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. After the auxiliary heating circuit has been operating for a predetermined period of time, the auxiliary heating circuit is turned off first and then the inverter is turned on; or otherwise the inverter is turned on first and then the auxiliary heating circuit is turned off.
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:
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.
Abstract:
The configurations of a discharge lamp system and a controlling method thereof are provided in the present invention. The proposed discharge lamp system includes a discharge lamp, a converter circuit coupled to the discharge lamp and having a switching switch, a ballast controller generating a first driving signal and controlling the switching switch accordingly, and a voltage sensing apparatus receiving the first driving signal and generating a sensed voltage accordingly, wherein the discharge lamp is switched among a plurality of operating modes according to the sensed voltage.
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:
The configurations of a dielectric barrier discharge lamp (DBDL) system and the driving method thereof are provided in the present invention. The proposed DBDL system includes a driver circuit receiving a DC input voltage and generating an AC output voltage, including a transformer having a primary winding and a secondary winding, a dielectric barrier discharge lamp coupled to the secondary winding and a burst mode dimming circuit including a first switch. In which, the first switch is turned on when the first switch is starting such that the first switch and the primary winding forms a conducting path so as to apply a driving high voltage to the DBDEL and turn off the first switch after the DBDL is breaking through by the driving high voltage such that a driving normal voltage is applied to the DBDL.
Abstract:
The configurations of a single-phase dual buck-boost/buck power factor correction (PFC) circuit and a controlling method thereof are provided in the present invention. The proposed circuit includes a single-phase three-level buck-boost PFC circuit receiving an input voltage and having a first output terminal, a neutral-point and a second output terminal for outputting a first and a second output voltages, a single-phase three-level buck PFC circuit receiving the input voltage and coupled to the first output terminal, the neutral-point and the second output terminal, a first output capacitor coupled to the first output terminal and the neutral-point, a second output capacitor coupled to the neutral-point and the second output terminal, and a neutral line coupled to the neutral-point.
Abstract:
The present invention discloses a transformer structure. The transformer structure comprises a first primary winding, and a first secondary circuits. The first secondary circuits comprises a filtering capacitor, a conductive Cu windings and a rectifier configured onto the printed circuit board (PCB) forming the first secondary circuits PCB winding. The first primary winding and the secondary circuits are interleaved with each other.