Railway switches and signals – Block-signal systems – Automatic
Patent
1978-10-23
1980-02-12
Eisenzopf, Reinhard J.
Railway switches and signals
Block-signal systems
Automatic
324 87, 328133, 329 50, B61L 2106
Patent
active
041880021
ABSTRACT:
A vital circuit network, equivalent to a two element, alternating current track relay used as a synchronous detector, has a first input transformer directly coupled across the local track circuit source and second input transformer coupled across the track rails through a band pass filter tuned to the track circuit frequency. The transformers are designed to normally produce secondary output signals of the same range, which are connected into a series circuit network including a second band pass filter, a varistor, a full-wave rectifier, and a protective fuse, with a biased track relay connected across the rectifier D. C. output. From the two voltage signals in the series network, the varistor produces a product current signal which is rectified to provide an output sufficient to pick up the track relay only when both input signals are present, are of the track circuit frequency, and are within a predetermined phase relationship. The varistor circuit network has a sharp rejection of input signals outside the predetermined phase relationship or of a nonselected frequency.
REFERENCES:
patent: 3662227 (1972-05-01), Morrison
patent: 3986691 (1976-10-01), Ehrlich
Eisenzopf Reinhard J.
McIntire, Jr. R. W.
Westinghouse Air Brake Company
Williamson, Jr. A. G.
LandOfFree
Vital power varistor circuit for railroad signaling systems does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vital power varistor circuit for railroad signaling systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vital power varistor circuit for railroad signaling systems will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1852070