JPS54157244A - Voltage equilibrating relay - Google Patents

Abstract

PURPOSE: To enable a relay to use 3 input transformers and to cope with higher harmonics with high accuracy by making connection of an input transformer primary side so that 2 voltages of the system are provided with mutually inverse polarities and by connecting a capacitor to the transformer's secondary side.

CONSTITUTION: Higher harmonics absorbing capacitors 52, 54 and 56, provided between secondary side output terminals of transformers 4 through 6, are provided with resistant elements 46, 48 and 50, variable resistant elements 47, 49 and 51, and transformer secondary output adjusting variable resistant elements 53, 55 and 57. And these are all provided in parallel. In this mechanism, taking a transformer 4 for instance, from a measuring voltage given through a resistant element 46 and also from a voltage to be measured given to the measuring voltage and inverse polarity through a variable resistant element 47, a differential voltage ED is set by a variable resistant element 47, and if an output of all-wave rectifying circuit 42 exceeded a set level of a level detecting circuit 43, a driving circuit 45 is actuated to operate a judging element 41 and close a contact 41a, and therefore, it enables a relay to utilize 3 transformers and also to cope with higher harmonics with high accuracy.

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