What’s the right voltage for HO scale model railroads and trains?
HO Scale trains are hugely popular the world over, especially on American model railroads, and while very similar to other scales they have a slightly different voltage requirement.
While other smaller scales run at 10 to 12Volts, HO is designed for 14V.
This is because they have slightly bigger motors and need more power.
On the controller of a typical HO railroad (as they’re better known in America), turning the throttle up increases the voltage from 0Volts when it’s stationary to 14Volts when the locomotive will go flat out.
Using higher voltages will cause the motor to heat up and possibly burn out.
The best way of ensuring you don’t over supply and damage your trains is to use a transformer and controller provided by the manufacturer (Atlas, Athearn, Bowser, Kato or Walthers) or one of the excellent units made by Gauge Master in the UK. I have no links to them but having used them over many years I’ve come to trust them and now recommend them for N, OO and HO scale model railways. See the lastest prices on Gauge Master controllers.

OK, my brother is trying to build up a HO train set. He had one that got stolen. What is the best way to test used engine being sold at flea markets and yard sales to make sure they are not burned out? Some kind of pocket power pack or something. If using a DOM what ohm reading should I get?
Hi David, as a very basic test (for DC locos), a small battery connected to the wheels with the pickups would test the motor, gears etc. This doesn’t catch everything but does show if the pick-ups work, the motor runs and the gears turn the wheels. Hope this helps. Andy