How critical is it that lead spacing matches the board?

Discussion in 'DIY' started by z-adamson, Jun 14, 2018 at 5:53 PM.

  1. z-adamson

    z-adamson AK Subscriber Subscriber

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    I am replacing some aluminum electrolytic capacitors, filter caps to be exact, and they are the solder-down type.

    They measure 82mm tall, 41mm diameter and the lead spacing is 25mm.

    I cant find an exact match in lead spacing which means I will have to bend the leads to get them into the board to solder them down and the body of the cap will basically be "floating" and I don't really like the idea of all that weight of the floating cap pushing and pulling on the leads. If would be great if the body of the cap was up against the board and glued down to keep from stressing the leads and solder pads.

    Hmmm, what to do.
     

     

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  2. petehall347

    petehall347 the brandy coffee man Subscriber

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    is there enough copper to drill a hole ?
     
  3. z-adamson

    z-adamson AK Subscriber Subscriber

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    Maybe.

    I will look into that.

    Great idea by the way. I have never drilled a PCB and the idea of doing so is a bit scary however (I don't want to screw this up).
     
  4. petehall347

    petehall347 the brandy coffee man Subscriber

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    1mm bit works for most things
     
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  5. sKiZo

    sKiZo Hates received: 8641 Subscriber

    Spot of hot glue on the board between the leads does the trick. Stuff's non conductive, so just press the cap into place before the glue sets.
     
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  6. z-adamson

    z-adamson AK Subscriber Subscriber

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    Due to the lead spacing of the caps not matching the holes in the board, the air space between the caps and the board will be too much for a spot of glue to be effective. I would have to glue a spacer to the board then glue the caps to a spacer.
     

     

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  7. bberkom

    bberkom AK Subscriber Subscriber

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    Drilling a pcb is not very difficult, and I’ve done it a few times installing filter caps with different lead spacing. Use the slower speed setting on your drill and let the bit do the work without applying much pressure. You may have to scrape off some mask to create a new solder pad around the new hole, and some flux will help the solder take to the new area.
     
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  8. elnaldo

    elnaldo Addicted Member

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    I drill the PCB if the capacitor is large (even used a small flat screw driver). With small caps bending the leads is ok.

    Anyway I'd expect such a large cap (40mm diameter) to be "snap in" type, not leads.
     
  9. z-adamson

    z-adamson AK Subscriber Subscriber

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    Definitely leads.

    They have 5 leads. One for +, one for -, the other three for support. Sadly, I can't find anything like this.
     
  10. ghazzer

    ghazzer Sansui addict Subscriber

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    You should be able to bend the leads flat to the bottom of the cap, over to the hole(s), then 90° to go thru the PCB. Then a few dabs of hot glue should work nicely.

    A reverse layout of the pins might help you determine the bends that will work.
     
  11. OMGCat!

    OMGCat! AK Subscriber Subscriber

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    What are the values of the caps? Cornell makes some caps in a 5 lead 22.5mm spacing. I just put some 10kuf/100v filters in an SU-V8 and they matched the originals perfectly.
     
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  12. z-adamson

    z-adamson AK Subscriber Subscriber

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    Do you have the part number for that cap?

    10,000uf, 80v is what I need.
     
  13. z-adamson

    z-adamson AK Subscriber Subscriber

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    I just cruised mouser and digikey. A search for everything Cornell makes in a 10kuf cap at 80v and 100v yielded nothing but screw and snap in.

    I would be very interested in using what you used. I could use some help finding them though as my search came up empty.
     
  14. OMGCat!

    OMGCat! AK Subscriber Subscriber

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    I am at work but I'll get you the PNs when I get home this afternoon.
     
  15. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    https://www.mouser.de/ProductDetail...GAEpiMZZMtZ1n0r9vR22RSFeKT/CuZ6%2bTXe5TLUhmE=

    United Chemi-Con KMH. 10000µF/80v 105°, 5 pin w 25mm spacing, in stock at Mouser at the moment. What's not to like?

    When I can't find something that fits exactly I use 1.5mm solid core wire to make a leg extension and then find a 4 or 5mm thick rubber o-ring of the correct diameter and glue it to the bottom of the cap to act as a spacer.

    With small caps the thing is not to bend the leads more than ca 15° at the base of the cap to avoid breaking the base seal. Instead bend the leads a few mm below the cap base, out and then down to fit.

    Cheers,
    James
     
  16. z-adamson

    z-adamson AK Subscriber Subscriber

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    Description.....

    Aluminum Electrolytic Capacitors - Snap In 10KUF 80V

    Data sheet says the same thing....snap in. NOT leaded. How is this a 5pin solder lead capacitor? What am I missing?
     

     

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  17. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    And yet, that's what I ordered...

    DSC05501.jpg DSC05502.jpg DSC05503.jpg

    ...and if you look at Mouser's page for that part it shows 25mm lead spacing, which is what I got. I realize that it looks implausible considering the data sheet but the photos show what I did in fact receive through that link. They also show "snap-in" for all of the 5 lead KMH parts that they sell. Confusing yes, but I did get the 25mm 5-lead parts.

    Cheers,
    James
     
  18. z-adamson

    z-adamson AK Subscriber Subscriber

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    I am definitely intrigued. I need to install these caps onto the "component" side of the board and solder down to the "solder" side of the board. I don't know if those snap in leads can be soldered down on this particular fashion. What I had in mind is something like this with 5 leads rather than 3 and 80v rather than 25 (see pic).
     

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  19. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

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    OK. One last try before I give up.

    The caps that I linked to are suitable for use in power supplies. In spite of what Mouser states they have straight small tab leads and are not snap-in. They are soldered the same way as any other through hole lead cap. They have a 25mm spacing between + and -. I just used a set of dial calipers and measured a through hole lead width of 1.5mm.

    If the caps that you are talking about are for a PSU, have 5 leads, and have 25mm lead spacing between + and -, and the pcb holes are the usual 1.6mm then the caps that I linked to will work. The photos show what the caps look like. The tabs/leads shown in the photos are only bent a small amount because that's what it took to reduce the spacing to 22.5mm for my amp. I don't know what else to say.

    Cheers,
    James
     
  20. z-adamson

    z-adamson AK Subscriber Subscriber

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    Thanks!
     

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