Sanken Electric Co., Ltd.

Shimane University

Nagoya University

Shigeyuki Funabiki

Mamoru Tsuruya

Hideki Asuke

Hideharu Takano

Masayoshi Yamamoto

Masaki Kanazawa

Takahiro Kawashima

Masashi Ochiai

Hiroyuki Horii

Hirotaka Hara

In order to achieve an object to reduce a surge voltage and suppress noise generation, the present invention provides a DC-DC converter with a snubber circuit, which boosts a voltage Vi of a DC power supply. The snubber circuit includes: a series circuit connected to both ends of a smoothing capacitor Co and including a snubber capacitor Cs and a snubber resistor Rs; a snubber diode Dsconnected to a node at which the snubber capacitor Cs and the snubber resistor Rs are connected, and to a node at which a reactor Lrand an additional windingof a transformer Tare connected; and a snubber diode Dsconnected to the node at which the snubber capacitor Cs and the snubber resistor Rs are connected, and to a node at which a reactor Lrand an additional windingof a transformer Tare connected.

DC-DC converter with snubber circuit

The present invention provides a DC-DC converter including a first series circuit connected to both ends of a first switch and formed of a winding of a first transformer, a first reactor, a first diode, and a smoothing capacitor, a second diode connected to a connection point of a primary winding of the first transformer, the winding of the first transformer and the first switch, and to one end of the smoothing capacitor, a second series circuit connected to both ends of a second switch and formed of a winding of a second transformer, a second reactor, a third diode, and the smoothing capacitor, a fourth diode connected to a connection point of a primary winding of the second transformer, the winding of the second transformer and the second switch, and to the one end of the smoothing capacitor, a third reactor connected to both ends of a series circuit of a secondary winding of the first transformer and a secondary winding of the second transformer, and a control circuit which alternately turns on the first switch and the second switch every &#xbd; cycle, turns off the first switch during an on-period of the second switch, and turns off the second switch during an on-period of the first switch.

DC-DC converter

A current-mode controlled DC-DC converter includes a comparator comparing a first or second current detection signal with a first or second reference current that is based on an error voltage of a voltage detection signal, a pulse generator generating a first pulse signal whose ON time is longer than an interval between when the second current detection signal reaches a minimum value and when the second current detection signal reaches the second reference current, a pulse generator generating a second pulse signal whose ON time is longer than an interval between when the first current detection signal reaches a minimum value and when the first current detection signal reaches the first reference current, the second pulse signal being behind the first pulse signal by a half period, and a PWM circuit generating a first or second PWM signal according to the pulse signal and an output signal from the comparator, thereby turning on/off a switch.

Current-mode controlled DC-DC converter

A bi-directional DC-DC converter includes a first series circuit connected to ends of a first DC power source and including a first winding of a first reactor and a first switch; a second series circuit connected to ends of the first switch and including a second winding of the first reactor, a second reactor, a second switch, a third switch, and a second DC power source; a third series circuit connected to the ends of the first switch and including a fourth switch and the second DC power source; and a control circuit configured to turn on/off the switches and thereby carry out step-up and step-down operations between the first and second DC power sources.

Bi-directional DC-DC converter

Growing community of inventors

Matsue, Japan

Shigeyuki Funabiki