Title:
POWER SOURCE CIRCUIT
Document Type and Number:
Japanese Patent JP3281052
Kind Code:
B2
Abstract:
PURPOSE: To reduce rush current at the time of turning ON power source and to unnecessitate a protective resistance and a power source relay by providing a coil for voltage detection on a power transformer and operating the operation starting point and the interruption time of a rectifying circuit at the zero cross point of a power source.
CONSTITUTION: When a commercial power source is imparted to a power transformer T2, the output of a secondary coil T2b is rectified in a rectifying circuit E1. When this voltage is imparted to the input end P1 of a control part 2 and a switch SW 1 is turned ON, the control part 2 becomes operating state. The both waves rectifying is performed also for alternating voltage generated in the secondary coil T2c with a rectifying circuit E3, pulsating current is outputted to series connector of a diode DZ and a resistance R3, the current is imparted to a slice circuit 3 and a waveform rectifying is performed for the current. Next, the control part 2 detects the zero cross point of the commercial power source, using a pulse signal to be inputted from the slice circuit 3 and generates a zero cross point. This control signal is imparted to the base of a transistor Q1 and a relay RL becomes conductive. At this time, a rectifying circuit E2 starts to rectify from the zero cross point of an AC power supply.
Inventors:
Unemura Toyoake
Masahisa Furuya
Masahisa Furuya
Application Number:
JP23307892A
Publication Date:
May 13, 2002
Filing Date:
August 06, 1992
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
G05F1/10; H02M7/06; H02M7/12; H02M7/21; (IPC1-7): G05F1/10; H02M7/06; H02M7/21
Domestic Patent References:
| JP4110566A | ||||
| JP33136U | ||||
| JP1143520U |
Attorney, Agent or Firm:
Yoshiki Okamoto