Nanofarads?

How much do you weigh? 85kg4? Do you describe a frequency as 33Hz65? Does 4u7 describe an inductor or a capacitor?

4.7 nF describes a value in SI units. 4n7 does not.

John

Well obviously, you don't see farads printed next to a resistor, or henries printed next to a capacitor. That's an obvious use of context.

I believe it is also traditional to omit the Omega when calling out resistors, eh John? ;-)

But 4n7F would, using the British decimal > multiplier convention. And with the F, or H, or Omega implied by the symbol beside, the unit also becomes extraneous, convieniently saving a keystroke. Not bad I'd say.

Tim

--
Deep Fryer: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

I'll weigh in here and say that I am becoming used to nF but rarely use it. The decimal point issue is a factor, so I usually precede it with a zero to avoid confusion. I grew up in the 50s with mickeymikes, and the conversion to pF in the 70s was painless, but I still like the sound of it, especially if used for parts in old tube equipment. I still have to make a mental conversion for nF, but it's becoming easier.

Some time ago I was organizing a database of manufacturing parts, and wanted the components to be ordered correctly by value. I came up with a construct of:

C1P470CD600V05A for a 470e01=4700 pF capacitor, Ceramic Disc, 600V, 5%, Axial leads

This worked for non-fractional pF capacitors up to a maximum of 999000 uF which would be C9P999AE016V20S (for instance).

BTW, it seems that high capacitances are generally described in uF up to hundreds of thousands, rather than using millifarads. There is probably still some confusion using mF, so we are stuck with 470,000 uF, although there is more usage of Farads, as in 0.47 F. I have never seen 470 mF. Even more rare would be 47 cF (centifarads), although it is often used for linear measurement. I think it has become fairly standard to use factors of

1000 for almost everything now, although I think some other prefixes are still popular. I still use pounds and ounces here in the US, but I have heard that lunch meats in Europe are usually bought by the decagram, or "deca" for short. I guess a normal purchase would be two or five decas.

That brings me to something I've always wondered about. In the US, a standard piece of lumber is a 2x4, which is nominally 2" x 4" before shaping to 1.5" x 3.5". What is the European or metric equivalent? I figure it would be a 5x10 (cm), but are they known by that term? And what about a

4x8 piece of plywood? A Yankee needs to know ! :)

Paul

It's not uncommon for frequency, e.g. 32K768 would not be out of place, I've seen it lots of times and have used it myself. I find dropping the decimal point handy on quick hand draw schematics. Zero error when you (or a less sighted engineer perhaps) translates into the computer later. Especially so if you use grid paper to draw stuff and the decimal point just happens to be on the crosshairs!

It'll usually be next to a capacitor or an inductor symbol, so no real problem. Or in a parts list it'll have C1 or L1 next to it. Pretty obvious I would have thought, a lot of people don't bother putting the "F" or "H" on 4.7u when it's next to the symbol. The ultra paranoid can put 4u7F if they really want.

That brings up the next argument! - who bothers to put the "F" "H" or "ohms" on the end anyway? Is it redundant?

Care factor in most cases is zero. Those who can't figure it out probably don't deserve to figure it out! :->

Dave :)

In Australia a 2" x 4" length of wood, pronounced "two-bee-four" is any dimention of wood that "gets the job done". e.g. to beat the crap out of someone, to get your car out of a bog, stir a paint tin, to prop something up etc It's almost never actually 2" x 4"

Dave :)

How would you know what happens in "The Civilised world"?

--
Service to my country? Been there, Done that, and I\'ve got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Which six dot color code? There were several used over the years. I created some javascripts to decode the different color dot codes, but you have to know which one to use for each capacitor.

--
Service to my country? Been there, Done that, and I\'ve got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

"Joerg" a écrit dans le message de news:dfokg.44947$ snipped-for-privacy@newssvr27.news.prodigy.net...

Charged at 44.7kV, that's 0.1kJ

--
Thanks,
Fred.

Yep, my era also...

Another easy method I use is where I see nF eg. 1nF, I simply convert it by saying 1nF = 1000pF. That is, simply multiply the nF value by

1000 and express it as pF.

I hate the use of milliFarads... a most inconvenient method of expressing capacitance I think. If a cap value can conveniently be expressed in either nF or uF (as has been the case for the past 50 years) then why complicate it by introducing yet another value method which you have to convert in your head to get an idea of the actual value in terms you are more familiar with.

Australia uses the metric equivalent of "four-be-two" (4" x 2") with regard to timber (lumber). It is simply 100mm x 50mm which is near as damn the same as 4" x 2" for all practical purposes given shrinkage and milling variation.

You reckon that the Wild West counts as civilised ? ;-)

Graham

How would I know? I've never been to the Wild West, but I have watched the old TV show," The Wild Wild West". ;-)

--
Service to my country? Been there, Done that, and I\'ve got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

on

We here in Phoenix have been ranked second rudest drivers in the country... BUT ranked FIRST in SAFETY. Go figure ;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

It simple. Everyone there knows that all the other drivers that they encounter are incompetent assholes, so they drive accordingly! ;-)

--
Service to my country? Been there, Done that, and I\'ve got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

What is that, Michael, Florida-style reasoning ?:-)

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

| 1962 | I love to cook with wine. Sometimes I even put it in the food.

Hello mc,

although I prefer to use nF I know the advantage from not to use this. Have you ever had a 10 nF only labled as "10" and then you tried out whether it should be 10 p or 10n? Or more a cercap labled "100" (is it 10 or 100pF?)

10000 is clear on a ceramic capacitor. 0.1 on an other cercap too.

But I aggree, 10n it is clear too as well as 100n...

Marte

Just the Rebublicans here.

--
Service to my country? Been there, Done that, and I\'ve got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

I have usually seen markings like 103, where the last digit is a power of ten or zero counter, so this would be a 10 nF. It is confusing for small values with a multiplier of 10**0.

Paul

In fact, in three-digit notation, the third digit is never 0. So 470 and

471 mean the same thing, and 47 is written as just 47.

Regarding nanofarads, someone very sensibly suggested using them to minimize the number of zeroes in the written number, i.e., 10 nF (not 0.01 uF) but

0.1 uF (not 100 nF).

Everyone knows that in digital electronics the only two capacitances are 0.1 uF and 22 pF anyhow :) :)

Does Radio Shack use nanofarads on parts packages yet?

Just a corrolary of the axiom:

"Every driver, except me, is either a speeding maniac or a snail-brained idiot."

Mark