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What does the bottom symbol mean on this capacitor? (the "U<" marking)

curious capacitor

Am I correct reading:

B = +- 0.1% tolerance

222K = 222000pF or 222nF

1KV = rated for 1000V

Was unable to find any 1KV's on mouser or digikey with that tolerance so am assuming I'm reading it incorrectly.

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2 Answers 2

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Not sure what the B is.. maybe someone else knows. Similar letters appear on capacitors from various manufacturers so perhaps they are aping the markings of a well-known supplier.

222 is 2200 pF or 2.2nF. 22 for value followed by 2 zeroes.

K is the tolerance code (+/-10%) according to JIS

1kV is the voltage rating.

This value and voltage rating of capacitor is typically used in X or Y applications (across or from mains to ground), however properly certified products will have parts festooned with safety agency marks.

The bottom marking is probably a manufacturer's logo or initials of their name. There are many, many such manufacturers. I don't think it's directly relevant to the ratings.

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    \$\begingroup\$ Thanks! Especially helpful to know the K is a tolerance code. \$\endgroup\$
    – Bob Levy
    Aug 20, 2022 at 13:49
  • \$\begingroup\$ Of course, if the part is counterfeit, then whatever safety agency marks it has are likely fake as well. Counterfeiters have a wide variety of skill, with some being professionally indistinguishable from the real thing...until it kills a product...or people. \$\endgroup\$
    – AaronD
    Aug 21, 2022 at 1:34
  • \$\begingroup\$ @SpehroPefhany I only mentioned it because you mentioned the marks. As long as counterfeiting is a significant problem, no mark can be trusted on its own. How good is your supply chain, and how well do you know that? \$\endgroup\$
    – AaronD
    Aug 21, 2022 at 3:58
  • \$\begingroup\$ So what does that U< mean? \$\endgroup\$ Aug 21, 2022 at 6:21
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    \$\begingroup\$ @aconcernedcitizen The bottom marking is probably a manufacturer's logo or initials of their name. There are many, many such manufacturers. I don't think it's directly relevant to the ratings. \$\endgroup\$ Aug 21, 2022 at 13:25
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I would say that this is a varistor:

varistor photo

Photo source: https://commons.wikimedia.org/wiki/File:Varistor_S14K385_photo.jpg

Michael Schmid, CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons

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    \$\begingroup\$ While they do look similar (there are technological reasons for this similarity), the markings on the element in the OP are consistent with capacitance and voltage rating. \$\endgroup\$
    – fraxinus
    Aug 20, 2022 at 22:28

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