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This is both a specific and general electronics question.

I've about 10 or so Menards structures on my layout, and while most require 4.5 volt DC and draw less than 1000 mA, a few larger ones (with motors and/or lots of LEDs) require > 1000 mA, e.g., the York Hotel, Brewery, and Sash & Shutter.

I've had mixed results with Menards adaptors, and have replaced some of them with Lemax adaptors (which have switching (are power regulated) and are also rated at 4.5 V DC and 1000 mA. The Lemax adaptors seem like a quality product; and the instructions state that "ensure the combined current draw does not exceed 1000 mA, otherwise, it may cause damage to the adaptor.

The York Hotel requires 3200 mA, yet it lights fine with the Lemax 1000 mA adaptor. My question: if a building or combination of buildings lights fine with a 1000 mA adaptor; does this mean that damage to the adaptor is occurring because the buildings are drawing more current than the adaptor can put out? I would've thought the buildings just wouldn't light up?

Since I spend a good deal of time and energy drilling holes to accommodate power cables, soldering them back together, and arranging adaptors under the layout, I want to head-off future issues if at all possible, thus my question on these myriad and complicated-to-power buildings.


Last edited by Paul Kallus
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You are certainly not doing that adapter any good by overloading it to that degree!  Electrical devices won't draw more current than they need if the source has more current capability than the load requires, but you can certainly cook the supply if you demand more current that it's rated for.

If you have a bunch of these, why not add a DC power distribution bus and supply them with one large power supply?  You can use an old discarded PC power supply and one of these inexpensive ATX Breakout Boards to supply enough power for all the buildings and then some.  The beauty of this arrangement is if the PC power supply craps out for any reason, you can simply replace it with another one and plug it into the breakout board and you're back in business.

This board supplies 3.3V, 5V, and +/-12V.  For 4.5 volts, a single large diode in series with the 5V output will give you a nice 4.5 volts for all the buildings.

Onyehn 2pcs 24 Pin Benchtop Power Board Computer ATX Power Supply Breakout Adapter


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You need a power supply from an old computer with its main connector intact and, also, its power cord. Then you need to buy a "breakout board" like the one(s) shown.

The computer power supply then plugs into a standard wall outlet using its own cord and its connector plugs into the new breakout board. The output side of the breakout board has multiple taps of different voltages that you can then use to power items on your layout.

Thanks everyone. If I was starting to install the Menards buildings then I would likely pursue a sole power source and distribution blocks like those presented, however 9/10ths of my wiring work is currently finished via means of Menards and Lemax power adaptors. This represents many hours of work due to cutting wire and re-soldering those PITA barrel plugs. The big York hotel is the remaining question - and I just confirmed it needs 5 amps, so will need to buy either the Menards 5 amp adaptor or another brand. Can anyone recommend a good brand adaptor? Preferably one that is regulated (switching I think it is termed).

I made a DC Power Supply from an old PC Power Supply and AC Power Supply using a Lionel CW-80 Transformer then fused all the outputs and used banana jacks and put banana plugs on cords with test probes. I have +12 V, +5 V, +3.3 V, and -12 V DC from the PC Power Supply, and Adjustable 0-18 V AC for both Track and Accessory Power from the Transformer for doing testing on my workbench before putting it on the layout. Works Great! It won't win any awards for looks but it does the job. That is a 10 ohm 10 watt Power Resistor mounted on the outside right side for the load required to trigger on the PC Power Supply.20220406_21590520220406_21593420220406_22000720220406_21584720220406_21590520220406_21593420220406_22000720220406_215847


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USB C type power supplies for laptops have outputs for 20 VDC, 15 VDC, 9VDC, 5VDC, between 2 and 3 amps each depending on the manufacturer.


They have short circuit protection and Female USB Type C breakout boards are available. Another way to go.

USB C breakout

Update:   Further research has found that the only the standard USB voltage ( 5 VDC ) is available from USB Type C power supplies by adding 5.1K ohm resistors ( marked green, brown, red, gold or silver ) between the CC1 and CC2 terminals and ground to enable the power supply.

There are 4 VBUS connections and 4 grounds. Each VBUS to GND connection can handle 1/4 of the 3 amp supply.

If you need all 3 amps to power one circuit, you''ll need to connect the four VBUS terminals together and the four GND terminals together so as not to overload the powersupply to breakout board USB-C connector. Similarly, for 1.5 AMPS you'd connect two sets together.

SAM_0597 edit

5 VDC between VBUS and Ground

SAM_0596 edit

A configuration controller on the CC1 and CC2 connections is needed to get the other listed voltages.


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Last edited by JET

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