Document Type and Number:
Japanese Patent JPH041571
Kind Code:
B2
Abstract:
A static protective relay at least includes a plurality of current transformers inserted in poly-phase AC power lines, a half-wave rectifying circuit for rectifying the output voltages from said current transformers, wave-shaping circuits for wave-shaping two of the pulsate output voltages from the half-wave rectifying circuit into rectangular wave output voltages, and a negative phase failure detecting circuit including a data flip-flop for detecting the level of the rectangular wave output to be phase-retarded at the instant of rising up of the rectangular wave output to be phase-advanced.
Inventors:
IIDA TAKASHI
Application Number:
JP4661879A
Publication Date:
January 13, 1992
Filing Date:
April 18, 1979
Export Citation:
Assignee:
TOKYO SHIBAURA ELECTRIC CO
International Classes:
H02H3/13; G01R29/16; H02H11/00