Large Scale Central

DIY Power -- Good, Bad, or Neutral

Aloha,

I have been looking into upgrading from my ancient p

It’s a valid approach, years ago I matched a switching power supply to an Aristo Throttle for bench power.

I was given this link for cheaper sources. They have 20v too.

https://www.mpja.com/24-Volt-Power-Supply/products/541/

Go for it, when is the last time your computer power supply quit?

I agree, 5 amp, 24 volt for $15

https://www.mpja.com/24-Volt-Adapter-Power-Supply-5A-Megmeet/productinfo/32885+PS/

Now you need a 5 amp controller, perhaps a used LGB or Aristo, but maybe not cheap.

Is there a reason you want “clean DC” as opposed to a PWM controller that you can get much cheaper?

Greg

Gents, thanks.

@Bill: Due to our humidity and proximity to the coast, our computer power supplies typically have a 24-36 month life expectancy.

@Greg: I may have stumbled across a loaded term by using “clean DC.” I should have said “basic, no frills, analog power control.” My current power supplies, though, do have selector switches “pulse” and “full.” “Pulse” results in the trains not moving so well. Also, I’ve noted over the last 12-18 months several product reviews saying such-and-such thing did not run well on “pulse power.” I am wondering if I am conflating something here. I get neutrons. Electrons blow my mind.

Eric

Quick follow-up…

With the power supplies suggested above, it seems like a reversible motor controller like this https://www.droking.com/motor-driver-pwm-controller-module-dc-9-60v-20a-dc-motor-speed-controller-pwm-stepless-speed-control-module-adjustable-driver-module would be a pretty bullet-proof way to make trains start, stop, and reverse. I note that the minimum voltage on this example, though, is 9V. Given that my 0-4-0s regularly putter around at ~12V, or 2/3 my rated voltage, does this mean they would go from “all stop” to “all ahead half?” Do I need to look for a controller that operates across the spectrum of voltages, from 0-24 Volts?

From what it seems, I could mount a power supply and two controllers in a used computer case and be in business.

Thanks. Much to ponder.

Eric

Eric - this article that I posted last year may be of interest.

http://www.trainelectronics.com/PowerController/index.htm

dave

Eric, normally trains have better low speed response on “pulse power” whether it is the old school half wave AC or PWM, so can you explain “trains not moving so well”…

If your reason is from your experience with the 501’s, since they are not G voltage and not G current, and the pulse switch is only half wave AC, I would figure they would run slow and not have a lot of pulling power.

Those packs on their best days are 16 volts and under an amp.

In any case, all modern locos work fine on PWM, no matter what old wives tales say… except for analog locos with “analog” sound cards. Then the sound card freaks out, loco still runs fine.

More info please.

greg

Some USA trains lighting will not work with PWM

David Bodnar said:

Thanks for reposting, Bill

Eric - this article that I posted last year may be of interest.

http://www.trainelectronics.com/PowerController/index.htm

dave

Yes actually I have had less issue with USAT, since they normally use linear regulators, it’s just their flashing circuits, like on the caboose, and ditch lights.

Aristo’s are worse, that is because some use a microprocessor to do voltage regulation, and PWM really messes them up.

Greg

Bill Barnwell said:

Go for it, when is the last time your computer power supply quit?

I lost 3 this past year. Out of a hundred or so, I would guess that isn’t a bad ratio.

@Greg. In pulse, the locos pull more slowly or not at all in the case of the mogul, ten wheeler, and LGB railbus. And, yes, they have 16 Volts at the terminals sometimes. Usually they read 14-15 Volts, which can drop to as low as 9 Volts if I’ve let track connections work loos ore get dirty. At 9 Volts, the 0-4-0s slow; the “heavies” stop, especially on curves. Almost all the trains are 1980-s vintage LGB, so I am not sure it that counts as “modern.” Nothing has a sound card.

@Dave B.: Thanks for the article! This confirms my suspicion this could be ridiculously easy. I noted your warning about using computer style, metal cased power supplies to “NOT use this style of power supply unless you properly insulate the high voltage side of the unit.” Are there precautions beyond making sure the terminals are out of reach? I had been leaning in this direction, so I could have two speed controllers on one supply, but with “crew” as young as three, your warning gives me pause. I am sharing this link with my father-in-law who is a collector of bits and master tinkerer among other skills.

@David M.: The odds, it would seem, are in my favor. Thanks!

OK, barring any glaring safety things, this seems doable.

Eric

Eric - no special precautions are needed so long as you make sure the box you use cannot be easily opened exposing the screws - You might also want to cover the AC power screw terminals with hot melt glue or silicon glue to make sure no one can touch them.

dave

So Eric, your issue is not pulse power not working, your power supply is so marginal that when you “cut it in half” there’s not enough power to run your loco.

Greg

Gents, thanks! I think I see my way forward. Let me see what my father-in-law has ready to hand and proceed from there. I also have to do a final comfort check with CINCHOUSE. Very important!

All,

CINCHOUSE authorized me to proceed. I have confirmed effectively nothing is available locally beyond wires and DPDT switches. I will submit a parts list for review early this week, because I hate paint $15 to ship a $0.35 part…

Thanks for all the inputs!

Eric

All,

I just wanted to run a parts list by folks who speak the mystical language of electronics. I chose them from the Marline P Jones & Associates website based on the recommendations above. I did not include wiring or the case, as I can procure those locally:

  1. Extension Chord to power supply. Power Cord, 5ft. NEMA 5 to IEC C-13 / Stock No: 31447 CB
  2. Power supply. 24 Volt Adapter Power Supply, 5A, Megmeet / Stock No: 32885 PS (I went with the lap-top style to add a bit of durability. I am also somewhat concerned about cooling given our location using a “desk top computer style” power supply if I had to pack it into a carrying case.)
  3. Power Supply to Throttle. 4 Pin Chassis Connector for 32885 PS / Stock No: 33004 PL
  4. Throttle. DC PWM Motor Speed Control 10A / Stock No: 33371 MD (Currently out of stock. I could get the bigger one, but that seems like overkill, and the controller with pre-installed on-off-on switch was only rated to 3A.).
  5. Direction Control. DPDT On-Off-On Toggle Switch / Stock No: 12221 SW
  6. Output to leads running to track…stumped…Right now I use screw terminals. I’d prefer to use a plug to make it easier to assemble / disassemble, but was a bit overwhelmed by the choices.

Thanks for bearing with my abundance of caution. I will lose DIY permission for a while if this fails! (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-tongue-out.gif)In reality, as mentioned, the extra set of eyes will save shipping costs.

Have a great week!

Eric

might want to consider some type of fusing or resettable circuit breaker to protect your engines like if the short out on a switch, etc. I would think 5 amp would be ok, Bill

Eric Mueller said:

CINCHOUSE authorized me to proceed.

That thar is funny. And shows wisdom. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)