Design of a $10-20 DCS-TIU Port Tester Tool?

Looks doable Stan, I'll work something up.  I actually order stuff like this from SEEED Studio if I want a few, ten boards of any reasonable size are around $12.70 shipped, and it takes about a month to get them.  I just got my TIU Buffer boards for the surface mount version back, and I ordered them just about a month ago.  The restrictions are they are 1/16" DS boards, no options, and quantity 10.  However, they're two sided boards with silk screen and solder mask both sides, so they're nice boards.

OSH Park is great for little modules, but once the boards get more than about 1 sq/in, I look for other options.  I like the little boards from OSH Park as I can get them in 1/32" and with heavier copper so I can run narrower traces and still have decent current capability.

I can get boards like this from China about $40 for 100 pieces if I want a lot of them.

I updated my Digikey cart for the "go , maybe, no-go" variety!  You twisted my arm!!  

Stan,

Yes, I was planning to do some more fiddling and would be happy to add your ideas, but GRJ will probably have it done and posted by the time I finish writing this...  GRJ's design will probably be more compact and 'correct' as well. 

I plan to still fiddle with the Diptrace program some more as well, so willing to try anything at least once or twice! Unlike GRJ, I will probably need the full board review (with revisions) prior to boards and parts or Gerbers.  

Sorry, I have been busy with Dr's appts and a dental implant the last half of this week and haven't gotten much of anything else done. Good news is cardiologist scheduled me back again in one year. I'm taking that as a good health report! May even have time to finish a Diptrace drawing... 

Mark, thanks for the kind words above. Asking questions is my strong point, the rest not so much. 

Looks like I may now have one of each type. Good thing I ordered extra parts! 

RTR, Congratulations on your good report from the cardiologist!!  Yes, I would say one year is a very good sign!!

Maybe I'll add a connection for a power switch as well.

rtr12 posted:

Stan,

Yes, I was planning to do some more fiddling and would be happy to add your ideas, but GRJ will probably have it done and posted by the time I finish writing this...  GRJ's design will probably be more compact and 'correct' as well.

I'm fast, but not that fast.   However, I think this is fast enough.  

Here's the "Stan0004" upgrade version.

• Two level detection and indication.
• Strain relief for battery connection.
• Provision for external power switch.
• Cap and diode to allow power from AC or DC sources.

Needless to say, the PCB got larger since this is an all thru-hole design, currently 1.15" x 2.35".  I thought about making it for 1/8W resistors except for the LED's, but decided to stick with what I have using the 1/4W parts.

TIU Signal Tester Rev. 1.1 Gerber.zip

GRJ, are you going to make anything available as a kit, like some of your earlier excellent kits?

Thanks, GRJ, that was plenty fast!  I was just fiddling with Stan's adds to the schematic, but not finished just yet.  Now I can see how I did for correctness. I hadn't thought of the diode and cap on the supply, probably would have thought of that unless you or Stan said something. Some added learning for me for next time. 

Glad you stayed with the 1/4W resistors, I have lots of those, 1/8W not too many (if any?). 

OSH Park says the PCB order has gone to the board maker, shouldn't be long now for Rev 1.0. Maybe sometime next week? 

Also, thanks Mark! 

RJR, if my parts are all correct and fit the PCBs I ordered, I will 'Share' the PCBs on OSH park and post a link here. I can also make a detailed parts list of what I ordered. I was hesitant to do that until I see if it all fits together and works correctly with my ordered parts. And also there were still discussions of added features going on with the first PCBs.

Then I will try the Rev. 1.1 project and do the same for it. 

Only thing I didn't order was the jumper for the power switch, I have a ton of those already, from years of fiddling with computers.

I guess I can go ahead and share the 1.0 boards now, I will just mark them Rev 1.0. I'll do that later today and report back.

I've been watching sense day one of the thread. This would indeed be a handy little devise if one has any doubt as to weather any of there channels is having an issue in regards to signal strength. I was all set to build Adrian's original version with GRJ's first OSH zip file but thought I'd wait in hopes the other electrical gizmo gurus would jump in a crank this thing up a couple of notches. Low and behold, BAM!

A kit would be nice. However, a zip file and a parts list would work for me thank you very much.

RJR posted:

GRJ, are you going to make anything available as a kit, like some of your earlier excellent kits?

I hadn't considered it, I was considering maybe just ordering a bunch of the blank boards and putting together a BOM for Digikey for all the parts so it would be easy for someone to build them. 

OSH Park wants $13.70 for an order of three of the 1.1 boards, so they're more than $4/ea.  I can get them for less than a buck if I order 100.  Of course, I have to be able to recoup my money for boards, so offering kits is always somewhat risky.

milwrd posted:

A kit would be nice. However, a zip file and a parts list would work for me thank you very much.

Ask and you shall receive.  I'd wait a day or so until Stan and Adrian "review" the schematic to see if I screwed something up.  it all "looks" good to me, I don't think I scrambled anything.

GRJ, I assume that if you made boards available and a BOM, that you'd be including a schematic so us neophytes could see where to place the components, and that it would be thru-hole so we needn't have surface mount skills???

RTR, I understand from my son just south of you that cold weather has struck your area---that it's below 90.  :-}

Obviously, there would be a schematic.   I could also actually put the component values right on the silkscreen of any production board, that's sometimes useful for hand built stuff.  This is all thru-hole construction, there are no significant size restraints, and all the components are "full sized".

What would be slick is a nice little box for it so it was a "finished" unit.

As for the weather, we had great weather for quite a stretch, in the 80's, low humidity, no rain, etc.  Now it's turning wet.

GRJ, the weather comment was for rtr.  He lives a few miles from my son out in Kansas.  I was talking to my son and he said it was the first sub-90 day since early June.

Let us know when you have a package ready for sale.  I would expect to order one.   

Yes, it was only 89 so far today! Been way too hot this year. Maybe even some low 80s later in the week too, finally!

As for the boards and parts, I will defer to GRJ on all that unless he wants me to do something.

I'll wait on GRJ for the OK to share them on OSH Park too, he did do all the heavy lifting as Stan said above. And GRJ, I agree that project box would be a nice touch for these.

Here's a little enhancement.  Before I make any "final" boards, I'll spin the Gerber files from this.  Should make it easy to figure out where the parts go.

If you're game for some minor mods:

Without increasing board size, I think you could add 1/8" mounting holes in diagonal corners as shown.  This would take #4 screws.  I like to mount tiny boards like this on a piece of acrylic so the nothing shorts out on the bottom of the board.  Example:

I'm not sure what everyone's plan is for connecting the TIU input wires, but perhaps a strain-relief hole is needed for those two wires too.

I think the components in the upper left can be moved down to make room for the mounting hole.  I note that your 3-D cap body looks much larger than the actual 0.2" lead-spacing component...where the leads are actually bent out to make them wider.  Point being there is more room available than the component outline suggests.

It looks like the 3-D rendering of the LEDs shows the flat-side on the left while the silkscreen shows the flat side on the right.  Trivial but for whatever reason caught my eye right away!

I'm not sure on what the call the 2 LEDs (weak, good, whatever).  But note that for a "good" signal, both L1 and L2 should blink.  For a "weak" signal, only L1 will blink.  The trigger voltage to the #1 half of the 123 chip gets the larger trigger voltage.  The schematic calls L1 "good" and L2 "weak".  

Good input, I stuck the "weak" and "good" in at the last minute, I'll have to go back and fix that.

Here's the "latest".   Let's see how close this is.

I added holes all over the place, changed the caps to .1 spacing as those are more common, not to mention smaller footprint.  Of course, I did change the LED colors, you were right.  I figure the power switch might just be a .1" jumper pair with a jumper on them, that's the simplest case.

TIU Signal Tester Rev. 1.1 Gerber.zip

Edited 7/22/18 at 22:00 to insert latest files and graphics.

Very nice John!  I'm sold on the "no go - weak - good" model!!  I'll add to my Digikey cart tomorrow.

I have just been watching and holding off for now.

I still want to say thanks to all involved in developing this for their work.

I like to see things move forward and eliminate any guesswork. I am a big MTH fan and have met and heard from people who are not.

I have been blessed overall with well performing DCS equipment. I don't believe I put it under extra undo stress! I always thought 2 rail would have worse shorts then 3 rail would. Just something I stumbled on and kept in the back of my mind. Probably is not correct but was something I heard in the wind....

Note that I changed the spacing on the caps to the .1" ones.  As it turns out, I have a ton of those anyway.   Got lots of 1/4W resistors as well.   I'll add the current Gerber files to the previous post as well.

Link to post with current files: TIU SIgnal Tester Rev. 1.1 Build Files.

I'll try these at OSH Park again. If you are going to go with the kits, I will just leave the OSH Park ones un-shared. If you don't want to do the kits, let me know and I will share them if you want so others will have them available. 

If you do the kits I will order one myself, just to compare parts, boards, etc. to see if I am close. I think there will be some takers for the kits.

Thanks again for all the design work! I am still fiddling with Diptrace, but I have a long way to go before mine looks anything like yours does!

Thanks to all, Adrain, GRJ, Stan, and everyone else!  

GRJ, I like your jumper switch too, Diptrace and Digikey were not cooperating at all with me on a slide switch. 

I thought about a slide switch, but then I figured that was another unique part that I might not be able to find.

I'll probably use SEEED Studio to get ten boards as they'll be as cheap as three from OSH Park.  I'd like to actually build one of these and make sure it works as expected before I turn it loose on the public.

If you share stuff on OSH Park, you really need documentation as well as the boards.  Stuff like the BOM, schematic, assembly notes, etc.  Otherwise, it's not very useful for folks that find it there.

I'm still not happy with the LED situation.  

Per the schematic, the 2 cathodes (pin 1) are connected together.  For virtually all LEDs, the flat-side of the body is the cathode.  On the PCB drawing, the square-pads (presumably pin 1) are indeed connected together... yet the flat side of the LED silkscreen is on the right side? 

As for the on-off "switch" presumably you are assuming someone is using a 1-cent shunt to install on the 2-pin header.  I'm sure there are many variants but you can also get 2-pin switches that have similarly narrow profiles in the same footprint.  

Next thing you know the peanut gallery will be demanding an LED to indicate power is on!  

GRJ, I will just wait on the sharing. If someone wants one from OSH Park it is very easy to order there with your posted Gerber files. Then there is the Documentation, probably not something I could explain? If you go with the kits that will be a much better setup for those wanting one anyway (that part probably also being slightly over my head, then there is the docs thing again). I'll stick with the Diptrace struggle for now. 

Stan, I have a bin full of those jumpers for the on/off headers, but I do like those little switches.  Not sure I have seen those before? I may just go have a look for some. Maybe I can finally one up Diptrace here (since GRJ already has the pins selected)...I have extra LEDs as well, just in case the need arises! 

Stan, that's the pattern that they have for a 5mm LED in DipTrace, I'll check and see if they're backwards.  If so, I'll make my own pattern with the correct footprint.   I actually rotated the 3D part to match the silkscreen, I guess that may be a mistake!

I never saw that switch before, that drops right into the spot for the jumper!   Where did you see those?  Got a source?

Believe it or not, I thought of a power LED, but since this was battery powered, I decided that was overkill.

OK, found the issue I think.  They have both flavors in the library for LED's, don't know why they have a reversed image one, but I changed them for "standard" LED's.  I'm going to update the build files "again", but I'd wait a day or two before actually using them in case we find something else.

Link to post with current files: TIU SIgnal Tester Rev. 1.1 Build Files.

No source for that switch - one of those parts in the stash that I've had since the last century.  I'd think it would be easy to find but then again, Nothing is so easy as the job you imagine someone else doing.

Regarding the power LED:  the LM340 standby (quiescent) current is about 3 mA typical...so a 9V battery would only last a few days if left "on" inadvertently.  While a power LED would also draw a few mA, presumably it might catch one's attention at the end of the day reminding to turn it off and save the battery.  A tradeoff for sure.  Of course if track-powered using your optional power method, the LED power is not an issue.  Matters of this significance are above my pay grade. 

Stan, I looked around for a switch like that, and I'll be darned if I can find anything like it.  It's a slick idea, too bad it's not obvious how to find it again!

A power LED with a big resistor might make sense, make it only draw a mil or two, you don't have to have them smokin' hot to indicate power.

How about the S-812C50AY-B2-U regulator, 500na quiescent power.  Only 16V input voltage, but it sure doesn't waste power.   99 cents at Digikey.

I was looking for those switches too, same results as GRJ, nothing found so far. And I agree, it is a very neat little switch!

I found some that were sort of similar, but they were all momentary, tactile or whatever they call them. Morse code to your Arduino maybe? 

I suspect it is nowhere as popular as a slide switch with 0.1" lead spacing such as - about a dime in modest quantity:

I suppose you could whack off the 3rd pin for use as a basic 2-pin OFF-ON SPST switch assuming there's space for the body.  The somewhat annoying aspect of the previous 2-pin switch is you must lift the actuator to turn off.  It is not spring-loaded for push-on-push-off action.

After some web searching, I found it interesting that hobby and Robotics related sites "get it" and sell these switches (and only a few other types) making a point of the 0.1" lead spacing - perfect for DIY prototyping boards with the 0.1" grid hole pattern.  You go to DigiKey and hunt around forever trying to narrow down the thousands of choices.  

gunrunnerjohn posted:

...

A power LED with a big resistor might make sense, make it only draw a mil or two, you don't have to have them smokin' hot to indicate power.

How about the S-812C50AY-B2-U regulator, 500na quiescent power.  Only 16V input voltage, but it sure doesn't waste power.   99 cents at Digikey.

Not sure about the 16V limit.  I figure in this specific application some guys might hook the tester to AC track voltage which of course would be 18V command-voltage since this is for TIU testing!

If it were up to me (which it is not!), I would forego the AC option (9V battery only)…and use the real-estate and cost savings from the large electrolytic and diode for an on/off slide-switch and a resistor and power LED (1 mA).

I may be able to squeeze in the a switch of some kind, I just wanted a readily available switch that was cheap.  If I could use surface mount, I could squeeze a lot more in!

If someone doesn't want AC capability, they can just omit the parts and run a wire.

Here's the latest build.  I updated the previous post with all the build files, link below.  This adds Stan's power switch and the 1ma power indicator, it's the blue LED.  I also shrunk the LED's to 3mm LED's no reason to make them king sized for such a small board.

I think we have reached critical mass, if I want to put more on it, I suspect it's time to to to 1/8W resistors.

Link to post with current build files: TIU Signal Tester Rev. 1.1 Build Files

So for a summary of your device John, are you anticipating this is attached to TIU all the time?  Or just for testing?  What are the Voltages that light the LEDs from the TIU DCS output?  Thanks, G

George, it's only for testing the TIU, not for permanent connection.  The one downside of this design approach is due to the parts used (cheap was a primary goal), you have to calibrate each unit using the pot on the board.  That being the case, I'll probably just calibrate mine using my 'scope for around 11 volts P-T-P for the "good" signal.  The "bad" signal ends up being approx. 50% of the amplitude of the "good" signal, in this case around 5.5 volts P-T-P.  If you have a known good TIU, you can simply use the good channel as a standard and calibrate so that the good channel indicates a good signal.  In my mind the "bad" signal is primarily to tell you that the TIU is putting out some signal, but appears to have a weak channel.  I envision the unit to be calibrated to really require the "good" signal to consider the TIU channel to be fully functional.

The usage is to simply power up the TIU, and connect voltage to the input of the channel being tested, and the tester to the output of the channel.  Power up the tester and check the lights, job done.

I'll be generating a BOM for the parts in the near future, so many projects, so little time.

Regarding the AC-power version.  I realize this measures the DCS amplitude with no load on the TIU output except the tester itself (or an oscilloscope).  That said, since the tester is such a minimal load, is there any chance it can be powered by the TIU output itself?

That would make for a simple 2-wire connection.  I'm imagining the temptation will be great to see how the LEDs blink at various points on a large layout (no trains, just the track).  Not clear where you'd get the AC power in such a situation.  But then, ironically, the tester would need a 22uH choke!  

I suppose, since you are having to power the TIU channel to initially generate the DCS signal that you could just connect the power to the DCS output.  As you say, adding a choke would be the only requirement.

That thought never occurred to me, but it seems it should work.  In that case, you wouldn't need the power switch or the extra set of pins for the power.  It appears that just adding a choke to the input and sending the TIU channel 60hz through the existing rectifier and filter would be all that's required.  Since you're powering the channel, you have gobs of 60hz power available, no need to worry about what you're using.

gunrunnerjohn posted:

Here's the latest build.  I updated the previous post with all the build files, link below.  This adds Stan's power switch and the 1ma power indicator, it's the blue LED.  I also shrunk the LED's to 3mm LED's no reason to make them king sized for such a small board.

I think we have reached critical mass, if I want to put more on it, I suspect it's time to to to 1/8W resistors.

Link to post with current build files: TIU Signal Tester Rev. 1.1 Build Files

I think I know where the post is with the latest design files, but I could also have lost my way?   Now the 'New Linky No Worky' at least not for me.    However, if the link goes to the last post with an upgrade, which I think it does, I think I got it!  

You guys go way too fast for me, by the time I partially figure out the latest changes you are at least a board design or two ahead of me.

Any chance you guys could type a bit slower... 

I agree, they move too fast for me.  That is good!!!  I’m just waiting until the dust settles, or as John said the feature creep runs itself out!

Carry on men,  I’m glad to see progress.  The place I am spending what I think will be the last months of a career in electronics isn’t like this.  Everyone talks about doing things, but progress moves at a snail’s pace!  LOL

Sit tight for a few days, the landscape is changing.   I like the self-powered idea, glad Stan thought of that.  I don't see how it should affect the DCS signal in any way, and it really simplifies the usage of the tester.  I'm still looking at it an making "tweaks".  For one, it occurred to me that the .5" spacing for a 1/4w resistor was generous, they fit just fine in .4" spacing, so I adjusted the layout to accommodate them.  This makes it easier to fit stuff on.

Here's a shot of what I have right now, the LED's are now 3mm units, and the resistors and diodes are all .4" spacing.  It's not quite so crowded now, though the board is getting full.  Thru-hole stuff takes a lot more real estate than surface mount, this would be on a board half this size or less.

I kept the board at the same size as before so far.

Question:  If no track power is being applied to a TIU input, and a remote button is pressed, will the TIU (assuming powered thru AUX) send out a signal?

Phrased otherwise, if (IF) the signal generator is powered by the AUX rather than track power, why wouldn't it send a signal? 

As long as we're dreaming, why not have packaging in the form factor of 3 rail track.  You could just set the tester on the track anywhere you want and measure signal strength.

Track power MUST be provided to the channel under test or it won't generate the DCS signal.  If you're seeing the DCS signal on a TIU output, that channel is powered.

GRJ, yes I get that.  Isn't the issue in part DCS signal strength ?  Power on the track makes the tester work.  Seems like you could measure signal strength anywhere the tester is located.  What am I not understanding ?  Seems like it's important to know the strength of the signal the engine is receiving ?

Steve, you're trying to do a lot more than this was designed to do.  This tester was a simple answer to the question of testing the signal strength out of the TIU channels as there are faults that reduce the signal strength from an individual channel while still producing some DCS signal.  You're really looking for a much more sophisticated solution to measure exact signal strength.  A multitude of factors influence the track signal available on the track at various locations.

I have such a device, it's called an oscilloscope.   This tool is not intended to replace such a device.

Yes, I realize there is a degree of design creep.  I was rather fond of your 4 led approach.  Don't really need an exact measurement.  Just, seems like it would be nice to help differentiate DCS signal degradation's between TIU output, track sections, etc.   Simple tool, for most users.  No need to reply.  Just an idea.

We're already had a lot of design creep, remember the original idea?

Then there's where we are currently!

gunrunnerjohn posted:

We're already had a lot of design creep, remember the original idea?

Then there's where we are currently!

That's not design creep John.  That's iterative improvement!

Maybe iterative design creep improvement?

Mark, I agree, I do like the 'feature creeps' proceeding quickly! I just get lost easily.   I guess I will join you in awaiting the dust making it's way to where ever it's going...Then try to catch up. 

We are in good hands with the designers at work here!

GRJ, maybe a dumb idea here, but would you consider leaving Gerbers posted for the other designs as they have progressed? Might be neat to have a variety of designs for folks to choose from?

Not suggesting they would all be supported, and one could not expect a kit of any model they chose. For use only if someone wants one of the other designs...of course they would be on their own to create it from what has been posted. I'm certainly not wanting to create a problem for anyone with this suggestion. 

Actually, I don't keep copies of old versions unless they're a useful version.  In this case, I didn't keep any.  I'm actually going to try and experiment and see if I can get more boards for less money from SEEED.  I'm putting three copies on one panel and if I get ten panels, I'll get 30 boards when I cut them apart.  The only slight oddity is when I duplicate the design, I get different component ID's, but that's not really that significant.  Here's an example of what I mean.  I'll simply cut along the white lines to make three boards.

Ok, just thought it might be neat to have different designs. I have the first and maybe second or third and that is all, think I have two different files anyway. I have the originals still at OSHPark, boards are being fabbed now. Will be neat to compare the different versions, at least for me anyway. 

Three boards on one makes it cheaper I guess? I have gotten some ebay stuff that came as multiple boards that had to be separated for use after getting them. Must also be easier to assemble that way at the PCB builders/assemblers, I guess? Makes sense to do in quantity. Will be interesting to see the price differences too, I bet.

For SEEED Studio, they make ten boards for a fixed price, and they don't go by size.  I suspect if I sent them a huge board it would be different, but I got ten of my TMCC Buffer Boards for around $13, the composite size is very similar to three of these.  That being the case, I'd have thirty of these for around $13, not a bad price.

All of my stuff gets panelized at the PCB house, when I get them they're in panels.  It greatly increased productivity of the placement of parts as they don't have to do as many board changes to run production.  Mine are small runs, for really large runs, the boards can be 18" on a side, they're huge!

Here's a few examples of my stuff when I get it.

Super Chuffers

LED Lighting Regulators

Chuff Generators

This up to date PCB planning and buying is an education in and of itself.

Hi John: Three questions.....    DCS-TIU Port Tester Tool

(1)  Can this test be done on the layout, clip the alligator clips to the track? 

(2)  What information will I receive by doing this test, and how will I apply this information?

(3) I used to like to built Heathkit projects, they are a Michigan Company and they are still in business but not like their golden days.  My first project was a single channel transmitter and receiver for a RC Airplanes.  (1968) • I even did the color TV with a friend in the 70's.

With this being said:  If you can put this project into bag, with the directions and all the parts, I would be interested in building  this new item? If you have plans to do this I would purchase this kit. Is this part of the big plan?  (Right Price)

Gary

Mark Boyce posted:

This up to date PCB planning and buying is an education in and of itself.

Absolutely!  I am curious how the boards are cut apart for the first 2 units shown.  The Chuff Generator seems easier since it has nice gaps between the boards, but the first 2 look pretty well packed with components that would be a high risk of damage when separating.  (I assume there is some specialized tool made to do exactly this and I just don't have a clue what it looks like)

-Dave

trainroomgary posted:

Hi John: Three questions.....    DCS-TIU Port Tester Tool

(1)  Can this test be done on the layout, clip the alligator clips to the track? 

(2)  What information will I receive by doing this test, and how will I apply this information?

(3) I used to like to built Heathkit projects, they are a Michigan Company and they are still in business but not like their golden days.  My first project was a single channel transmitter and receiver for a RC Airplanes.  (1968) • I even did the color TV with a friend in the 70's.

With this being said:  If you can put this project into bag, with the directions and all the parts, I would be interested in building  this new item? If you have plans to do this I would purchase this kit. Is this part of the big plan?  (Right Price)

Gary

Gary, this is really a tool to test the TIU channel without a layout in the mix.  It would take a more sophisticated tool to actually test with the layout and wiring in the picture as well.

You just get a go/no-go indication as to the channel's signal strength.  If you get only the red light, the channel is weak, if you get both, the channel is normal.  If you get neither, either there's no DCS signal or you have something connected and/or configured wrong.

Currently, I'm not planning on a kit, though I may make the PCB available for a good price.  Shipping will probably cost as much as the board, or more.

Dave45681 posted:

Mark Boyce posted:

This up to date PCB planning and buying is an education in and of itself.

Absolutely!  I am curious how the boards are cut apart for the first 2 units shown.  The Chuff Generator seems easier since it has nice gaps between the boards, but the first 2 look pretty well packed with components that would be a high risk of damage when separating.  (I assume there is some specialized tool made to do exactly this and I just don't have a clue what it looks like)

-Dave

Dave, the boards are V-Scored to make separation possible.  You just break them apart at the separation line.

Hi John, 

Is it too soon to take an order for one of your DCS-TIU Port Tester Tools?

     Steam Forever

            John

I am amazed at the progress. . . .still waiting for the dust to settle!

me too.    I want one! 

I don't really have to have it, but I want it.

Warm up your soldering irons.

GRJ, that SEEED pricing is quite good! I'd have to go back and look but I think you posted that one of the later PCB designs at OSHPark was $13 and something for 3. That is a big reduction, 30 PCBs for $13.   I doubt that I will ever be needing that many, but it's good to know anyway.

The Asian ones I got were about the size of your lighting boards in the pic above. I think it was the small DC-DC regulators. I can see where combining the PCBs like that would make things much easier to create and populate. 

Soldering iron is sitting in it's stand idling and ready to go! Now, I just have to figure out how to set them up after making them...I think Adrian or maybe it was you posted something earlier about that. Maybe a thread re-read is in order soon. 

The setup is pretty simple, you have one adjustment.  I'll be doing mine with a signal generator and a 'scope.  However, failing that equipment, connect to a good TIU channel all set up to get,and then "tune" the pot to turn on both lights.  You'll probably want a "tiny" bit more toward the lights on to compensate for small variations in the outputs, but not enough to let a bad TIU pass as good.

I was hoping to hear from Adrian and Stan on the "final" version to see if we've missed anything before I go to press on a bunch of PCB's.

Thanks, I think I can handle that. I have one TIU channel (Var 2) that has never been used, so that should be a good one, I hope.

I imagine Adrian and Stan will be along before too long. It's always good to have them (as Stan described the process above) look at things before production. I have noticed it's really difficult to get something past Stan! (He must get up really early! ) Also, I really like all your cooperative design projects, very interesting and informative to follow along with. Especially for a rookie greenhorn like me!

The back and forth works out well, what one person misses, the other one catches. 

rtr12 posted:

GRJ, that SEEED pricing is quite good! I'd have to go back and look but I think you posted that one of the later PCB designs at OSHPark was $13 and something for 3. That is a big reduction, 30 PCBs for $13.   I doubt that I will ever be needing that many, but it's good to know anyway.

Well, it wasn't quite that good a deal.   Turns out, they take exception to multiple designs on one panel, so I couldn't do my trick of having three on one "board".  Also, since ten of these boards exceed the maximum first class shipping weight, the freight is more as well.

Still a lot better deal than the $13 for three of them.

Still not bad and better than the other place. Looks like the shipping really went up. And I agree, 2 (or 3) heads is always good!  

The latest incarnation hasn't wandered too far from Adrian's original design.  As I look at the latest schematic I believe you can even implement his exact original circuit by selectively populating the board with the original parts.  The modified version does add a half-dozen or so line-items but it still looks to me like $10 or so in parts.

Some of the components are needed in quantity 1 whereas even at DigiKey you can save quite a bit per unit by going to quantity 10.

Adrian shows a red-black pair of alligator-clips to attach to the TIU output jacks.  Obviously they don't have to be red and black, but try finding "just" 2 alligator-clips leads.  Or maybe everyone already has these clips lying around.  At DigiKey it looks like you buy a set of 10 double-ended cables for about $3... of which you only need half of a red and half of a black.

https://www.digikey.com/produc...1568-1582-ND/7056460

My guess is most guys would prefer a built-and-tested version...rather than firing-up the soldering iron, ordering DigiKey components, ordering bare circuit board(s) from OSH Park / SEEED, etc..   I might have missed it in the conversation but has anyone stepped up to providing completed units...or if not then at least a kit of parts?  

Are you suggesting alligator clips just to keep the cost lower?

Since the TIU has banana jacks built in, and this project is intended to just test at the TIU itself, I'd be inclined to put banana plugs on the end intended to mate to the TIU posts.  Just the plugs seem to be about a buck a piece.  Using a pre made test lead would raise the cost of the project significantly though, I guess (well, maybe $5 per lead - not expensive, but double the $10 we started with )

-Dave

stan2004 posted:

My guess is most guys would prefer a built-and-tested version...rather than firing-up the soldering iron, ordering DigiKey components, ordering bare circuit board(s) from OSH Park / SEEED, etc..   I might have missed it in the conversation but has anyone stepped up to providing completed units...or if not then at least a kit of parts? 

You're right, most of the folks probably do want a completed unit.  That was my experience with several other projects, I started them out to be kits, and almost everyone wanted assembled and tested.  I may consider doing a kit of parts, but I'm not willing this time to have to put it together.  Perhaps we can recruit someone else to build them.   They're fairly easy as they're all thru-hole.

I'll probably buy ten sets of parts for the ten boards I'm getting.  Actually, I really only need the HCT123's, and the 2K pot, I think I have all the resistors, caps, and diodes in quantity anyway.  I know I have a ton of 22uh chokes left over from a quantity buy for another project.  LED's?  Tons of them.

FWIW, I agree with the dual banana plug, or at least individual banana plugs.  No sense in using alligator clips, they're not nearly as easy to use.  Now that it's just one connection to the TIU channel, it'll be a quick PnP test setup. 

I think the alligator clip leads are cheaper than a couple of good banana plugs by themselves. I think Stan's linked set of alligator clips are less than a pair of the banana plugs I have been using, which are heavy duty and fit tightly in the jacks. They don't loosen up like many of them do these days.

I have alligator jumpers, and was originally thinking of just cutting a red/black pair in half as Stan says above. The banana plugs sound like a good idea too (hadn't thought of that) and I also have plenty of those on hand.  

The thing about alligator clips is the small one Stan illustrates don't clip will the the posts on the TIU.  I have a bunch of similar ones, and they don't work well with that style of post, they keep popping off.

GRJ, let me see how I do on mine? If all goes well, I might consider building some if there are not too many orders for them. I like the kit idea myself, but my direction writing would probably be a major disaster. They would all be throwing shoes at me!

Maybe a small quantity of assembled units and a kit option would work? Hopefully more kits than assemblies.  

I like bananas, coconuts, and grapes!

Yes, I’ll do banana plugs.

gunrunnerjohn posted:

Track power MUST be provided to the channel under test or it won't generate the DCS signal.  If you're seeing the DCS signal on a TIU output, that channel is powered.

Actually if you have voltage on the aux power in, and no channel power the packet still comes out... I figured this out like a day ago.

gunrunnerjohn posted:

stan2004 posted:

My guess is most guys would prefer a built-and-tested version...rather than firing-up the soldering iron, ordering DigiKey components, ordering bare circuit board(s) from OSH Park / SEEED, etc..   I might have missed it in the conversation but has anyone stepped up to providing completed units...or if not then at least a kit of parts? 

You're right, most of the folks probably do want a completed unit.  That was my experience with several other projects, I started them out to be kits, and almost everyone wanted assembled and tested.  I may consider doing a kit of parts, but I'm not willing this time to have to put it together.  Perhaps we can recruit someone else to build them.   They're fairly easy as they're all thru-hole.

I'll probably buy ten sets of parts for the ten boards I'm getting.  Actually, I really only need the HCT123's, and the 2K pot, I think I have all the resistors, caps, and diodes in quantity anyway.  I know I have a ton of 22uh chokes left over from a quantity buy for another project.  LED's?  Tons of them.

FWIW, I agree with the dual banana plug, or at least individual banana plugs.  No sense in using alligator clips, they're not nearly as easy to use.  Now that it's just one connection to the TIU channel, it'll be a quick PnP test setup. 

Ive updated the title of the forum thread accordingly based on all the design progress...

gunrunnerjohn posted:

The thing about alligator clips is the small one Stan illustrates don't clip will the the posts on the TIU.  I have a bunch of similar ones, and they don't work well with that style of post, they keep popping off.

Well, for less than $1 shipped (from Asia) you can choose your poison!    This pair has bananas on one side and alligators on the other.

I have no problems making a firm, solid contact using the alligator style to the TIU jacks.  Additionally, though not the intended application, you can easily attach alligators to the track which would be quite the hat-trick with banana plugs.  

The key is the strain-relief hole to loop the red/black wires thru so that the soldered-wire connections don't fatigue/fail over time.

And if you don't mind waiting for shipping from Asia, what appears to be the same set of 10 double-ended alligator cables is available for about 1/2 the price on eBay.

Adrian! posted:

gunrunnerjohn posted:

Track power MUST be provided to the channel under test or it won't generate the DCS signal.  If you're seeing the DCS signal on a TIU output, that channel is powered.

Actually if you have voltage on the aux power in, and no channel power the packet still comes out... I figured this out like a day ago.

Isn't that the definition of passive mode?

Chris Lord posted:

Adrian! posted:

gunrunnerjohn posted:

Track power MUST be provided to the channel under test or it won't generate the DCS signal.  If you're seeing the DCS signal on a TIU output, that channel is powered.

Actually if you have voltage on the aux power in, and no channel power the packet still comes out... I figured this out like a day ago.

Isn't that the definition of passive mode?

Sort of.  The channel will output a WD signal only when power is first applied to a channel, and not again until a power cycle on that channel.  Truthfully, I never checked to see if the signal was coming out with just aux power, but it's an interesting tidbit.

FWIW, the tester should work exactly the same, connect to the port and you'll see a signal.  The filter allows the DCS signal to pass, so it's pretty much transparent whether there is 60hz to filter or not.

Obviously banana jacks can't connect to the track.   Considering the discussion that resulted when that topic came up a few times earlier in the thread, I considered that a benefit rather than a hindrance. 

If one can't easily attach the probes to the track, one is less likely to try to use it that way and then wonder why the results aren't what's expected.

I used regular Digikey prices when suggesting what the jacks would add.  I didn't try to go to eBay for direct from Asia pricing or anything like that.

-Dave

You'll note that all my BOM stuff is Digikey, but I don't get all the stuff from them.  I typically buy some stuff in bulk from other on-line sources, eBay, AliExpress, etc.  The nice thing about specifying Digikey components is you can get a full spec sheet and know what to substitute from other sources if you desire.

John:

Like many others, I have been watching this thread and enjoying the discussion.  Please count me in for a kit, bare board, completed unit or whatever you decide to make available.  Setup for testing of DCS signal output on customer TIU's has been time consuming and inconvenient.

Thanks to all the electronics gurus for all the time you put in here.

Long time, no talk Pat.   I'll keep you in mind. 

John,

I'm interested in a kit or preferably a completed unit as well.

      Brad

The long wait is over, I finally got the 10 boards from SEEED Studio.

Here's the tester after I put it together, one small glitch in the layout, I got the pot backwards.  Didn't have one to look at and thought the legs went the other way.  Still works, you just have to adjust it from across the board.

I connected it to a TIU and fired it up.  It calibrated just fine, so I think it's probably doing it's intended purpose.  I have to do some more testing with various signal levels to see how it reacts, but it seems to function as expected.  I didn't have the 330 ohm resistors for the LED's, but it's perfectly happy with 470 ohm resistors.  The large leads go to the TIU, the board is powered through the TIU, so that's the only connection required.

When can I get one John? Make sure I'm on the list for one. Could also use it at The N.J. Hi- Railers, besides for my own use.

    Steam Forever

           John

Looks great, John!!

I'm in.  A TIU just came in over the weekend the guy wants me to check out.

Take my money!

Jim

"RED"   "GREEN"  on the silkscreen that's funny.  looks great though. Hope it works well.

Great work John. Hope you'll bring some to York.

Slow down guys.  

My contribution to this effort was to lay out the board and build a prototype for testing.  I don't have the time right now with all my other projects to actually produce these.  However, I will make the board layout files, schematic, and BOM available when I get them all gathered up in a coherent form.  I'll also make the DIPTRACE files available in case anyone wants to "improve" the design.   You can work on this board with the free version of DIPTRACE, so no cost to tinker.  All the parts are commonly available, so there should be no issue in putting these together.

Perhaps someone else would like to pick up the baton and build some of these?

I like the red boards, yours looks neat and works. Much more colorful too!

I got my order from OSHPark, the v1.0 boards, assembled one of them and so far no worky? I haven't tried to see what's wrong yet, but upon examination nothing appears to be out of place? Or maybe my TIU is not performing properly, but I have only tried one channel so far.

I did manage to goof up my capacitor order, I got some funny looking tantalums instead of the ceramic I thought I had selected? Oh well, I still have 2 more boards to play with and I do have some ceramic caps around here somewhere. 

I still want one of your current versions though, and I'll be watching for the updated Diptrace files to order from.

Thanks again for doing all this GRJ, it's really a big help for us (me anyway) still trying to learn! 

Edit: If I figure out how to make one work and then am able to test them somehow, I would be willing to try and make a few for some of the other forum members.

I'll turn the pot around in the design files and then post the whole package.  They are easy to assemble, they're all thru-hole parts.  If you pick up the parts in quantity, they're also pretty cheap, even from Digikey.

Here are the design files for the TIU Signal Tester.  Included are the Gerber files for PCB fabrication, the Diptrace files to tinker with the design, and the BOM for ordering parts.  There are several other ZIP files in the overall ZIP file, the Diptrace files and the Gerber files are all separated out.  I did flip the pot around in this design as it was backwards in my original boards.

TIU Signal Tester Design Files.zip

You don't have to use the exact parts I used, they're all sourced at Digikey.  Most of the parts are very generic, and for any kind of quantity, you can probably find cheap eBay parts.  However, the BOM does give you industry standard parts and specs so you know what to look for.  Even sourcing them from Digikey, they'd be pretty cheap.  Stuff like the 2K pot will probably want to be the exact part as it fits the PCB footprint.  Have fun!

John, Thank you very much!  I will see how it goes!

Have fun!

Yes, thanks GRJ!  Think I'll try out the SEEED place this time and see what happens. I take it that is where you got the red ones? I like those! 

Digikey is fine by me for parts, I like them too. Good place and fast shipping.

Yep, you can specify any color for the solder mask, I thought the red might be a nice change.