# What are you using for supplemental 12V power



## kenf (Dec 7, 2019)

Eventually, I'll need to power a bunch of supplemental electronics (mostly digitrax) with 12v DC.

What products do you recommend, and why?\


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## flyboy2610 (Jan 20, 2010)

I used a converted computer power supply. I have one on the layout which provides 12, 5, and 3.3 volts through separate buses. I also made one for use at the workbench.








Computer power supply for layout power


First, let me say right off the bat: Don't use this to power your DCC system. For that application, use the power source recommended by the manufacturer of the system you use. Second, these power supplies can kill you! Did that get your attention? Good! They have some heavy duty capacitors in...




modelrailroadforums.com




If you have a used computer with a good power supply, even better! I actually wound up buying mine from FleaBay, but even then they weren't that expensive. A little time and effort and you'll have plenty of power!


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## gunrunnerjohn (Nov 10, 2010)

The computer power supply is a good high current regulated source.

There are simple breakout boards that cost less than $20 that have terminal blocks for connecting to all the voltages from the supply.


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## kenf (Dec 7, 2019)

Flyboy,

There was a period of time in my youth, perhaps as many as 17 days, when I would have listened to you and not modified computer power supply for my situation.

Alas, those days were almost 60 years ago and now, I will do your modification just to spite you even if I don’t end up using it!

But seriously, thank you for the suggestion and the excellent instructions.


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## kenf (Dec 7, 2019)

gunrunnerjohn said:


> The computer power supply is a good high current regulated source.
> 
> There are simple breakout boards that cost less than $20 that have terminal blocks for connecting to all the voltages from the supply.


Thank you!


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## Jack Barry (Apr 19, 2017)

Old cheap DC train controllers. I think I purchased a lot of 4 or 5 of them for around? Less than $10 🤷‍♂️


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## Jscullans (Jul 8, 2019)

I use a crappy old model power controller to run the lights on my layout. That being said I’m running all led lights inside my buildings so that pulls next to no current


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## T-Man (May 16, 2008)

Keeping colors straight.


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## kilowatt62 (Aug 18, 2019)

I have a half dozen old H0 transformer/power supplies from days of old. You know the type. 12v variable out in dc, 16v fixed out in ac, or there abouts voltage wise. A direction switch and grainy feeling 60deg rheostat. All metal casing held together with pop rivets. Probably can be had now for $5 ea on fleabay. I, like many others have a plethora of old wallwarts of various voltages, ac & dc. All are great for various accessories. For direct connection to digi trax use though? Might not be a good idea I’d think.


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## 65446 (Sep 22, 2018)

Are you referring to what others are suggesting ? IE. Are you asking about a unit to power things such as building lights and street lamps ? Or, are you referring to DCC mechanisms (since you say 'digtrax') ? If it's the former, just get a cheap old analog DC power pack such as an MRC Tech II on ebay and hook them up to the AC accessory posts on its back. Or, is that not what you mean ?...


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## kenf (Dec 7, 2019)

telltale said:


> Are you referring to what others are suggesting ? IE. Are you asking about a unit to power things such as building lights and street lamps ? Or, are you referring to DCC mechanisms (since you say 'digtrax') ? If it's the former, just get a cheap old analog DC power pack such as an MRC Tech II on ebay and hook them up to the AC accessory posts on its back. Or, is that not what you mean ?...


Powering BDL 168, DS74 etc.


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## Jack Barry (Apr 19, 2017)

Forgive my ignorance...What are BDL 168, DS74? Thanks. Oops I just used the Google machine and found out the answer to my questions. I'm not sure old AC/DC controllers is the way to go with DCC stuff?


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## kenf (Dec 7, 2019)

thanks for all the responses. I need to clarify my question.

Eventually I will have a dozen DigiTrax stationary decoders such as the BDL 168 and the DS 74.

I know that I can use an individual wall wart for each one, But I was hoping for a single DC bench power-type solution.

I asked DigiTrax if I could use their PS2012E. They said “no” because it was meant to only power command stations/boosters. They recommended that I use their PS 14 wall wart.

In the still leaves open the question of wheather a decent DC Bench power supply could be used to replace s dozen wall warts.


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## Lemonhawk (Sep 24, 2013)

Or Jameco Meanwell power supplies. The DS2012E is a noisy beast. Some of those devices may require their own power supply and don't like to be set up on a single PS. Also the bigger the power supply the bigger the smoke generated when things short, so maybe using those wall worts isn't such a bad idea!


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## kenf (Dec 7, 2019)

Lemonhawk said:


> Some of those devices may require their own power supply and don't like to be set up on a single PS.


In fact, this is what DigiTrax claims.

Is it possible that a clean 12 V from any source distributed to two or more devices is untenable?

This is mysterious to me.


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## Lemonhawk (Sep 24, 2013)

I looked at my wiring again and the 2 DS64's are powered by a single 1.5 amp 12 wall wort. That means all the stall motors (7 or 8 ) are all powered by this same power supply. The 3 amp power supply goes to the display panel and power the led's. I should really switch things around as the panel probably takes the least amount of power. This is my DCC test layout that some day I hope to replace, but I really like the electrical end hence its way overboard for the simple 5x9 layout, but it was great for testing building techniques and wiring things,
















It looks complicated but all the block switches are wired the same and all the turnout pusbuttons and lights all go to connectors that allow me to adjust resistors and how things connect to the swichmaster stall motors. The DS 64's allowed me to program in a route to yard so pushing just the yardline button sets all the correct turnouts. turnout indicators are a 2 terminal bi color LEDs in series with the stall motor so it a very positive indication of which way the turnout is set. I sort of documented the wiring in a power point presentation, which I would send you if I can figure out how to do that.

Virtually all the wiring is by .1 crimp connectors with the only soldering being the switch terminals. The layout itself started with using flex track, but then I removed all that and used some foam to see how that worked and in the process discovered I could actually make my own turnouts using CV ties and hence changed over to using all CV ties and gluing the rail down to the ties with contact cement, worked far better than I could imagine and what I would use again. see www,cvmw.com. Also used a lot of stuff from proto 87 stored (www.proto87.com) like the points and frogs.


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## kenf (Dec 7, 2019)

Thanks, Lemon!


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## Jack Barry (Apr 19, 2017)

I was kinda thinking, not that i know anything about the subject...But You don't throw all the turnouts at once so why have a seperate wall wart for each? Unless you have programed route changes that initiate simultaneous throws?
Thanks Lemon!


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## cfurnari (Aug 2, 2020)

seeing as you will probably be throwing one, or two switches at a time, one wall wart, for the group of turnouts, would probably be fine. lets be real. you are not using the wall wart for a whole bunch of stuff. just a couple of things, at a time, with not a heavy draw.


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## Djsfantasi (Mar 19, 2019)

Many people have suggested several rules of thumb. But electronically, there is an easy way to answer your question.

First, create a power spreadsheet. Got every electrical device, note how much current they need. Then, for each power supply, note how much power they can give. The total of all the currents for all devices must not exceed the power available from a power supply.

As far as needing separate power supplies, leds or electronics should be on a supply separate from one used for motors or solenoids. All grounds (or connections to the negative supply can often, but not always, be tied together. Different voltages should be different.


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## scottmac99 (Dec 3, 2019)

Jack Barry said:


> Old cheap DC train controllers. I think I purchased a lot of 4 or 5 of them for around? Less than $10 🤷‍♂️


I've got a few LED lights - I just gave up on trying to do it the "proper" way, and simply plug in a 9V battery (the type that goes in smoke alarms) when i want to play trains in the dark. When done, I unplug it.


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## Djsfantasi (Mar 19, 2019)

scottmac99 said:


> I've got a few LED lights - I just gave up on trying to do it the "proper" way, and simply plug in a 9V battery (the type that goes in smoke alarms) when i want to play trains in the dark. When done, I unplug it.


There’s a lot more to your story than you’re telling us. Plugging an LED into a 9V battery will quickly destroy your LEDs. So they must be wired in a special way and/or they have resistors.

A wall wart is much more efficient (and less expensive). If I only knew the electrical requirements of your LED lights, I could teach you how to use them.


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## scottmac99 (Dec 3, 2019)

Well, they are 12 volt LEDs, so I figured that 9V wouldn't hurt. But I am (always) more than happy to be wrong


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## Djsfantasi (Mar 19, 2019)

So all you need is a 12 V DC Wall wart. You need to observe polarity when wiring the 12V LEDs to the wall wart.

Then, you can either find the current drawn by one LED and divide it into the current supplied by the wall wart. That will give you the most of your 12V LEDs you can hook up.


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## kenf (Dec 7, 2019)

Jack Barry said:


> I was kinda thinking, not that i know anything about the subject...But You don't throw all the turnouts at once so why have a seperate wall wart for each? Unless you have programed route changes that initiate simultaneous throws?
> Thanks Lemon!


On Digitrax turnout controller, the input power is independent of the switching action. Therefore, your idea has merit!


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## DAVID CONDIE (Apr 8, 2021)

kenf said:


> Eventually, I'll need to power a bunch of supplemental electronics (mostly digitrax) with 12v DC.
> 
> What products do you recommend, and why?\


HORNBY/SCALEXTRIC TRANSFORMERS (I use them for powering my lights on my Nscale layout


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## Lemonhawk (Sep 24, 2013)

I power my 2 Digitrax DS64's with a single 1 amp 12 volt wall wort. That's how the the stall motors on the turnouts (8) get power via the DS64. They are always drawing current, along with the LED's in series with the stall motors. You can power the DS64/74's with rail power, but that seems to be to be a waste of rail power - much better to use a wall wort! If you set the DS64/74's up for solenoid operation, you get a nice Capacitive Discharge circuit to generate a short pulse to the turnout solenoid, which means they might take even less power, however you lose the positive throw indication that the stall motor- LED combination gives you. I don't like to use old train power packs, because they are likely not filtered and hence may harm the electronics.


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## Birdman (Jan 14, 2021)

kenf said:


> Eventually, I'll need to power a bunch of supplemental electronics (mostly digitrax) with 12v DC.
> 
> What products do you recommend, and why?\


You might consider a ham radio power supply, like the Alinco DM-430T. AC120V, Adjustable 5-15 VDC, 30A (MAX), 25A (Continuous)


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## gregc (Apr 25, 2015)

Birdman said:


> You might consider a ham radio power supply, like the Alinco DM-430T. AC120V, Adjustable 5-15 VDC, 30A (MAX), 25A (Continuous)


for $100+ ???

why not this generic 12V 1A  for $5?


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