Power for Menard lighted vehicles

The Menards lighted vehicles are designed to be powered at ~4.5 volts DC.  So as long as your AC power source gets to 4.5vdc at the vehicle, it will be fine.  Of course that can be through a dc wall wart, ac-dc buck converter(from transformer), or any number of methods you may choose.  Click screen shot for larger view

Seems to me like you would need to do the following:

1. Find out what the current draw is on each lighted Menard's vehicle - I don't have that spec but I'm guessing it's in the 500 mah range.

2. Multiply that figure by the number of vehicles you want to light to figure out your total amp draw.

3. Purchase an ac/dc buck converter that accepts 5-16 acv input with a 4.5 volt (fixed or adjustable) output rated for more than the total current draw you calculated in #2 to connect to your transformer output.

4. Connect the ac/dc buck converter output to some sort of terminal block and run a port from that to each lighted vehicle.

5. You will need to purchase a barrel jack converter (5.5/2.1) to go from wire leads to barrel jack output to connect to the barrel jack of each lighted vehicle.

6. You will then have to splice in a switch from your control panel to the outputs to the vehicles. It's not clear to me whether you want to control each vehicle separately or all at once, so you may need to adjust how many switches you need and exactly how they are wired in. If you want to control each vehicle independently, the switch would have to be wired in after the terminal block. If for all of them at one time, the switch would go in before the block.

Thanks for the inputs. The ac/dc buck converter approach is what I have been considering. I have not used them before but a quick internet searched turned up one that appears to fit the requirements. Does anyone have a suggestion on a source for buck converters.

Kinda depends on how quick you want them.  A US source may cost more but ship quicker.  Off shore will take weeks to months generally.  Search “ac/dc-dc buck converters” in Amazon, Ebay or Alliexpress you’ll get lots of sources and variations in design.  Some require soldering connections, others have screw type connections, still others have dc voltage meters for easy setting without a multi-meter.

Thanks again, will do some research. They look to be fairly inexpensive so domestic might be best bet.

I've used the above AC-to-DC converter.  You have to buy 2, but the above Amazon price is not much more than what you'd pay from eBay-Asia.

The top photo is recycled from a previous OGR thread and shows you can attach a 2-wire "self-powered" voltmeter to give you ease of adjustment without a meter.  I buy 2-wire meters for about $1 from eBay-Asia.

To your point, the integral voltmeter is handy but I've only seen them on the inexpensive DC-to-DC converters. Another option is to pair a bridge-rectifier (to convert AC-to-DC) followed by a DC-to-DC converter with meter.  I think you might actually save some money this way since a suitable bridge rectifier should be, say, 50 cents.

But when dealing with onesy-twosy quantities and shipping charges, it sometimes comes down to getting lucky and stumbling across the right eBay-US seller, Amazon, etc.. or if you have a Radio Shack (not a typo!) down the street.

Finally, whether it be an AC-to DC or a DC-to-DC voltage converter module, do NOT select one that has LM317 in the description.  For the application at hand, the LM317 (a type of IC chip) will waste more power as heat than providing lighting power for your cars. 

Thanks for the additional guidance, it is so helpful to get your first hand experience and recommendations. I have seen the Amazon device and will look for the volt meters. This approach appears to be a basic building block for handling this type of power requirement from a central power source. It is cost effective enough to be used to supply specific voltage to individual operating units. Even on my 6x12 layout I can see multiple applications for its use.

I found this additional photo that I no doubt posted in a previous OGR thread.  It's a different AC-to-DC converter module.  And there's that 2-wire voltmeter again this time at 4.5V so we were probably discussing a Menards application!  The other thing is what Richie mentioned earlier, you can buy pre-wired coax plugs as shown on the right.  Look for the 5.5mm / 2.1mm dimension.  The wire lengths in above photo are obviously not long enough to connect to anything useful on a layout and are just by way of representation.

And if you want ugly on an ape...  

Ugly is in the eye of the beholder!   Plus it's under the layout (out of sight, out of mind).

I use those male and female adapters ALL THE TIME!  Make your own 4.5V power extension cable for Menards buildings or vehicles - NO SOLDERING REQUIRED! 

Actually I was considering cutting the connectors off the wire from the vehicle and using a 2 wire spring connector to connect the vehicle to the 4.5v source. Simple connect/ disconnect. I am not sure the connectors provide any advantage over a connector. I use the connectors from Woodland Scenics although I am sure there are other sources.

As long as you mind the DC polarity - positive-to-positive, negative-to-negative ...

Yup as Stan sez mind your polarity.  Here’s the old battery(3x1.5vdc) powered Menards ambulance hard wired for the layout.  I actually hooked it up to a timer relay to come on for a time and go off for a time.  But it works fine.  This is the JST type(style) plug that is much smaller.  Pick your poison.

Yes I have had to be careful with polarity and can see where the m/f connector simplifies removal and replacement. Something to consider.

I like your idea here but I ended up just buying a 5v 8a power supply on Amazon for ~$20. I will use it for a number of 5v microcontrollers for sound, LED's and of course Menards buildings and cars. I saw @Gunrunnerjohn mention using a diode as a simple way to step down to 4.5v which has worked great and is certainly less expensive than a pick converter. I feel like this is a much more stable setup for my layout and is enough for all of those 5v range add ons.

I have installed the first vehicle with the recommended electrical setup. I have allowed for a second voltage requirement on the strip. I just need to find some screws small enough for the meters.

Thanks again for the technical assistance, the forum is a great source!