Abstract: The present disclosure provides a power frequency current converter, including: an input side and an output side, wherein a current of the input side or the output side is a power frequency current; a switching device; and a controller, configured to control the switching device to be turned on and turned off at an operating frequency, wherein within a half of a power frequency cycle, the controller generates at least two fixed-frequency control signals and the operating frequency of the switching device alters at least twice according to the at least two fixed-frequency control signals, so as to reduce junction temperature of the switching device.

Abstract: There are disclosed a driving circuit of an organic light emitting display panel and an organic light emitting display apparatus.

Abstract: The present application discloses a converter system, a driving circuit and a driving method for a semiconductor switch. The driving circuit includes a driving unit, a sampling unit and a selection unit. A plurality of turn-off driving units with different turn-off parameters is provided in the driving unit, and a turn-off driving unit having a turn-off parameter adaptive to the working state of the semiconductor switch is selected according to the working state of the semiconductor switch so as to turn off the semiconductor switch.

Abstract: The present invention provides a display system and a diagnostic method. The display system comprises an information preprocessing module, a display panel and a control circuit electrically connected to the display panel, the information preprocessing module is used for starting the control circuit and the display panel, the control circuit is used for controlling the display panel to display an image, the information preprocessing module comprises a sensor used for collecting physiological information of human body; the information preprocessing module further comprises a preprocessing circuit used for preprocessing the physiological information of human body collected by the sensor and transmitting the preprocessed physiological information of human body to the control circuit; the control circuit is used for receiving and diagnosing based on the preprocessed physiological information of human body to obtain a diagnosis result; and the display panel is used for displaying the diagnosis result.

Abstract: The present application discloses a TNPC inverter device, comprising: a TNPC inverter module and a short circuit detecting module. The TNPC module at least comprises an inverting bridge arm and a bi-directional switching bridge arm. The inverting bridge arm comprises at least two switches connected in series; the bi-directional switching bridge arm comprises at least two switches. The short circuit detecting module mainly consists of two switch detecting unit corresponding to the two switches in the inverting bridge arm respectively. Increasing the voltage drop of the switches in the inverting bridge when a short circuit occurs in the TNPC module by some way, then it could realize the short circuit detecting module is able to detect all the paths of the short circuit in the TNPC module to simplify the peripheral circuit of the TNPC module in the TNPC inverter device.

Abstract: A power module includes: a base plane; at least one switch chip assembled on the base plane; and a voltage clamping circuit for clamping a voltage of the at least one switch chip and comprising components of a charging loop, wherein a projection of at least one of the components of the charging loop on the base plane is located within at least one first circle, defined with a center point of the at least one switch chip as a center of the first circle, and with a product of a maximum of a length and a width of the at least one switch chip and a first coefficient, as a radius of the first circle.

Abstract: The disclosure provides a driving apparatus and a method for driving a semiconductor light-emitting device assembly. The apparatus includes: a driving unit configured to drive the semiconductor light-emitting device assembly; and a cycle by cycle control unit. The cycle by cycle control unit may include: a sampling circuit configured to sample a current instantaneous value of the driving unit or the semiconductor light-emitting device assembly; and an adjusting circuit configured to adjust an output of the driving unit when the current instantaneous value sampled by the sampling circuit is larger than or equal to a preset reference value. The driving apparatus and method for driving the semiconductor light-emitting device assembly may effectively reduce an inrush current on the light-emitting devices and have a lower cost.

Abstract: Provided is a lamp ballast having a filament heating apparatus for gas discharge lamp, including a PFC converter for receiving an AC input voltage and converting the AC input voltage into a DC bus voltage; an inverter connected to an output end of the PFC converter for converting the DC bus voltage into an AC output voltage for driving gas discharge lamps; and a filament heating apparatus connected to the output end of the PFC converter. The filament heating apparatus includes an auxiliary heating circuit for converting the DC bus voltage into a heating power for pre-heating the filaments of the gas discharge lamps; and a control circuit connected to the inverter and the auxiliary heating circuit for generating an auxiliary voltage according to the heating power to activate the PFC converter.

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

Abstract: A high intensity discharge lamp (HID) control circuit and method are provided in the present invention. The circuit includes a first winding and a second winding, both of which are coupled with a series-connected inductor of an HID lamp circuit; a current zero point detector for detecting an inductor current zero crossing signal in the HID lamp circuit; an inductor current signal generator for generating an inductor current signal in the circuit to indicate a current value of the HID lamp; a modulator having input terminals connected to the current zero point detector and the inductor current signal generator, respectively, and an output terminal connected to a driving circuit for the HID lamp; and the driving circuit for driving switches in the HID lamp control circuit.

Abstract: Disclosed is an end-of-life detector for gas discharge lamp and the ballast incorporating the same. The end-of-life detector includes a lamp state signal detecting circuit for detecting the lamp state signal of at least one first gas discharge lamp and generating a positive voltage signal and a negative voltage signal accordingly; a comparing circuit for comparing the positive voltage signal with a positive selecting voltage and comparing the negative voltage signal with a negative selecting voltage, and in response thereto generating a positive control signal and a negative control signal; and a positive/negative duty time interval detecting circuit for generating a lamp life state signal which is generated by a difference between a positive duty time interval and a negative duty time interval. The lamp life state signal is varied along with the difference between the positive duty time interval and the negative duty time interval.

Abstract: The disclosure provides a lighting device and a voltage reduction method thereof, wherein the lighting device comprises: an AC power supply generator for generating an AC power source to supply power to other accessories and circuits in the lighting device; m load components, every two adjacent load components forming one head common connection point and one end common connection point respectively for each load component from head to end alternatively; and (m?1) current balancing cells each respectively connected between one head common connection point or one end common connection point and one of two output terminals of the AC power supply generator; wherein the m load components comprise (m?n) low impedance load components therein. The present application can reduce the output voltage of the AC power supply generator with lower cost.

Abstract: The present application discloses an open circuit protecting circuit, an open circuit protecting method and an illuminating apparatus. The open circuit protecting circuit is configured in an apparatus with a LED load being supplied with power by a current source, and comprises: a switch circuit, a timer circuit and a detecting circuit. When the LED load malfunctions, the open circuit protecting circuit carries out the following operations: the detecting circuit sends an enabling signal to the timer circuit, the timer circuit sends a driving signal with a set time to the switch circuit and the switch circuit is in the on-state during the set time, so as to make the LED load be short circuited to protect the circuit from being damaged. The open circuit protecting circuit can also resume to normal work automatically after the open circuited malfunction is cleared, and thus a hot-plugging function can be realized.

Abstract: In various embodiments, a method for determining whether a signal includes a wanted signal may be provided. The method may include determining a frequency at which the signal has a signal energy above a first pre-defined signal energy threshold and determining whether the signal includes a wanted signal, based on whether the signal has a signal energy above a second pre-defined signal energy threshold in a pre-defined frequency range in a frequency neighborhood of the determined frequency.

Abstract: The present invention provides an illumination device, an illumination system, and a lamp. The illumination system includes the illumination device and a light modulation module. The illumination device includes a light emitting diode (LED) array, an alternating current (AC) current source, and an output power control module. The AC current source is electrically coupled to the LED array. The output power control module is electrically coupled to the LED array and the AC current source. The LED array, the AC current source, and the output power control module together form a closed-loop control loop. The light modulation module is electrically coupled to the closed-loop control loop for modulating illumination brightness of the LED.

Abstract: The present application discloses a light emitting diode lighting device and a light emitting diode lamp, the light emitting diode lighting device includes: a fluorescent lamp ballast outputting an alternating current; and at least one first light emitting diode lamp coupled with the fluorescent lamp ballast, and comprising a rectifying and filtering circuit and at least one light emitting diode string coupled with the rectifying and filtering circuit. The present application directly replaces a conventional fluorescent lamp tube with a properly designed LED lamp without any other modifications when reinstallation a conventional fluorescent lamp lighting device into a light emitting diode lighting device, which may reduce the cost of reinstallation, and greatly facilitate the user.

Abstract: An electronic ballast for driving a light-emitting device, includes a square wave generator having a plurality of switch elements for converting a DC input voltage into a square-wave AC voltage. A transformer has a driving winding and a plurality of inductive windings mutually connected with each other, in which at least a portion of the inductive windings are respectively connected to a control terminal of the switch element. A resonant circuit connects the driving winding and a light-emitting device and converts the square-wave voltage into an AC output voltage to drive the light-emitting device. An auxiliary control unit connected to the transformer regulates a voltage waveform of the driving winding or a voltage waveform of the inductive winding according to a control signal, thereby changing the voltage waveform of the inductive winding connected to the switch element to adjust the switching frequencies of the switch elements.

Abstract: A method and circuit for improving the crest factor of the gas discharge lamp. The method includes: the signal of the gas discharge lamp can be sampled to get a status signal; whether the present stage of the gas discharge lamp is at warm up stage or constant power stage can be judged based on the result of comparison between the status signal and a preset value; preset parameters can be selected based on the stage of the gas discharge lamp, the first parameter can be selected when the gas discharge lamp is at a warm up stage, and the second parameter can be selected when the gas discharge lamp is at a constant power stage; a control signal can be outputted during the lamp current commutation based on the selected first or second parameter to improve the crest factor of the gas discharge lamp.

Abstract: A ballast which controls the open-circuit voltage of the ballast. The ballast includes a power factor corrector (PFC) for receiving an AC input voltage and converting the AC input voltage into a power factor corrected DC voltage; a DC/DC converter connected to the PFC and having a switch placed at a low-voltage side of the DC/DC converter for converting the DC voltage of the PFC into a DC output voltage according to the switching operation of the switch; a controller connected to a control terminal of the switch of the DC/DC converter for sending a switching control signal to control the switch; and an open-circuit voltage controller for detecting a voltage associated with the open-circuit voltage of the ballast and regulating the duty ratio or pulse density or switching frequency of the switching control signal in response to the results of the detection, thereby controlling the open-circuit voltage.

Abstract: The electronic ballast includes: a square wave generator that includes a plurality of switching elements to convert a DC input voltage to an AC square wave output voltage; a transformer that includes a driving winding, a plurality of control windings, at least one inductive winding and at least one control driving circuit. The control windings controls the plurality of switching elements to turn on alternately; a resonant circuit that constitutes a resonant loop together with the driving winding is electrically connected with an output terminal of the square wave generator to drive the light emitting element. The control driving circuit is connected with two terminals of the inductive winding in parallel and receives a control signal to control a voltage across the inductive winding so as to control conducting time of at least one of the switching elements.