Title:
POWER SOURCE CONTROL CIRCUIT
Document Type and Number:
Japanese Patent JPS5781625
Kind Code:
A
Abstract:
PURPOSE:To make a DC power source unnecessary to simplify the circuit constitution, by subjecting an AC voltage, which is obtained by shifting the phase of the AC power source voltage at 90 deg., to full-wave rectification and by using this rectified voltage as the control input of a solid relay. CONSTITUTION:A load 12 is connected to an AC power source 1 through a solid relay 5 consisting of a photocoupler 6, a zero cross circuit 7 and a TRIAC8. The control input of the solid relay 5 is obtained through a diode bridge 4 from both ends of a resistance 9 connected in series to a capacitor 10. When a switch 3 is turned on, an AC voltage which has a phase advancing more than that of the AC power source 1 by 90 deg. is generated at both ends of the resistance 9 and is subjected to full-wave rectification and is applied to the photo-coupler 6. The photocoupler emits the light with a maximum brightness when the momentary value of the AC power source 1 becomes 0, and at this time, the photocoupler 6 triggers the TRIAC8.
Inventors:
IIDA MUTSUMI
Application Number:
JP15707680A
Publication Date:
May 21, 1982
Filing Date:
November 10, 1980
Export Citation:
Assignee:
HITACHI LTD
International Classes:
G05F1/10; H02M1/08; H02M5/257; (IPC1-7): G05F1/64; H02M1/08