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Help finding capacitor kit — Parallax Forums

Help finding capacitor kit

AwesomeCronkAwesomeCronk Posts: 1,055
edited 2019-12-29 22:14 in Accessories
I have a dilemma on my hands. I own zero capacitors and I cannot even use my ne555 timer due to this. So, I jump onto Amazon and look for a capacitor kit. I find electrolytic caps in the range I want (0.1uf to 100uf), but I cannot find the same for 3.3v-5v ceramic caps. I would like to get a kit of ceramic caps rather than electrolytic caps, due to the fact that electrolytic caps dry out. I require caps which will operate in the 3.3v to 5v range and are rated from 0.1uf to 100uf. Can anyone help in this endeavor?

Comments

  • Cluso99Cluso99 Posts: 18,069
    Ceramics (t/hole) are usually 50V. It's only the tiny 1nF=100uF that have smaller voltage ratings due to the size constraint. Even so, 16V and 25V are the more common ratings although the higher values 6V3 and 10V are quite common.

    You also need to read up on the ceramic types. 1pf-1nF are often disc ceramics in t/hole, although caps used in oscillator circuits tend to be NPO these days.

    For 100nF-10uF you should try and get MONO X7R or X5R ratings - definately not the cheaper Z5U.

    Disc ceramics are those round orange/brown ones and have gone out of favor, compared to the monolithics.

    I'll leave you to do the research why ;)
  • AwesomeCronkAwesomeCronk Posts: 1,055
    Okay, thank you. Curious, though, could I use the 16v caps in a 5v circuit? I would think the 16v is a max rating.
  • kwinnkwinn Posts: 8,697
    AwesomeCronk wrote: »
    Okay, thank you. Curious, though, could I use the 16v caps in a 5v circuit? I would think the 16v is a max rating.

    Yes, 16V caps work fine in a 5V circuit.
  • AwesomeCronkAwesomeCronk Posts: 1,055
    Thank you!
  • AwesomeCronkAwesomeCronk Posts: 1,055
    So, does anyone here know where I can source polypropylene film caps for 50 cents or less apiece? Specifically from 0.1uf to 100uf.
  • msrobotsmsrobots Posts: 3,709
    edited 2019-12-30 03:40
    I warn you before I say it, @rosco_pc did not warn me.

    You might buy things you did not really need, but...

    Anyways try https://www.banggood.com on your risk of your own sanity. Delivery takes a while but up to now I have no complains.

    Enjoy!

    Mike
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2019-12-30 04:27
    50 cent monster caps with an itty-bitty 5 cent 555?
    If you are going to use th caps then there is no reason not to use electrolytics for the 10uf up range because they work, they are cheap, and they don't just dry out unless you use them in power supply filtering with high ripple currents and too close to hot regulators. If you are that worried, which you shouldn't be, use tantalums instead but even PC motherboards use e-caps.
  • AwesomeCronkAwesomeCronk Posts: 1,055
    Thank you for that, Peter. I think I got bought with the big electrolytic capacitor scare that’s been going around. Everything I see emphasizes the dangers of them, and I wonder if maybe the articles I read weren’t funded by the fancy shmancy capacitor manufacturers.

    I’ll just get a kit of electrolytic caps. From what you guys say, they aren’t all that bad, so I’ll take it.
  • Peter JakackiPeter Jakacki Posts: 10,193
    AwesomeCronk wrote: »
    I think I got bought with the big electrolytic capacitor scare that’s been going around. Everything I see emphasizes the dangers of them, and I wonder if maybe the articles I read weren’t funded by the fancy shmancy capacitor manufacturers.

    That scare was going around well over a decade ago and only applied to manufacturers from a certain region. Seems if you are going to steal "the formula", you had better make sure it is the right formula for high ripple current e-caps :)

  • JRoarkJRoark Posts: 1,215
    edited 2019-12-30 17:04
    I restore vintage radios and computers when I have the time. Lots and lots of 35+ year old caps are still making flat lines out of squiggly ones. I fired-up an old S-100 system the other day. Everything on that backplane was electrolytic and circa 1982. Nothing smoked. And that old ferroresonant-based p/s with monster toilet-roll electrolytics was still pumping out wonderfully flat DC.

    Be not afraid of electrolytics. They may even outlast *you*! :)
  • AwesomeCronkAwesomeCronk Posts: 1,055
    Love the media! *sarcasm*

    Thank you for all of the input, everyone!
  • frank freedmanfrank freedman Posts: 1,983
    Unfortunately NVIDIA had some of those caps. A few years ago, while shutting down my main Linux station at the time, I heard a string of fire crackers. No big deal, it was the 4th of July after all. Next time power back, no video. Opened the box, lots of confetti...... Yes, that board was mentioned in one of the class actions, but was not worth the postage to get my $.50.
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