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nf pf uf?
Posted: Sun Mar 19, 2006 7:58 pm
by rockstah
ok i get that 1000pf is = to 1nf and 1nf is = to .001uf
but why the different break downs? why are some caps in pf.nf.uf?
- am i to interperate 22n as .022u if read it on a schemtac? or should i get a cap that actually says 22nf on it? and would they have any reason to write 22n over .022uf?
thanks in advance.
Mark
Re: nf pf uf?
Posted: Sun Mar 19, 2006 8:33 pm
by SDM
rockstah wrote:
- am i to interperate 22n as .022u if read it on a schemtac? or should i get a cap that actually says 22nf on it? and would they have any reason to write 22n over .022uf?
No difference 22nf is .022uf is 22nf schematics or otherwise. The units a manufacturer uses don't matter, it's the same cap. Maybe writing 22n saves a bit on printing costs, or easier to squeeze in there, who knows?
Posted: Sun Mar 19, 2006 8:38 pm
by marshman
I can read the difference...It's like metrics, sorta. ".1 km=100m=100,000cm=1,000,000mm." The distance is the same, it's just how it was written.
So, it doesn't matter how it was written on the cap/manual/catalog/website, it's the same cap. The difference is only in the mind of the "writer", or how that person thinks. I've assumed that they've printed the figures on their product in a manner which requires the fewest characters, saving on printing costs. .1uf is easier/cheaper to print than 10000pf, because of the number of zeros.
Posted: Sun Mar 19, 2006 8:49 pm
by rockstah
i hear ya - it makes sense. it just through me on a handwritten schematic on coupling caps that someone wrote 22nf (.022uf) and then for another point wrote 2200pf - i figured he would just write 2.2nf ( which is .0022uf) instead sense he favors nf all over the rest of the schematic. was just curious is all.
thanks,
Mark
Posted: Sun Mar 19, 2006 10:35 pm
by marshman
Some folks are real anal itikel about having the fewest digits around a decimal point. I recall a perfesser who was like that--he'd rather use a dozen different prefixes (milli, centi,hecto,kilo, etc) than sci notation/lots o' zeroes. Other folks will scribe things like '2k2' rather than '2.2k'. Just keep a calculator or whatever math props you need handy and you should be alright.
I get a chuckle out of trying to teach kids metrics. They couldn't be bothered, but I know in 10 years or so, they'll be bashing their heads against a wall cause the can't tell the difference between a kilo-meter and a centi-meter. Sadly, they can tell the difference between a penny and a 100 dollar bill, but can't transfer that understanding.
Posted: Sun Mar 19, 2006 11:30 pm
by sub
marshman wrote:I can read the difference...It's like metrics, sorta. ".1 km=100m=100,000cm=1,000,000mm." The distance is the same, it's just how it was written.
1km=1000m
Posted: Mon Mar 20, 2006 5:40 am
by Flames1950
sub wrote:marshman wrote:I can read the difference...It's like metrics, sorta. ".1 km=100m=100,000cm=1,000,000mm." The distance is the same, it's just how it was written.
1km=1000m
He wrote " .1" (as in 0.1) which is 100m.......
Posted: Thu Mar 23, 2006 9:40 pm
by sub
Flames1950 wrote:sub wrote:marshman wrote:I can read the difference...It's like metrics, sorta. ".1 km=100m=100,000cm=1,000,000mm." The distance is the same, it's just how it was written.
1km=1000m
He wrote " .1" (as in 0.1) which is 100m.......

You are right!
Sorry.......

Posted: Thu Mar 23, 2006 10:07 pm
by Billy Batz
Damn Americans and their metric ignorance. Its pretty simple though. You cant study anything in school in math or science without knowing it for good. But uF pF and nF are so small I dont think their units most of the world is familiar with unless your in some areas scientific fields and obviously capacitors. A uF is still like a millionth of a F.
It goes
Deci 1/10
Centi 1/100
Milli 1/1,000
Micro 1/1,000,000
Nano 1/1,000,000,000
Pico 1/1,000,000,000,000
I think I usually for something like .005u pick one at random. I know I regularly use 5000p and 5n as well.
Posted: Thu Mar 23, 2006 10:41 pm
by sub
Billy Batz wrote:Damn Americans and their metric ignorance. Its pretty simple though. You cant study anything in school in math or science without knowing it for good. But uF pF and nF are so small I dont think their units most of the world is familiar with unless your in some areas scientific fields and obviously capacitors. A uF is still like a millionth of a F.
It goes
Deci 1/10
Centi 1/100
Milli 1/1,000
Micro 1/1,000,000
Nano 1/1,000,000,000
Pico 1/1,000,000,000,000
I think I usually for something like .005u pick one at random. I know I regularly use 5000p and 5n as well.
Correct
