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Patent Searching and Data


Title:
COMMUNICATION EQUIPMENT
Document Type and Number:
Japanese Patent JPH01129536
Kind Code:
A
Abstract:

PURPOSE: To execute the communication for using an underground buried pipe as a transmission line with high reliability being free from the influence of a noise by executing the transmission of a signal based on an nCr communication system and setting a frequency of a signal to be used to a frequency of a commercial power source and a frequency which has avoided a higher harmonic frequency.

CONSTITUTION: A transmitter 1 transmits a combinating of one wave or plural waves of a frequency of a commercial power source and a frequency which has avoided its higher harmonic frequency, to a transmission line 3 as a signal for showing prescribed information. A receiver 2 receives a signal which is transmitted through the transmission line 3, the received signal is brought to frequency discrimination by a signal deciding circuit 23, a prescribed signal is outputted in accordance with each signal, and only when a combination number deciding circuit 24 decides that the number of received signal waves is equal to a prescribed number and a time width deciding circuit 25 decides that time width of each received signal is within a range and a time difference deciding circuit 26 decides that a difference of the time width of each received signal is within a prescribed range, a signal selecting circuit 27 outputs a prescribed signal outputted by the signal deciding circuit 24.


Inventors:
Nakada, Kenji
Application Number:
JP1987000287659
Publication Date:
February 02, 1999
Filing Date:
November 14, 1987
Export Citation:
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Assignee:
NIPPON SIGNAL CO LTD:THE
International Classes:
C01G5/02; C07C211/63; C07F1/00; C07F1/10; G03C1/015; G03C1/035; (IPC1-7): C07C211/63; C01G5/02; G03C1/015; G03C1/035
Attorney, Agent or Firm:
吉田 研二 (外2名)



 
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