Baffled with Menards power adaptors and buildings

That's a good question.  When you look at the power adapters from Menards, Miller, and so on you don't see "LM317" or "linear" in the description.  It will instead say "powers up to 5 buildings" or "powers up to 10 signs" or whatever.  End-users want to know WHAT the product can do.  HOW it is done is less important...ignore the man behind the curtain! 

That said, suppose we dive into the HOW.  There are two basic circuits for voltage conversion/regulation:  Linear and switch-mode.  The LM317 is just an IC chip that employs the Linear circuit method.  For the "buck" modules frequently discussed on OGR, you might see "LM2596" which is a different IC chip that employs the switch-mode circuit method.

Generalizations can be mis-leading but I'll make one anyway in this specific context.  Linear converters are horribly inefficient when there's a large difference between the input voltage and output voltage.  Converting from, say, 18V command voltage or 14V accessory voltage down to 4.5V is a large difference.  For every Watt of 4.5V power going to the building lights, you will throw away or "waste", say, 3 Watts of power in the form of heat.  OTOH, a typical switch-mode converter will "waste" only  1/4 Watt for that same 1 Watt of power going to the building lights.  It's quite dramatic and hence I call it a "problem."

OK.  So it's fair to ask why would anyone even think of using a "linear" circuit in 2020 for this specific O-gauge use/context.  That's what I'm thinking!  The LM317 was introduced in 1976...almost 50 years ago!  That's an incredible run as IC chips go...and it's still going strong.  In fact, GRJ uses the LM317 in his popular LED lighting module.  Again, context is everything.

I see the eyes starting to glaze over but allow me to tell one more "story" ... again in this specific use/context.  If there is any interest in the technical nitty-gritty or how/why of linear vs. switch-mode circuits I refer you to Wikipedia or just do a web search.

But specific to the topic of Menards OGR building lighting...and this is just my version of history.  When Menards introduced lighted buildings you would choose your building and buy a DC adapter to power the building.  Buy a building, buy an adapter.  Buy another building, buy another adapter.  Lather, rinse, repeat.

The original (discontinued and no longer sold) Menards adapter were "unregulated" DC-output adapters.  They were regulated in the sense that if you paired the recommended adapter with a particular building then the DC-output adapter would indeed provide about 4.5V DC and all was well.

But who wants to buy 6 wall-wart adapters to power 6 buildings?  And with those fat wall-warts you typically could only plug 3 adapters on a standard 6-outlet power strip!   "Say it ain't so, Joe!"

So as I see it, what happened was guys tried to use one "bigger" adapter to power 2 or 3 or more buildings.  This really upset the apple-cart as it was a roll of the dice as to whether some combination of buildings would properly mate with a particular adapter so that the desired 4.5V was the final output.  In other words, it was a poor method of voltage regulation - depending on the end-user to properly pair adapter to building(s).  But this was resolved and now the Menards adapters are essentially inter-changeable and Menards now publishes the power requirements of their buildings so you can choose a suitable DC-output adapter for your particular combination of building(s).

You can often spot a switch mode buck converter by the small transformer roughly in the middle of the pc board. In case it does not say in the ad.

      I'm totally sold on this device.  What do you guys suggest to do to make the 110 volt input safe?  At the connection point, you would need some sort of plastic cover or housing the same way you wouldn't leave a junction box in your house wide open, right?

Would it make sense to just build a small wooden box with a lid to screw on and off to get at the terminals?

FWIW, here’s another version of a power source(set to 12vdc) which has a cover over the connections, as you describe.  Although in my opinion, the connections are covered and secure enough that extra protection may not be necessary.  Further, in my application, the supply never moves.  YMMV  click photo for larger view.

Well, I suppose YMMV is one way to look at it, but:

N = Neutral = WHITE.

L = Line/Live (hot) = BLACK

TedW,

Perfect.  Thank you!

Stan, Thank you very much for that explanation and in making it real world.  I just happened to see a converter a few weeks back that warned that a heat sink (included) must be used for ‘higher’ voltages and just thought it was odd that others did not seem to require that.  I now have a better understanding as to why.  And my eyes did not glaze over - lol!

Bob

This thread has been an interesting read and highly informative.  A good diagram or photo showing the transformer and its completed assembly is always very helpful.   Due to the varying Amperage needs of the Menards buildings there are multiple avenues to arrive at a suitable solution.   

However I do agree that there is a huge void that could be filled if a standalone power supply, with multiple outlets, designed for Menards or other 4.5V draw applications could be made available.   

The general public isn't capable of sitting down and summing up their total mA needs and then purchase a power supply online that they have to partly assemble to make it work.    Instead they'll purchase a dozen Wallwarts if need be since it is a simpler solution.

As noted in one of the responses, a smart tech could put something like this together and offer it up for sale.  In reality, they could put them together on a as needed basis, thus saving on inventory and product investment.

You have me thinking about the converters...what power supplies are you guys using to provide the AC power into the converters?

Given the large number of various O-scale buildings around my basement, I tend to like those with spring-loaded contacts, as I have half-dozen or so terminal blocks stationed around the basement powered by AC transformers. Menards buildings are an anomaly due to DC and the silly barrel plug which, as mentioned, is a PITA to run, cut, splice, solder (unless you don't mind big holes in your layout). Menards lighting is also strange, very bright LEDs, unnatural IMO. I paint them all with an orange or yellowish latex paint that brings them down into the warmer part of the spectrum, which is another PITA, but they put out some interesting industrial buildings that are unique to the hobby.

Again, if you buy one of the power supplies from Jameco with an output or 40 amps like stan2004 suggested, attach a line cord and run a couple wires to a distribution panel like the one from Miller Engineering, that'll beat every issue. Then buy the green coaxial connectors to attach after you run the thin wire from the distribution panel through a tiny hole to the sign or building. I don't think any tech can manufacture and  beat the cost of this setup.

@Paul Kallus posted:

You have me thinking about the converters...what power supplies are you guys using to provide the AC power into the converters?

Given the large number of various O-scale buildings around my basement, I tend to like those with spring-loaded contacts, as I have half-dozen or so terminal blocks stationed around the basement powered by AC transformers. Menards buildings are an anomaly due to DC and the silly barrel plug which, as mentioned, is a PITA to run, cut, splice, solder (unless you don't mind big holes in your layout). Menards lighting is also strange, very bright LEDs, unnatural IMO. I paint them all with an orange or yellowish latex paint that brings them down into the warmer part of the spectrum, which is another PITA, but they put out some interesting industrial buildings that are unique to the hobby.

Paul, I too used to have the AC transformers distributed around the layout, but a number of years ago, I disconnected the transformer and used 12volts dc.  All the lionel, MTH, and other buildings run on DC just fine.  It also Makes it simple to use the LED strip lighting that has become popular.

A 200 watt power source consumes only the total  watts that the items plugged into it use, right?  I'm asking because I am ready to purchase a device discussed here for the Menards buildings and I don't want to overload my circuit in my train room.  Or does it consume the 200 watts just by turning it on, regardless of the items you are running?

This answers the questions on other transformers, too.  Forgive my forgetfulness but it's been awhile since I asked myself this question.

The datasheet for the 200W supply shown first says the so-called "No Load" power consumption as less than 1 Watt.  So when plugged into the wall with nothing connected to the DC output terminals it hardly draws any power.

Then a separate spec provides the typical power conversion efficiency as 87%.  Efficiency = output/input.  So if you're drawing 87 Watts DC output, you'd be pulling 100 Watts out of your wall plug.

stan2004,

That's what I thought but even more detail, which is great.  Thanks for your response.

Good grief. Sounds like they could use Menard's buildings electrical hookups as projects for double E students. So much for plug and play. More like plug and maybe blow up. 

There are two Menards building users:  1. small layout or loop customers -- little John and his dad that got a train set for Christmas;  2. medium and large sized layout builders.

Menards addresses 1. with their plug and play extension cord system.  The folks left are the LAYOUT BUILDERS, the champions that respect Menards buildings enough to want to wire them into their medium and large sized layouts.  Unfortunately we are on our own so we've created layout forum topics to address our unique needs.   Thank God for all the smart dudes that chime in here.

Having been raised in the Chicagoland area, I can't help but think that architects like Burnham would be proud.  We are finding ways to build the models and layouts of our dreams using  limited resources that the manufacturers unknowingly place limits on.

There might also be third practical and pragmatic Menards building customer that says:

"What the ****, Menard's extension cord system actually works for my small or medium sized layout".

As nice as they are, I've avoided purchasing them for two reasons:

1.  I like building/painting my own.  (Which is why I don't buy the new Plasticville "built ups")

2.  I like having a unified wiring system that runs off my accessory transformer.

Jon

@IRON HORSE posted:

There might also be third practical and pragmatic Menards building customer that says:

"What the ****, Menard's extension cord system actually works for my small or medium sized layout".

That is where I fall in.

I have a 26x18 around the wall layout, I have11 of their building and a few of their cars.  I use three of their wall plugs with their extension cords, they works great.  The three wall plugs are on three different walls, controlled by remote control outlets, so I just push one button on a remote and they all turn on.  Did I spend more than any of the above ideas, possibly.  Did I have to drill bigger holes in the layout to get their plug to the building, yes.  Does it work great as intended, yes.

I also love their cars, got a bunch, sometimes you need to tweak them, but I have never had to send one back.

Tony

I just finished making a Menards 4.5 volt DC transformer based on this post.  I call it a "transformer" because it is a completely separate plug-in power device that can now power all of my Menards buildings and Miller Engineering signs.   This puppy puts our 200 watts of power and I can run 2 wires (+ and -) to all reaches of my layout.  I custom made a wooden box so the a/c household cord is secured like an outlet box and the electronics/wires are concealed.  I made the box to fit the power supply box exactly and the tight fit actually helped secured it in place.  I'm not sure if it would be approved by UL (primarily because it is wood and not metal) , but I feel safe having it in my house.  I left a part of the cover open for ventilation, though not sure if it heats up at all (doesn't appear to).  The external barrier strip screwed on the cover allows me to hook up my layout wires easily and the digital DC meter shows it runs at a constant 4.5 volts.    As an added touch I put 4 felt buttons with adhesive as feet so it will not scratch anything I put it on.  I bought the LRS-200-5 as described above from Jameco for $44 including tax and shipping and it was money well spent.  There is a switch to choose from 220 volts or 115 volts -- 115 volts is where it needs to be.  Thanks to Rich883, Stan2004, Cjack and Paul for dumbing it down to my level.  I am very grateful for the wisdom you have shared.  I've looked at step down bucks and other ideas over the years and this solution is awesome because, as Rich883 says, it covers your entire layout and therefore, is truly a Menards building/Miller sign transformer.  Here are my pictures.

Pretty slick, glad you’re all set.  Lot’s of accessories can be run off DC power.  Looks like you have power to spare.