Title:
SWITCHING ELECTRIC POWER SOURCE
Document Type and Number:
Japanese Patent JPS5617411
Kind Code:
A
Abstract:
PURPOSE:To exercise practical output control with simple circuit constitution by varying the duty ratio of a switching transistor by making it possible to vary the flyback voltage of blocking oscillating circuit. CONSTITUTION:Blocking oscillating circuit 10 oscillates by collector-base feedback circuit coupled with feedback winding 20B and switching transistor 11 repeats on-off operation by self-exciting. In the on period of the transistor 11, electric current flows through a primary winding 30A of output transformer 30 by way of rectifier 1, a primary winding 30A, diode 31, transistor 11 and rectifier 1 and an AC voltage develops across a secondary winding 30B of output transformer 30 accordingly and is rectified and smoothed by rectifying-smoothing circuit 40 to obtain DC output voltage E0, which is output between output terminals C and D. The output voltage E0 can be controlled by varying flyback voltage Ef (in direct proportion to said duty ratio) of blocking oscillating circuit 10.
Inventors:
FUJITA KATSUO
Application Number:
JP9215979A
Publication Date:
February 19, 1981
Filing Date:
July 20, 1979
Export Citation:
Assignee:
TDK ELECTRONICS CO LTD
International Classes:
H02M3/325; H02M3/338; (IPC1-7): G05F1/64