Author Topic: Controlling loco with module connected to track?  (Read 7676 times)

ON28

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Controlling loco with module connected to track?
« on: May 06, 2020, 01:11:46 PM »
I have a Roundhouse EMD Model 40 critter that has insufficient space for a module. Can I control the loco by connecting the module to a given segment of track instead of directly to the engine? This would be for an industrial plant electrically insulated from the rest of the layout. There is a small TCS DCC decoder to fit the 8-pin plug in this loco but I'd rather go RP.
mrr-pr0406_33.jpg.
« Last Edit: May 06, 2020, 01:15:25 PM by ON28 »

Smoke

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Re: Controlling loco with module connected to track?
« Reply #1 on: May 06, 2020, 09:23:30 PM »
I don't see any reason why it wouldn't work. You would have to wire the power pickups directly to the motor. Track power for the industrial plant would be variable based on the "speed" of the locomotive. Lighting would be an issue since you wouldn't always have enough power to light the LED/Bulbs. You could have a really nice speaker for the smallest loco since you would have extra space under the layout.  ;D
« Last Edit: May 06, 2020, 11:00:43 PM by Smoke »
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Re: Controlling loco with module connected to track?
« Reply #2 on: May 06, 2020, 11:17:03 PM »
Someone did / was going to do this type of install for a trackmobile. Yes you can do it but there is a few things to know:

1. The locomotive will essentially be a plain old DC loco, so you can't run it anywhere else on the layout; unless you want it to take off as an uncontrollable rocket that is. You also can't use it on any DCC powered track.

2. As you've already noted the section of track has to be isolated from the rest of the layout.

3. Lighting will be the same as a plain old DC loco, ie directional. You won't be able to use RP's lighting.

4. Power shouldn't be a problem as long if the track length isn't too long (it's PWM so it's still ~14 volts). If the track length is fairly long you'll want to have the LM powering a track bus with droppers like for any other track.

The easiest way to think of it is as a microprocessor controlled plain old DC system; instead of an old variable voltage throttle sitting between the power supply and the track it's an LM instead.

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ON28

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Re: Controlling loco with module connected to track?
« Reply #3 on: May 07, 2020, 01:16:25 PM »
Thanks for the responses. It's a nice little model that runs well. I'll update as things progress.