DCC is sooooooo boring...

[selector]

That is F7 for most of my QSI locos (not the older Hudson). You get instant brake squeel and hiss, and the loco stops in about half the space over which it would normally brake with the input settings in CV4 and throttle closed to "00".

[NZRMac]

QUOTE: Originally posted by olequa

QUOTE: Originally posted by wjstix

I haven't read all the threads, so I assume someone mentioned that there are CV's for momentum etc. and that momentum is controlled by the decoder in the engine, not the DCC system. Plus the center "off" setting on a Digitrax Zephyr (and other units have something similar) does work like a break - but on real trains, they don't stop on a dime like DC engines do !! They really coast a LONG way before stopping.

p.s. not all diesels used eight notches, Baldwins originally had a system that was a continuous range like a model throttle, with slight adjustments in speed possible.

Yes it's true that the Zephyr has a center off position and I think it is actually labeled 'brake' if I remember correctly. But all it does is command zero speed as if you turned the knob to zero. So if you have momentum programmed on cv4 it will slow down at that rate. What I want is another button that will cause a more rapid slowdown to occur, ie braking, not coasting. I want to coast when I feel like it and to brake when I need to.

Thanks for the input.
george

I have that function on my Lenz decoders, if I put my throttle to zero then decide that I'm running out of room I can push F4 and the momentum is reduced to zero and the loco stops

Ken.

[olequa]

QUOTE: Originally posted by wjstix

I haven't read all the threads, so I assume someone mentioned that there are CV's for momentum etc. and that momentum is controlled by the decoder in the engine, not the DCC system. Plus the center "off" setting on a Digitrax Zephyr (and other units have something similar) does work like a break - but on real trains, they don't stop on a dime like DC engines do !! They really coast a LONG way before stopping.

p.s. not all diesels used eight notches, Baldwins originally had a system that was a continuous range like a model throttle, with slight adjustments in speed possible.

Yes it's true that the Zephyr has a center off position and I think it is actually labeled 'brake' if I remember correctly. But all it does is command zero speed as if you turned the knob to zero. So if you have momentum programmed on cv4 it will slow down at that rate. What I want is another button that will cause a more rapid slowdown to occur, ie braking, not coasting. I want to coast when I feel like it and to brake when I need to.

Thanks for the input.
george

[Paul3]

cjcrescent,
That's what stall current is! The motor is not allowed to spin at all...A.K.A. "stalled".

To test your motor for stall current, hook it up to your track power and amp meter while holding the flywheel or driveshaft and don't allow it to spin. Turn on the power at whatever your full voltage is... The amp meter will jump to whatever is the stall current.

This is the maximum current the motor will ingest.

Paul A. Cutler III
*****************
Weather Or No Go New Haven
*****************

[cjcrescent]

Paul

I'll take your word for it.

But its difficult for me to call it "testing for stall" when the motor hasn't starting turning yet.

[fwright]

Sir Peter

Whether or not you use DCC, walk-around control has much to recommend to it. Although I still use DC, I prefer walk-around control for the following reasons:

1) When I'm running my train, I prefer to be the engineer and not at the command console of a space ship and it's light show (all the position lights, etc). This is also why I do not want a DCC system where I have to sit at the command station to operate it. If I going to be sitting at a console light show, why not go all the way and just use a computer train simulator to begin with?

2) I can see the position of the turnouts by looking, and I don't need to wire position lights/LEDs. I can wire turnout throw switches (or even better and cheaper, use manual throws) mounted where I will be operating the train and viewing the turnout.

3) I can visually see my markings for where the uncoupling devices are, or use bamboo skewers if I want to subject my layout to the "hand of God". I can see to put a little slack in the train at the right location to achieve uncoupling. Between turnout positioning and uncoupling, switching becomes so much more practical with walk-around control.

4) I can more easily trouble-shoot derailment causes with walk-around control. It gets pretty tough to watch carefully as a loco creeps over a turnout if the control panel is 6ft away!

5) I get to see my scenery from different perspectives on a frequent basis.

If there is more than one operator and more than one loco in use simultaneously in a small area, DCC makes walk-around control and wiring much simpler. Since I am a lone wolf MR, this is not a great advantage to me at present.

Sound is the other DCC advantage, but again does not apply well to the small switching, geared, and HOn3 locos I have. I would probably have to go with a position reporting system like Digitrax's to move the sound among speakers buried in the scenery, or implement my own sensors and logic.

Last thought on DCC. If you already have DC block wiring (assuming no common rail), you CAN substitute a DCC throttle for a DC power pack while you equip all your locos with decoders. If you do this, I STRONGLY RECOMMEND you operate all DCC or all DC during any given operating session. There is a risk of releasing factory-installed smoke somewhere if you cross the 2 systems, either through metal wheels bridging the block gaps between DC- and DCC-controlled blocks, or selecting the wrong control system for a particular locomotive. Usually, the protection circuits will protect the throttles, most decoders can handle either DC or DCC, and most DC locos can handle DCC for a few seconds. But the key words are "most" and "usually".

my thoughts, your choices
Fred W

[Paul3]

cjcrescent wrote:

QUOTE: It didn't make sense to me that a motors current needs to break the friction at startup could be higher than the current at stall as you have stated, but as I said, over the time I have done decoder installs, I have run across this situation just enough times that I feel I better checking for this, (not easy to see at times, since it can be a momentary spike), especially when an old open frame is involved.

Well, I talked to a fellow RR club member last night who is an electrical engineer, and I put the question to him. "Bob," I said, "Is it possible for the start up current to be greater than the stall current of a DC motor?" He replied, "I'd have to check my books, but if you pressed me for an answer I'd have to say no." He went on to describe what happens... Essentially, at "stall", the motor is at a "dead short". He said that at start up, there is an amperage spike as the motor has to overcome it's own momentum and the drive train, the load, etc. But, logically, that can't be any higher than stall, or "dead short", amperage.

QUOTE: This is how I tested the start up. I placed a meter between the power supply and the mech to be tested, using the leads from the meter as one lead off the pack to the test track. Slowly start up the voltage, watching the amps on the display. The amps will climb to a point close to or right at the stall rating of the motor and the motor would normally start turning.

Ok, that's how you tested "start up" amperage. How have you tested "stall" current?

QUOTE: Occasionally it wouldn't and the amps kept climbing until the motor "broke" and starting turning, then the amps would fall to the continuous rating for that motor. But if the motor basically stays stalled, then the current will keep increasing until either the motor finally overcomes the friction and starts running, or smokes, burns, or melts or the breaker in the pack exceeds its limit and throws.

Well, that sounds like stall current to me. The amp load on the motor will only increase up to the voltage given to it. For example, if you put 12v to a 1amp motor, it will only take 1amp...no matter how long you put 12v to it...provided the motor doesn't melt. But that's "stall" current for you. [:)]

Paul A. Cutler III
*****************
Weather Or No Go New Haven
*****************

[tstage]

QUOTE: Originally posted by selector

QUOTE: Originally posted by kbfcsme

QUOTE: Originally posted by tstage

Tom,

Most DCC systems (except NCE) will allow you to run one (1) DC locomotive on your layout. It will, however, emit a somewhat annoying audible "buzz" when you are running it. (Kinda painful to listen to but tolerable.)
,<SNIP>
This buzz will not harm the motors on your non-DCC locomotives when running them, BUT you should be very careful about leaving them idle on the track for extended periods of time. Some claim that the motors can eventually heat up too much and get damaged.
<SNIP>
(Another) Tom

Not always true! I've personally witnessed a Digitrax system wipe out a coreless motor in 2 brass steamers by trying to run them on "00" (Dc on DCC)
The owner was dismayed, then handed them to me to repower them and add decoders.

I feel that any system that generates that kind of racket in a little HO drive can't be doing it any good over time, so I don't run DC locos on my layout. I tried it once, and vowed never to bother again. Who needs to hear a high-pitched "ZZZZEEEEEEEEEE" drowning out many of the other legitimate sounds on a DCC layout?

I believe that Tom is basically correct in that few motors will succumb to DCC current on the 00 address unless allowed to languish on the layout doing nothing....except squeeling like a lost piglet..and, again, can anyone tell me the point in that?

Crandell,

With that in view, there's another advantage to the NCE DCC system: You will NEVER have to be subjected to hearing a "squealing piglet" while running a locomotive - that is, unless you favorite locomotive derails and decides to take the big 4' plunge down onto the cement floor below. Course, you can do that in either DC or DCC. [xx(]

Tom

[tstage]

QUOTE: Originally posted by SirPeter

I must admit that DCC does nothing for me. Imagination is the key and cost nothing. And what's the attraction of 'Walk-around' controllers? Is this the only way you get your exercise?
Only joking!

Peter,

The question for you is: Have you personally tried DCC yourself? To have actually tried DCC and say it does nothing for you, is one thing. To make a blanket statement without honestly and personally assessing the technology and its advantages yourself, is an entirely different matter.

If you haven't tried DCC, I'd encourage you to spend no less than 10-15 minutes at the task. Find a friend or an associate who has DCC on their layout (and has had for at least a year or two) and ask them if they would have the time to let you see and try running a locomo...no, TWO locomotives simultaneously - on the SAME track, at the SAME time. After you've done that, then drop back by the forum and share your experiences with us.

Peter, 17 years ago I had the same attitude about computers. Now look where it's gotten me. [swg] If you haven't, you REALLY ought to give DCC a try. If you've tried it already and STILL don't care for it, hey, that's fine. I'll still talk to you. [:)]

Okay, I'll get off my soapbox now...

Tom

[SirPeter]

I must admit that DCC does nothing for me. Imagination is the key and cost nothing. And what's the attraction of 'Walk-around' controllers? Is this the only way you get your exercise?
Only joking!

[cjcrescent]

QUOTE: Originally posted by Paul3

cjcrescent,
Just to make sure, we are talking about the same thing WRT "stall", right? A "stalled" motor cannot turn at all. To test stall current, you have to jam the motor drive so that it can't turn, and then hit it (quickly, you don't want to melt it) with your top operating voltage (say, 12v) while watching the amp meter. Where this peaks is "stall current". This is the maximum amperage that a motor uses (we'll call it "short time" rating, because if used too long it'll melt the motor). As soon as it starts spinning, the amperage load should drop.

I'm thinkin' that maybe you're testing the slip amperage? IOW, holding the loco in place and letting the wheels (and therefore the motor) spin. This would be the normal operating maximum amperage of the motor... The "continuous" rating, if you will.

This is where decoders get their 1.0 amp normal (continuous), 1.5 amp peak (short time) ratings.

When starting, the motor is obviously not turning. And for a short time until it actually does, the amp load will go up as the motor is, technically, stalled. This can pop decoders that aren't rated high enough. But it still shouldn't be any higher an amp load than when the motor is truly stalled...

Corrections welcome...my college didn't put me into too many electronics classes. [:)]

Paul A. Cutler III
*****************
Weather Or No Go New Haven
*****************

Paul;


My background is definitely not electronics, (medical/nursing) and I'm not disputing anything that you have said.[^] But I humbly do know the difference between,"slip"; the loco's wheels are turning but its not moving, (slip used to be considered a "safety device" to prevent the motor FROM reaching it stall current and burning out), and "stall"; the loco's motor is not turning at all but getting full voltage. So, what I'm testing for is, not just the slip and stall, but also the amount of current needed to overcome the friction of, the motor bearings, the gears, the axles in the frame/bearings, the side/main rods, the valve gear, as well as the mass of this mess.

It didn't make sense to me that a motors current needs to break the friction at startup could be higher than the current at stall as you have stated, but as I said, over the time I have done decoder installs, I have run across this situation just enough times that I feel I better checking for this, (not easy to see at times, since it can be a momentary spike), especially when an old open frame is involved.

This is how I tested the start up. I placed a meter between the power supply and the mech to be tested, using the leads from the meter as one lead off the pack to the test track. Slowly start up the voltage, watching the amps on the display. The amps will climb to a point close to or right at the stall rating of the motor and the motor would normally start turning. Occasionally it wouldn't and the amps kept climbing until the motor "broke" and starting turning, then the amps would fall to the continuous rating for that motor. But if the motor basically stays stalled, then the current will keep increasing until either the motor finally overcomes the friction and starts running, or smokes, burns, or melts or the breaker in the pack exceeds its limit and throws.

I have also found on a few other motors, that a bind in the mech would also raise the amps needed to get and keep the loco running, but after the bind was corrected the amps needed dropped considerably.

(I hope that I have explained this well enough so everyone understands. Its pushing WAY past my bedtime and I tend to ramble when I'm this sleepy.)[|)][|)][|)]

kbfcsme:
I generally recommend can motor replacements for DCC installs. (I replaced all my open frames, and the original gears in 99% of my brass over 20 years ago). Unfortunately when the person you're doing the install for has the attitude that the open frame motor was good enough when the loco was new, its good enough now, the only thing I can say is, I won't guarantee the install once it leaves my hands.
When you're installing decoders for others for "feelthy lucre" (money), ya duzs it the way they say, or ya duzn't get paid.[:D]

[pastorbob]

I think you should get a bank loan, and start your own DCC company. Certainly you should be able to knock out all those ideas and have them on the market in 6 months.
right?

Small companies usually have to move a little slower as the brain trust is smaller, and so is the capital funding.

Bob

[Walter Clot]

What about a chair that you have to sit in and if your train wrecks, the chair tips over and throws you on the floor!

[aluesch]

QUOTE: Originally posted by AntonioFP45

Art,

Your post is interesting.

Most of us are familiar with Digitrax, ESU,NCE, TCS, MRC, and "EZ DCC"; but ZIMO is I don't hear that often. But it's good to know that you're in the command control arena. This market has benefited a good deal from healthy competition.

Hope to see more of your posts.

Hi Antonio.

ZIMO has been a DCC supplier since 1979 and offers many innovative features not found in other systems.
If you are interested, the 2006 ZIMO system flyer is available from the ZIMO web site here: http://w3.zimo.at/web2003/pdf/ZIMO_Systempr_DCC_2006_E.pdf
Be prepared though, it is 16 pages long.
English manuals can be downloaded from my web site or ZIMO's.
And of course, if you happen to be in the Philadelphia area this summer you could visit us at the NMRA show, booth #223/233.

Regards,
Art
Zimo Agency of North America
http://www.mrsonline.net/

[aluesch]

QUOTE: Originally posted by olequa

QUOTE: Originally posted by aluesch

QUOTE: Originally posted by olequa

I have to vent.

For example...
How about those throttles? Why wouldn't someone get the idea that maybe they should build a lever throttle that has 8 notches on it? That plus a little (or a lot, your choice) of momentum would make for very much more interesting and satisfying control of the locomotive.

And I've mentioned here before what I think of the current straight-line velocity curve that is produced by all decoders today when using momentum. It shoudn't be that way. The actual velocity should approach the terminal velocity asymtotically (spelling may be off on that one).

george

Hi George.

Ever checked out ZIMO equipment? The ZIMO mini-system is pictured in the May issue of the MR. It doesn't have notches but at least it is a slider.

Non-linear momentum? A feature ZIMO decoders have been using for many years and it really is [8D]. Check the decoder manual, it's CV #121 and 122. You can include between 10 to 90% of the speed range in the "extended" momentum and select from various curves.

Regards,
Art
Zimo Agency of North America
http://www.mrsonline.net/

ART!!! YoudaMAN!
It's nice to see a real factory rep here. And no I'm not familiar with Zimos but I will take your advice and look into it. My experience has only been with Digitrax, NCE, Train Systems and Soundtrax decoders, and the decoders that I have are all sadly similar. Perhaps Zimos are what I'm looking for.

Thanks!
george

George,

they will soon be available with sound, if you are into that.

Also, when you look closely at the MX31 cab, you can see at the right speed scale (right side of slider) two little arrows in the center of the scale pointing up and down. This was included in this cab design because ZIMO is planning on adding brakes as you suggested. With the slider in the center of the scale your train would be at stady speed (or maybe coasting, I have no details yet) , moving the slider down would apply your brakes for example. Since all ZIMO cabs, command stations and decoders can be updated by the customer via the Internet, all that is really required to implement this feature is a firmware update.
Another possibility would be to add the brakes to the encoder wheel on the side....

Regards,
Art
Zimo Agency of North America
http://www.mrsonline.net/

[wjstix]

I haven't read all the threads, so I assume someone mentioned that there are CV's for momentum etc. and that momentum is controlled by the decoder in the engine, not the DCC system. Plus the center "off" setting on a Digitrax Zephyr (and other units have something similar) does work like a break - but on real trains, they don't stop on a dime like DC engines do !! They really coast a LONG way before stopping.

p.s. not all diesels used eight notches, Baldwins originally had a system that was a continuous range like a model throttle, with slight adjustments in speed possible.

[Anonymous]

I never needed the use for dcc because I ran live cantenary and I could control the running of two seperate trains on one track. With out the use of the live overhead the dcc is a big plus. felix

[AntonioFP45]

Art,

Your post is interesting.

Most of us are familiar with Digitrax, ESU,NCE, TCS, MRC, and "EZ DCC"; but ZIMO is I don't hear that often. But it's good to know that you're in the command control arena. This market has benefited a good deal from healthy competition.

Hope to see more of your posts.

[Anonymous]

DCC seemed a no brainer to me. At first I was not sure I'd be able to wire it, but after seeing that it's SO MUCH EASIAR to wire a layout for DCC, I know which direction I'm heading![:D] And, after running my first DCC operating session a few weeks ago, that just drove me in deeper. Anyone here with a huge yard, long mainline, multiple industries and a lot of trains can tell you it'd be a pain in the neck to run it on anything but DCC.

[olequa]

QUOTE: Originally posted by aluesch

QUOTE: Originally posted by olequa

I have to vent.

For example...
How about those throttles? Why wouldn't someone get the idea that maybe they should build a lever throttle that has 8 notches on it? That plus a little (or a lot, your choice) of momentum would make for very much more interesting and satisfying control of the locomotive.

And I've mentioned here before what I think of the current straight-line velocity curve that is produced by all decoders today when using momentum. It shoudn't be that way. The actual velocity should approach the terminal velocity asymtotically (spelling may be off on that one).

george

Hi George.

Ever checked out ZIMO equipment? The ZIMO mini-system is pictured in the May issue of the MR. It doesn't have notches but at least it is a slider.

Non-linear momentum? A feature ZIMO decoders have been using for many years and it really is [8D]. Check the decoder manual, it's CV #121 and 122. You can include between 10 to 90% of the speed range in the "extended" momentum and select from various curves.

Regards,
Art
Zimo Agency of North America
http://www.mrsonline.net/

ART!!! YoudaMAN!
It's nice to see a real factory rep here. And no I'm not familiar with Zimos but I will take your advice and look into it. My experience has only been with Digitrax, NCE, Train Systems and Soundtrax decoders, and the decoders that I have are all sadly similar. Perhaps Zimos are what I'm looking for.

Thanks!
george

[Anonymous]

QUOTE: Originally posted by cjcrescent



Tom;

After installing decoders in over 100 brass locos, for myself and mostly others, I can tell you this. Each one is different. So what works on one loco may or may not work on the next. There are several criteria I look at when installing a decoder into a brassie.

1. How smooth does it run on DC? If it is a good runner on DC, it'll be just as good if not better on DCC.
2. What room is available to install the decoder in? Can I put it into the boiler, or do I have to install it into the tender.
3. How easy will it be to isolate the motor? Will brush isolation work or do I need to isolate the motor from the whole frame?
4. If it has an open frame motor, what is the stall current, slip current and probably most important, what is the startup current? Many people forget that the startup current of a motor can be as high or higher than its stall current. Even though startup current lasts only momentarily, until the motor starts to turn, this is what will let the smoke out of a decoder just as fast if not faster than a short. If it is an open frame motor and tests shows it stays below the maximum rating of the decoder, no problem, the decoder gets installed using the open frame, unless the owner wants a new can installed.
5. If the motor is replaced, will new gearing be required? Some older brass comes with a somewhat slower running open frame, and installing a new higher speed can motor causes such breakneck starts that it requires that a new gearbox be installed.

Like I said, I look at all this criteria, but overall installing a decoder into a brass engine is no more difficult than installing a decoder into any engine without a DCC plug.

Having done close to 100 installs in brass myself, all I can say is...
True, true true,,,
Even when working on working on multiple, identical make and model units, I find subtle differences from engine to engine when installing decoders. Gotta love that hand built quality!!!!!!! One thing different I do is recommend a can motor to replace ALL open frame motors. If its all torn apart anyway, the conversion expense is minimal, and the benefits are great![:D]

[selector]

QUOTE: Originally posted by kbfcsme

QUOTE: Originally posted by tstage

Tom,

Most DCC systems (except NCE) will allow you to run one (1) DC locomotive on your layout. It will, however, emit a somewhat annoying audible "buzz" when you are running it. (Kinda painful to listen to but tolerable.)
,<SNIP>
This buzz will not harm the motors on your non-DCC locomotives when running them, BUT you should be very careful about leaving them idle on the track for extended periods of time. Some claim that the motors can eventually heat up too much and get damaged.
<SNIP>
(Another) Tom

Not always true! I've personally witnessed a Digitrax system wipe out a coreless motor in 2 brass steamers by trying to run them on "00" (Dc on DCC)
The owner was dismayed, then handed them to me to repower them and add decoders.

I feel that any system that generates that kind of racket in a little HO drive can't be doing it any good over time, so I don't run DC locos on my layout. I tried it once, and vowed never to bother again. Who needs to hear a high-pitched "ZZZZEEEEEEEEEE" drowning out many of the other legitimate sounds on a DCC layout?

I believe that Tom is basically correct in that few motors will succumb to DCC current on the 00 address unless allowed to languish on the layout doing nothing....except squeeling like a lost piglet..and, again, can anyone tell me the point in that?

[trainfan1221]

DCC is not worth it for me, but either way I am content with a regular but good quality transformer and a little imagination. At least until it is made outdated and we are left with no choice, and yeah, I am willing to believe that's coming.

[Anonymous]

QUOTE: Originally posted by tstage

Tom,

Most DCC systems (except NCE) will allow you to run one (1) DC locomotive on your layout. It will, however, emit a somewhat annoying audible "buzz" when you are running it. (Kinda painful to listen to but tolerable.)
,<SNIP>
This buzz will not harm the motors on your non-DCC locomotives when running them, BUT you should be very careful about leaving them idle on the track for extended periods of time. Some claim that the motors can eventually heat up too much and get damaged.
<SNIP>
(Another) Tom

Not always true! I've personally witnessed a Digitrax system wipe out a coreless motor in 2 brass steamers by trying to run them on "00" (Dc on DCC)
The owner was dismayed, then handed them to me to repower them and add decoders.

[aluesch]

QUOTE: Originally posted by olequa

I have to vent.

For example...
How about those throttles? Why wouldn't someone get the idea that maybe they should build a lever throttle that has 8 notches on it? That plus a little (or a lot, your choice) of momentum would make for very much more interesting and satisfying control of the locomotive.

And I've mentioned here before what I think of the current straight-line velocity curve that is produced by all decoders today when using momentum. It shoudn't be that way. The actual velocity should approach the terminal velocity asymtotically (spelling may be off on that one).

george

Hi George.

Ever checked out ZIMO equipment? The ZIMO mini-system is pictured in the May issue of the MR. It doesn't have notches but at least it is a slider.

Non-linear momentum? A feature ZIMO decoders have been using for many years and it really is [8D]. Check the decoder manual, it's CV #121 and 122. You can include between 10 to 90% of the speed range in the "extended" momentum and select from various curves.

Regards,
Art
Zimo Agency of North America
http://www.mrsonline.net/

[Paul3]

cjcrescent,
Just to make sure, we are talking about the same thing WRT "stall", right? A "stalled" motor cannot turn at all. To test stall current, you have to jam the motor drive so that it can't turn, and then hit it (quickly, you don't want to melt it) with your top operating voltage (say, 12v) while watching the amp meter. Where this peaks is "stall current". This is the maximum amperage that a motor uses (we'll call it "short time" rating, because if used too long it'll melt the motor). As soon as it starts spinning, the amperage load should drop.

I'm thinkin' that maybe you're testing the slip amperage? IOW, holding the loco in place and letting the wheels (and therefore the motor) spin. This would be the normal operating maximum amperage of the motor... The "continuous" rating, if you will.

This is where decoders get their 1.0 amp normal (continuous), 1.5 amp peak (short time) ratings.

When starting, the motor is obviously not turning. And for a short time until it actually does, the amp load will go up as the motor is, technically, stalled. This can pop decoders that aren't rated high enough. But it still shouldn't be any higher an amp load than when the motor is truly stalled...

Corrections welcome...my college didn't put me into too many electronics classes. [:)]

Paul A. Cutler III
*****************
Weather Or No Go New Haven
*****************

[tstage]

Tom,

Most DCC systems (except NCE) will allow you to run one (1) DC locomotive on your layout. It will, however, emit a somewhat annoying audible "buzz" when you are running it. (Kinda painful to listen to but tolerable.)

Unlike DC layouts that have the track voltage regulated by the power pack, DCC layouts are AC and at 100% power ALL THE TIME. The command station sends "packets" of digital information that tells the decoder what duration of time the motor is turned off and on hundreds of times a second. Simply put, in order for a train to go slowly, the motor is "off" more than it is "on". The faster the speed; the higher the percentage the motor is "on" than "off".

The "buzz" emitted from non-DCC locomotives is the DCC signal being "stretched" to mimic a DC signal. (I'm sure someone will explain it much better and more accurately than I just did.) This buzz will not harm the motors on your non-DCC locomotives when running them, BUT you should be very careful about leaving them idle on the track for extended periods of time. Some claim that the motors can eventually heat up too much and get damaged.

Tom, if you should decide to go DCC, and you know it's going to take time for you to convert them over, the best advice would be to just put the locomotives you want to run on the track when using a DCC system and leave the others completely off or on an isolated track somewhere so that they don't receive any current from the track.

Hope that helps, Thomas...

(Another) Tom

[cjcrescent]

QUOTE: Originally posted by Paul3

Ok, I know I went to school for mechanical engineering, but can you explain how start up current can be higher than stall current? Stall current is the application of power to a motor that isn't turning at all...just like start up current. At worst, it'd be the same...wouldn't it?

Paul,

You definitely have the advantage. I am not a mechanical engineer, nor do I play one on TV. Startup current was something that I had never considered at all until I had an old KTM motor that after testing for slip and stall current, around .75A but still let the smoke out of a decoder on startup. A friend of mine asked what the startup current was. I didn't know. We tested it and sure enough, its startup was over an amp! I have found two other motors that did this, one a PFM, the other a Pittman. How its possible, or the theory behind it, I do not know, except to say that at least in these cases the current needed to get the motor turning was greater than what it would stall at.

[twhite]

Antonio, Joe & Carey--thanks for the information on the viability of installing decoders in brass steam locos. As I re-power some of my older brass with NWSL can motors, I automatically isolate them from the frame anyway--I mount them with silicone putty. So it seems that I have one step forward to begin with.
Thanks guys, for giving me something to think about. I appreciate it.
Now, another question. I know that my newer BLI's are DCC ready, but if I decide to convert some of my brass, can I still run the other locos on DC, or do I have to scrap and convert everything to DCC all at once? This is the part that confuses me.
Tom
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