Having learned my electronics units many years ago and now getting back to
it, I am puzzled over the unit of capacitance, the nF. I know uF and pF but
nF is new to me. Could someone please explain nF to me?
On Thu, Mar 10, 2005 at 03:49:25PM -0500, Vic Fraenckel wrote:
> Having learned my electronics units many years ago and now getting back to
> it, I am puzzled over the unit of capacitance, the nF. I know uF and pF but
> nF is new to me. Could someone please explain nF to me?
>Having learned my electronics units many years ago and now getting back to
>it, I am puzzled over the unit of capacitance, the nF. I know uF and pF but
>nF is new to me. Could someone please explain nF to me?
>
>Any enlightenment will be appreciated.
>
>
>
>Having learned my electronics units many years ago and now getting back to
>it, I am puzzled over the unit of capacitance, the nF. I know uF and pF but
>nF is new to me. Could someone please explain nF to me?
>
>Any enlightenment will be appreciated.
>
>TIA
>
>Vic
>
>
> Having learned my electronics units many years ago and now getting back to
> it, I am puzzled over the unit of capacitance, the nF. I know uF and pF but
> nF is new to me. Could someone please explain nF to me?
>
> Any enlightenment will be appreciated.
>
> TIA
>
> Vic
> ________________________________________________________
>
> Victor Fraenckel - The Windman
> victorf ATSIGN windreader DOTcom
> KC2GUI
>
> Home of the WindReader Electronic Theodolite
> Read the WIND
>
> "Dost thou not know, my son, with how little wisdom the world is governed?"
> -Count Oxenstierna (ca 1620) to the young King Gustavus Adolphus
>
> "People sleep peacefully in their beds at night only because rough
> men stand ready to do violence on their behalf."
> -George Orwell
>
> "When a true genius appears in the world you may know him by this sign: that
> all the dunces are in confederacy against him." -Jonathan Swift
>
> Having learned my electronics units many years ago and now getting back to
> it, I am puzzled over the unit of capacitance, the nF. I know uF and pF
> but
> nF is new to me. Could someone please explain nF to me?
>
> Any enlightenment will be appreciated.
>
> TIA
>
> Vic
> ________________________________________________________
>
> Victor Fraenckel - The Windman
> victorf ATSIGN windreader DOTcom
> KC2GUI
>
> Home of the WindReader Electronic Theodolite
> Read the WIND
>
> "Dost thou not know, my son, with how little wisdom the world is
> governed?"
> -Count Oxenstierna (ca 1620) to the young King Gustavus Adolphus
>
> "People sleep peacefully in their beds at night only because rough
> men stand ready to do violence on their behalf."
> -George Orwell
>
> "When a true genius appears in the world you may know him by this sign:
> that
> all the dunces are in confederacy against him." -Jonathan Swift
>
>
>
> Having learned my electronics units many years ago and now getting back to
> it, I am puzzled over the unit of capacitance, the nF. I know uF and pF
> but
> nF is new to me. Could someone please explain nF to me?
>
> Any enlightenment will be appreciated.
>
> TIA
>
> Vic
> ________________________________________________________
>
> Victor Fraenckel - The Windman
> victorf ATSIGN windreader DOTcom
> KC2GUI
>
> Home of the WindReader Electronic Theodolite
> Read the WIND
>
> "Dost thou not know, my son, with how little wisdom the world is
> governed?"
> -Count Oxenstierna (ca 1620) to the young King Gustavus Adolphus
>
> "People sleep peacefully in their beds at night only because rough
> men stand ready to do violence on their behalf."
> -George Orwell
>
> "When a true genius appears in the world you may know him by this sign:
> that
> all the dunces are in confederacy against him." -Jonathan Swift
>
>
>
On Thu, 2005-03-10 at 21:49, Vic Fraenckel wrote: {Quote hidden}
> Having learned my electronics units many years ago and now getting back to
> it, I am puzzled over the unit of capacitance, the nF. I know uF and pF but
> nF is new to me. Could someone please explain nF to me?
>
> Any enlightenment will be appreciated.
>
> TIA
>
> Vic
> ________________________________________________________
>
> Victor Fraenckel - The Windman
> victorf ATSIGN windreader DOTcom
> KC2GUI
>
> Home of the WindReader Electronic Theodolite
> Read the WIND
>
> "Dost thou not know, my son, with how little wisdom the world is governed?"
> -Count Oxenstierna (ca 1620) to the young King Gustavus Adolphus
>
> "People sleep peacefully in their beds at night only because rough
> men stand ready to do violence on their behalf."
> -George Orwell
>
> "When a true genius appears in the world you may know him by this sign: that
> all the dunces are in confederacy against him." -Jonathan Swift
> Having learned my electronics units many years ago and now
> getting back to
> it, I am puzzled over the unit of capacitance, the nF. I know
> uF and pF but
> nF is new to me. Could someone please explain nF to me?
> -----Original Message-----
> From: EraseMEpiclist-bouncesspam_OUTTakeThisOuTmit.edu [piclist-bouncesspam_OUTmit.edu]On Behalf
> Of Vic Fraenckel
> Sent: Thursday, March 10, 2005 3:49 PM
> To: PICMIT
> Subject: [PIC] What is a nF?
>
>
> Having learned my electronics units many years ago and now
> getting back to
> it, I am puzzled over the unit of capacitance, the nF. I know uF
> and pF but
> nF is new to me. Could someone please explain nF to me?
>
> Any enlightenment will be appreciated.
>
> TIA
>
> Vic
> ________________________________________________________
>
> Victor Fraenckel - The Windman
> victorf ATSIGN windreader DOTcom
> KC2GUI
>
> Home of the WindReader Electronic Theodolite
> Read the WIND
>
> "Dost thou not know, my son, with how little wisdom the world is
> governed?"
> -Count Oxenstierna (ca 1620) to the young King Gustavus Adolphus
>
> "People sleep peacefully in their beds at night only because rough
> men stand ready to do violence on their behalf."
> -George Orwell
>
> "When a true genius appears in the world you may know him by this
> sign: that
> all the dunces are in confederacy against him." -Jonathan Swift
>
>
>
> Having learned my electronics units many years ago and now getting back to
> it, I am puzzled over the unit of capacitance, the nF. I know uF and pF
but
> nF is new to me. Could someone please explain nF to me?
Apparently, warm beer causes a phobia for decimal points, so instead of
writing .001uF, the Brits like to write 1nF.
> > Apparently, warm beer causes a phobia for decimal points, so
> > instead of writing .001uF, the Brits like to write 1nF.
>
> I probably should have also mentioned that this decimal point
> phobia forces them to write 5k6 when they mean 5.6k.
I ALWAYS use the 5k6 format. Been confused by too many scruffy
scans and photocopies that are ambiguous wrt decimal points that
might be a bit of dirt. And IMHO 1n0 is tidier than 0.001u anyway
> I think it may be related to the 'Z' phobia that, sadly, causes them
> spell initialize with an S, but I haven't seen any studies to validate
> this
That's an odd turn of events. The spelling of -ise / -ize words was
- ize in both the UK and US until the 60s. Then the UK suddenly
started using -ise. The US is actually correct historically, although
I like the look of -ise more
=================
> Simple. 1nF is 1/1000 pF
>
> Peter O
O Peter, 1nF is 1000*pF. 1/1000p is femto. Would anyone dare
write uuu ? (p used to be uu)
>>Apparently, warm beer causes a phobia for decimal points, so
>>
>>
> > instead of writing .001uF, the Brits like to write 1nF.
>
>I probably should have also mentioned that this decimal point phobia forces
>them to write 5k6 when they mean 5.6k.
>
>
There is a valid reason for the above. As components got smaller it
became more and more difficult to read the printed values, therefore
writing 5K6 was easier to read than 5.6K as the decimal could easily be
lost. The same applied to diagrams, is that a decimal point, a pencil
mark, a bad photocopy 'blob' or a speck of fly shit?
>I think it may be related to the 'Z' phobia that, sadly, causes them spell
>initialize with an S, but I haven't seen any studies to validate this.
>
>
Errr...... the English language belongs to the English/British so
whichever way they spell a word *has* to be the correct spelling as it
is *their* language! The American version of English was 'bastardised'
in the 1700's (at around the time of their independence IIRC) when it
was decided to simplify spelling to make it easier for the large number
of semi-literate or totally illiterate people flooding into the country
(a bad move in my opinion).
As far as a 'Z' phobia is concerned I believe the phobia lies squarely
on the left side of the 'pond'. It seems to be a case of 'if you don't
know how to spell a word correctly just stick a ZED in there somewhere!'
If you are not happy with the spelling of 'correct' English I suggest
you invent your own language and get it accepted by your political leaders.
--
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Vic Fraenckel wrote:
> Having learned my electronics units many years ago and now getting back
> to it, I am puzzled over the unit of capacitance, the nF. I know uF and
> pF but nF is new to me. Could someone please explain nF to me?
The only strange part is that "many years ago", milli and nano weren't
commonly used for Farads. Nobody seems to have a problem with milli-seconds
or nano-seconds, so why should nano-Farads be any different?
*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com
> Actually, it's also a disdain of large numbers of zeroes: instead of
> 100000p they write 100n. Why make it simple when you can make it
> complicated? :)
So I would write just "u1" :)
Wouter van Ooijen
-- -------------------------------------------
Van Ooijen Technische Informatica: http://www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: http://www.voti.nl/hvu
John J. McDonough wrote:
> Apparently, warm beer causes a phobia for decimal points, so instead of
> writing .001uF, the Brits like to write 1nF.
I don't do warm beer either, but I think 22nF is a lot nicer than .022uF or
22,000pF.
Again, if this were seconds instead of Farads we wouldn't be having this
discussion. I've never understood why Farads were singled out to skip milli
and nano.
*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com
Larry Green wrote:
> Errr...... the English language belongs to the English/British
It belongs to English speakers, of which the British are now a minority.
That's the price of no longer having a world-dominating empire or economy.
It's been more than 200 years now, time to get over it.
*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com
> Apparently, warm beer causes a phobia for decimal points, so instead of
> writing .001uF, the Brits like to write 1nF.
I believe it was continental Europe led the way on this one.
But once one gets used to it, it does make a lot of sense. Going in 1k
increments instead of 1 million increments is a lot easier. Using the
abbreviation as the decimal holder also works extremely well, especially
when attempting to read a circuit that has been reduced by a linear factor
of 2 (i.e. quarter area) or smaller, which is what you often end up with in
service manuals, as you can typically work out what the individual digits
should be, but should it be 5.6, 5.6k (have they left off a character, or
should it be 56 'cos its a laser printer speck on the page) where 5R6 or 5k6
makes it completely obvious what it should be.
> Larry Green wrote:
>> Errr...... the English language belongs to the English/British
> It belongs to English speakers,
Indeed. ENGLISH speakers. Not new fangled obfuscated or "simplified"
variants thereof.
Only somewhat related: I had someone tell me that nowadays LASER was
spelled LAZER. I explained why this was not so :-)
Even the USites have not yet got as far as zimulated :-).
I commonly use nF. Many many years ago, we didn't have pF. We uuF (or mmF)
which we called "mickey mikes". I don't think nanoseconds "existed"
either. That was too short a time to see on my Dumont scope...
Harold
> The only strange part is that "many years ago", milli and nano weren't
> commonly used for Farads. Nobody seems to have a problem with
> milli-seconds
> or nano-seconds, so why should nano-Farads be any different?
> Vic Fraenckel wrote:
>> Having learned my electronics units many years ago and now getting back
>> to it, I am puzzled over the unit of capacitance, the nF. I know uF and
>> pF but nF is new to me. Could someone please explain nF to me?
>
> milli (m) = 10^-3
> micro (u) = 10^-6
> nano (n) = 10^-9
> pico (p) = 10^-12
>
> The only strange part is that "many years ago", milli and nano weren't
> commonly used for Farads. Nobody seems to have a problem with milli-seconds
> or nano-seconds, so why should nano-Farads be any different?
And a quick question for the tube/valve guys: What was that old
capacitance unit, the cm, that appeared in many vintage radio schematics
(1930's and before). My hunch is plate capacitance for a 2-plate cap
that many cm on a side an 1 cm apart. Correct ?
> Apparently, warm beer causes a phobia for decimal points, so
> instead of
> writing .001uF, the Brits like to write 1nF.
The phobia of decimal points is caused by all the cases where the point was
missed by someone reading the schematic or assembling the PCB. I personally
like the way the letter can be used in place of the decimal. E.g. 4.7K
written as 4K7. That is REALLY easy to read on a PCB silkscreen so you don't
have users trying to find a 47 ohm resistor.
Warm beer is caused by using Lucas refrigeration. Or that is what my Dad
told me after trying to get the A/C working in his '68 E-Type.
P.S. I inherited a 1956 XK-140 Coupe that I would like to sell to a true Jag
collector. It is basically this car: http://www.highwayone.com/Classifieds/Jaguar/BlackXK140.html but with a
black interior and yellow paint. And I expect to get something closer to
$20,000 rather than $80,000.
Please change the subject line if you reply regarding Lucas, Beer, or
Jaguars.
> > Errr...... the English language belongs to the English/British
>
> It belongs to English speakers, of which the British are now a
> minority. That's the price of no longer having a world-dominating
> empire or economy. It's been more than 200 years now, time to get over
> it.
Good point. Perhaps the language should be called "Microsoft" or
"would you like fries with that ?".
:-)
> milli (m) = 10^-3
> micro (u) = 10^-6
> nano (n) = 10^-9
> pico (p) = 10^-12
>
> The only strange part is that "many years ago", milli and nano weren't
> commonly used for Farads. Nobody seems to have a problem with milli-seconds
> or nano-seconds, so why should nano-Farads be any different?
They aren't, but I think in the USA there is a bit of a strange (to me)
phobia against /something/ -- don't know whether it's against
standardization, or against doing it the same way everybody else does it if
it wasn't invented here, or against whatever. There are a number of
expressions for this.
One is that many people don't make a difference between k (kilo) and K
(something else), or even between m (milli) and M (mega) -- the meaning is
not taken from the exact letter, but from the context. (How often have you
seen "ma" or "MA" for "milli-Ampere"? :) This works in most cases, which
seems to be enough for most. :)
Another is that the simple and beautiful logic of the SI still hasn't
caught on, at least not in a large scale outside the scientific community
(which of course uses it). If it had, its basic rules would be known by
every technician (and most non-technicians) and "nF" would be /very/
obvious.
Alan B. Pearce wrote:
| ... should it be 56 'cos its a laser printer speck on the page) where 5R6
or 5k6
| makes it completely obvious what it should be.
> every technician (and most non-technicians) and "nF" would be /very/
> obvious.
Units are kind of funny. I think pretty much any technical person would
recognize nF once he thought about it, but some things, like units, are so
pervasive that analysis never gets involved when you see them. When I see a
pF, I have an immediate gut feel for what that means. Ditto for a uF. But
here in the colonies, we don't see nF all that often, and when we are
looking at something as innocuous as a cap, we aren't tempted to switch from
intuitive to analytical, so even though it is obvious, it makes the
schematic about 100 times more difficult to read.
That being said, I think the older "standard" of skipping ove nF makes
little sense. It does have one neat feature, though. For caps, anyway, you
can generally skip the units on the schematic (as used to be quite common
practice). If you see a .01 or .001 you know immediately that it's not pF,
and if you see 10 or 47 it will be pretty obvious from the context which is
it. So all those uF, nF, pF are really just unnecessary clutter. Once you
start using nF the difference isn't quite so great, so you really need the
clutter.
On Mar 12, 2005, at 2:06 AM, Gerhard Fiedler wrote:
>> Nobody seems to have a problem with milli-seconds
>> or nano-seconds, so why should nano-Farads be any different?
>>
Perhaps in the fuzzy print found on components, n and u look (looked?)
too much alike? 6u8 or 8n9 ?
>>> Nobody seems to have a problem with milli-seconds
>>> or nano-seconds, so why should nano-Farads be any different?
>>>
> Perhaps in the fuzzy print found on components, n and u look (looked?)
> too much alike? 6u8 or 8n9 ?
There might have been reasons to make the /component prints/ a certain way.
Even though I think when you can't distinguish between an "n" and a "u",
you might have other problems in reading the print -- and I can't recall
any problems related to that with the components I used 35 years ago.
But independently of that, I still fail to see the reason that would make
me use the same string that's used in component marking in the parts
catalogs or schematics.
Try to apply the same logic (using the component print in schematics) to
SMT caps -- usually no print at all, so we stop putting any value at all in
the schematics? :)
Or to the voltage ranges. Many cap manufacturers encode voltage ranges in
letters or letter/number combinations. But you probably still specify "25
V" in your schematic, and not "B" (or whatever).
Or I have that nice part here in front of me, with "LTQB" printed on it. I
still name it in my schematic LT1790, and that's also under which you find
this part listed in Linear Tech's catalogs, and not "LTQB".
So, no matter how the manufacturer of a cap marks that 100n part (some use
".1", others prefer "100000"), I still use "100n". Makes more sense in a
schematic, is correct (the others aren't: one misses the µ, the other
misses the p), leaves less to guess and is safer: "is that 0.1 µF, or 1 µF
(can't see the speck in front of the 1 clearly), or maybe 1 pF?"
That's the same story as with "mA" and "MA" and "ma", and other cases like
these. In most cases the context is clear, but why take the chances with
the other cases (and send a mars rover off course, maybe <g>)? Taking the
proper units through your calculations (and schematics) is a pretty good
safeguard against a few types of silly (and easily avoidable) mistakes.
Gerhard
On Sun, 13 Mar 2005 10:03:28 -0300, Gerhard Fiedler wrote:
>William ChopsWestfield wrote:
>
>>>> Nobody seems to have a problem with milli-seconds
>>>> or nano-seconds, so why should nano-Farads be any different?
>>>>
>> Perhaps in the fuzzy print found on components, n and u look (looked?)
>> too much alike? 6u8 or 8n9 ?
>
>There might have been reasons to make the /component prints/ a certain way.
>Even though I think when you can't distinguish between an "n" and a "u",
>you might have other problems in reading the print -- and I can't recall
>any problems related to that with the components I used 35 years ago.
>
The use of nF is a relatively recent occurrence in the US. It was
common practice at most companies to omit capacitance units on
schematics and show capacitor values only in uF and pF, which were
called uuF at the time. (Please bear in mind, this was while the earth
was still cooling, according to my kids.)
A cap marked 0.01 clearly wasn't in pF and a cap marked 200 wasn't in
uF (unless it was an electrolytic which would be indicated by the '+'
on the terminal and/or the curved line in the symbol).
> The use of nF is a relatively recent occurrence in the US. It was
> common practice at most companies to omit capacitance units on
> schematics and show capacitor values only in uF and pF, which
> were called uuF at the time. (Please bear in mind, this was while
> the earth was still cooling, according to my kids.)
Hey, Grandpa ;-)
"Like the time we went over to Shelbyville during the war, I wore an
onion on my belt....which was the style at the time...you couldn't get
those white ones, you could only get those big yellow ones..............
...now where was I........oh yeah,..."
I've seen some of those schematics, and often there's an "All values
in uF unless otherwise stated" legend. Which is OK because at least
you know where you are. Still don't like DPs though
What about the 3-digit format ? eg 104 for 100n, 222 for 2n2 etc
(101 for 100pF, 100 for 10pF !!!) That never made it into schematics
AFAIK (possibly because you have the luxury of space in a schematic
that you don't have on a component) although it's a perfectly clear and
succinct label - SMT resistors for example
>The phobia of decimal points is caused by all the cases where
>the point was missed by someone reading the schematic or
>assembling the PCB. I personally like the way the letter can
>be used in place of the decimal. E.g. 4.7K written as 4K7.
>That is REALLY easy to read on a PCB silkscreen so you don't
>have users trying to find a 47 ohm resistor.
Or 4.7 ohm in place of a 4.7k as happened in one instance that occurred
during my apprenticeship. (I was not responsible for the mistake
thankfully).
>Warm beer is caused by using Lucas refrigeration. Or that is what
>my Dad told me after trying to get the A/C working in his '68 E-Type.
<VBG> one of my colleagues used to work for Lucas :))
>P.S. I inherited a 1956 XK-140 Coupe that I would like to sell
>to a true Jag collector. It is basically this car:
>http://www.highwayone.com/Classifieds/Jaguar/BlackXK140.html but
>with a black interior and yellow paint. And I expect to get
>something closer to $20,000 rather than $80,000.
I would have thought you would get a tidy sum for one of those in almost any
condition, but then I guess where you are, 20k is a tidy sum for a vehicle.
> What about the 3-digit format ? eg 104 for 100n, 222 for 2n2 etc
> (101 for 100pF, 100 for 10pF !!!) That never made it into schematics
> AFAIK (possibly because you have the luxury of space in a schematic
> that you don't have on a component) although it's a perfectly clear and
> succinct label - SMT resistors for example
This format has a few limitations; it can get ambiguous if you also need
higher resolution (more than two digits) and higher values (more than 9
zeroes). In both cases, you'd add an additional digit, but in one case it's
part of the number (as with resistors), in the other it's part of the
exponent. Could probably be resolved by resorting to letters for the
exponents beyond 9, which would leave the exponent as always the last
character.
But I still think the traditional SI style is pretty clear, flexible, and
succinct too. And it looks... don't know, maybe "nice"? :)
> > OK, What's this R business all about?
>
> A resistor less than 1k
I think more accurately: representing the decimal point in resistors less than 1k
> 100R = 100 ohms
> 5R6 = 5.6 ohms
> 0R033 = 33 mohms
>
> To be consistent with capacitors, I suppose you could say
> 0k1 for 100 ohms but I've never seen that
I think the aim is to get the whole into three characters if possible, so 100 is sufficient in the above case.
You only really need 4 characters in the range 100k - 999k and 100M - 999M, although the latter is a tad
rare... I'm also not sure where you'd buy a 33mohm resistor! :-) As far as I'm aware, this
character-for-decimal is only used in component specs, not for (eg) measurements. I don't think you'd say
that you'd measured the ESR of a capacitor at 0R3, or that a power rail should be 3V3 +/- 0V06.
> > > Errr...... the English language belongs to the English/British
> >
Olin wrote:
> > It belongs to English speakers, of which the British are now a
> > minority. That's the price of no longer having a world-dominating
> > empire or economy.
I'm not sure I follow your logic - when "the Sun never set on the British Empire" native British were always
outnumbered by the others, and they still are.
> > It's been more than 200 years now, time to get over it.
Ah, the American History version! The USA may have been founded 220 years ago, but most of the rest of the
British Empire was around until about 60 years ago - India, for example, gained independance in 1947, and we
only returned the rented Hong Kong five years ago!
A language doesn't "belong" to anyone, and as for the number of English speakers, the non-Americans outnumber
the Americans by at least three to one, and mostly use English spelling and grammar.
> Good point. Perhaps the language should be called "Microsoft" or
> "would you like fries with that ?".
> :-)
I just wish Americans wouldn't call it "English" - what's wrong with calling it "American"?
I await with interest (and some trepidation) to see how the American Empire progresses.
> I'm also not sure where you'd buy a 33mohm resistor! :-)
>From now on, be sure - I bought some from RS a couple
of weeks ago to use as motor sense resistors (yes, I do still
work !!). They have Meggitt resistors down to 10mohms
gmail.com
