High amperage decoder

[TBat55]

I put a can motor in an old Mantua 0-6-0 (repower kit), but it smoked the tiny decoder I tried.  Amperage was ~2A.  I see Digitrax has a DG380L decoder rated at 3 Amps that might fit.  Any recommendaton for other high-amp but small decoders?

[RR_Mel]

2 Amps is very high for a can motor, I have dozens of can motors none of them draw more than .6 amps full load.  Most are under .2 Amps.  

 

Mel

 

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

[richg1998]

I have done some like this over the years.

The first thing I would do is roll the loco on a piece of window glass without the motor to see if it rolls freely. Got this idea many years ago out of a MRR magazine.

Then install the motor, looking for minimum backlash between the motor worm and worm gear.. A slight amount of backlash is desired and at this time, verify no wobble on the worm or the worm gear. Got that idea from NWSL many years ago.

Then check current at 12 VDC with light pressure from one finger on a driver. Never found a need to lock the drive for this test.

Rich

[TBat55]

Thanks for the replies.

The drivers are quartered correctly and turn freely. I tried to set 0.010" between the gears so it's not excessive pressure.

The problem measuring current draw is it's not the same up on rollers with the heavy die cast body removed. I put it together on a piece of track (with no decoder) and an old power pack at max ~12V.  I held it back a little to simulate a train pull. 

Maybe I didn't use my VOM correctly on the second try, but it did fry the N/HO decoder rated at 1A without the track and body.  That's why I thought a higher amperage decoder would be the easiest fix - worse case I overheat the motor, but it is a little switcher that should only go short distances between stops.

[richg1998]

Pull the motor and try it while holding in one hand with the ampmeter in series with one motor lead.

Rich

[rrinker]

2 amps is about a high as they go for decoders small enough to fit in that loco. The 4-8 amp decoders are quite large, meant for S and O scale locos. Besides just getting a decoder that can handle the current, if your one loco draws 2+ amps, you're sucking up half your DCC power running one loco. No way should a can motor draw 2 amps. If the mechanism isn;t tight or jamming, you may have a defective motor.

                      --Randy