My layout has both a full walkaround set up as well as a duck under secition that lets me get up close to a few heavy turnout areas. In order to avoid the duck under if at all possible I have tried to power some of the Atlas snap turnout switch machines with multiple power switches, some inside the duck under ond others outside for demo running for the kids so I don’t have to bend over if at all possible. I have 24 turnouts on my layout and 41 control switches, Most of the extra 17 control switches are doubled up but several have 3 switches wired to 1 turnout.
The problem is that the multiple controlled units don’t seem to have any power to them. All the single units work fine but if I have 2 or 3 control power switches they don’t fire off and throw the points. On half of the multiple control switches one of the hooked up switches will throw the points but the others don’t and as noted several of the doubled switches don’t do anything.
Are you running all those switches off the same power pack that’s running your trains? Your post didn’t say…It might not be powerful enough to throw multiple switches…if you are, I’d suggest finding another pack to run just the switch machines.
Let me see if I understood correctly - you have several Atlas track switches that you are trying to power from two or three different locations.
I presume that you are using Atlas control pads, and the original Atlas wiring. That wire might be part of the problem - it’s really very small for the load. Also, if you are using the AC connections of the original train control power pack, there probably isn’t enough power available, especially if a train is running at the same time.
The answer is, use a separate power supply with ample power (mine is built around a 12.6 VAC, 3 amp filament transformer) and replace the hair-fine wire with something in the number 20 - 22 (awg) range. You might also want to consider something more robust than the Atlas control pads, which are notoriously prone to failure (and usually take the switch machine with them.)
To achieve maximum bang, install a capacitive-discharge circuit. It will provide a BIG surge of power to kick the most sluggish switch machine over, and then limits the current so that a stuck electrical switch won’t smoke the switch machine.
If I have misunderstood your situation, feel free to clarify it for me.
Chuck (Modeling Central Japan in September, 1964 - with twin-coil switch machines)
I agree that your problem is likely to be lack of sufficient power. And, like Chuck, I recommend a Capacitive Discharge circuit. You can buy these for thirty or forty dollars, complete with power supply, or you can Google up a circuit and build one for 4 or 5 dollars in parts from Radio $hack. It’s literally two capacitors, two resistors and, if you’re using an AC supply, you’ll also need a bridge rectifier.
Since you’re running these from multiple locations, I’d imagine that there is considerable distance between the power supply, the pushbuttons and the turnouts. Therefore, your wire runs are long. This increases the resistance of the wire runs, and means you need more power. So, while you may bench-test your turnouts and they’ll run fine, once you put them over yonder past the cornfield, they won’t get enough power to turn over. Again, that CD circuit is just what the doctor ordered.
Want another reason to use a CD circuit? It’s those blue-on-black Atlas pushbuttons. They are notorious for failure, and often they fail in the closed position. When this happens, you’re putting continuous power into the switch machines, something they’re not designed for. They will literally melt down, leaving you with a foul odor and a trip to your LHS for another switch machine. But, a CD circuit limits the current flowing to the switch machine after the first few milliseconds, so the machine is protected even if the toggle sticks on. By the way, I don’t use those Atlas buttons, but I’ve also had a common toggle hang up the same way. My CD circuit saved a Peco switch machine, and paid for itself several times over that day.
Chuck, thanks for thinking what could be the issue. I am trying to run several of my switch machines from different location. I am powering the turnouts with a separate power unit, the MRC Tech II model 1500 unit from my last layout. I am trying to convert to DCC. On my old layout some of the power lines runs were over 20 feet and worked well. On this new rebuilt layout the maximum run of the power line from any control unit is less than 12 feet. All my line runs are 18 or 22 guage wire.
As noted I have a fair size investment in these Atlas pads with over 40 of them on the layout. Will this capacitive-discharge circuit you mention replace or augment them? What else can I use.
The base question really is, will the Atlas switch machines actually work if they are to be controlled from different locations and if so what could I have done wrong.
The CD units turn the Atlas pads into the equivalent of momentary contact push-buttons.
An example of lower cost CD units is the SwitchWitch from TracTronics; a kit with circuit board for one turnout is $8.95.
It is possible to control more than one turnout with this circuit if they are used in a ladder arrangement for example.
The CD circuit either replaces the power supply you’re now using (store-bought version) or goes between the power supply and the turnouts (home-built version, mostly.) So, it’s simply a matter of disconnecting the line that feeds the buttons and putting in the CDU.
The buttons are really just Single-Pole, Double-Throw (SPDT) momentary-contact toggles. If wired correctly, you should be able to use multiple buttons for one turnout, or run multiple turnouts off of one button, as you might in a crossover.
It may not be a power problem. If the turnout works with one push button attached and fails to work when the second pushbutton is attached, it’s most likely in the wiring.
Can you post a diagram of how you’ve wired the push buttons? That might help us spot a wiring problem. Also, just drawing up a diagram might indicate where a wiring problem exists.