Specifications for Cullen Hayes crossing signals, from Western Safety Products, Inc.: http://www.westernsafety.com/products/wch-railroadproducts/wchpg1.html
This could come in handy when building crossing signals from scratch.…
When LEDs turn on, they reach their full brightness more quickly than incandescent lights do, and when they turn off, they reach full darkness more quickly than incandescent lights. The effect is particularly noticeable when comparing flashing LEDs with flashing incandescent lights, such as the red lights on railroad crossing signals. The difference is slight, but it’s perceptible enough that they don’t look quite right on layouts depicting a time before LEDs were used in crossing signals. To look right, there should be a barely perceptible moment in time when you can see some amount of light in both lights at the same time. I’ve wanted to find a way to simulate that effect by making the LEDs in my signals fade on and off at a similar speed, instead of having them just alternate between on and off. Having recently discovered Arduinos, I’m excited that I can achieve this look on my future crossing signals (and other types of lights) by using an Arduino to control them.
I wrote code that creates a timer for alternating between two phases, and initiates fade-on and fade-off functions for both lights each time the phase changes, at a suitable rate for …
While building the 3-Light Signal Drivers on printed circuit boards (PCBs) I bought from Rob Paisley, it occurred to me that the resistors in the original circuit (which I had been using in my breadboard test circuits) aren’t necessarily of the rating that I’ll need for the signals that I’ll build. They were fine for the testing I was doing with some generic LEDs on a breadboard, but I think the LEDs on my signals will need to be a little less bright than that in order to look realistic. The circuit has separate resistors for each of the three LEDs in the signal (red, yellow and green), so I just assembled all parts of the circuits except for those three resistors. Once I know which LEDs I’ll use in the signals, I’ll be able to determine the appropriate resistors to use. This has prompted me to start some more serious planning for building signals.
While I had free trial access to the Model Railroader Digital Archive last year, I downloaded a PDF of an article they published in July 2006 about building your own signals from commercially available parts. I’m going to base my signals off of that plan, …
Rob Paisley has a lot of model railroad circuits on his website, complete with detailed diagrams and notes for electronics beginners. For some projects, he also provides a parts list with DigiKey part numbers, and for some, he sells kits that include printed circuit boards.
I’m going to try his Infrared Proximity Detector Circuit to use with my signal system. I’ve looked at a few other block occupancy detection (BOD) methods, but the others have what I see as downfalls. With DCC, you can use a system that detects the voltage draw from the track power, which tells the system where on the line the locomotive is. The problem with this, for me, is that the rest of the train doesn’t normally draw current, and so in order to make the rest of the train trigger this type of occupancy detection, you have to install power-pickup wheels on at least some of the cars, with a resistor between the two wheels. That sounds problematic and like a lot of unnecessary hassle.
With an IR proximity detector circuit, an IR LED, hidden inside a tube below the track, in between two ties, shines invisible light straight up. An IR receiver is …