Engine Motion Detection and Triggering Circuit

Hey John, as long as I have a picture of what the finished board looks like (paint by number) I have no problem doing the assembly part. Besides, it'll give me another chance to almost burn my fingers.

Milwrd

These are a mix of through-hole and SMD, correct?

I dunno, an 0805 resistor is about a 1/16th inch long and 1/32 inch wide. You aren't going to assemble those very well with Radio Shack soldering iron!

All the parts are surface mount.

The 805 resistors are a bit larger than that, I think you're describing a smaller parts.  They're are still pretty small, so you will want a decent soldering station to assemble these.

Here's the board scaled up 600%.  The only holes are for the ten external connections.

OK, you convinced me, I'm ordering a set of boards.  I'll build one of these and then I'll have examples.  There's a small change from the previous version, a missing resistor was added for this version.  Previously, I did a "hack-n-whack" to put it in.  They should be in around the time I get back from vacation.

I'll put a note here and post them in the For-Sale forum.  For your reference, here's the instructions I created for the board and a PDF of the BOM.  I may expand the instructions with a better assembly drawing, we'll see.

The boards are in!  I assembled one to make sure all was well, and everything went fine, works like a champ.  After thinking about this, I realized that I would probably create a real mess for myself and be buried with questions with just a bare board.  I've decided I'll order all the parts and kit them up and post a complete kit.  A kit will consist of a single PCB and all the parts necessary to assemble a working Locomotive Motion Sensor module.  I managed to find the 5A version of the IM06 relays, so these will have a fairly robust current handling capability.

This will not become a off-the-shelf product, at least that's not in my plans.  I'm just doing this as a number of people have expressed interest in obtaining one of these.  Since hand assembling them, or committing to an assembly house production would be either time or cost prohibitive for a small quantity, they'll be kits only.   My plan is to accept reservations for kits in the for-sale forum, and when I get a suitable number, I'll order enough parts to send them out.

For your amusement, I had previously offered these in the for-sale forum and got zero interest, not sure why:

Locomotive Motion Detection Modules

Note that there have been changes in the BOM I published previously, I had changed some parts to more suitable sizes for their use, specifically the diodes were really large for the job and just expanded the thickness of the module for no reason.  The Rev. 3 board was already laid out for the new smaller diodes, that just didn't make it's way into the BOM.

I've attached the instructions for comments, suggestions, corrections, questions, etc.

Hi John,  I ordered all the parts from the previous BOM you had listed. Will they work with this board?

Doug

Compare the two.  Here's the old BOM and below it the new one.  The big change is I screwed up the part number of the cap at C1, that was totally wrong.  I also changed a couple of other parts for cheaper alternatives since I was doing parts kits.

Here's the corrected one.

Just went back through this thread and it was interesting to see how this project has evolved. Thanks for sharing it all with us.

Also, you didn't by chance purchase horse did you? There was a horse named 'Gun Runner' in the Traverse stakes at Saratoga last Sat.  If so congratulations, you came in third! 

Must have been my brother.

Just thought that was a pretty interesting coincidence when I saw it and you might like it. 

Here's how I package these when I install them.  The clear heatshrink allows me to see the internal wiring, but also insulates everything and allows me to just tuck them into a likely crevice.

Are you including a few inches of that heat shrink tubing in your kit of parts?  That may actually be the most inconvenient item to buy in small quantity!

I remember ordering the 4 ft "standard" length of tubing from DigiKey along with some small electronic parts and the package was a 4+ ft long box!  Imagine the postage!  The next time I told them to fold it as many times as possible and I promised not return it ... and it still came in a 4+ ft long box.    

No heatshrink.   I buy it on eBay, you can get it dirt cheap.  Also, Harbor Freight has a lot of different packages. 

Fair enough.  Perhaps share the size of heat shrink?

I can do that Stan, it's 1/2" heat-shrink.

eBay: 330754643355, about $1.20 shipped for 1.6 feet in black.

If you like the clear, eBay: 381585003459 $1.90 for a foot of the clear.

GRJ, where do you get your wire in the assorted colors and what gauge do you use the most? That's been one thing I have had trouble finding and deciding on what to get so I can have an assorted supply on hand. I have some from the Radio Shack close outs, but it's not a very good selection

Also, if anyone is near a Micro Center, they have a large assortment of heat shrink tubing up to maybe 1-1/2" or maybe even 2", it's very large anyway. I am sure it's more than ebay, but they are local to me, they now have a ton of electronic parts, most pricing is pretty reasonable and they are really handy to have around. Micro Center is kind of like a train store, I just like to go there to look around sometimes. Also like a train store, I usually end up purchasing something every visit.

Funny you should ask, I just peel a roll of this for nice #24 wire in various colors.  I buy rolls of it and strip it, cheapest multi-colored wire I've ever found.

That's a good idea, Thanks! I will go look around on ebay for some ribbon cable.

John, where do you by  that cable, EBay also?? I have used telephone wire in the past.. Is there anything wrong with that?

I buy my ribbon at the cheapest place, typically eBay.  Nothing wrong with Telephone wire, however much of it is solid and doesn't stand up to flexing.  Stranded telephone wire is just fine, it's just wire.

I just ordered this one. First one I came to that was 40 conductor.

Nothing wrong with that choice.

Just came across this thread. I did a similar circuit for Train America using a PIC. Used the fwd and rev outputs directly from the R2LC pins 16 and 18. So it would dim or brighten the front and rear headlights according to engine direction. Also had control of red/white marker lights and the serial data output 24 to turn the lights on/off, And flashing ditch lights when the horn was activated. This was 15 years ago and I don't know what happened to the product.

Since TAS isn't around anymore, it probably died with them as did all the other products.