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Okay here's one for you DCC Gurus to ponder:
Why is it that when I have any kind of short, either a wheel fouling a switch or other, there is one (and only one) loco that takes off like a rocket?
It doesn't matter if it's idling or dispatched it will zoom!
Tends to make things interesting when you hear it fire up (it has sound) while in the hidden staging yard then make the unmistakable sound of wheels going over trailing points and dragging along the ties!
The loco in question is an HO Kato F40PH with the Digitrax SDH104K1C & FN04K1 combo.
While I've got your attention and I'm at the keyboard... has anyone ever thought of making DCC caboose brakes? I'm playing with the thought of a tortoise machine dropping a rod or something to hold the train while switching on a grade. Could be a cool addition or just a disaster in the rough.... hmmmmm.
Rico
Go back into your programming and disable the analog (DC) mode of the decoder. Sometimes the decoder sees a short and misinterprets it as an analog signal to go, and with the decoders ability to convert AC to DC current, power flows like mad since it thinks it just got an analog signal to go.
I've had this happen to a lot of my older Digitrax decoders for some reason. Now they are all turned off, and I havn't had it happen since.
Karl has the right answer. It's when the decoder still has dual capability. Disable the DC option and you won't have any runaways. I've never heard of using DCC for a caboose brake but there no technical reason couldn't be done and is not a bad idea if you regularly switch on grades.
Thanx guys, I'll look into the disable thing when I get home. I forgot to mention what system I was using but you figured it out.
As for the brake thing, I am picking up some decoder interfaces for the hidden switches, I think I'll try the tortoise in the caboose thing, and yes with a little added weight.
Stay tuned!
I've had this happen on an NCE system, with older Digitrax decoders. A short or power surge would trigger it. As has been said, disable DC mode and you should bo fine. I had a Proto PA-1 hit the floor because of it. That wasn't pretty!
I'll add my voice to those above, who recommend turning off the DC capability. I had that runaway problem with a Kato GP35; disabled the DC, and no problems ever since!
No, it is not a Digitrax failing, it happens on other systems also. All DCC systems shut off power when there is a short. The runaways happen when the power comes back on after a temporary short.
