Test Rig for Kato EM13 Decoder

[KenS]

I've been trying to install Kato EM13 decoders in some trains, and encountering the usual problems (the decoders often make poor contact in the slot, and need to be fiddled with).  After one particularly recalcitrant E231 had me tearing my hair out, I decided I needed to prove to myself that the decoder actually worked.  At first I hooked it up to my ESU Decoder Tester, with some aligator clips, but that didn't work, and I was worried that the motor might be too large, as it looks more suited for HO.

So I took some styrene and brass strip, and made myself a test rig.  The Command Station connects (through the RRampMeter in the photo) to the "track" side, and the track with the DE10 on it connects to the "motor" side.  If the decoder works, it will output DC to the track, and the DE10 (which is just an ordinary DC model) will move back and forth as I adjust the throttle.

Basically it's just a few styrene blocks glued to a slab of 2mm styrene, and the brass strip (which I bent to shape with small needlenose pliers) just fits into a slot between blocks, which have a large block glued down across them to hold it loosely in place. It was an evening's work, mostly spent waiting for the glue to set up enough to add the next part (I did one side, let it set for the full 2-hour setting time of the glue, then did the other as it presses against the first and I didn't want the block to shift).

It worked pretty well.  Most of my decoders are fine, but one did indeed have a bad output (no matter what I do, even a reset, the DE10 never twitches). That may well have been the one I tried on the ESU, or it might have been bad from the start.

I used wires with alligator clips on them on both sides of the rig (connected to the blue terminal blocks), so I can quickly move the "track" input from the Command Station's "Rail" outputs to the programming track (I just clip onto the programming track itself) to switch between testing and programming.

I'll eventually build a similar rig for the cab lighting (FL12) decoder, although that one needs six contacts and two LEDs, and a more complex "slot", so it will be a bit more work.

[CaptOblivious]

Very clever!

[The_Ghan]

Ken,

I like the way you think.  Would it not have been easier to hook the circuit up to a multimeter instead of a DC train on a piece of track?  I have a comical vision of your DE10 shooting off the table.  Also, you lose a couple of points for not colour-coding your wiring properly ... 

Cheers,

The_Ghan

[KenS]

I have the same vision of the DE10, so I ordered a set of Stationary Rollers for the rig. They should show up in a few days.

The reason I used the DE10 instead of the multimeter was to have a load on the output circuit.  I'll probably connect a multimeter (and my oscilloscope) across the leads to see how the EM13 works, but without a load that wouldn't really be giving me correct data. And I want to be able to use a train with an exposed flywheel (the DE10 isn't really the right one for that), so I can get RPM readings off it with an optical tachometer.  I've done that with the ESU tester and a DZ123 and I'm curious how the EM13 compares.

Proper color-coding wasn't in the cards.  My alligator clips came from a pack that had red/black and yellow/green, but not gray/orange, and I'd used the red for something else.  Additionally the wire on the rig is from a spool of radio-shack wire left over from my HO days. I could have color-coded the rig itself, but oddly black isn't a color I have in a reasonable gauge, and I wanted to finish it quickly.  With only four wires, even I should keep it straight.  When I build a rig for the FL12 I'll color code it, just to keep the lights straight, but it may not be the correct colors, as I won't necessarily know which pad does what in advance.

[The_Ghan]

I'm humbled ... optical tacho ... what more can I say?

Cheers

The_Ghan

[quinntopia]

Great idea Ken, I need to build one of these as well!  Thanks!