Hi I'm new to the HO DCC scene, my interests have been in Large scale (F) narrow guage, battery powered trains. I was wondering how N and Z scale decoders operate in smaller HO scale locos? The Digitrax site shows the DZ123 for certain HO locos that I have but then a dealer told me they would burn up because they are too small? I'm a lil confused and would assume to trust digitrax but the dealer says he's speaking from 'experience'. I would assume as long as the motor draw is under the rating of the DCC card it would be ok? Currently I will be running a Digitrax zephyr and expanding to boosters and such later on. Thanks Terry
You just need to measure the stall current of your loco. Connect a power pack to a loop of track, and turn it up till you read 12 volts across the rails with the loco running, then mark the 12v position of the throttle knob on your power pack. Next, connect your meter, set to amps, in series with the power pack, and crank it up the the 12v setting, and hold on to the rear coupler, so the loco is spinning it's wheels but not moving. You can use a railcar coupled to the loco to hold the coupler for you. With the loco wheels slipping at 12v, that is your actual stall current as determined by the DCC companies. Now just pick a decoder that's current rating is greater thant the stall current of your loco.
Hi Robert - Stall current is measured with the wheels slipping? Why then do the reviews in MRR show current measurements for both stalled (a high value) and slipping (a much smaller value)? - Jeff
Hi Robert Just letting the wheels slip only measures the load current, to measure the stall current the loco has to be held down on the tracks with enough pressure to stop the motor and wheels turning completely. You will have to take this measurement quickly, like, within 5 seconds, or you run the risk of cooking (burning out) the motor. Regards Bob
An "N" decoder rated a 1 Amp continuous, 2 Amp peak is no different from an HO decoder of the same rating except for size. Decoders made to fit certain locos are scale specific only because the locos and the physical mounting arrangements are. Hard wired decoders can go anywhere they fit so long as they are not electrically abused. Your dealer likely experienced an N decoder whose ratings were exceeded. Coulda happened with an "HO" decoder as well.
