# Capacitor ratings

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Can someone explain the me the different rating on caps and how the relate to each other. Not like the difference between .001 mf and .02 mf, but the difference between pf, mf, uf and so on. Thanks for the help.

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correct me if I'm wrong...

I don't recall the exact orders of magnitude (the corresponding numbers) that go with each... but I hope that helps.

Quick search:

milli -> 10^-3

micro -> 10^-6

pico -> 10^-12

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correct me if I'm wrong...

That's right..

1mf = 1x10^(-3)f = 0.001f

1uf = 1x10^(-6)f = 0.000001f

1pf = 1x10^(-12)f = 0.000000000001f

Incidentally, u should actually be a µ but that's a pain in the arse to type in every time..

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Dammit!! Beaten to it again.. I've got learn to reply faster..

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I thought that was right (excpect the picofarad I didn't know about), but StewMac uses uf and mf both for micro it seems like here: http://www.stewmac.com/shop/Electronics,_p...apacitors).html

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correct me if I'm wrong...

That's right..

1mf = 1x10^(-3)f = 0.001f

1uf = 1x10^(-6)f = 0.000001f

1pf = 1x10^(-12)f = 0.000000000001f

Incidentally, u should actually be a µ but that's a pain in the arse to type in every time..

whoh, how did you make the micro sign?

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All the ratings are metric...

so you'd have a normal farad...(or other unit of measurement)

and then you have deci,centi,milli,micro,pico...and on into really small

then there's the other direction...

deca,...,kilo,mega,giga,tera ect...into really really big

I forget what the 100 magnitude is...it's not used often though...

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... StewMac uses uf and mf both for micro ...

It's a holdover from the days when American publishers (especially amateur radio and hobby magazines) used the abbreviation mfd for microfarad (probably because they didn't have the micron (µ) symbol in their font sets) . Since we very seldom use caps in the millifarad range, it's usually safe (not always) to assume that mf means microfarad, unless you're talking serious power supply filters or some other low frequency application. Using uF is more commonplace, and makes schematics easier to read, like the convention of using 2K7 to represent 2700 ohms rather than the old 2.7K. We're also starting to see the use of nF (nanofarad) for the fractional ratings of uF. A nanofarad is 1000 picofarads, or .001 microfarads.

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correct me if I'm wrong...

That's right..

1mf = 1x10^(-3)f = 0.001f

1uf = 1x10^(-6)f = 0.000001f

1pf = 1x10^(-12)f = 0.000000000001f

Incidentally, u should actually be a µ but that's a pain in the arse to type in every time..

whoh, how did you make the micro sign?

Character map.. Just pasted it onto the text box and it worked.. Was a bit surprised myself, actually..

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Character map.. Just pasted it onto the text box and it worked.. Was a bit surprised myself, actually..

Or you can type Alt-0181 -> µ

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OK...I'm looking at the caps on this site, and they have both mf and uf. Is it same to assume they mean milli instead of micro? 100 magnitude is hecto if I remember correctly.

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What site are you looking at?

<edit>

Sorry, that was kinda thick- I guess "Where on this site are you looking?' would make better sense. Sorry!

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First question was right...it wasn't this site as in PG, it was this site as in the one I'm currently looking at. Maybe I"m the dense one

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Sorry, couldn't find any marked mF on that page - in general, unless they're physically huge and expensive, you can assume they mean microfarad rahter than millifarad.

<edit> Oops, should have looked at the previous page - my bad! This cap must be the one you were referring to. It's listed as .1 µF on the detail page, so I assume they use the two terms synonymously.

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Yup...I'm definitely the dense one. I had two different electronics suppliers open at the same time, and the other one had mf instead of uf. Thanks for the help you guys

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oops for me too...didn't look on that other pages the second time...maybe we're both not-so-bright .

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I won't tell anybody if you don't

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I forget what the 100 magnitude is...it's not used often though...

centi

often confused with centa, which is used for .01, like in centameter. centimeter is actually 100 meters, while centameter is 1/100th of a meter.

i do believe...been a long time since latin lessons...

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I forget what the 100 magnitude is...it's not used often though...

centi

often confused with centa, which is used for .01, like in centameter. centimeter is actually 100 meters, while centameter is 1/100th of a meter.

i do believe...been a long time since latin lessons...

Um, it must have been a long time

hecto seems to be be *100.

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100 magnitude is hecto if I remember correctly.

deja vu

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