Title:
Switching power supply unit
Document Type and Number:
Japanese Patent JP6247176
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To implement efficiency improvement, noise reduction and reduction of cost by implementing a soft switching operation regarding an insulated converter circuit.SOLUTION: A switching power supply is formed from a synchronous rectification step-down chopper circuit including a main switching element 14, a commutation element 16, a choke coil 18 and a buffer capacitor 20 as a primary side. As a secondary side, a serial circuit of a rectification element 26 and an output capacitor 24 is connected to a primary coil 22 that is provided in the choke coil 18. The inductance of the choke coil 18 is set at such a predetermined value that, when an output current is equal to or less than a maximum output current, within one cycle of switching, a choke coil current IL that flows in the choke coil 18 flows in both positive and negative directions over zero. A switching control circuit 30 performs soft switching on the main switching element 14 and the commutation element 16 in the switching cycle through complementary ON/OFF control while providing a dead time.SELECTED DRAWING: Figure 1
Inventors:
Kazuhiro Horii
Application Number:
JP2014167049A
Publication Date:
December 13, 2017
Filing Date:
August 20, 2014
Export Citation:
Assignee:
Cosel Co., Ltd.
International Classes:
H02M3/28
Domestic Patent References:
| JP2013251938A | ||||
| JP2000308365A | ||||
| JP2010124524A |
Foreign References:
| WO2013058175A1 |
Attorney, Agent or Firm:
Susumu Takeuchi