Title:
CHOPPER CONTROLLING EQUIPMENT
Document Type and Number:
Japanese Patent JPS5743567
Kind Code:
A
Abstract:
PURPOSE:To prevent malfunctioning while the controlling power source is off, by a method wherein a phase squeezing instruction circuit is provided, and said circuit intercepts the phase output of a comparing phase shift circuit which transmits circulating instructions by comparing a limited current value pattern with a feedback value. CONSTITUTION:A comparing phase shift circuit C transmits circulating instructions by comparing a limited current value pattern and a feedback value. An AND gate 2 is provided between an output terminal of the phase shift circuit C and one of the input terminals of an AND gate 1. A phase squeezing instruction circuit A is provided between another input terminal of the AND gate 2 and a voltage detector D through an inverter INV. When a controlling power source P is at OFF, the voltage detector D functions so that the phase squeezing instruction circuit A operates so as to control the output of the comparing phase shift circuit C to squeeze its phase output.
Inventors:
YATSUNO HIDEMI
ARAI SHINICHI
SATOU HIROSHI
ARAI SHINICHI
SATOU HIROSHI
Application Number:
JP11598780A
Publication Date:
March 11, 1982
Filing Date:
August 25, 1980
Export Citation:
Assignee:
JAPAN NATIONAL RAILWAY
HITACHI LTD
HITACHI LTD
International Classes:
H02P7/29; H02M3/135; H02M3/156; (IPC1-7): H02M3/10; H02P7/28