Large Scale Central

Is stall current generally > 2.4 amps on O/G scale locos ?

General Discussion
#1

I have a chance to buy some affordable 2.4 amp and 2.6 amp decoders that run at 22-24 volts max. After this fall I might inherit some O scale and G scale locos (I do not have details on the specs). Do most O-scale and G-scale locos have a stall current that exceeds 2.4 or 2.6 amps? I know it depends on the loco, but I’m looking for some averages.

So my question is, do a fair percentage of O/G scale locos might operate at or below 2.4 or 2.6 amps?

Thanks

#2

I do not know about stall current, but running current, on my railroad, rarely exceeds 1.5 to 1.75 amps. Usually my equipment runs around an amp. Thats Bachmann big haulers, the Spectrum Climax, LGB Moguls, USA F3, Aristo RS3 and C16, and some Heartland stuff.

#3

Interesting and controversial subject.

Stall current should be the current drawn at full voltage with the drivers “stalled”, i.e. you prevent them from turning.

Testing this is tough, some locos can be damaged by this test.

Let me ask you why you want to know stall current? Are you sizing a control system? If so, what system?

And stall current of an LGB is WAY lower than that of the USAT locos. There is no general answer.

Greg

#4

Maybe a better question is maximum peak current.

#5

Often, decoder manufacturers say “stall current”, but how would you define maximum peak current?

Are you on chat? I’m all by myself!

Greg

#6

There is more to it than motor stall current as decoders have a rating for total current drawn, therefore one must add in the lights, smoke and sound plus the motor stall current.

So, I find a single motor LGB engine will run from a 1.2 amp Zimo HO decoder (Zimo decoders have a 30volt or more voltage rating) with only one light in each direction. If the decoder overloads it means the motor is bad.

#7

Great answers. I appreciate that.

So what happens if you put a decoder in a loco, and at some stage down the line the current draw ever exceeds the max spec of the decoder? Does this damage the decoder or the loco?

Thanks again.

#8

Depends on the decoder. Some will shut down, some will release the magic smoke. I have not heard of one damaging a locomotive.

#9

Ditto

#10

Zimo has programmed the over current (most likely overheated mosfets) to flash the lights and automatically restarts when the problem goes away (cools down), I believe this is a heat sensor on the decoder. After I replaced the motor, all was well on 2 different engines.

#11

Most SoundTraxx decoders flash the lights when in overheat / overcurrent situation, they turn off the output transistors.

Greg