Abstract: A driving circuit system for a gas discharge lamp includes a power circuit having a switch for converting an input voltage into a lamp voltage for driving the gas discharge lamp, a lamp current detecting circuit connected to the power circuit or the gas discharge lamp for detecting a lamp current, a feedback circuit connected to the lamp current detecting circuit for generating a lamp current feedback signal, a constant power control circuit for generating a corrected current reference signal, and a power control circuit connected to the feedback circuit, the constant power control circuit, and the switch of the power circuit for generating a first modulating signal in accordance with the lamp current feedback signal and the corrected current reference signal for driving the switch to turn on or off, thereby substantially maintaining a lamp power of the gas discharge lamp at a constant value.

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: 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: The configurations of a DC/DC resonant converter and a controlling method thereof are provided. The proposed converter includes an over-current protection apparatus including a first switch element having a first and a second terminals, and a first voltage element having a negative terminal coupled to a positive terminal of a DC input voltage source and a positive terminal coupled to the second terminal of the first switch element.

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 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 configurations of a parallel-connected resonant converter circuit and a controlling method thereof are provided in the present invention. The proposed circuit includes a plurality of resonant converters, each of which has two input terminals and two output terminals, wherein all the two input terminals of the plurality of resonant converters are electrically series-connected, and all the two output terminals of the plurality of resonant converters are electrically parallel-connected.

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 parallel-connected UPS circuit are provided in the present invention. The proposed circuit includes a neutral, a battery having a positive and a negative terminals, and a plurality of PFC boost converters, each of which includes a PFC circuit including an inductor having a first terminal coupled to the positive terminal and a second terminal, a rectifying bridge coupled to the second terminal of the inductor, and having a first terminal and a second terminal coupled to the negative terminal, a switch bridge having a first terminal coupled to the first terminal of the rectifying bridge and a second terminal coupled to the second terminal of the rectifying bridge, and a control switch having a first terminal and a second terminal coupled to the neutral.

Abstract: The present invention relates to multi-phase parallel-interleaved converter circuits with each phase having two or more transformers and two or more rectifiers electrically coupled to the two or more transformers, and layouts of the transformers and the rectifiers of the multi-phase parallel-interleaved converter circuits. In the layouts, the multiple transformers and the multiple rectifiers of the multi-phase converters are interleavingly arranged to be symmetrical to common output polarized capacitor(s) so as to ensure the rectifier outputs of each phase relative to the common output polarized capacitors is symmetrical, thereby reducing the output ripples of the current of the output capacitors.

Abstract: In one aspect of the invention, a three-phase rectifier circuit having three input terminals and two output terminals includes a three-phase diode bridge, three switching circuits, and a voltage source. The three-phase diode bridge has three pairs of first diodes electrically parallel-connected to the two output terminals. Each pair of first diodes has two first diodes series-connected defining a first node therebetween, and electrically connected to a corresponding input terminal at the first node. Each switching circuit has a first terminal, a second terminal and a plurality of switches electrically series-connected between the first and second terminals. The first and second terminals are respectively electrically connected to a second node and a third node, respectively between the first node and the two first diodes of the corresponding pair of first diodes. The voltage source is electrically parallel-connected between the two output terminals and electrically connected to each switching circuit.

Abstract: In one aspect of the present invention, a converter circuit with input voltage balance includes a plurality of modules having inputs electrically series-connected to each other and outputs electrically parallel-connected to each other and a plurality of switching circuits with each electrically connected to an input connection node of a corresponding module and its immediate next module, and configured such that when an input voltage of the corresponding module or its immediate next module is in a desired range from a first predetermine value to a second predetermined value greater then the first predetermined value, the switching circuit operates in an open state, while when the input voltage is out of the desired range, the switching circuit operates in a conductive state so as to regulate the input voltage of the corresponding module or its immediate next module in the desired range.

Abstract: The configurations of a parallel-connected resonant converter circuit and a controlling method thereof are provided in the present invention. The proposed circuit includes a plurality of resonant converters, each of which has two input terminals and two output terminals, wherein all the two input terminals of the plurality of resonant converters are electrically series-connected, and all the two output terminals of the plurality of resonant converters are electrically parallel-connected.

Abstract: A connector and a power transformer structure comprising the same are provided. The power transformer structure comprises a connector and an integrated transformer. The connector comprises a plurality of connection units, and the integrated transformer comprises a plurality of transformation units. The transformation units are sequentially stacked and electronically connected to the corresponding connection units in contact connection to reduce the current conduction consumption and contact resistance.

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 three-phase buck-boost power factor correction (PFC) circuit are provided. The 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 third phase voltage and coupled to the first and the second output terminals and the neutral-point, a first to a fourth thyristors, each of which has an anode and a cathode. The anodes of the first and the third thyristors and the cathodes of the second and the fourth thyristors receive a second phase voltage, and the cathode of the first thyristor and the anode of the second thyristor are coupled to the first single-phase buck-boost PFC circuit.

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: 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 configurations of a resonant converter system and a controlling method thereof are provided. The proposed resonant converter system includes a resonant converter receiving an input voltage for outputting an output voltage, a rectifying device having a first rectifying switch and a synchronous rectification control circuit coupled to the resonant converter and including a signal generation apparatus generating a weighted turn-off signal to turn off the first rectifying switch at a zero crossing point of a first current flowing through the first rectifying switch.

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.