Title:
SWITCHING POWER SUPPLY
Document Type and Number:
Japanese Patent JP3344356
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To eliminate energy loss incident to short circuit of a parasitic capacitor by short-circuiting the primary winding of a transformer through second and fourth switching elements during an interval when both first and second switching elements are turned off thereby enhancing power supply loss significantly.
SOLUTION: First and third switching elements 3, 7 are turned on/off in response to the PWM signal from a PWM circuit. First and second switching elements 3, 5 function complementarily and a micro pause interval where they are turned off simultaneously is present. Output voltage is controlled by the on/off ratio of the first switching element 3 and the on/off ratio of the third switching element 7. During the off interval when both first and second switching elements 3, 5 are turned off except the micro interval, primary winding 11a of a transformer is short-circuited and controlled by means of the second and fourth switching elements 5, 9.
Inventors:
Koji Yoshida
Application Number:
JP8112999A
Publication Date:
November 11, 2002
Filing Date:
March 25, 1999
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
H02M3/28; H02M3/335; H02M3/337; (IPC1-7): H02M3/28; H02M3/335
Domestic Patent References:
| JP9140635A | ||||
| JP9163740A | ||||
| JP1189232A | ||||
| JP7194107A |
Attorney, Agent or Firm:
Fumio Iwahashi (2 others)
Previous Patent: CONNECTOR HAVING LOW-PASS FILTER FUNCTION
Next Patent: DIELECTRIC LINE NON-REVERSIBLE CIRCUIT ELEMENT AND RADIO DEVICE
Next Patent: DIELECTRIC LINE NON-REVERSIBLE CIRCUIT ELEMENT AND RADIO DEVICE