Title:
SWITCHING POWER SUPPLY CIRCUIT
Document Type and Number:
Japanese Patent JP3142755
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To realize low power consumption under light load at low cost while saving the space.
SOLUTION: When the output voltage increases and a light load state is detected through a load state detection circuit 20, a voltage is fed back to a converter 15 through a photocoupler comprising a diode D3 and a phototransistor Q2. The oscillation frequency of an oscillation circuit 13 is thereby decreased by an oscillation frequency decreasing circuit 11 in the converter 15 and the frequency of gate pulse being fed to a switching element Q1 is decreased. Consequently, the loss of converter 15 increasing in proportion to the oscillation frequency of switching element Q1 comprising an MOSFET is reduced at low cost through a space saving structure thus reducing power consumption.
Inventors:
Katsumi Inaba
Kenji Hachimura
Kenji Hachimura
Application Number:
JP25656695A
Publication Date:
March 07, 2001
Filing Date:
October 03, 1995
Export Citation:
Assignee:
Sharp Corporation
International Classes:
H02M3/28; H03K17/78; (IPC1-7): H02M3/28; H03K17/78
Domestic Patent References:
| JP62135270A | ||||
| JP638519A | ||||
| JP746828A |
Attorney, Agent or Firm:
Kenzo Hara