Title:
OVERLOAD PROTECTING DEVICE FOR MULTI-OUTPUT SWITCHING POWER SOURCE
Document Type and Number:
Japanese Patent JPS5827215
Kind Code:
A
Abstract:
PURPOSE:To improve response characteristics, by detecting a forward current by a current transformer installed in the secondary winding of a conversion transformer and controlling on-time of a switching transistor so as to make the peak value of momentary current constant. CONSTITUTION:A DC power source 1 is supplied to a conversion transistor 3 through an NPN switching transistor 2, and at the same time, smoothing chokes 6, 11 and current transformers 4, 9 that detect a forward current are installed in each of the secondary winding of a conversion transformer 3, and two constant voltage V1, V2 are outputted. Conversion circuits 8, 13 consisting only of resistance are connected to both ends of the secondary windings of current transformers 4, 9 and the momentary peak value of the forward current is detected for each cycle. The On-time of the switching transistor 2 is controlled by a controlling circuit 14 to make the momentary peak value constant. By this way, the number of parts can be reduced and response characteristics can be improved.
Inventors:
TABUCHI KATSUMI
NAGAKI TOSHIICHI
NAGAKI TOSHIICHI
Application Number:
JP12428781A
Publication Date:
February 17, 1983
Filing Date:
August 08, 1981
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
H02M3/28; H02M3/335; (IPC1-7): G05F1/64
Domestic Patent References:
| JPS5622577A | 1981-03-03 |
Attorney, Agent or Firm:
Toshio Nakao