公开(公告)号：WO1988002326A1

公开(公告)日：1988-04-07

申请号：PCT/JP1986000508

申请日：1986-10-03

Applicant: THE NIPPON SIGNAL CO., LTD.

Inventor： THE NIPPON SIGNAL CO., LTD. ,  FUTSUHARA, Koichi ,  SUZUKI, Takakazu ,  HARUTA, Masanori ,  TAKAHASHI, Kazuo

IPC: B61L01/18

CPC classification number: B61L1/187

Abstract: A device for detecting the presence of a vehicle on a track, which includes a first fail-safe AND circuit that converts a local signal applied to a specific section of the track and a track signal into phase decision signals that vibrate with a reference voltage level as a center, and that generate an output depending upon the logical product of the two phase decision signals when the two phase signals are in phase, and a second fail-safe AND circuit that generates a vehicle signal depending upon the logical product of the output of said first AND circuit and an output of a fail-safe level decision circuit that generates the output provided that the voltage level of the track signal is greater than a predetermined value, when the above two outputs are simultaneously generated.