Power supply for Digitrax Zephyr etc.

Can I use the same power supply for my Zephyr, the “91” transmitter, and my structue lighting?

I have an old Lambda 3 Amp, regulated supply that can be either “floating” or grounded.

I only run 1 or 2 locos at a time, all sound equipped. My Tortoises are powered from the track with stationary decoders. (Switch-8)

As a rule of thumb, I wouldn’t. The Zephyr does come with it’s own power supply (the PS315 at $30), normally.

On my home layout, I have the $8.50 PS12 power supply for my UR91, and the PS315 for my Zephyr.

I would keep that Lambda for layout lighting, and use the Digitrax power supplies meant for their use. The main reason I can think of not to is if you have a short with the layout lighting, you won’t be running trains until you fix it.

Paul A. Cutler III


Weather Or No Go New Haven


I agree with Paul. If you try to share a supply, your power usage will creep up on you, and one day you’ll start having weird little problems.

I was using an old Lionel transformer to drive my Lenz DCC system, plus some structure lighting. After a while, I found that my subway trains were running slower when I had the lighted passenger cars up above, being pulled by a sound-equipped steamer. I’d run out of amps on that old transformer. Once I picked up a 5-amp NEC supply to run the Lenz, everything was back to normal.

you can use your 3amp power supply for your zephyr but the current being drawn by the lights will reduce the amount of current available to run your trains. if you have an old powerpack with accessory ac teriminals use that for your lighting. don’t use a higher rated power supply for your zephyr than is called for. the wall wart for the ur91 puts out 12volts dc. the two screws on the ur91 are to hook up to the rails to monitor track power and do not power it. if you are in n scale that should be plenty.