Menards building led draw

Actually, virtually all the common LEDs max out at 20ma, I have no reason to believe Menards has used high-power LED's. 

5V power bricks up to around 8-10 amps are dirt cheap on eBay.  Add a 6 amp diode in series and you have your 4.5 volt supply, job done.

I checked two buildings(farm supply, depot) about 55 led and a fan motor totaled 590mA. So I figure around 10mA per led as a general current draw. TW

So far my 1033 is driving about 20  led bulbs in my structures plus 4 scale street lamps using mini bulbs. Each LED bulb uses an array of 5 individual Leds with an internal resistor.  If we do the math that's 100 leds + 4 tiny Lionel street lamp bulbs. The transformer load measures about .4 amps or 400 ma. @12V. I would say that the fan motor is drawing most of your current as we are probably under 4 ma draw for each LED

Just for the arguments sake, I disconnected the fan motor. 7 leds, .07A. 

Then with fan.  This fan barely turns by design.  Suffice to say, the per led draw is substantially less than 40mA that the OP was originally told. TW

Thank you to everyone for providing the info.

I thought that 40ma per led that I was told sounded awfully high.  But not being very knowledgeable about led draw I am glad I asked the question on the forum and got the good advice.

When I first heard the 40ma per led I did some quick math and then had visions of needing a bank of power supplies.

I think I will go with John's suggestion for a power supply.  I can run the feed to a buss in the center and then run individual feeds to the 4 different areas.

Thank you all very much for the help.

Ed

TW - thank you for going to the trouble disconnecting the fan.  I very much appreciated that. 

Is is folks like you and the others who helped that make this forum hands down the best place to get help and make friends along the way.

Thanks,

Ed

John, with your experience w/leds, how can you turn down the intensity of these Menards lights?  The buck converter puts out the 4.5vdc, so I presume turning that down further simply causes the lights to go out. Absent a "pot"(dimmer) to adjust leds are either on or off, correct?  See picks below, as the two buildings are so much brighter than the 3 woodland scenics building around them. What can be done to match the intensity a little closer?  (Remember, I'm an electrical/electronic tyro) 

If it's just LED lighting, you just need a variable DC supply, turn down the voltage a bit and it'll turn down the intensity.  The issue with voltage control is it's a small range from bright to off, so you need pretty precise control.  The best way is with a constant current supply, but that's something you'd probably not find off the shelf.

Here's one that would work with a meter so you can see what you're doing, eBay 262459413739 for $6.72.  This is probably really good for maybe an amp.

So based on that info, I went down and turned down the buck converter to 2.75vdc and the lights dimmed, and are much much better. Might even go down a titch more. Am I missing anything here?  Won't ruin anything, right?  Leds should actually run longer shouldn't they due to reduced voltage?  Thx in advance for help and advice. Ted

If all there is is LED's, you're fine.  Motorized stuff might object to lower voltages.

Thx again, Gotcha about the motor. I dont use it anyway. Leave it unplugged. Too noisy for my liking. Thx again. I am surprised the lights work nicely at such a low voltage. I have the woodland scenics buildings at 10vac. TW