摘要:
A resonant reset dual switch forward converter is disclosed. The resonant reset dual switch forward converter includes an input for accepting a DC voltage; a transformer having a primary winding and a secondary winding; a first and a second switch connected in series with the primary winding of the transformer for periodically connecting the input to the primary winding; a resonant capacitor for resetting the transformer during the OFF time of the first and second switches; and an auxiliary switch remaining OFF during the ON time of the first and second switches, and connecting the primary winding to the resonant capacitor during the OFF time of the first and second switches. The resonant reset dual switch forward converter provides a switching duty cycle greater than 50%, obtains a zero-voltage-switching condition for the first and second switches, and maintains the voltage stress of the f first and second switches around the input voltage.
摘要:
A forward-flyback DC-DC converter topology includes a transformer, a main switch, a clamp circuit, first and second rectifying switches, an LC resonant circuit and an output capacitor; a primary winding of the transformer and the main switch are connected in series between a first input terminal and a second input terminal, the clamp circuit constituted by a clamp capacitor and a clamp switch connected in series is connected in parallel with the primary winding or with the main switch, a secondary winding of the transformer includes a forward winding and a flyback winding, a terminal of the primary winding through which current flows into is a dotted terminal of the primary winding, and a connecting mode of a secondary side of the transformer is: the dotted terminal of the forward winding being connected with a first output terminal via the first rectifying switch, a dotted terminal of the flyback winding being connected with a second output terminal via the second rectifying switch, the LC resonant circuit being connected with the first and the second output terminals and an unlike terminal of the forward winding and the flyback winding so that the first and the second rectifying switches implement zero-current switching, and the output capacitor being connected between the first and the second output terminals.
摘要:
An integral DC to DC converter for converting at least one input DC voltage into at least one output DC voltage is provided. The integral DC to DC converter includes a first input capacitor and a second input capacitor for providing the at least one input DC voltage, a DC to AC circuit, a transformer, a rectifying circuit, a filtering capacitor, two input DC voltage switching elements and an output voltage switching element. The integral DC to DC converter is implemented by switching the switching elements.
摘要:
The present invention discloses a DC-to-DC converter. The DC-to-DC converter includes a square wave generator for generating a sequence of output voltages having a waveform of square wave. The DC-to-DC converter further includes a resonant tank connected to the square wave generator comprising a series capacitor connected to a series inductor and a parallel inductor. The DC-to-DC converter further includes a transformer having a primary side connected in series with the series inductor and connected in parallel to the parallel inductor. The transformer further includes a secondary side for connecting to a rectifying circuit for providing a rectified DC voltage to an output load circuit. The series capacitor functioning with the series inductor to provide a first characteristic resonant frequency represented by ƒs, and the series capacitor functioning with the series inductor and the parallel inductor to provide a second characteristic resonant frequency represented by ƒm wherein ƒs>ƒm. The converter runs at variable frequency switching to perform output regulation. The converter features high conversion efficiency at high input operation by switching at frequency between the first and second characteristic resonant frequency. In a preferred embodiment, the parallel inductor is integrated to transformer as primary magnetizing inductor and in further the series inductor may also be integrated into transformer.
摘要:
An integral DC to DC converter includes an input capacitor, a DC to AC circuit, a transformer, a rectifying circuit, a filtering capacitor and a control signal generator. The DC to AC circuit is connected with the input capacitor for converting the input DC voltage to a high frequency first AC voltage and the DC to AC circuit includes four full-bridge switching devices. The transformer is used for converting the first AC voltage into a second AC voltage. The rectifying circuit is connected to the secondary winding of the transformer for rectifying the second AC voltage to the output DC voltage. The filtering capacitor is connected to the rectifying circuit for filtering the output DC voltage. The control signal generator is used for providing a control signal to control the full-bridge switching device.
摘要:
A forward-flyback DC-DC converter topology includes a transformer, a main switch, a clamp circuit, first and second rectifying switches, an LC resonant circuit and an output capacitor; a primary winding of the transformer and the main switch are connected in series between a first input terminal and a second input terminal, the clamp circuit constituted by a clamp capacitor and a clamp switch connected in series is connected in parallel with the primary winding or with the main switch, a secondary winding of the transformer includes a forward winding and a flyback winding, a terminal of the primary winding through which current flows into is a dotted terminal of the primary winding, and a connecting mode of a secondary side of the transformer is: the dotted terminal of the forward winding being connected with a first output terminal via the first rectifying switch, a dotted terminal of the flyback winding being connected with a second output terminal via the second rectifying switch, the LC resonant circuit being connected with the first and the second output terminals and an unlike terminal of the forward winding and the flyback winding so that the first and the second rectifying switches implement zero-current switching, and the output capacitor being connected between the first and the second output terminals.
摘要:
A pre-stage boost device, comprising: a selector switch (130); a power factor inductor (140), a common boost circuit (150), a rectifier circuit (160), and a filter circuit (170). The common boost circuit includes: connected in series a first switch (Q1), a second switch (Q2) and a third switch (Q3). The rectifier circuit includes two rectifier diodes (D5, D6). The filter circuit includes connected in series two capacitors (C1, C2). Maximum multiplexing of the main power components under the battery mode and the commercial power mode is achieved by this invention, the cost to performance ratio is also improved.
摘要:
A self-driven synchronous rectifier circuit applied to a forward converter is provided. The circuit includes a transformer having a primary winding and a secondary winding for converting an input voltage into an output voltage, a first synchronous rectifier switch and a second synchronous rectifier switch connected to the secondary winding for rectifying the output voltage; and an auxiliary switch, wherein the gate terminal thereof is connected to the gate terminal of the first synchronous rectifier switch and the positive end of the secondary winding, the source terminal thereof is connected to the drain terminal of the first synchronous rectifier switch and the negative end of the secondary winding, and the drain terminal thereof is connected to the gate terminal of the second synchronous rectifier switch.
摘要:
An active clamped-mode DC-to-DC converter with synchronous rectifiers and a combined transformer-inductor device is provided. The power converter includes a combined transformer-inductor device having a primary winding, a secondary winding, and an auxiliary winding where the primary and the secondary windings perform a transformer function and the auxiliary winding performs an output filter function, a switching circuit for periodically providing a positive voltage to the primary winding and a negative voltage to reset the primary winding, and a synchronous rectification circuit connected for enabling conduction from the secondary winding to an output port in which the auxiliary winding is coupled between the output port and the synchronous rectification circuit for providing an inductance to filter an output signal.
摘要:
An asymmetrical full bridge DC-to-DC converter comprises an asymmetrical full bridge circuit which includes main switches and auxiliary switches, a capacitor connected in series to the branch circuit of the auxiliary switches, and a transformer having a primary winding and a secondary winding. The primary winding of transformer is connected to the common point of each leg of the full bridge. A rectification circuit is connected at the secondary winding of the transformer to obtain dc voltage output. In operation, an asymmetrical control method is applied for these main switches and auxiliary switches. Main switches and auxiliary switches turn on and turn off compensatively. A linear control characteristic of output voltage to switching duty cycle and an optimal reset of the transformer core is achieved by this invention.