Flashing relay

[c50truck]

The other night I was conversing with folks on a toy train chat room. I asked the following question; Which method of triggering your signal devices does any one here use? The metal clips over the rails, or insulated pins, or a variation of both on tubular track?
Answer was: I use blocks, when that section of track is "hot" then the signals flash (I use one of the flashing relays).

My next question I asked which went unanswered: Flashing relays?

So my question is, what is a flashing relay?
Rod LaFrance

[phillyreading]

Flashing relays control the lights going on & off, also relays can be expensive depending on the job you want to perform from them.  How old is the flashing unit or highway light signal?  If it is over 15 years old I would recommend using a more basic set up like a clip-on connector or two breaks in the outside rails about an inch long and wiring from those sections to the signal.

Lee