To follow up my earlier post/thread, I’ve got a Digitrax zephyr coming in a couple of days to use as the power source for testing/maintenance of DCC locos.
Now I know that mixing DC and DCC is NOT recommended (especially by me) on a layout. But what about a 3 ft test track?
Said another way, if I have a test track hooked to the zephyr, and set a DC (no decoder whatsoever) on it, would it do nothing, operate as normal, or smoke and burn?
Thanks all, I’m sure others have tried this, but I have not.
I don’t know why, you would want, to test a DC, loco,with DCC, it will,hum and buzz. If you want to test a DC, loco, why not test it with a DC, power source? If you just want a test track, have both.DC and DCC, switched, with a DPDT, center off switch. You will only have one power source, working, at one time,that way.
This is a system-specific question, unfortunately. I have a Lenz system, and it supports running a DC engine as “Engine Zero,” that is, select 0 as the locomotive ID on the throttle, and you can actually run the engine. You will note, however, that you are back to "running the track, " like in DC, and forward/reverse will revert to left-to-right vs. right-to-left, regardless of which way the DC engine is facing. (DCC engines will continue to work normally.) Auto-reversers will cause your DC engine to ping-pong, or maybe short.
Like I said, this is the way a Lenz system behaves. I think Digitrax works the same way, but I’m not sure, and I know that some systems don’t support this option at all.
In any case, the DC engine will run slowly and will buzz loudly. There are anecdotal reports of DC motors actually burning out under these conditions, particularly if left idling for too long, but that’s never happened to me.
I just gave you one, if you want to test a DC loco, for instance,before you convert it,to DCC, USE, DC, on your test track. You may also have,DCC, connected,to your test track,with a DPDT, center off switch, your test track will be controlled, by the switch,regarding,what system,you want to use.
mobilman, since you apparently did not like the responses that you already received, then take Mister Beasley’s response as gospel truth. Sure, the Digitrax Zephyr has a feature that allows you to run non-DCC locos, at your own risk. But, yes, theoretically, your curiousity ONLY - “what if” question, can be answered in the affirmative.
It’s very much a roll of the dice what happens. The general thing is that the “artificial DC” possible with some DCC systems (NCE does NOT support DC at all, for instance) is hard on motors.
That buzz that some mentioned will happen is the motor reacting to the quickly reversing polarity, which is biased in either F or R, depending on the direction of the loco. Some of the more sensitive – and generally more expensive – can motors can actually be destroyed by this effect.
An old BB Athearn? Probably not a problem. But if you aren’t in the mood to research each and every loco you want to run this way, then you’re rolling the dice on what effects DCC will have on it. And at most you can run ONE loco on DC at a time on a DCC layout on DC (assuming you’re probably only going to run one at a time on the test track.) And you’d be well-advised not to let it sit idle on the layout under DCC power when not being used, as the buzzing effect continues even when not in motion – it’s simply balanced between F and R and just sits there, buzzing away.
The armature is slightly oscillating at the DCC frequency when the loco is not moving. Where the two brushes contact the armature segments, heat will develop. A few years ago I did some measurements with an infra red temperature scanner. The scanner could pick out this heat spot quite accurately.
Bottom line, you don’t want to do this. There is absolutely no reason to do this if the controller cannot run a DC only loco.
Thank you (and others that did likewise) for the meaningful answer. As I tried to explain earlier, I have no intention of doing this (run a DC motor with a DCC power source); I just wanted to know what would happen.
My experience is different, at the club we had a member, now deceased, that run all his loco on DCC address Zero. In fact he never had a loco with a decoder in it. He used to do that for 10 years without any ill effect or collateral damage to either his locos or the DCC system, of course he was not leaving locos idle on the layout. He became so good with running DC locos on a DCC system that he could even cross a reversing loop without stopping or creating a short. He could reverse direction on his throttle on the precise moment to avoid problems.
I think the wording that you can only run one DC loco on DCC is misleading. One can run as many locos as he wants as long as the amp. of the system support them. They will behave as they would on a DC layout, that is they will all go the the same speed and direction.
So my experience is you can run DC locos on a DCC layout as long as you run them and don’t leave them idling on a powered track.
It is very obvious that you can run more than one DC only loco. It all depends on the capability of the controller which many are not aware of. Also, if the different locos run at different rates with the same voltage, Obvious Man says, don’t do it.
Manufacturer’s of a controller that can run a DC loco usually say, runs one loco for that reason so the answer is not that misleading.
Atlas installs a small resistor on their factory DC boards that doesn’t affect anything when running on DC, but when the engine is placed on a DCC layout, it will shut down the system (presents a small short) preventing you from running it on DCC. This was done because they got tired of all the fried motors that were being sent in to be replaced.
You have to figure if Atlas does something like that, and some DCC systems now won’t even allow address 0 to be accessed, there must must be a good reason to avoid doing it.
I don’t keep up with all the latest and greatest in DCC, in particular any extended DC capabilities. I’m an NCE guy and long ago just got used to the idea it’s not a big deal to put a decoder in a loco – any loco.
Perhaps my wording would be more accurate to say most DCC systems that do have DC capability can only control one DC loco, presuming you could of course run a consist of up to the amp capacity of the system. Splitting hairs there, I would say. If the union consider a lashup as one loco these days, I got no problem doing the same.[:)]
Now if there are DCC systems that control multiple DC locos in different directions and speeds, that’s news to me. I presume you gotta know what to ask for and assume it’s something of a premium to get such things over and above the cost of a regualr ol’ DCC system. I’d have to ask WHY? though, because you can do that a whole lot easier and cheaper by using, ummm, DCC and decoders in each loco…[:o)]
Pretty sure I wasn’t trying to “mislead” anyone in any case.
The OP says that he is looking for a meaningful answer but it seems like a meaningless question.
If you set up a test track and connect it to a Digitrax Zephyr and set a non-decodered DC loco on the test track, will it do nothing, operate as normal, or smoke and burn?
If you set a shaving cream can near an open fire, will it explode? Maybe yes, maybe no.
It would do nothing but humm for a while. Eventually (hours, days, weeks, months - who knows) the motor would stop working either burnt out because of heat build up or because the magnets have been demagnetized.
I believe the Zephyr is one of the systems where you can call up channel zero and run it.