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Advanced ESR meter question.

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grant1842:
Hi all I am new to electronics engineering as a hobby.
I am looking at a post here  http://arduino.cc/forum/index.php?topic=80357.0   .

This guy did a great job on this ESR meter using an Arduino. He informs me that the current schematic and design will not get the ESR of a nf cap but will get the higher pf and up.

As I work on computer MB, LCD TV, etc I would like to be able to get ESR of nf, pf, and up.

So I am worndering if the current schematic can be modifed to be able to get the ESR of nf ,pf,etc ?

Thanks in advance for looking at this.

PS 
nf= Nanofarid
pf= PecoFarid

jimmc:
I think you may have your multiliers confused
The order is Farad, millifarad (mF), microfarad (uF), nanofarad (nF) and picofarad (pF) where
1 mF= 0.001 F
1 uF = 0.001 mF
1 nF = 0.001 uF
1 pF = 0.001 nF


Only electrolytic capacitors have a common failure mechanism by increasing ESR.
99.9% or more of these electrolytic capacitors have a value of 1uF or more so there is no requirement for a general purpose ESR meter to operate below this value.
Lower value capacitors (say less than 100nF) have plastic film or ceramic dielectrics and (almost) never fail with high ESR.

There is no simple way to measure the ESR of a small value capacitor.
RF techniques need to be used to prevent the reactance of the capacitor swamping its ESR.

For examples of how it is measured see
http://www.atceramics.com/Userfiles/esrmeas.pdf
http://www.johansontechnology.com/images/stories/tech-notes/rf/JTI_Q&ESR_12-04.pdf and
http://www.kemet.com/kemet/web/homepage/kechome.nsf/file/KEM_RF_FAQs/$file/KEM_RF_FAQs.pdf.
 
Jim

grant1842:
Thanks for your reply.
I will study the links.

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