I'd like to build a Monon Greenlight grade crossing. (Light was on green when there wasn't a train, and when a train hit the signalling circuit, the green light was triggered off. This way, if the light burnt out, a car was forced to stop until they determined there was no train coming and moved on). http://www.monon.org/Images2/greenlight.jpgIn practice, that much I know how to do, I figure two green LEDs, a resistor so I don't blow them out, a brass pipe, two Ditch Light detail parts, some brass wire, and a piece of Styrne for the caution sign, and I'm golden. The problem is, form there, I don't know how to mate it into a detector of some kind. I figure that the crossing light would be on a detecotr, not the track signals, but I suppose they could go into that once that stretch of track is signalled. However, that could be a while.
-Morgan
Do you have any idea what track detector you plan to use? Most any one of them can easily handle the current of a single LED, or a pair of them, directly on their output connections. So basically you'd hook the detector to the track to sense a train, and the output connection of the detector acts like a switch to turn the LED on and off.
Or jsut do it by hand and put a simple toggle switch there, when trains come to the crossing the are to turnt he LED off, and reset it when they get past. Naturally some peopel will forget to turn it back on - well when the next crew comes along, it will be the 'burned out' situation and they will have to stop. Kinda makes the operation situation take care of itself. Or if you want to be sneaky, turn the LED of when no one is looking - or wire to the dispatcher's panel so the dispatcher can turn it on and off. Is the DS has control, then he can 'schedule' a crossing train through the junction even if it's not fully modeled.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hmm. I'll check with type tomorrow when I can get by and get one. The crossing was to make motorits stop more than the train, but Monon wiried it into the Signal system versus havong a true crossing detector as I understand it. Still, a forgotten crossing would require a train to stop and check it, possibly flag across at walking pace, though these signals tended to pop up at mostly rural streets, so they might also just stop, look, and gun it when the car has passed still an Operations twist.
Cool then, sounds easier than I thought she'd be.
If you want it driven off the signal system, well, once you install one you'd hook the green light up as any other signal head, with just the green connection. Your signaling logic will have to control if the green light is on or not, but the conditions are basically the same. Sort of, the light is green of the opposing block is empty and the signals for the opposing track are set to red.
I use a tdp signal controller which uses optical sensors for input. it also drives the signals.
Here's their manual
http://www.trainspeed.com/ABSMaster_manual_v1_0.pdf
Springfield PA
So it sounds (and looks) like it would be easier to use a sensor than a signal, especially one that isn't in place yet, but not by much. Cool guys, Thanks! I'll be sure to get back here with the light as its built and wired.
Well, it's kind of hard to have signal logic if all the blocks aren;t detected and there is no signal controller to handle it. If you really do intend to build a complete signal system later on, what I'd probbaly do just for now is have it manually operated. But the same block detector you use now to automate the green light could be used for your signal system later on, since you need to have the detectors either way. Before jumping in though you should think about what your actual plans are so you don't buy stuff now that won't work later.