I run basically all older DC locos from various builders. yesterday my friend bought a atlas GP40-2w unit with sound. problem is, he cant run it with any of the other units we have as it takes too much voltage to run the unit. Now… the question… is there a way to fix that so the unit can run with any DC loco? Also, I have a intermoutain SD40-2w without sound in layaway at the LHS. will i be able to run that on DC and have it work and run ok with say a bluebox athearn unit, or a red box atlas unit?? I dont want to buy a unit i have to run by itself. Thanks for all your help in advance.
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Your claim that a single engine uses too much electricity is unlikely. There must be something else at work here. Please clarify. Is the SD40 DC or DCC? What is your power source for your DC layout?
The answer is no. Your DC locomotives start running at 1-2 volts. DCC locos w/sound even in DC mode don’t start moving until about 4-5 volts. the first 4-5 volts are used by the sound generator. There is no way to “fix” this. Get 2 of the DCC/sound engines and run them together.
Aren’t sound locos great?
In addition to sound DCC locos requiring more volts to start moving, they also use more amps than a nonsound DCC unit, at least enough that you have to consider it when you get a bunch together. So, if your powerpack has 1.5 amps available, that is something to consider too, especially if the older DC locos pull a lot of amps as they can–(an older DC loco likely pulls more amps than a new sound loco). Therefore you should be safe if you’re running about the same number of locos and not just adding them to your session.
Depending on the mfg of your sound loco chip, there should be a way to maximize it for running on DC. But you’ll need a DCC system to change the CVs.
Richard
You "might maximize” the decoder but there are different levels of maximization.
When you get say, four to maybe eight sound locos on a layout, they tend not to be so “great”.
There is no way to get the DCC locos running at around 1 to 2 volts. All decoders have a microprocessor with associated IC’s that needs 5 volts to become operational. The processor chip thn looks for DCC pulses. If none, it shifts into DC mode to be controlled by a varying DC voltage.
Pull the decoder and put in the DC adapter if the loco comes with one.
Going from DC to DCC is a bigger ste
ok, I guess what i ment to say was that my friend had the atlas GP40-2W with sound. we know it wont run with anything else. but will my non sound Intermoutain unit run with other older units ok? I haven’t picked it up yet and if its not gonna work with my older units, i’m not gonna buy it. also, do the NON sound Atlas GP40-2w’s run like the sound units do? or can those be run with older units? thanks… srry to confuse.
DCC non sound and sound locos will most probably not run very well with any DC only locos on a layout controlled by a DC power pack.
Ty to remember to specify, which locos are DC, which are DCC non sound and DCC sound.
You might be able to run a DCC non sound and a sound together but they might have to be fine tuned on a DCC layout, first.
Some have issues trying to run a two DCC locos together on a DCC controlled layout.
Rich
AFAIK, the non-sound locomotives have no DCC decoder installed, so they will run as well as any other DC locomotive with yours. There can be a big difference in running characteristics between different DC locomotives, however. There will probably be some of your older locomotives that just won’t run well with the newer ones.
John
It may depend on whether your DC-only engines you currently have are new enough to have lightboards for constant lighting. That usually drains some power (the idea being you can turn the power down until the engine stops, but it still is getting enough power to keep the lights on) so a DC engine with a lightboard won’t start as quickly or run as fast as a similar DC engine without a lightboard.
If the DCC-equipped engine runs slower than other engines, you could remove the decoder and hardwire everything together. That will make the engine run faster.
However, as I’m sure you’ve been told, you’ll never be able to “speed match” two DC engines to run together like one unit the way you can with DCC engines.
Apparently you missed the video by Dr Wayne of his double headed train with a pusher - DC powered.
Or all the reams of info posted my me, Tom White, Dr. Wayne, and others on how double and tripple heading of steam, and multi unit diesel operation is really no problem in DC.
My Bachmann 2-6-6-2’s run with my Bachmann 4-8-2’s and my Proto2000 2-8-8-2’s just fine, without any “speed matching” magic of DCC.
Will DCC make “anything” run with “anything” - yes with enough work - work most people are not really interested in.
Are there a few DC match ups that are just impossible - YES, but most of them would serve little purpose anyway.
Sheldon
Sheldon,I also run Two and sometimes Three locomotives in DC without problems,so yes you dont have to speed match.
Please point out the video we missed.
Remember the OP’s original post, matching DCC locos with DC only locos being controlled by a DC power pack.
Rich
Hello,
I know how you feel. I have the same issues. The other posters that said that the sound decoder uses a certain amount of voltage before the locomotive starts to run is correct. So what I have done is wire the motor directly up to the power pick up. Here are some of the posts regarding speed matching locomotives.
The Intermountain ES44AC and SD40-2W use the same circuit board http://cs.trains.com/TRCCS/forums/t/184157.aspx
Speed matching other engines http://cs.trains.com/TRCCS/forums/t/198347.aspx
I hope that the above posts help you.
Frank
Actually, the answer is YES. However, you need to rewire the motor leads to bypass the decoder all together. As well, a resistor might be needed between the m- and m+ leads comming from the decoder.
Remember that the decoder still requires around 7 volts to wake up and wont come alive until you are running at about 40 MPH.
David B
You are correct David. The two links that I posted explain everything exactly as you stated.
Frank