My NJI FLASHERS (continued)
Weeks ago I posted that I was wiring up a set of NJI flashers on a grade crossing outside of a portal. I had installed the 3 LED sensors at tie level per the instructions. In that post I wrote that I expected to finish the rest of the installation the next day. It did not happen that way for a bunch of reasons. Today, I resumed work on the project.
Looking at the photos I posted, it is difficult to understand that there would be so much involved in getting the lights on two tiny sets of crossing signals to operate as designed, but there is.
I should have learned by now that starting a wiring project, leaving it partially done, and returning to it weeks later is poor judgment on this old man's part. I am a slow learner unfortunately. I spent much of my time today figuring out what I had gotten done, and what still needed doing!
Tomorrow, I am hoping to see the flashers in operation.
Once an understanding of how the NJI flashers are designed for prototypical operation, one begins to appreciate all that is involved in installing and wiring them. I am fairly comfortable doing layout electrical wiring, but when it involves electronics I am a novice and I get stressed out. The first thing , in this case, that I needed to do, was draw myself what I call a layman’s diagram of the schematic. You can see my attempts at doing this in the photos.
How they operate prototypically, without any track power:
There are four sequence phases
The first phase is when any START sensor is triggered. This will turn on the lights. A train covering either the right or left sensors in the ties triggers this. The FlashMaster board will then wait until it sees that the hold sensor (middle of the crossing) is covered AND the START sensor that started the sequence is finally uncovered once again.
This is the second phase: The system now waits for the HOLD sensor to be uncovered (the sensor in the middle of the grade crossing). Six flashes after the hold sensor is uncovered, the lights will go out, and phase three starts.
In phase three, the FlashMaster board will wait until the last (the 3rd) sensor is covered by the train – this is the sensor that DID NOT statr the sequence.
Phase four then begins, where the FlashMaster will wait until it sees the opposite START sensor is UNcovered for 3 seconds. There is a reason for this – This ensures that if the sensor 'sees' light in the gap between the cars' passing over it, it will not incorrectly trigger another grade crossing sequence.
Is that not something!
My head hurts.
Bruce Vincelette
