Help to I.D. Atlas electronics

Hi Chris

Early AtlasO 2 rail command and control locomotives had TMCC boards - not DCC. After several years of market resistance Jim Weaver finally realized that most 2 railers wanted nothing to do with a proprietary command and control system and finally Atlas switched to QSI designed DCC decoders for 2 rail models.  Unfortunately AtlasO  always seems to be a generation behind the QSI decoders/sound sets available to us on the open market from QSI Solutions (in Vermont). This may be due to product licensing agreements between Atlas and QSI Industries (in Oregon), the folks that hold the design rights..  My first call would be to tech support at AtlasO.  They may have you do a decoder reset if it's not responding properly.  While talking with AtlasO find out which model of QSI decoder you have.  Though QSI Solutions didn't manufacture the decoder, they do have downloadable users manuals for the various versions (latest being the Titan, previous the Revolution).

Ed Rappe

Some of the very early SW units, 3 rail, had Dallee electronics.  It does not look like the Dallee board I recently removed from one. TMCC has a distinct bottle board, 3 board set up, plugged into a mother board. It was a split board built to accommodate the small space. That has changed recently when the provider was no longer Train America Studio, now Electric Railroad.

http://tonystrains.com/product/digitrax-dg583s/

looks just like it? (tilt your head! )

http://www.digitrax.com/produc...ile-decoders/dg583s/

I agree it looks like a DG583S. That means it was added after purchase, not factory.

The manual is here: 

http://www.digitrax.com/suppor...als/#mobile-decoders 

The larger board is the standard "dog-bone" board that comes in most Atlas DC only but "DCC-ready" engines. There are 2 sets of leads on the decoder. One set has the red and black rail pickup leads and the orange and grey leads to the motor. The other is the small multi-lead plug on the side.

Looks like the installer connected the pickup and motor wries to the dogbone with an Atlas-style plug to connect to the rails and motor through the dogbone.

But all the functions for lighting etc. don't seem to be connected in your picture. The blue lead in that harness is +ve common to all. The other colours are one each for each function. Typically white for headlight, yellow for rear light, (F0 on Digitrax) then the others are for F2,3 etc. Each can be programmed for on-off, or various effects e.g. beacon. There's a narrow white socket on the dogbone labelled "to DCC" that you could in theory connect those function leads to. But I'm not sure of the pin-outs.

The screw terminals on the decoder are for the pickup and motor leads plus the blue +ve for the functions out. The rest of the functions come out in the small harness on the side.

The dogbone has some of the wiring traces to connect lights etc. You'll see that the bare pads around the dogbone are labelled for the common and various F1,2,3 etc. function outputs. However, my advice is to remove it and just use the DG583 directly to each item. You'll have a lot more room if you want to add a sound decoder such as Soundtraxx DSX and speakers, plus the dogbone may or may not have the resistors you'll need to use LEDs, depending on its age. 

HTH

Cheers,

Pete   

Yeap. That's a shame! Waste of controlling functions.

Agreed Joe. I bet the original installer gave up trying to figure out all the connections through the dogbone, Took me a few DCC installs to figure out the best thing to do is just pull out the dogbone and go direct to the pickup, motor and lighting/function connections (with resistors for LEDs) right from the decoder. The DG583S at least has screw terminals and plugs rather than being hardwired or just solder pads! Some soldering to do but you can still take the shell off again easy enough when needed.  

Cheers,

Pete 

Terrific, thanks very much for the help.

The Digitrax decoder is rated for 5 amps!

I will save it for a much larger engine(s) and use a NCE D13SR for the SW8. This decoder is in my other SW's. It is sufficient.

if you click on the link above for digitrax, you get associated documents.

http://www.digitrax.com/static...documents/DG583S.pdf

Good call. Use that big sucker in a Pittman-motored unit! By the way a regular sized (not micro) HO Tsunami or Loksound will power the SW8 nicely with added sound for a few $$ more. I use a brass plate to sit above the drive in the hood to provide a decoder mount and heatsink. Plus there's plenty of room for a decent speaker. Both those decoders offer great sound and amazing slow running with a bit of tuning. There's lots of good info online about settings to fine tune the starting and slow running, which is pretty darned good with that single motor drive anyway. 

Enjoy!  

Pete