I doubt you will be within the current limits of the regular 3.5 with O scale equipment. The stall current probably far exceeds the decoder limits. XL it will probably have to be.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
The V 3.5 is good for 1.1 Amps. steady state, 1.5 Amps. stalled. As long as you particular motor does not exceed that, you will be OK. Measure your steady state with an ammeter, connected in series to one of your track leads, with your largest loco with your longest trains on your steepest grade. As long as you don't exceed the 1.1 Amps., you will be OK. The sound and motor control are superb with these decoders. If/when you install this or any other decoder, ensure your motor is isolated from any stray track voltage. Not doing so will cause you difficulty (like a shorted decoder). LokSound has a very good warranty program but I'm not sure it covers installation errors.
Does any one know if the Lok sound V3.5 decoders will work in O scale Weaver diesels engines? I'm also using a Digitrax DCC system with the booster set on O scale. The V3.5 has more sound options than the XL V3.5.
Jack Bartman