LK&O

A Railroad with Relevance

Hello world!

Written By: Alan - Mar• 31•10

Thanks to my great friend and all things Internet whiz kid Greg, I now have a place to share my experiences while enjoying the world’s greatest hobby – model railroading. This is going to be so cool!

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18 Comments

  1. Bill Orr says:

    You are too hip…..wish I had something of value to add….know very little about mdoel trains….

    Hey, you need to follow Tim’s lead and have an Acoat Bodyshop in one of the villages that your train passes through….

  2. Dan says:

    I am not sure this is the place but here goes.

    I have commented on your pages about the single push button control for Tortoise machines and received some good answers.

    However, there seems to be a few updates. I have been trying to put together a spreadsheet with the items that I need to replicate your “invention”. Is there one place on your site that I can go and get the latest component list and supplier?

    I believe you mentioned in one article that the Latching Relay was cheaper from Arrow Electronics but there was no part number and I can find it. The ones at digi-key are 4.67 qty 1 and 2.83 qty 100.

    In another update your provided the part number for the circuit board from MCM Electronics. Yet I just read that you have given up on the circuit board with some later enhancements.

    So now I don’t know “who’s on first”.

    How can I reach you to get specifics or where do I need to go on your site to find the definitive answer to the control?

    Thank you (or anyone) for any help you might provide!

  3. alan says:

    Hi Dan,

    Yeah, a blog is not ideal for documenting technical projects. The date sequenced flow of posts makes it hard to know “who’s on first”. I really should create separate pages for some of the LK&O gadgets. But for now you need answers.

    Here is the post you need: http://www.lkorailroad.com/tortoise-printed-circuit-boards/ This post describes the units in use on my railroad. They work well BTW.

    The schematic is latest version and a link to etching mask art is provided.

    The schematic has Digi-Key and Mouser part numbers on it although the only part you really need a part number for is the relay. For the rest of the pieces any component will do.

    Note: The switchstand LED must be in the circuit. Doesn’t matter where you place the LED. I happen to use it for switchstands hence the schematic labeling. The panel led is optional and the circuit works fine without it.

    The relay is TE Connectivity #V23079B1203B301.

    Arrow, Digi-Key, and Mouser are all over 4 bucks each at the moment. Electronics prices are like oil. You have to check every day.

    I see Allied has them for $2.89 ea.
    http://www.alliedelec.com/te-connectivity-v23079b1203b301/70346463/

    Online Components has them for $2.01 ea.
    http://www.onlinecomponents.com/te-connectivity-p-b-brand-v23079b1203b301.html?p=12116708

    I have dealt with both of these companies in the past. They are reputable.

    I get my UV circuit board material from Circuit Specialists. The brand is MG Chemicals. You can find their stuff everywhere even on eBay and Amazon. Availability of MG Chemicals products can be sketchy so I am not so much a price shopper as I am an availability shopper. Circuit Specialists has been the most reliable in-stock so I use them.
    https://www.circuitspecialists.com/printed-circuit-board-fabrication

    Let me know if you have further questions.

  4. alan says:

    Dan, my first reply contains a misleading statement. It is not important there is a switchstand LED in the circuit. It is important the path (wire) it is in be in the circuit. You don’t necessarily have to put a LED in the path.

    As the schematic is drawn there is both a reason for and a critical difference between the switchstand LED indication and the panel LED indication:

    The switchstand LED changes color only after the Tortoise has completed movement. The panel LED changes color as soon as the button is pressed.

    I did this for a reason. The panel LED visually confirms I pushed the panel button enough to make contact. The switchstand LED visually confirms the turnout is fully thrown.

  5. Dan says:

    Thank you. I will attempt digest your very thorough answer.

  6. Dan says:

    I watched the etching video. Looks like a challenge for me. But ??? Looks like you gave me everything I need to know. I do like the price from Online Components!!

    Thank you so much!
    Dan

  7. alan says:

    Give the etching process a try. Once you do it you will realize how easy it is.

    I use an old fashioned 5W incandescent nightlight to light the area now instead of working in the dark. It is so low wattage it doesn’t give off any UV. And I can see what I am doing.

    Use an old picture frame and its glass to hold the mask on the PCB. Masking tape everything in place.

    Plastic kitty litter pans make great developer and etch pans. I set the bottle of etch in the kitchen sink full of hot water an hour before I begin to warm it up so it works faster.

    A 23 watt CFL bulb (100W equiv) in a table lamp makes a great UV source. Hold it 10″ above the mask for 8-10 minutes.

    Put the board in the developer until you see the circuit appear (about 5 minutes). Rinse with water and put the board in the etch. Slosh the etch back and forth until excess copper is gone (about 20 minutes). Rinse with water.

    Only thing to watch for is don’t let the etch get on anything. It stains just about everything. Use an old plastic bucket full of water for the etch board rinse to keep from staining your sink.

    After you have done it once you will have no fears making more boards.

  8. Dan says:

    Thanks Alan,
    I am going for it.

    One more question perhaps not the last is, I have the PDF of the etching mask. Sometimes getting to the printer causes some differences in size. Do you and could you provide the actual size of one of the PC Boards?

    The 8×12 boards are back order, so I was going to see what I might do with a 6×9 board. So the actual size is important, I think.

    I will attempt to convert the PDF to a JPG and then stuff a bunch into a word document with an area laid out that will end up being 6×9, using the margin settings.

    Thanks again for you help!!!

  9. Dan says:

    OOPS!, I just went back through the info and find they are 1×1.75 in. That should be what I need.

  10. alan says:

    Don’t convert the PDF to JPEG. That will fuzz the line edges. The mask files on the site (PDF, AI, EPS) are vector art. JPEG is raster. You definitely want to print from vector.

    Here, I laid out the masks for you on 6×9 in a PDF.
    http://www.lkorailroad.com/aeb/6×9.pdf

    Place the ink side against the PCB when exposing.

    Each individual mask is nominally 1.75″ x 1″.
    Actual is 1.7505″ x 1.0002″.

  11. alan says:

    Here is a file that will help guide you in wiring the PCB to the Tortoise motor.

    http://www.lkorailroad.com/aeb/tortoise%20control.pdf

  12. Dan says:

    Looks like I can get 21 on a 6×9 board. Actually with some modifications I was able to get 23 on one 6×9.

  13. Dan says:

    You are so fast to respond. I will use your PDF file. Thank you so much. I just finished ordering parts. Next is the boards. In the etching video then show two different solutions but when I was on the MG site they made it look like there was just one chemical???

    Thanks as always!

  14. Dan says:

    Just looked at the mask you laid out. WONDERFUL!!! Watch out … I am off and running …

  15. Alan says:

    You will need Positive Developer and Ferric Chloride etch.

    Developer is mixed 1 pt developer to 10 parts water.

    Etch is used as packaged. Warm it up some. Save etch for later projects.

  16. Alan says:

    Some printers may not print totally opaque black. I print 3 transparencies and stack them using scotch tape on the edges to hold them in alignment.
    If UV gets through the black ink then the developer will wash away your circuit.

  17. Dan Foltz says:

    I have everything I need but have yet to take the plunge. I will use the three transparency idea to be sure to get a good opaque mask.

    One “final” question. If I want two panel LEDs, one for each track after the switch, what do I need to change in the schematic and components (other that get more LEDs)?

    Thanks as always. I just looked at your Module 13. Your wiring and component layout is just plain awesome!!!! Do you want to come for a visit and work on mine?????

  18. alan says:

    Just get more LEDs! Put the two LEDs in series. No other parts needed. If you reverse bias one LED (short lead of LED1 hooked to long lead of LED2) then the LEDs will always be opposite color of one another. You must use 2-lead bi-color LEDs in this arrangement. 3-lead bi-color LEDs won’t work in this schematic.

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