voltages on DCC locos

snipped-for-privacy@hotmail.com spake thus:

Not quite: two options open to you:

1. Install a DCC "decoder" (what you called a "chip"), which runs the motor on DC like [insert name of deity here] intended it.

1. Use a DCC feature called "zero-stretching" to run (one) DC loco on DCC. May make weird noises, and will definitely overheat *some* (but not most motors). Not an ideal solution, but a work-around.

Ok... So installing a dcc decoder on a loco with a 12v motor wouldn't give me full 'computerized' funcionality on a dcc layout.I would have to buy new locos specifically designed for dcc control... am I getting this right, or have I got completely the wrong end of the stick??

Installing a DCC decoder will give you the same as buying a locomotive with one pre-installed.

With the voltage drop across the controlling transistors, your motor will still be seeing about its normal 12 volts. If you are worried about that and are using DigiTrax, just set it to the N scale setting. This reduced the maximum output voltage.

Howard R Garner

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This might help:

Model Railroader's "DCC Made Easy" is an inexpensive book that has a wealth of valuable information:

Many of the books are up to 32% off list price and include free shipping and handling on orders over $25.

Bill Bill's Railroad Empire N Scale Model Railroad:

History of N Scale: Railroad Bookstore: to 1,100 sites:

snipped-for-privacy@hotmail.com spake thus:

No. It's the same thing buying a DCC-ready loco or installing a decoder into a regular (DC) loco; you end up with a DCC loco.

But yes, you can't get "computerized" functionality (that is, all the DCC functions) on a DC layout. For that you need DCC locos *and* a DCC layout (meaning a DCC controller and "booster", the part that delivers the DCC waveform to the tracks at sufficient voltage and power to run the locos).

Does that help?

The DCC Decoder takes the 15 volt AC (really square wave) and does two things:

1) Decodes the square wave pulses for 'data': turns them into 1s and 0s, and assembles them into bytes, which in turn are assembled into 'messages' (eg: "loco #1234: Stop" or "loco #6789: blow whistle", etc.) 2) Rectify the 15 volt AC and run it through a regulator circuit (which in under control of the decoder logic) and feeds 0-12 VDC to the motor, lights, and other 'accessories' (eg a sound generator, etc.).

The short answer: the *motor* (and lights) on your old 00 scale locos will work just fine. Installing a DCC decoder might be easy or hard, depending on how the motor is 'integrated' into the frame of the loco and how much/little space there is for the DCC decoder and how good you are at dealing with the electronics involved. Steam profile locos can be partularly troublesome to retrofit, although I understand that the tender is often a good place to stash a DCC decoder board.

You don't need new locos. You will just need to get DCC *decoders* for your old locos.

You don't *need* new DCC-equiped/ready locos. It might be difficult to retro-fit some locos, and yes for some 'impossible' *might* apply, partitularly smaller locos with older 'larger' motors (motor techology has improved over the years resulting in smaller more powerful motors

-- this leaves more room for a DCC decoder).

In additional you will need:

A DCC 'command station' -- this encodes the commands into a DCC signal format. A DCC 'booster' -- this takes the DCC signal and modulates a raw power source which is then fed to the tracks

(There are command station / booster combos.)

One (or more) throttle / control units. You hold this in your hand and use it to control your trains.

You also need to properly wire your layout.

A basic DCC set up (as above) will only control the *locos*. You need extra stuff: stationary decoders and a suitabled programmed computer if you want stuff like signals and switches under computer control.

Unless your OO scale locomotive is smaller than a Micro Ace C type _N_ scale 3 axle industrial switcher (about 2 inches long...) or _Z_ scale F units, then "impossible" is simply a synonym for "too lazy to try it."

With the tiny decoders available today, I don't believe there is any locomotive in any scale larger than Z or smaller than live steam that _cannot_ be done.

I suggest you check out this on-line DCC primer:

-- Bill McC.

snipped-for-privacy@hotmail.com skriver:

Yes

Yas

You install the decoder, then you run som test on the track and measures how fast it goes. You are able to set top speed as one of the CV parameters, it limits the maxmum voltage to the motor and gives the loco a natural top speed as in real life, but still keeping the maximum number of steps between standstill and full speed.

Be aware that the laps in the loco will get 16 volts instead of 12 volts. Some decoders are able to dim the outputs to the lamps, so you get an apppropriate voltage to the lamp, other just gives the full 16 volts and your lamps (bulbs) will wear out quick. Then replace the bulbs with 16 volt bulbs or LED's and they will last "forever".

Klaus

Fantastic - thanks for all your replys - it all makes sense to me now!

Cheers,

Dan

What, exactly, are you replying to? It helps to quote enough of the post you're answering so that the next reader knows what you're on about - and in this case, just what you misunderstood.

Yes, it would. You just have to find a decoder that fits mechanically, and has enough wattage capacity to run one of those older motors, which usually draw 1/2 amp and more.

No, as long as the decoder fits and is not overloaded, there's no problem. You will likely have to isolate the old motor from the frame, though. With some older locos, that can be a tricky business, requiring mounting screws with isolating bushings, etc.

HTH

Sorry Wolf, someone (you) finally got past my 'drivel' quotient with this next sentence.

MOST motors do NOT have to be isolated. The problem is with the construction of the older DC motors, where one of the motor brushes is physically & electrically connected to the frame of the motor. All that is needed is to isolate that motor brush FROM the motor frame, and DCC installation is then quite simple. ( A LOT of the old motors, Pittman and clones for example, only need a piece of 'insulating spaghetti', and soldering a lead to the 'brush', and the deed is done.)

Chuck D.

[...]

And you just exceeded your quibble quota. What do you think I meant? Isolating the motor brush is the same as isolating the motor in my book.

For all practical purposes, yes. The point being, 'Isolating the motor' is quite often a daunting (to impossible) task, that in some cases isn't needed. The 'Isolating the motor' problem is often used as the excuse to 'Eliminate', 'Junk', 'Throw away' otherwise useful locomotives. (And maybe even a root excuse for NOT converting to DCC.)

Chuck D.