Help!! Hooked up DCC last night and my loco is making a strange noise

[Anonymous]

I hooked up my MRC Prodigy DCC last night (no program track yet, just two wires to the track). The decoders are on order, but I wanted to give it a spin so I put a DC loco on the layout and used address 1, just as the instructions tell you to. I noticed as soon as the throttle is turned, the loco started making a squawking noise, kinda like radio interference. Funny thing is, the more I turn the throttle up, the lower the pitch of the noise. Also, the loco moved pretty slow compared to my standard DC transformer. I tried another DC loco, and it performed exactly the same way.

Is this normal [%-)]? If not, what could be the source of the trouble, and will it damage my DC locos? Thanks!

[brothaslide]

Yankee,

Some Hamsters don't like DCC. If you feed them soft food instead of the hard crunchy stuff, they'll run your locos all day long on DCC.

[cacole]

Most straight DC locomotives do not like to be run on DCC, and you could wind up overheating and burning out the motor because of the way a DCC system tries to run a DC motor by sending pulse-power to it.

[Anonymous]

QUOTE: Some Hamsters don't like DCC. If you feed them soft food instead of the hard crunchy stuff, they'll run your locos all day long on DCC.

I wonder if a turtle would do better...[:D]

[Isambard]

QUOTE: Originally posted by yankeejwb

I hooked up my MRC Prodigy DCC last night (no program track yet, just two wires to the track). The decoders are on order, but I wanted to give it a spin so I put a DC loco on the layout and used address 1, just as the instructions tell you to. I noticed as soon as the throttle is turned, the loco started making a squawking noise, kinda like radio interference. Funny thing is, the more I turn the throttle up, the lower the pitch of the noise. Also, the loco moved pretty slow compared to my standard DC transformer. I tried another DC loco, and it performed exactly the same way.

Is this normal [%-)]? If not, what could be the source of the trouble, and will it damage my DC locos? Thanks!

Don't know about a squawking noise, but if you're referring to a buzzing sound, that's normal for a DC loco without a decoder installed when DCC powered. The buzz will start as soon as you apply DCC power to the rails, even with the throttle in zero position and will reduce in level as you turn the throttle and begin to move the loco. It normally should not harm the loco.

With DCC a more or less constant voltage of about 15 volts is provided to the track as a series of square wave pulses as soon as you switch on power to the track, even with zero throttle. At zero throttle setting the "plus" pulses cancel out the "minus" pulses so the motor doesn't turn but sits there buzzing gently. When you crank up the throttle the plus pulses become stronger than the minus pulses (or the other way around when you change direction) causing the motor to turn and the loco to move. You'll also probably see that the loco lights are on at max brightness at all times, unlike with DC.

Hope this helps and that my simplified description of how DCC works isn't misleading. I'll bet you'll get quite a few other responses. I

[Isambard]

QUOTE: Originally posted by yankeejwb

I hooked up my MRC Prodigy DCC last night (no program track yet, just two wires to the track). The decoders are on order, but I wanted to give it a spin so I put a DC loco on the layout and used address 1, just as the instructions tell you to. I noticed as soon as the throttle is turned, the loco started making a squawking noise, kinda like radio interference. Funny thing is, the more I turn the throttle up, the lower the pitch of the noise. Also, the loco moved pretty slow compared to my standard DC transformer. I tried another DC loco, and it performed exactly the same way.

Is this normal [%-)]? If not, what could be the source of the trouble, and will it damage my DC locos? Thanks!

Don't know about a squawking noise, but if you're referring to a buzzing sound, that's normal for a DC loco without a decoder installed when DCC powered. The buzz will start as soon as you apply DCC power to the rails, even with the throttle in zero position and will reduce in level as you turn the throttle and begin to move the loco. It normally should not harm the loco.

With DCC a more or less constant voltage of about 15 volts is provided to the track and the loco motor as a series of square wave pulses as soon as you switch on power to the track, even with zero throttle. At zero throttle setting the "plus" pulses are the same voltage as the voltage of the "minus" pulses and cancel out the minus pulses so the motor doesn't turn but sits there buzzing gently in response to the pulsing. When you crank up the throttle the plus pulses become stronger than the minus pulses (or the other way around when you change direction) causing the motor to turn and the loco to move. You'll also probably see that the loco lights are on at max brightness at all times, unlike with DC.

Hope this helps and that my simplified description of how DCC works isn't misleading. I'll bet you'll get quite a few other responses.

[:)]

[Anonymous]

QUOTE: Originally posted by cacole

Most straight DC locomotives do not like to be run on DCC, and you could wind up overheating and burning out the motor because of the way a DCC system tries to run a DC motor by sending pulse-power to it.

I also saw in the MRC online manual that it will run a "standard" (non-decoder equiped) locomotive at the same time as a decoder-equiped one. I've read that Digitrax also seems to allow this by setting the address to "0."

Not really sure how this works but being able to run a tiny non-decoder switcher seems like a great feature. and am wondering about the above comment.

Is this based on personal experience, anecdotal evidence or hard facts? I'm trying to decide on a system and operation method. Often, much of what I read here and elsewhere is in direct contradiction to manufacturer's literature and claims.

Not to say anyone is wrong or trying to mislead, just trying to sort out relevant info & hopefully, not fry any motors.

Wayne

[Isambard]

QUOTE: Originally posted by cacole

Most straight DC locomotives do not like to be run on DCC, and you could wind up overheating and burning out the motor because of the way a DCC system tries to run a DC motor by sending pulse-power to it.

Hmmm, that's interesting, as I've been reassured by my DCC-experienced LHS that I don't need to worry about my Spectrum and Proto HO locos, which have yet to be decoder equipped, even though I run them on my new Digitrax system. I also believe I've read the same. Are some types of motors or brands more susceptible than others? I'm anxious to learn more.
[?]

[rrinker]

Coreless motors WILL overheat and melt the windings, they don't have a solid iron core to dissipate the heat. haven't had any problems with any other motors in Athearn and P2K locos, but even witht hose, it is NOT a good idea to leave them sitting still on DCC powered track. The most heat is built up when they are not moving.

The smaller the motor, the faster it will heat up - N scalers probably shouldn't even try running a non-decoder locomotive on DCC.

Athearn motors seem to be the noisiest, probably because the magnets are not fastened to the motor in any way, and thus vibrate against the motor casing.

[jfugate]

The high pitched noise from a straight DC loco on DCC is normal, as is the pitch lowering as the pulses are lengthend to get a positive voltage bias between the rails.

While this works in a pinch to run a DC loco on DCC, you can only run one loco/lashup this way, and the speed control is marginal.

I don't recommend it for more than a desperation technique. For regular operations, get a fleet decoder (less than $20) and put it in your loco. You'll be much happier with the result.

[Anonymous]

"Coreless motors WILL overheat and melt the windings, they don't have a solid iron core to dissipate the heat. haven't had any problems with any other motors in Athearn and P2K locos, but even witht hose, it is NOT a good idea to leave them sitting still on DCC powered track. The most heat is built up when they are not moving."

I've got a P2K BL2. I don't have the manual for it right now, so I'm wondering if the motor is coreless or not. Any idea?

[Anonymous]

Great help so far. Still wondering though, what about the slower running speed? Does this have to do with the pulse-power aspect of DCC?

[Isambard]

QUOTE: Originally posted by yankeejwb

"Coreless motors WILL overheat and melt the windings, they don't have a solid iron core to dissipate the heat. haven't had any problems with any other motors in Athearn and P2K locos, but even witht hose, it is NOT a good idea to leave them sitting still on DCC powered track. The most heat is built up when they are not moving."

I've got a P2K BL2. I don't have the manual for it right now, so I'm wondering if the motor is coreless or not. Any idea?

Are coreless motors common in HO and if so can readers advise what brands/models use them?
[?]

[fmilhaupt]

QUOTE: Originally posted by yankeejwb

I've got a P2K BL2. I don't have the manual for it right now, so I'm wondering if the motor is coreless or not. Any idea?

Nope. Coreless motors are not very common in commercial models, and are unheard of in mass-produced plastic locomotives. I think that a few high-end brass models have been manufactured with them, but out of the common North American prototype manufacturers (Life-Like P2K, Athearn, MDC, Atlas, Stewart, Kato, BLI, Intermountain, Rivarossi and Mantua), not even one of them uses coreless motors. For one reason, they're currently MUCH too expensive for the mass market.

For the most part, coreless motors are an aftermarket refit. Frankly, they're not that common. HOWEVER, if you have refit some of your locomotives with coreless motors, you need to know that running them as analog locomotives on a DCC system will cause serious heat problems with them.

[AntonioFP45]

Good responses.

A friend of mine who is a technician told me that among electronic/computer techs the term used for the buzzing or whining from the DC motor is "Singing".

[rrinker]

QUOTE: Originally posted by yankeejwb

"Coreless motors WILL overheat and melt the windings, they don't have a solid iron core to dissipate the heat. haven't had any problems with any other motors in Athearn and P2K locos, but even witht hose, it is NOT a good idea to leave them sitting still on DCC powered track. The most heat is built up when they are not moving."

I've got a P2K BL2. I don't have the manual for it right now, so I'm wondering if the motor is coreless or not. Any idea?

No, the P2K motor is not coreless. It's a pretty good motor though.

[rrinker]

QUOTE: Originally posted by yankeejwb

Great help so far. Still wondering though, what about the slower running speed? Does this have to do with the pulse-power aspect of DCC?

Yes, even with the maximum zero-stretching of the DCC signal , the DC component is not going to reach the 12-14 volts typical of a DC power pack. If it did, there would be no DCC signal for the decoder locomotives to react to.

Like Joe says, it's really only a desperation type of thing, ok for short tests and so forth, but not really practical for regular operations. In quantity you can get decoders for $15-$16 now (TCS, I am planning on aquiring a large supply of these and standardizing on them, easy to keep spares and so forth) so there really aren't a whole lot of reasons to run DC locos on DCC anyway.

[Anonymous]

Yeah, basically I was just running them as a test since I'd just hooked up the system. Definitely will NOT run my locos as DC for anything other than that. Besides, they run too slow anyway.

[dehusman]

That's why the NCE system doesn't allow running a DC locomotive on DCC, too much of a chance of burning up the motor.

Dave H.

[darth9x9]

Being able to run a non-decoder equipped loco is a neat feature but there are drawbacks:
1. It will ruin the motor eventually (coreless or not)
2. It is not NMRA compliant

This is enough to make me spend $15-$22 for a decoder for a loco that I want to keep around.

BC