Abstract: The present invention is provided with: a series circuit consisting of a coil and a switching element; a rectifying and smoothing circuit consisting of a rectifying element and a smoothing capacitor; a calculating unit configured to calculate a multiplied voltage, obtained by multiplying an error voltage between an output voltage of the smoothing capacitor and a reference voltage by an output of the rectifying circuit, and a voltage corresponding to a current flowing through the switching element or a current from the output terminal of the rectifying circuit; a superimposing circuit configured to superimpose a signal based on the output of the rectifying circuit on a reference signal of a reference oscillator; and a control circuit configured to generate a pulse signal by comparing an output of the superimposing circuit with an output from the calculating unit, and turn on/off the switching element with the pulse signal.

Abstract: A rectification circuit rectifies an alternating current voltage of an alternating current power supply. A parallel converter comprises converters that correspond to phases and that are connected in parallel to an output terminal of the rectification circuit. Each converter comprising a reactor, a switching circuit that is connected in series to the reactor and a diode that is connected in series to the reactor. A smoothing capacitor is connected to an output terminal of the parallel converter. A control circuit generates pulse signals corresponding to phases based on an error voltage between an output voltage of the smoothing capacitor and a reference voltage and on an output voltage of the rectification circuit, and switches the switching circuits in the converters using the pulse signals. Current detection circuits are provided corresponding to the converters and that detect currents flowing through the switching circuits.

Abstract: A rectification circuit rectifies an alternating current voltage of an alternating current power supply. A parallel converter comprises converters that correspond to phases and that are connected in parallel to an output terminal of the rectification circuit. Each converter comprising a reactor, a switching circuit that is connected in series to the reactor and a diode that is connected in series to the reactor. A smoothing capacitor is connected to an output terminal of the parallel converter. A control circuit generates pulse signals corresponding to phases based on an error voltage between an output voltage of the smoothing capacitor and a reference voltage and on an output voltage of the rectification circuit, and switches the switching circuits in the converters using the pulse signals. Current detection circuits are provided corresponding to the converters and that detect currents flowing through the switching circuits.

Abstract: A bidirectional DC-DC converter includes a series circuit of a first winding of a first reactor, a second reactor, and a first switch connected to both ends of a first DC power source, a series circuit of a second switch and a second DC power source connected to both ends of the first switch, a series circuit of a second winding of the first reactor, a third reactor, a first selector switch, and a first diode connected to both ends of a series circuit of the second reactor and the first switch, a series circuit of a second selector switch, a second diode, and the second DC power source connected to both ends of a series circuit of the first selector switch and first diode, and a controller turning on/off the switches and the selector switches.

Abstract: A DC-DC converter includes a coupling transformer that has windings 11 and 12, switches (Tr1, Tr2) that are connected through the windings to both ends of a DC power source Vi, a series circuit that is connected to both ends of each of the switches and includes a diode and a smoothing capacitor, and a controller 100 that alternately turns on the switches Tr1 and Tr2 and simultaneously turns on the switches Tr1 and Tr2 for a predetermined overlapping period on every half cycle. The coupling transformer 1 includes an I-shaped core 4, two E-shaped cores 2 and 3 holding the I-shaped core 4 between them, and a gap 5 formed between each of center legs 2a and 3a of the E-shaped cores 2 and 3 and the I-shaped core 4. The windings 11 and 12 are wound around the I-shaped core 4.

Abstract: A bidirectional DC-DC converter includes a series circuit of a first winding of a first reactor, a second reactor, and a first switch connected to both ends of a first DC power source, a series circuit of a second switch and a second DC power source connected to both ends of the first switch, a series circuit of a second winding of the first reactor, a third reactor, a first selector switch, and a first diode connected to both ends of a series circuit of the second reactor and the first switch, a series circuit of a second selector switch, a second diode, and the second DC power source connected to both ends of a series circuit of the first selector switch and first diode, and a controller turning on/off the switches and the selector switches.

Abstract: A resonant power conversion apparatus includes a transformer T1 having a primary winding n1, a secondary winding n2, a tertiary winding n3, and a reset winding nR, a series circuit of switches S1 and S2, a capacitor Cr1 and diode D1 to the switch S1, a capacitor Cr2 and diode D2 to the switch S2, a series circuit of the winding n1 and a diode Dn1, a series circuit of the winding nR and a diode DR, a reactor Lr connected between a connection point of the switches S1 and S2 and a connection point of the windings n2 and n3, a switch S10 connected between the DC power source and the winding n2, a switch S20 connected between the DC power source and the winding n3, and a controller 10 configured to perform a zero-voltage switching operation of the switches S1 and S2.

Abstract: A resonant power conversion apparatus includes a transformer T1 having a primary winding n1, a secondary winding n2, a tertiary winding n3, and a reset winding nR, a series circuit of switches S1 and S2, a capacitor Cr1 and diode D1 to the switch S1, a capacitor Cr2 and diode D2 to the switch S2, a series circuit of the winding n1 and a diode Dn1, a series circuit of the winding nR and a diode DR, a reactor Lr connected between a connection point of the switches S1 and S2 and a connection point of the windings n2 and n3, a switch S10 connected between the DC power source and the winding n2, a switch S20 connected between the DC power source and the winding n3, and a controller 10 configured to perform a zero-voltage switching operation of the switches S1 and S2.