# What do you think is the best power supply for the buck?



## Daniel Peck (Mar 31, 2009)

What do you think is the best power supply for the buck? Need to upgrade from aristo craft 7000 to something bigger!!!!!
Thanks


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## Greg Elmassian (Jan 3, 2008)

Regulated or non-regulated? 

I'd say the 10 amp MRC unit with the big handle. 

Regards, Greg


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## Daniel Peck (Mar 31, 2009)

I am using track power. On the MRC about what is the max of number on locomotives have you ran with one supply?


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## Greg Elmassian (Jan 3, 2008)

5 USAT F3's, on a 3.4% grade... it will do more... 

Regards, Greg


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## toddalin (Jan 4, 2008)

For the bucks??? No doubt about it.

http://www.allelectronics.com/make-a-store/item/PS-6524/24VDC-6.5A-POWER-SUPPLY/1.html


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## lownote (Jan 3, 2008)

Toddallin is linking to what looks like a Mean-Well power supply. I have one--a 10 amp, 24 volt model, which costs a bit more--and it has been rock solid. It's regulated, so there's no "slow down" as more lcos are added. It has built in circuit protection. They're really a good buy


You should note it has no throttle--it just feeds a steady 24 volts to the rails

You can use one of these as a throttle 


http://www.electronickits.com/kit/complete/motor/k166.htm 

That would be less than 50 bucks for a power suppply and a throttle 



When I was running on track power I bought an aristocraft/crest 10 amp throttle, which has worked out just fine


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## Greg Elmassian (Jan 3, 2008)

Actually, I use meanwell too, but I was interpreting the question to mean a DC supply with a throttle. 

The controller kit above iis 5 amps, and I'm guessing he wants more like 10 amps by his question of how many locos. 

The street price on the 10 amp crest throttle is $65, so a meanwell at 10 amps and that throttle will be a bit more than the MRC all in one box. 

Options...options 

Regards, Greg


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## Torby (Jan 2, 2008)

Last I was using track power, I got 2 of those from allelectronics.com. They were only 6 1/2A each, but that's still a lot of current. The Chicago Botanic has Aristo Elites and they never give us trouble. They just got rid of their last Aristo Ultimas, which did their jobs very nicely. 

With the power supply rated less than the throttle or the fuse, any time I had a short, the power supply would shut down. I'd just cycle the power and everything came back to life.


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## George Schreyer (Jan 16, 2009)

for a regulated supply, try this one 

24 v, 12.5 amp $25 

http://www.mpja.com/prodinfo.asp?number=17429+PS


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## Curmudgeon (Jan 11, 2008)

Hoover Dam. 
Always has been, with Grand Coulee a close second. 

Best power for the buck.


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## krs (Feb 29, 2008)

Posted By George Schreyer on 05/04/2009 1:42 PM
for a regulated supply, try this one 

24 v, 12.5 amp $25 

http://www.mpja.com/prodinfo.asp?number=17429+PS




Wow - that is dirt cheap.
Last switching supply I bought was a Meanwell one at around $50.- and it was only 6.5A at 24 volts - but that was years ago.
Prices have really dropped since then.


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## Dwight Ennis (Jan 2, 2008)

Hoover Dam
Nahhhh - live steam.


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## Curmudgeon (Jan 11, 2008)

Posted By Dwight Ennis on 05/04/2009 2:47 PM
Hoover Dam
Nahhhh - live steam. " src="http://www.mylargescale.com/DesktopModules/NTForums/themes/mls/emoticons/wink.gif" align="absMiddle" border="0" />

Hooked to a generator.

So, vapourized water running a generator or liquid-state water running a generator........

Nuke Power!

Same as live steam, but glows in the dark!


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## toddalin (Jan 4, 2008)

Posted By George Schreyer on 05/04/2009 1:42 PM
for a regulated supply, try this one 

24 v, 12.5 amp $25 

http://www.mpja.com/prodinfo.asp?number=17429+PS 



Wow, they do have good prices. Never been there before. Thanks for the link.


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## Torby (Jan 2, 2008)

for a regulated supply, try this one 

24 v, 12.5 amp $25 

http://www.mpja.com/prodinfo.asp?number=17429+PS 


That would be hard to beat!


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## lownote (Jan 3, 2008)

That is amazingly cheap--12.5 amps? I'm tempted to buy one just to have on hand


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## krs (Feb 29, 2008)

Has anyone been able to find specs on this unit? 

I've googled and have come up empty. 

I'm specifically interested in a couple of parameters: 
- Output ripple 
- Input surge current and duration 
- Over voltage cutoff setting 
- Can I trim the output voltage and if yes, over what range


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## Greg Elmassian (Jan 3, 2008)

It's a lot cheaper than the usual price. Is this a closeout? You wonder how it can be sold for about 1/3 of the "normal" price of comparable units. 

Regards, Greg


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## Torby (Jan 2, 2008)

Electronics gray market. Somebody bought more than they needed, used what they wanted and dumped the rest to the gray market.


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## George Schreyer (Jan 16, 2009)

MPJA is an "industrial liquidator" in part. They have 315 of these things as of yesterday, don't know if they will get more. I bought two of them awhile back but I have fired neither one up. They don't come with any documentation. They support 110/220 input, although do not automatically switch. The switch came in the 220 position.


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## krs (Feb 29, 2008)

I googled a bit and made a couple of phone calls. 
Nothing to do with grey market - Potrans has gone out of the power supply business, that explains the close-out prices.


I also managed to get a spec sheet.

This supply with the 110/220V switch is a non-PFC model, the PFC models have a 90-264VAC input range.

Output ripple/noise is 150mV
Over voltage protection is 115 - 150% of rated output

Output is adjustable from about -5% to +10%
Efficiency is 80%


Looks like a perfect unit for our applications.


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## Dan Pierce (Jan 2, 2008)

I just got one and it had a voltage adjustment pot. 

Buy 48 at under $20!!!


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## Spule 4 (Jan 2, 2008)

The adjustment pot is for fine tuning for output, do not think of it a a throttle. I have one here, nice unit for the price. 

Still, the luddite in me loves my Stancor 18VAC transformer. With a Radio Shack 10 amp bridge, it does the job...


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## Greg Elmassian (Jan 3, 2008)

Big difference between a regulated switching power supply and an unregulated ac transformer with no filtering. 

But whatever works... I need regulated supplies... 

Regards, Greg


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## krs (Feb 29, 2008)

I was amazed how much better trains run in analogue using a regulated supply compared to a regular model train power pack which is unregulated. 

Although that's obvious once you think about it - having a constant voltage even though the current draw varies going up and down hills, keeps the train running closer to the speed one selected. 
With a regular analog power pack I always had to increase the throttle when going uphill and decrease the throttle going down hill - with a regulated supply and a throttle I just adjusted the throttle to change the speed. 
Going uphill the train still slowed a little bit, much more realistic, not the large amount as with a regular unregulated power pack where the voltage drops when the current demand increases.


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## Daniel Peck (Mar 31, 2009)

I got the MRC 10 amp unit I like it, thanks guys for the input!


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## Dan Pierce (Jan 2, 2008)

The 12.5 amp unit has a fan for cooling, plus an adjustment pot. 

I placed a large load on the one I purchased and the output did drop to 22.6 volts at 12 amps. 
I am sure part of the drop was the wires to my load which is where I measured the voltage.


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## krs (Feb 29, 2008)

Posted By Dan Pierce on 05/27/2009 5:20 AM
The 12.5 amp unit has a fan for cooling, plus an adjustment pot. 

I placed a large load on the one I purchased and the output did drop to 22.6 volts at 12 amps. 
I am sure part of the drop was the wires to my load which is where I measured the voltage.



That's probably true. My Meanwell switching power supply stayed within 0.1 volts of 24 about an amp past the maximum current specified and then dropped off very fast.
HOWEVER, at no load and up to few hundred milliamps, the output was well over the 24 volts, so I ended up putting a bleeder resistor across the output to bring that voltage down to 24 volts.

If you get a chance can you check this unit if it does the same?


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## Spule 4 (Jan 2, 2008)

Posted By toddalin on 05/04/2009 10:48 AM
For the bucks??? No doubt about it.

http://www.allelectronics.com/make-a-store/item/PS-6524/24VDC-6.5A-POWER-SUPPLY/1.html














I just found a potential problem with this unit (powering an Aristo TE).

My unit has an internal breaker that will trip quickly. As in, a metal wheel bumps a point rail at the frog, slight derailment, etc. Then the drill of unplug and then plug back in.... Anyone else experience this?

The old Stancor with bridge and cap (and a conventional fuse) does not do this, and soldiers on.


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## krs (Feb 29, 2008)

Posted By Spule 4 on 05/27/2009 4:51 PM
Posted By toddalin on 05/04/2009 10:48 AM
For the bucks??? No doubt about it.

I just found a potential problem with this unit (powering an Aristo TE).


My unit has an internal breaker that will trip quickly. As in, a metal wheel bumps a point rail at the frog, slight derailment, etc. Then the drill of unplug and then plug back in.... Anyone else experience this?

The old Stancor with bridge and cap (and a conventional fuse) does not do this, and soldiers on.



That's interesting. I wonder if this is specific to Potrans supplies only.

I used my Meanwell switching supply with the Aristo TE and have no such problem - not sure if I ever did have any shorts.
But I bench tested the Meanweel with resistive loads past it's current output limit and at that point the voltage rapidly dropped to zero and then automatically recovered when I removed the load.


However, I don't think I ever just shorted the output when testing - I was more interested to see how far beyond the rated capacity the supply would deliver.

PS: Maybe there is a reason Potrans got out of the switching supply business.


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## Spule 4 (Jan 2, 2008)

My father, (EE, with power supply experience) says in some applications surge/short protection is needed, this may be designed this way.


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