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0.5 uF 600 V dc or better UK capacitor source wanted.

Discussion in 'High Voltage' started by Analogue Robot, Apr 11, 2011.

  1. Analogue Robot

    Analogue Robot Member

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    Does anyone know where I can find 0.5 uF capacitors rated at 600 V dc or better in the UK, please? (Axial or radial, not surface mount).

    Tried Farnell: They have 0.47 uF at 1000 V.

    - Does anyone know of anywhere else?

    Analogue.
     
    Last edited: Apr 11, 2011
  2. Sceadwian

    Sceadwian Banned

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    Why is the specific value of .5uF critical? The .47 one should be fine, for the value, the rated precision will be a higher error value.
     
  3. Analogue Robot

    Analogue Robot Member

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    - Thanks for your reply.

    I realize that 0.47 uF should work, but many years ago I was able to find the precise value specified. The sources I was able to get them from back then either no longer exist or do not sell them anymore.

    I would just like to find out whether anyone knows where I could still get these high voltage capacitors which, in days of yore, were very easy for me to obtain.

    - Analogue.
     
  4. dave

    Dave New Member

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  5. Sceadwian

    Sceadwian Banned

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    There is no point of any kind in even looking, there is no reason for that specific a value, as I tried to explain the natural capacitance variation, and thermal drift of a capacitor of that nature are going to be higher than the difference in the stated value, they probably stopped making them because there was no need to make them anymore. Even a 10% manufacturing variance is more of a concern, the thermal variance I'm sure well surpasses that.
     
  6. Analogue Robot

    Analogue Robot Member

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    Thank you for your reply.

    1) As I explained in my response to you:

    I already realize that 0.47 uF can be substituted for 0.5 uF: If a capacitor has a nominal value of 0.5 uF and it has a tolerance of say 10% or 20%, the actual value of an individual capacitor of that type could be as low as 0.4 uF or as high as 0.6 uF with the latter tolerance and between 0.45 uF to 0.55 uF with the former. Since 0.47 uF lies within those bounds, reasonably, I would expect it to work.

    2) “There is no point of any kind in even looking…”, you write.

    - Respectfully, I disagree. Farnell in the UK even supplies a 0.47 uF 630 Volt capacitor. As far as the electronics goes, that will be fine, and the maximum voltage rating is even closer to that specified by the designer, (not that, under the circumstances, the maximum voltage rating is the problem). However, there exist two intractable difficulties:

    a) this capacitor is described thus: “U.S. stock: Delivery charge £15.95 once per order”. For a capacitor which costs only £2.37 (+ 20% Vat ) this seems quite an uneconomical proposition. Especially considering that I require only a couple of them now.

    b) Regardless of the U.S. stock delivery charge, Farnell UK also has a minimum order value of c. £30, below which a surcharge of c. £5 is made. Despite having nothing in particular against Farnell UK, I would rather not hand them £5 free of charge.

    Hence, to make the proposition viable in the financial sense, I would really rather wait until I have an order of at least £30 in which I could include the capacitors, either the 0.47 uF 1000 volt, or the 0.47 uF 630 volt. The latter, of course, attracting the U.S. stock delivery charge which would push the cost even higher.

    We may conclude, therefore, that there is certainly a “point” in looking: a source alternative to Farnell UK might provide these components without incurring a surcharge or demanding a minimum order value. - I could get them more quickly if all I need to pay for is the capacitors themselves and maybe a smaller delivery charge.

    Moreover, you may agree, it is seldom a bad thing to have greater choice among vendors…

    The third reason for looking is, of course, curiosity: I wonder if these things are still around.

    Thank you for your contribution.

    - Analogue.
     
    Last edited: Apr 13, 2011
  7. Sceadwian

    Sceadwian Banned

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    You didn't make the reason you were looking for an alternate supplier clear, your first and second post suggested that you thought you still needed the specific value and mentioned nothing whatsoever about shipping costs considerations. I can't read minds no matter how hard I try =)
     
  8. Analogue Robot

    Analogue Robot Member

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    Hello.

    Jumping to conclusions can certainly produce some unfortunate results. And I do agree mind reading is an activity best left to clairvoyants ;-). Thank you, once again.

    Returning the thread to its actual purpose; does anyone know where I can find a suitable capacitor? I already know about Farnell. - Is there anywhere else, please?

    - Analogue.
     
  9. geko

    geko Active Member

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  10. Analogue Robot

    Analogue Robot Member

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    Thanks, Pete: That's the sort of information I'm looking for. They both have a minimum order or surcharge, but at least I now have some alternative sources.

    - Analogue.
     
  11. Sceadwian

    Sceadwian Banned

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  12. Analogue Robot

    Analogue Robot Member

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    Thanks, Sceadwian. - Electronic Supplies in UK Net Guide appears a useful site.

    - Analogue.
     
  13. Sceadwian

    Sceadwian Banned

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    Glad I could be of assistance.
     
  14. Blueteeth

    Blueteeth Well-Known Member

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    Being in the UK, the standard places I order from are (generally in this order):
    Rapid | Distributors of electronic components, electrical products and educational supplies
    Farnell / Electronic Component Distributors / Suppliers / Electronics, Electrical Parts, Electrical Components and Wholesale Electronics. (you were right about the charge for US components, it can be annoying)
    RS Components | Electronic and Electrical Components
    eBay - one of the UK's largest shopping destinations

    Yep, you will be surprised at what you can get on ebay. No always ideal for continuous reliable sources, but some surplus sellers have literally thouands of a component in stock, and will probably happily offload as many or as few as you wish.

    Considering you are not bothered whether it is axial or radial, I suspect you are not after a true 'drop in replacement' part. So might I suggest paralleling caps for the correct capacitance? Or perhaps putting them in series for the correct voltage. (not always ideal).

    047uF @ 630V isn't all that rare at all - at least not in consumer goods (switch mode power supplies). Often though these are electrolytic, which perhaps you specified but I missed it. It owul dbe much more likley to find a polyester WIMA cap. Like this one:

    Rapid Electronics - Electronic Components

    For <1uF. Always search for nanofarads :)

    THeres no minimum order, but they do charge £4.95 delivery for orders under £20. Taht said, they do so much shouldn't be hard to make up a order of 'useful' parts.
     
  15. Analogue Robot

    Analogue Robot Member

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    Hello Blueteeth. - Just saw your reply.

    I've not used Rapid yet. - They look like a good outfit, but their search engine is rather odd: often throws up heaps of results frequently with scant connection to what I've sought. Or maybe I'm just not very good at putting myself into the frame of mind of whoever designed it... Thanks for the "nanofarads tip".

    I use Farnell frequently and can recommend them almost without reservation, but this time it just wasn't viable.

    RS - had a bad experience with them a few years ago and haven't bothered since then.

    Ebay - never bought any components from there, but as you say, probably worth checking from time-to-time.

    I also use Maplin for the easier to find stuff. - They're rather good for that, but I find these days the sales assistants aren't necessarily electronics enthusiasts / tinkers so they're not always as skilled at suggesting substitute parts as they used to be.

    I'd considered paralleling, as you mentioned, but I want a neater solution.

    Thanks for your help.

    - Analogue.
     
  16. Blueteeth

    Blueteeth Well-Known Member

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    I think rapid has become what Maplins used to be.... more components than cheap no-brand consumer goods. Although they are getting more and more computer and stationary supplies, they haven't reduced their component inventry, so its still my first port of call. Plus, for the most part, its a hell of a lot cheaper than farnell/RS, just doesn't have the same massive wide selection of specialist parts

    For passives/switches and basic semiconductors, maplins seems terribly expensive, with not much to offer, farnell seems almost 'overkill' (but ridiculously reliable), so Rapid fits right in the middle there.
     
  17. geko

    geko Active Member

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    Rapidonline are doing free delivery on orders over £10 ex VAT until 30/04/2011

    See attachement

    free-delivery-april-2011.gif
     
  18. Analogue Robot

    Analogue Robot Member

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    @blueteeth: Maplin certainly seem to be repositioning themselves in the market; their loss will be Rapid's gain. With the decline in popularity of experimenting / DIY electronics I expect there just isn't the commercial room for so many suppliers anymore.

    @geko: Thanks, Pete. - Rapid becomes ever more enticing...

    - Analogue.
     
  19. john1

    john1 Active Member

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    Hi,
    I have to post some words,
    or the machine will not accept it.
    So best of luck in your search.
    John :)
     

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  20. Analogue Robot

    Analogue Robot Member

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    Another useful source, this time based in the USA. - Thanks, John1.

    - Analogue.
     

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