Let me say here, I use none of these so called voltage regulators, etc., just something to add to lighting that is not needed when you can just use 12V LED’s (3mm and 5mm size LED’s, 12 v) and 100 ohm resistors, the resistors are used to adjust the light output of the LED’s and reduce voltage which is what is happing when you use resistors. There are both soft white and bright white LED’S, I mostly use the bright white ones. You won’t have to be a rocket scientist to do this, LED’s only have two leads, the longer one is the one the power goes in, don’t worry it you get it backward, nothing happen and it won’t light, just reverse the power leads. The resistor can go on either LED lead, I usually put them on the long lead, I just wire all them the same. You can get all of this on eBay, get the resistors in packs of many Ohms ratings, 25,50,75, 100, etc., just gives you better voltage and light brightness adjustment, the LED’S can be purchased in both 3mm and 5mm, I use the 5mm on headlights and the 3mm for all other lights, get the ones with the wire leads already attached, this just makes wiring easier. LED’s are usually priced around $12 for 20, resistors are priced somewhat the same. Watch videos on YouTube on LED install in model trains, many out there, just watch several to get the info that will work for you. If you need help on which ones to order I will look them up for you, just ask, plus you do not want to order electronics that come directly from China, order U S only, from China takes 30 plus days and you may never get them.