone of the carrier plate.

Abstract: In a testing method for an LD, an LD die is held. Then, electric current increasing with a fixed increment and having a sequence of current values is supplied to the LD die to drive the LD die to emit light and a sequence of voltage values across the LD die and corresponding to the sequence of current values, respectively, is metered. A sequence of power values corresponding to the sequence of current values, respectively, is also metered. Next, an electro-optical property of the LD die is determined according to the sequence of current values, the sequence of voltage values, and the sequence of power values. Finally, if the LD die is determined to be qualified based upon the electro-optical property of the LD die, the LD die is packaged into the LD.

Abstract: A circuit includes a power supply circuit and a measuring circuit. The measuring circuit includes a voltage meter, a current meter, and a connector connected to a zener diode under test. The voltage meter is connected to the connector in parallel. The current meter is configured to measure a current flowing through the zener diode. The power supply circuit is capable of providing an output voltage that becomes greater gradually. The voltage meter is capable of obtaining a breakdown voltage of the zener diode when the current flowing through the zener diode increases and a voltage across the zener diode is unchanged.

Abstract: A dark spot defect of an EL element is detected based on an emission brightness or a current flowing through the EL element when an element driving transistor which controls a drive current to be supplied to the EL element is operated in its linear operating region and the EL element is set to an emission level. A dim spot defect caused can be detected based on a current flowing through the EL element when the element driving transistor is operated in its saturation operating region and the EL element is set to the emission level. When an abnormal display pixel is detected based on an emission brightness, a pixel which is determined as an abnormal display pixel and which is not determined as a dark spot defect is determined, and the pixel is detected as a dim spot defect caused by the characteristic variation of the element driving transistor.

Abstract: A test system for Light-emitting diodes (LEDs) includes a microcontroller, a plurality of light sensors, a plurality of shielding members and a display module. Each of the plurality of light sensors is connected to the microcontroller and each of LEDs. Each of the plurality of light sensors is capable of detecting luminance of the plurality of LEDs respectively. Each of the plurality of shielding members is configured to prevent light outside of each of the plurality of shielding members from interfering with light emitted from each of the LEDs inside of each of the plurality of shielding members. The microcontroller is adapted to read light intensities sensed by the plurality of light sensors according to a predetermined sequence and send the light intensities to the display module to display the light intensities in the predetermined sequence.

Abstract: A stacked semiconductor device includes a first semiconductor device equipped with a first semiconductor chip 14 having a transistor circuit and protection diodes, and a second semiconductor device equipped with a second semiconductor chip 24 having a transistor circuit and protection diodes, and stacked on the first semiconductor device via a connection portion, wherein a power supply line connected to the first and second semiconductor chips is used in common, and a forward ON voltage of the protection diodes of the first semiconductor chip is set higher than a forward ON voltage of the protection diodes of the second semiconductor chip 24. When a connection test is executed, the forward ON voltage of the protection diodes of the first semiconductor chip or the second semiconductor chip is detected and then normal/open is judged.

Abstract: A method of the invention for performing burn-in test includes assembling, on a fixture stand, a plurality of light source elements and a plurality of light detectors for monitoring a light output from a corresponding one of the plurality of light source elements; and electrifying the plurality of light source elements in a state where at least the plurality of light source elements and the plurality of light detectors are immersed in an insulation liquid. Thereby, it is realized to hold a stable temperature in a short period of time, to maintain a temperature that does not deviate from normal load conditions, and to perform a sorting test between defect parts and good part for light source unit chips without causing damage to the elements.

Abstract: The present invention relates to a test equipment of direct current thyristor valve, and particularly relates to a fault current test equipment of direct current thyristor valve. This present invention equipment includes high voltage low current circuit and low voltage high current circuit, said test equipment includes fault current circuit, said fault current circuit includes resonant circuit, said high voltage low current circuit, low voltage high current circuit and fault current circuit are all connected with the thyristor sample Vt respectively. In his present invention, the thyristor sample is first heated through the high voltage circuit and low voltage high current circuit to reach the stable state. And then shut off the switch and carries out the test using the fault current which is produced by the fault current circuit. This prevents the power system from the short-circuit impact.

Abstract: An apparatus for testing light emitting diodes (LEDs) comprising a chamber which is configured to heat or cool LEDs inside the chamber by ambient heating or cooling of the LEDs and an optical sensing unit configured to sense light emitted by the LEDs whilst the LEDs are inside the chamber. A method for testing LEDs is also described.