Patent ID: 9610959
Date: 2017-04-04
CPC Classifications: B61L

Claim:
1. A monitoring system for a wayside signaling device comprising: a light emitting diode (LED) circuit comprising at least one LED, a LED driver unit for driving the at least one LED, and a mechanism for connecting and disconnecting the LED circuit; an optical light sensing circuit comprising at least one light-controlled variable resistor operably coupled to a resistor driver unit comprising relay functionality; and a vital processing system, the LED circuit and the optical light sensing circuit being operably connected to the vital processing system, wherein the LED circuit and the sensing circuit are arranged such that the at least one light-controlled variable resistor monitors an output of the at least one LED, and that the relay functionality triggers the mechanism to connect or disconnect the LED circuit based on the output of the at least one LED, and wherein the LED circuit further comprises a passive inductor arranged in series with the at least one LED, and a passive bandpass filter arranged in parallel with an output of the vital processing system for performing cold filament checks.