Title:
SELF-OSCILLATION TYPE DC/DC CONVERTER CIRCUIT WITH SWITCHING TRANSISTOR PROTECTING FUNCTION
Document Type and Number:
Japanese Patent JPS58172974
Kind Code:
A
Abstract:
PURPOSE:To safely and effectively obtain an operation of a DC/DC converter by limiting the collector current of a switching transistor to the value not higher than the prescribed value when a self-oscillation is stopped. CONSTITUTION:A starting bias circuit for the base of a switching transistor 13 is composed of a constant-voltage power source 21 and a starting resistor 20. Since a voltage between the base and the emitter of the transistor 13 has constant voltage characteristics, currents which flows through resistors 19 and 20 become constant. Accordingly, the base current of the transistor 13 becomes constant, and the collector current substantially becomes constant. Consequently, even if a trouble occurs, no overcurrent nor overheat occurs, and the transistor 13 can be sufficiently protected.
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Inventors:
WATANABE SADAO
Application Number:
JP5107182A
Publication Date:
October 11, 1983
Filing Date:
March 31, 1982
Export Citation:
Assignee:
DENGEN AUTOMATION KK
International Classes:
H02M1/00; H02M3/28; H02M3/338; (IPC1-7): H02M1/18; H02M3/335
Attorney, Agent or Firm:
Ezaki Mitsuyoshi