Abstract:
Disclosed is a test apparatus for measuring the common-mode parasitic capacitance between a first element and a second element being isolated from the first element. The test apparatus includes a signal generating device connected to the first element and having an internal signal source connected in series with a first internal impedance for sending a signal to the first element, and a signal receiving device connected between the second element and the first element and having a second internal impedance for measuring a signal response between the first element and the second element, thereby calculating the common-mode capacitance between the first element and the second element based on the signal response.
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:
A capacitor discharging circuit and a converter are disclosed. The converter comprises: a capacitor connected between the live line and null line of an AC power input terminals, a conversion module coupled to the capacitor and comprising an energy storage component at least, an energy transfer unit coupled with the energy storage component and the capacitor, an AC power-off detecting unit and a control unit; wherein the energy transfer unit comprises a switch device; when AC power is disconnected, the AC power-off signal triggers the control unit to output a switch driving signal, controlling the operation of the energy transfer unit to transfer the energy stored in the capacitor to the energy storage component to discharge the capacitor.
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.
Abstract:
Provided is a multi-channel LED driver circuit, including a power supply device for providing an independent voltage source; a plurality of regulating circuits connected to the power supply device and the light light-emitting diode arrays for receiving a voltage from the voltage source and providing a plurality of output currents to the light-emitting diode arrays, and thereby generating a plurality of error signals.
Abstract:
The present application discloses a transformer conductive structure, which comprises a primary coiling, a printed circuit board and a secondary coiling unit comprising a plurality of conductive sheets; wherein each conductive sheet comprises an annular body and an output terminal arranged at the edge of the annular body and protruded to the outside; the annular bodies of the conductive sheets and the primary coiling are staggered arrangement together; and the output terminal of the conductive sheet directly clamps on the printed circuit board. The present application further discloses a transformer, which can effectively reduces the output path of the transformer, the AC and DC loss and the volume of the transformer device, so as to increase the power density and efficiency of power supply.
Abstract:
The invention proposes a ballast control circuit and ballast control method for gas discharge lamp. The ballast control circuit and control method of the invention is advantageous by allowing the OFF time of the main switch of the ballast circuit to be fixed in order to prevent the transformer of the ballast circuit from being saturated when the gas discharge lamp is ignited and has a very low impedance, and allowing the OFF time of the main switch to be flexibly adapted when the gas discharge lamp is warmed up and its impedance has risen up to a certain value. The inventive ballast control circuit is configured to proceed with the switching of the main switch according to a lamp status signal indicative of the status of the lamp.
Abstract:
The invention provides a current balancing circuit, which includes a plurality of light-emitting diode assemblies; an AC power generator for providing currents required by the light-emitting diode assemblies; and a plurality of current-equaling elements connected to the AC power generator, each of which is connected to a common mode connecting two light-emitting diode assemblies for balancing currents of the light-emitting diode assemblies.
Abstract:
The configurations of a three-phase buck-boost power factor correction (PFC) circuit and a controlling method thereof are provided in the present invention. The proposed circuit includes a first single-phase buck-boost PFC circuit receiving a first phase voltage and having a first and a second output terminals and a neutral-point for outputting a first and a second output voltages, a second single-phase buck-boost PFC circuit receiving a second phase voltage and coupled to the first and the second output terminals and the neutral-point, a third single-phase buck-boost PFC circuit receiving a third phase voltage and coupled to the first and the second output terminals and the neutral-point, a first and a second output capacitors coupled to the first and the second output terminals respectively, and to the neutral-point also and a neutral line coupled to the neutral-point.
Abstract:
The configurations of a resonant converter system and a controlling method thereof are provided. The proposed resonant converter system includes a resonant converter and a hybrid control apparatus coupled to the resonant converter for generating a driving signal to adjust a phase angle and a frequency of the resonant converter such that the resonant converter would reach a relatively lower voltage gain and have a relatively lower loss during an abnormal operation.