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Trying to match an old terminal block

Discussion in 'General Electronics Discussion' started by sbhenkel, Mar 3, 2020.

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  1. sbhenkel

    sbhenkel

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    Mar 3, 2020
    I have some old terminal blocks that my dad left before he passed away. I am uneducated when it comes to the specifications of terminal blocks but they are 12 position blocks and they about 9 inches long each. What is the specification that would determine the length of the blocks? When going on the internet to try and find some replacements, the only 12 position blocks I can find are all about 5 inches long. Is there a type or specification that I could add to my search criteria to try and get results closer to what I'm looking for or are they not even made any more?
     
  2. dave9

    dave9

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    I'd guess nothing that big is made any more, but you could include a picture in case anyone has some of those or knows more.
     
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  3. sbhenkel

    sbhenkel

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    I can't seem to figure out how to upload a picture. The picture is on my PC but when I click on the "image" icon it wants me to put in a URL. The "Upload a File" button goes through the motions of uploading but then says "there was a problem uploading your file". Is there a Help area where I can go to learn what I'm doing wrong so I don't have to waste everyone's time on my learning?
     
  4. hevans1944

    hevans1944 Hop - AC8NS

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    Since the new owners took over the site, it has become more difficult to upload pictures, especially pictures with a large number of pixels. It seems the "optimum" size is something about 100,000 pixels or less in size. The question then is what software do you use to decimate your photo to fit within the optimum size limit? I usually use Microsoft Paint, but there is plenty of image editing software out there, some of it still free, that will do the job. Be sure to save your edited image with a different filename than the original, just in case you need to edit the original again.

    If you already have an image that meets the size criterion, just copy it to the Clipboard in Windows (type <ctrl> C) and then insert it somewhere in your text message (type <ctrl> V). Sometimes the Electronics Point forum software will ask whether you want a "thumbnail" or a "full size" image inserted in your post. I almost always choose to insert the full size image so the reader doesn't have to jump through yet another hoop just to view my uploaded image.

    PDF (Postscript Documentation Format) files are another animal entirely. If they are small enough, they can be inserted in-line using the copy-and-paste procedure described above. Or you can insert them as attachments, which I don't like. My version of Windows 10 will open a new window for attached PDF files, but then it calls my Adobe Acrobat application to display them. There is nothing in the opened window, and I have to remember to close it, lest it use up precious dynamically allocated memory.

    As for terminal blocks, or barrier terminal blocks, these come in a HUGE range of sizes and styles. Visit this link for some images and links to sources. If what you have is a screw-terminal (as opposed to a solder-terminal) block, these are often specified by the screw size or wire gauge used to secure forked or ring terminals attached to wires. Center-to-center spacing (pitch) of the screws is another common parameter that you could also search against.

    Because of the way terminal blocks are manufactured, lengths vary widely. I often scrounge terminal blocks with more terminals than I need, and then use a hack-saw to shorten them to lengths containing two more terminals than needed. The two unneeded end terminals are then drilled out (after removing their screws of course) and the now-empty holes on the end are used to mount the terminal strip to a chassis or breadboard or whatever.
     
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  5. Harald Kapp

    Harald Kapp Moderator Moderator

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    That is usually the case if the file size is too big. Keep each image under 100 kB, that usually works.
    You can also drag and drop images directly into the editor window - as long as they are under 100 kB each.
     
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  6. Harald Kapp

    Harald Kapp Moderator Moderator

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    @hevans1944 : Hop. you post from 5:47 shows to us mods as "deleted due to duplicate post in this thread". However, I do not see any duplicate, so your post doesn't show at all. Is that intended?
     
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  7. Bluejets

    Bluejets

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    You will find terminal strips are "sized" by their current rating rather than how long they might be.
    Current rating directly affects the size of the tunnels etc.
    As already stated, show a photo and perhaps some reference size such as a ruler close by the tunnels.
     
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  8. 73's de Edd

    73's de Edd

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    To me . . . .With that large dimension of overall length . . . . is being highly suggestive of a JONES barrier type of strip.

    Take yer pick . . . . 1,878plus . . . . (limit 6 ea per customer)

    https://tinyurl.com/snkflb8
     
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  9. hevans1944

    hevans1944 Hop - AC8NS

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    No, it is not what I intended, but I don't know what happened. There were two versions of the post I was trying to make, one being an earlier draft version than the other. I have no idea why two versions appeared. I tried to delete only the earlier draft version but both versions disappeared. I guess I will have to start saving my drafts periodically on the Windows clipboard, or maybe in a file, so I can restore them when they "disappear." The forum software pops up a statement periodically that says "Draft saved" but I don't know how to retrieve whatever it "saved." This is may be a "feature" reserved for moderator use.

    Anyhoo... @Harald Kapp's reply in post #4 covered in two succinct sentences what usually takes me a couple paragraphs to say. I don't think further elaboration on my part about image uploading is necessary, unless the OP asks for more "clarification." My now invisible post went on to provide a Google link, derived from the search string "barrier terminal blocks," which may or may not have been helpful. As you know, terminal blocks come in a huge range of sizes and configurations. I also stated that barrier terminal strips are identified by the "pitch" or center-to-center spacing of the terminal screws, along with (sometimes) the wire gauge sizes the strip accommodates using fork or ring terminals attached to the wire.

    There are so many variables to consider, but a picture from the OP would help to narrow the field.
     
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  10. Harald Kapp

    Harald Kapp Moderator Moderator

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  11. sbhenkel

    sbhenkel

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    I was wondering if there was some kind of size restriction. Here's the picture I hope it helps. The block is home and I'm at work right now. If you need more measurements, I'll have to do it when I get home. upload_2020-3-4_14-37-49.jpeg
     
  12. bertus

    bertus Moderator

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    Attached Files:

    Last edited: Mar 4, 2020
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  13. Bluejets

    Bluejets

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    I would not be considering using that particular strip anytime soon on mains level voltages.
    An important factor in a terminal stip is it's insulation properties and that old piece looks to be bakolite impregnated with dust and rust and general crud making it unusable.
    The rust factor would make for bad connections.
    As far as original current and voltage rating, there is usually some marking cast into the piece, perhaps on the underside.
     
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  14. hevans1944

    hevans1944 Hop - AC8NS

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    Excellent photo! It appears that the spacing (pitch) between terminals is about 0.75 inches, but you would need to actually measure that with a pair of calipers. I could not find a barrier strip with that terminal spacing, and the mounting bosses on each end are somewhat unique. However, this Digi-Key web page has hundreds (or thousands, depending on which parametric filters you apply) of barrier terminal strips, one of which is quite similar to the one in your photograph.

    Is it really necessary that you find an exact duplicate for the strip your father left you? Would a functionally equivalent strip be okay? What are you going to DO with these strips, assuming you can find them somewhere?
     
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  15. Bluejets

    Bluejets

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  16. shrtrnd

    shrtrnd

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    Looks like your dad salvaged them from someplace. There's a lot of helpful information in the posts above here.
    When I see one of these barrier strips, I look them over very carefully in trying to identify them. Often, if they are quality
    strips, the manufacturer will mark them with their name, or a company logo, and hopefully a series number. Did you look for
    any marking on the strips, to try to identify exactly who made them and what they might be?
     
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  17. sbhenkel

    sbhenkel

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    Wow! You guys are good! I apparently picked the right forum. You guys seem to know this stuff in your sleep. My dad used to repair x-ray machines and had a very good working knowledge of electricity which rubbed off a little on me. He's gone now so I'm not sure how he acquired these blocks, but he had an eye for those kinds of things that were going to get discarded and could maybe be used for some little project at home.

    No, it's not super critical that I match these. I did look into the Bussmann TB400-12 like someone above suggested. The best price I could find so far was about $23.00 each. My application is hardly high-tech or high-voltage for that matter. I'm getting back into my HO slot car hobby after a 2-3 decade lapse. I'm building a big table and was going to use these as power taps under the table at multiple locations. I liked the larger ones just simply because they gave me more room in between connections and I thought there might be more leeway on the gauge of wire I use. I know I will probably end up using ring terminal wire connectors, I just have to decide on which gauge wire to use. It's going to be anywhere from 18 to 24 volts DC with a fuse of probably just a few amps.

    I also saw the Ebay listing link that someone found above. It's amazing what you can find if you use the right terminology. I simply looked for "terminal block" and got back something that was real expensive and not what I wanted.

    Tonight I will take a look on the back side for any markings like you suggested. That was kind of a Duhhh moment. I should have done that first. Thank you again for sharing your knowledge.
     
  18. Bluejets

    Bluejets

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    I've used these Ebay type many times and found them to be rather good quality considering "made in China".
     
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  19. sbhenkel

    sbhenkel

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    Mar 3, 2020
    I tend to overthink things. I guess that's what makes me good at my job. In life, however, I tend to overlook the simple solutions. Someone in the group suggested looking on the back of the terminal block (duhhhh) to find identifying information. I'll try to insert the pictures of what I found below. There wasn't much, but what I did see was very familiar. What I saw was the Westinghouse emblem, the underlined "W" with a circle around it. I remembered that 50 years ago or so my dad worked for Westinghouse and also repaired Westinghouse xray machines. So I simply went back to the internet and put in "Westinghouse terminal block". I looked at the resulting images and saw something that looked strangely familiar. https://www.electronicsurplus.com/westinghouse-542247-terminal-block-12-x-2.

    It's virtually identical. Mine even has a place for that center strip although the center strip is long gone. Best of all the price is a lot more reasonable than the $23.00 I saw for the Bussmann substitute.

    Here's what's on the back on mine.
    IMG_9092(Edited).jpg IMG_9094(Edited).jpg
     

    Attached Files:

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