JPS54155441A - Indoor power cable carrier system - Google Patents

Abstract

PURPOSE: To prevent an error operation due to an out-of-synchronism, by making a length of time, for the receiver to discriminate each bit signal, shorter than that for the transmitter to transmit each bit signal.

CONSTITUTION: There are provided a transmitter 1, having an oscillating circuit 1b for generating a binary signal coded by using frequency signals fA, fB of two kinds, and a receiver 2, having a counter circuit 2b, for counting the frequency of each bit of the binary signal transmitted from the transmitter 1 through an indoor power cable l, and having a comparator circuit 2d, for discriminating fA, fB, with a comparison made between the before said counter output and the reference frequency, to output its corresponding signal, and so on. By using such transmitter and receiver as constituted in the above, with a length of half wave of the commercial power source frequency processed a time division into a prescribed number of bits, and timing point for the commercial power source voltage becoming zero individually detected by the transmitter 1 and the receiver 2, and each bit signal transmitted and received in a manner with a synchronization made with the above timing point, thus the setting is made so that a length of time for the receiver to discriminate each bit signal may be shorter than that for the transmitter to transmit each bit signal.

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