EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: gregfox151@gmail.com on March 15, 2013, 01:53:31 am
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Resistor and capacitor values U.S. vs. Europe
For years I never had a problem reading Resistor, voltages, and capacitor values but now…
A schematic would have 22k and I would know it’s a 22,000 ohm, or a cap may be listed as 22uF (22 microfarad) no worries!
Would someone explain what is a;
2R 10n
22R 10n2
2R2 23f2
22R2 2v5 5v5 etc. etc?
Many thanks
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2R - 2 ohms
10n - 10nF
22R - 22 ohms
10n2 - Not sure - would need a photo
2R2 - 2.2 ohms
23f2 - if this is a super cap, 23 Farads 2v
22R2 - 22.2 ohms
2v5 - 2.5 volts
5v5 - 5.5 volts
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Thanks, helps alot! one or two more
2u2
100n
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Seriously? Look at the pattern. They're exactly like the others. 2u2 - The letter is used as a decimal point. 100n - there's no secret code here. It's 100 nF.
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There still is a "secret code" in some countries of East Europe.
For a resistor, "10" means 10 Ohm and "10.0" means 10 MOhm.
For a capacitor, "10" means 10 pF and "10.0" means 10 uF.
This code is rarely used nowadays.
Everything else is just putting the letter in place of decimal point. That's because small decimal point may be hard to read on a poor copy. It was also commonly used in USSR for printing on small parts before the color code was accepted in USSR. The letter may be G, M, k (or K), m, u, p (with "Ohm" or "F" omitted), or "R" for Ohms, or "F" for Farads. "E" is the same as "R" and was sometimes used in 1960s.
One more letter may be used for tolerance. 1K2J means 1.2 kOhm "J" tolerance ("J" is 5%). Note that USSR used Russian letters, and i.e. Russian "C" (10%) is NOT the same as Latin "C" (0.25%).