I recently added a Menard's Schoolhouse and their Schneider Warehouse to my layout. All my lighting to date has been 14.5v. I ordered both white and soft white 14.5v LEDs online and use an MTH terminal block to light all my buildings. I have a 14.5v, 3.5amps supply from an old MTH RTR box and the milliamp load on my buildings hardly adds to 1.0 amps.
As mentioned somewhere online, maybe in one of these forums, there is some tolerance in those Menard 4.5v requirements. Initially, without thinking, I hooked the Menard's buildings to my 14.5v supply. Luckily nothing blew out, but boy did the forklift on the warehouse go in and out of the building fast and I pretty much had enough glow from the warehouse to cover my basement. Disconnected that fast.
Since I had some old USB micro-plugs left from old cell phones, I remembered they had a steady 5v, 2amp DC output. I simply cut the ends off of two cords, cut back the two data wires, tinned the power wires, and used a double travel plug to run one wire to each building. I measured 4.9v out of each cord. Still quite a glow from the warehouse, but it is back in a freight area of my layout; and often when dark you see well lit over-the-road truck warehouse areas along interstates. I am probably going to put some trim on the building to direct the light down more, but I am in my 70's and should be gone before the Menard's LEDs die. The school house seems like a soft glow of a closed building at night. I even added one of my bulbs for an extra 'security' light in that building.
