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chadbag

JNSF DIY lighting project (PCB based)

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chadbag
40 minutes ago, Ochanomizu said:

How long does it take you to build one board?

 

I need to do some better tests.  My last one was much quicker than previous ones.   

 

A few boards ago I did one in 50 min.  But I had to go look for each separate component, took some pictures, etc.    I will be doing 3 more for my Tomix Hikari Rail Star 700 set and will time them.  I will pre-gather the components, and concentrate.   I think they will be much faster than the one I did time at 50 min.  I am hoping to be able to do one in 15-20 min.  Maybe 4 an hour.

 

These are the steps:

 

#1 gather the components

#2 apply solder to the pads

#3 place components

#4 put on the hot plate and let solder melt

#5 fix anything that shifted (if you have too much solder paste it tends to "boil" a little as it melts and some components can shift.  With a hot air rework solder station they are easy to fix.  I usually have to fix 1-4 items.

#6 quickly check for shorts with a meter and then test with power (I use alligator clips hooked to DCC track that is powered)

 

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chadbag
23 hours ago, cteno4 said:

Cool. Yep 1.7v less to drop with the dimming resistor. Caps should last longer as well if on the outside of the voltage regulator.

 

same voltage drop on the rectifier with the two different limit voltages.

 

I knew the dimming resistor would not be the same as on the 5V regulator but I started there to create a base line.   Today I mounted the board in the Tomix 700 wagon and it is slightly dimmer than the dim version of the cab car with 0805 sized LEDs.   And now that dimmer look is growing on me though when the room is lit, it is hard to tell the lights are on.  When the room is dark you see it a bit better.   (Both light levels look fine and even the "bright" on does not look that bright to me in real life (compared to some of the factory light boards).

 

The 0805 sized LEDs have 2.2k dimming resistor in the less-bright version with a 5V regulator.   The 1206 sized LEDs with the 3.3V regulator and 1.2k dimming resistor is slightly less bright but somewhat comparable.  I will try a 1k on the next 3.3v board I do (for the same Shinkansen).  We'll see how that works out.

 

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chadbag
1 hour ago, Ochanomizu said:

How long does it take you to build one board?

 

I just did a board with 12 LEDs in 18 min to ready to test on the DCC track, 19 minutes including testing on the track.  I skipped the test with the meter but I did a visual inspection and got rid of any excess solder balls that can form.  I did not pre-heat my hot pad so that took an extra minute or two to warm up and there were a few areas I could probably improve on, so I think 15 min is very doable.  Not counting the gathering of the components (as you can do that for a lot of boards up front and the net effect per board is then minimal).

 

One thing I did on this board which I had not done previously was to use a lot less solder pastre.  I got a narrower tip for my paste syringe and just put small dabs on (which waspossible with the smaller tip).  This caused only 1 cap to slide a bit when heated so I only had to fix one component.   The other boards I had to fix 3-5 plus some LEDs needed to be pushed flat.  So that saved time to use minimal paste which resulted in fewer (in this case just one) components moving out of place.

 

 

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chadbag

Here is the layout for the V2 board -- Release 1.   I have tested this with discrete parts on a breadboard, but without the zener diode.  I need to test it with that to make sure I did that part right.

 

The V2 circuit is similar to the V1 except the voltage regulator is moved to be fed from the energy capacitors instead of feeding into the caps.  Also, instead of space for 9 energy caps, including one space for a tantalum, there is space for 21 ceramic (0805  or 1206).  You don't need to fill all the spaces.  Just leave blank the ones you don't need.  This allows you to use relatively low capacity caps and still get a large enough amount of capacitance to work how we need it.

 

Fits up to 14 LEDs.  The last 7 should be easily removable so you can make a short board if you need it up to the max length.  LED spacing is 10mm.  Can use 0805 or 1206 size.

 

I removed the option for the large L7805CV voltage regulator (the large one with the big heat sink and 3 long pins coming out).  It will work with the AMD1117 or also a smaller one (I forget the name and package number but will look it up).    The AMS1117 series of voltage regulators is however the best choice as they work fine, are relatively small, and are dirt cheap.

 

You can skip putting a rectifier on if you want to feed it directly from the outputs of a DCC decoder (and there are separate pads for that).  However, I've been putting the rectifier on and just putting the output of the DCC decoder into the rectifier, the same as track power.  

 

This should work with DC, DCC track power, or DCC decoder output.

 

Optionally you can install 1x2 of the 2.54mm pin header thingies (say the female side) and put the mail side on the end of you track wire so that you can remove the top shell of your wagon and disconnect it easily.

 

Layout-V2-v0.2.pdf

 

 

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Ochanomizu

Hello Mr chadbag,

 

Thank you for reporting the time to assemble a board.  I doubt I'd be as efficient as you.  I remain interested in fully completed, tested boards. Have you advanced that option with a supplier at all?

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chadbag
7 hours ago, Ochanomizu said:

Thank you for reporting the time to assemble a board.  I doubt I'd be as efficient as you.  I remain interested in fully completed, tested boards. Have you advanced that option with a supplier at all?

 

Hi.  I have not yet gone past looking at the website you sent and seeing what I need to do to get a quote.  I decided to not worry about it until the V2 boards are done and we have a good list of components that work with it well.    I would then redesign the board just for those components.   Then we can take it to the supplier you mentioned and get a quote on it.

 

I do think you could assemble at least 3 boards an hour with a little practice.  My first one was probably more than an hour.  My third one about 50 min.  My last one was 19 min including track testing.  I plan on shaving a few more minutes off that.   (With a stencil [should be easy to make] you can easily shave 2 or 3 min off -- allows you to more easily apply the paste).

 

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chadbag
Posted (edited)

Just noticed an issue where I did not swap pins on the SOT-223 voltage regulator for AMS1117 compatibility.  The AMS117 uses the same package as some other voltage regulators but has a different pinout.  Updated layout:

 

Layout-V2-v0.2-R2.pdf

Edited by chadbag

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chadbag

I mocked up the circuit on a breadboard including zener diode and realized I had left off a resistor.  So attached is a modified V2 PCB layout.

 

I also made a new PCB layout of a reduced version of the V2 circuit, without any LEDs, which is made to overlay an LED strip (like the 5V and 12V strips you can buy.  (I measured it roughly against my 5V strips I bought -- I need to measure it against my 12V strips as it would be nice to work with both).   This is for those wagons where the normal lightboard is not a good fit for some reason but you can stick a few LEDs from a strip in.  I will be making another variant of this one that is made to attach to "factory" lights.

 

Layout-V2-v0.2-R3.pdf

 

 

Layout-Strips-V2-v0.1-R1.pdf

 

 

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chadbag

I've ordered some PCBs to test V2 circuit, as well as 2 aux designs for driving factory lights and LED strips.  Probably about 1.5 to 2 weeks.

 

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chadbag
Posted (edited)

The V2 boards came today (about 15 min ago).  If people want some to play with and test/use, let me know.  The V2 board is 60 cents (each) and the V2 strip or V2 factory board is 30 cents (each).  V1 boards can also be had for 60 cents each.   Shipping is additional and is whatever it costs me to mail them to you.  If you need components let me know.

 

(The V1 board and V2 board are similar but the difference is where the voltage regulator is and so the length of the anti-flicker capacitor circuit).  I am using the V1 boards mostly in my Tomix trains that have all train power pickups.

 

Once I test the boards I will be able to start shipping.

 

The V2 board is the full board with LEDs and the complete circuit (on the left below).  The V2 factory board (middle in black below) is the circuit but no LEDs and is meant to connect to factory lighting that does not have it's own anti-flicker circuitry (think simple KATO or Tomix factory lighting).  The V2 Strip board is meant to be used with the LED strip stuff you can buy for 12V or 5V use and can cut to the desired length.  (The board should work with either 12V or 5V strips, but I have not tested it -- you will just use a different resistor in the "dimming" resistor location).

 

 

IMG_1063.thumb.jpg.1ba254e18b8a56b11aaaf17e3d727548.jpgIMG_1065.thumb.jpg.e75b3a0083a1a48ff5f7d838e786dcde.jpg

Edited by chadbag

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gavino200

I'll sign up for a hundred or so of the V2 strips and maybe a bunch of the 'V2 for strip' units (right). Unfortunately it'll be a while before I can play with them as everything I own is packed up.

 

Will there be another chance to get more in the future?

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chadbag
2 hours ago, gavino200 said:

I'll sign up for a hundred or so of the V2 strips and maybe a bunch of the 'V2 for strip' units (right). Unfortunately it'll be a while before I can play with them as everything I own is packed up.

 

Will there be another chance to get more in the future?

 

This first batch I just had 100 made.  The idea is, whoever is interested in testing them could get 10 or 20 or 30 or whatever and use them.  Once we all (who are interested) had tested and used them, we would see how many everyone wanted and I would do a large order (1000 ?) which should make the per-unit cost be much less.

 

I will also make the gerber file available (the file you upload to the manufacturer).  Once we have tested, and I have written up a user doc on what components should go where etc, I'll make the file available.  So that those who want to have their own made can do so.   Though it will be cheaper, at least at the start, for us to pool whatever we want for boards, into a larger order in order to drive the per unit cost down.  The "factory" and "strips" version are specialty ones and probably not ones we need to make more batches of.  I have an E26 Cassiopeia set I bought used that has very flickery factory lights in that I want to retrofit with boards, and I have enough factory lighting sets for 3 or 4 trains (KATO and Tomix) that I want to use.   I also have a few rolls of the strip LEDs to use up.   

 

Personally I will use the V1 boards I have on my Tomix trains, V2 boards on the rest of my trains, plus the factory as strip as I mentioned.  I probably have a few hundred wagons worth between my Euro and Japanese trains, EMUs, DMUs, Shinkansen, etc.

 

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chadbag

Here is a  pic of the V1 (blue) and V2 (white) boards.  The V2 is narrower overall but the bit on the left is slightly wider than the V1, but does not have the wide flair on the very left like the V1 and the skinny part is much narrower.

 

IMG_1068.thumb.jpg.bf42a260392372828dfc2b2e14671168.jpg

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Martijn Meerts

I wouldn't mind a bunch of these for testing. Not sure for which train yet, so not sure how many, but I'd say at least 8 so I can test them in for example the full Rheingold set (including current pickup cups and current conducting couplers)

 

Would be great if you could also add the components to build 1 of them at least, from there I can check if I can find the components myself, which is more difficult in the Netherlands than it should be really.

 

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gavino200
Posted (edited)
19 hours ago, chadbag said:

 

I will also make the gerber file available (the file you upload to the manufacturer). 

 

 

Chad, I'd suggest you might want to think about not doing that. The project has been a bit of a crowd source. But I don't think anyone would disagree that this file is your baby. It's intellectual property with potential value. You could probably sell these things on a website. 

 

Of course I wouldn't say no to a special JNS rate. But I don't think you need be more selfless than that.

Edited by gavino200
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chadbag

It's ok.  I've even marked (had printed in the silk screen layer) that the board is public domain.  I won't be releasing the design files used in the editor, just the files necessary to make your own.  Anyone who wants to take it to that level -- ordering using the file from a contract manufacturer -- is welcome to.

 

I will be selling them on my blog as I will have extras left I am sure, and I have a Square account, and they have a facility (at least did) free webshops for their users,  and will "inflate" the price to a normal retail price, but I am not in business to sell these.   I have other opportunities worth more per hour 🙂

 

Plus I am sure there are much more efficient circuits that I don't understand 🙂  (in fact I have one from someone I showed this to that he claims does a similar thing but I don't yet understand it so went with what I understood and know how to manipulate and change).

 

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chadbag

I was finally able to take some time to assemble a V2 board (it's been a busy week) (with 12 of 14 LED slots used).   I used all 21 capacitor positions as a test (you can leave ones you don't need empty).   I used a bunch of low capacity capacitors and only had a nominal 367 uF and it wasn't enough.  I added 300 uF more and it was OK.  I think 700-800 uF with 12 LEDs will work ok for momentary anti flicker. Using fewer LEDs means you need fewer capacitors.

 

I used a 5V regulator and only 1.2k ohm dimming resistor (as I am experimenting with this new circuit).  I need to test it for brightness but I will probably be making it more dim (which should increase the length of the anti dimming capacity).

 

But the board works.  So that is good.

 

Here is a picture of it lit up.  This is without the extra capacitance I added (as I just used some big electrolytic ones as a test).  For some reason my hot air rework station would not power up so I just used my iron to fix one bad solder joint on a resistor and to add the big capacitors to test with.

 

IMG_1078.thumb.jpg.fe484ad52a55bfa8840a67f5dd10e658.jpg

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chadbag

I figured out what was wrong with my hot air rework station.  The cheap chinese fuse holder self destructed.  I have some more cheap ones on order from Amazon.  Once I get it up and running again I'll work out some good values and writeup documentation on the board and what goes where.  The various pads are labeled but the labels are small and sometimes hard to read.

 

I also will get the two other boards -- the strip and factory ones -- tested.    Then I can start shipping out boards to those who want them.  So send me a personal message if you want boards and how many (in the low 10s of boards as I have a 100 of each right now).

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chadbag

Update:  I got the fuse holder for the rework station but have not had a chance to fix it yet.  We are planning to build a house next year and I am working on some plans for the architect to base his work on and have not had a chance to get to it.

 

Once I get my test board updated with better values and write up a small instruction sheet on what to put where I will arrange to ship boards to those who have requested some.   There are still boards available for anyone who wants some as well.

 

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chadbag

Just an update for all those following these, and especially for those who wants some of the boards.

 

Real life* has gotten in the way and I am a bit behind.  I need to test some more values to have some suggested values for things.   And do a small write up.  Then I will be able to send boards to those who want them as well as make the files available, etc.

 

 

* day job deadlines and also needing to get some stuff done for the house we are building next year (architect, ball park cost estimates, planning, etc)

 

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