Title:
POWER SOURCE CIRCUIT
Document Type and Number:
Japanese Patent JPS57182222
Kind Code:
A
Abstract:
PURPOSE:To prevent excessive increase in rush current, by installing a circuit which limits rush currents at the time of power making and when the power supply is recovered from instantaneous cut-offs. CONSTITUTION:After an input VAC is supplied at the initial stage, a voltage VC across both ends of a condenser 2 rises by the charging through a resistance 3, and a signal V1 is outputted by a timer circuit 4 which slowly returns to the original condition when a fixed time has passed after the charging of the condenser 2 is almost completed, and then, the titled circuit is returned to the nornal smooth condition and a prescribed DC output is obtained by shortening the resistance 3 by arcing a thyristor 5 connected to the resistance 3 in parallel. Moreover, when the input VAC is instantaneously cut off, a detecting circuit 7 starts working and turns off its output V0 and the output V1 of the timer circuit 4. Therefore, the thyristor 5 is turned off and the circuit is returned to the same condition as that before the input VAC is supplied.
Inventors:
KANO TAKANOBU
HATANO SHIGERU
HATANO SHIGERU
Application Number:
JP6551481A
Publication Date:
November 10, 1982
Filing Date:
April 30, 1981
Export Citation:
Assignee:
FUJITSU LTD
International Classes:
H02J1/00; G05F1/10; G05F1/569; (IPC1-7): G05F1/64