In the kit Model Railway Level Crossing Light a level crossing occurs where a railway line is intersected by a road or path on one level, without recourse to a bridge or tunnel.
In the kit Model Railway Level Crossing Light a magnet under the train operates reed switches positioned on the track. The trigger reed switch starts the sequence by switching on the amber light, a few seconds later the two red lights start to flash. When the train has passed the level crossing it operates the cancel reed switch which switches off the lights until the next train arrives. This kit Model Railway Level Crossing Lights uses a 555 mono-stable circuit to switch on the amber LED for a few seconds. When this switches off it triggers a 555 bi-stable circuit which switches on a 555 as table circuit to flash the red LEDs.