# Capacitors

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#### GRollins

The basic unit of capacitance is the Farad, named after Michael Faraday. To get microfarads (mF, mFd, or uF), multiply by 10**-6. To get nanofarads (nF), multiply by 10**-9. For picofarads (pF), multiply by 10**-12.
Microfarads and picofarads are the most common designators, with nanofarads coming in third. To get a whole Farad in one place (at least at anything over 12V) takes a fair hunk of change, so you won't be seeing a lot of schematics specifying capacitance in Farads.

Grey

Thanks Grey,
If I figured it right a capacitor with a 470pf value would equal .0047uf and a 470nf would equal .47uf. Is this correct or is my math bad as usual?

#### haldor

Something to watch out for is some schematics will use mF as millifarad (1 millifarad = 1000 uF).

This is usually a holdover from older designs (references to cycles per second instead of Hz is a dead giveaway), but not always. So be cautious, if the power supply filter caps on a power amp are 15 mF, you can bet they really mean 15,000 uF not 15 uF.

Phil

#### djk

"a 470pf value would equal .0047uf " No, .000470µf = 470pF

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