I'm sure this has been discussed before, but I can't find anything on it. Does anyone know offhand what kind of current is being sourced by the coil in an Atlas turnout? I'd like to control these via microprocessor and power transistor, but I'm not sure how big a transistor I would need. At 16V, I can throw one using a 2A power supply, but if I try to throw two at the same time, my power supply overloads. I guess each coil sources at least one amp. I'd like to switch either one or two turnouts at the same time, it depends on the location, so I need a FET that can handle the current for two. I have some TIP120's on hand which are good for 5A. As a bonus question, does anyone know how they might use a single power transistor to throw a turnout in either direction without using a relay? I'm trying to use a small microcontroller to handle my turnouts (maybe 4 per controller) as I can also drive signal LEDs and LEDs on my control panel from the same module. I'd like to use as few pins as possible for each turnout. I'm still reviewing 7400-series ICs to see if there's a flip-flop that I could drive with a single high/low pin and power my LEDs with a polarity-reversing circuit. For the turnouts, I think I'm going to need two pins, each driving the aforementioned transistor. I'd rather not use five pins per turnout (1 switch, 2 LED for signalling, and 2 for throwing the turnout) as well as two transistors, but it seems like this is the path of least resistance. This will get me about 2 turnouts per microprocessor which seems like overkill.
After reading your post my I suggest a DS64 by Dijitrax's based on what you wanted they will do everything you want and more These can be run separate of DCC and control Atlas turnouts, in fact they come from the factory set up to do this. here is the service manual so you can see if this is for you. Alan C. http://www.digitrax.com/ftp/ds64V4.pdf
