Resistor Notation on Schematics?
Mike V.
comes to resistors.
What does 4K7 or 2K7 mean? Is it 4.7Kohms and 2.7Kohms, respectively?
Thanks,
Mike
Kalman Rubinson
Yes.
John Popelish
Yes, the K or M stands for the decimal point and also the multiplier
(x1000 or *1,000,000. If the multiplier is 1, the decimal point is
replaced with R.
--
John Popelish
John Larkin
Silly affectation among europeans and audiophools. Pay it no mind.
John
Jim Thompson
Yep, But it lessens the errors due to losing the decimal point on
schematic prints.
I wish PSpice schematics could cope with 2K7 and netlist it as 2.7K.
...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.
Boris Mohar
Yes. K means thousand and it is also a separator. It saves one character. In
the old days before the computers and air conditioning a fly would buzz into a
drafting department, land on a schematic and take a dump right between hand
drawn 2 and 7 making 27K into 2.7K and royally messing up the bias for the old
tube. Not being finished it would take another dump right where two wires cross
thus planting a solid connection there. So they invented this. Or so I was
told ;)
Regards,
Boris Mohar
Got Knock? - see:
Viatrack Printed Circuit Designs http://www3.sympatico.ca/borism/
Aurora, Ontario
Chaos Master
> Yes. K means thousand and it is also a separator. It saves one character. In
> the old days before the computers and air conditioning a fly would buzz into a
> drafting department, land on a schematic and take a dump right between hand
> drawn 2 and 7 making 27K into 2.7K and royally messing up the bias for the old
> tube. Not being finished it would take another dump right where two wires cross
> thus planting a solid connection there. So they invented this. Or so I was
> told ;)
And if you print a schematic in the 'draft' resolution of a printer, the dot
would not be very noticeable. That's what happened with my Epson printer, at
least.
--
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John Larkin
<inv...@invalid.invalid> wrote:
>On Fri, 05 Dec 2003 18:39:29 -0800, John Larkin
><jjla...@highSNIPlandTHIStechPLEASEnology.com> wrote:
>
>>On 5 Dec 2003 17:51:41 -0800, vale...@yahoo.com (Mike V.) wrote:
>>
>>>I was wondering about certain notation i see on schematics when it
>>>comes to resistors.
>>>
>>>What does 4K7 or 2K7 mean? Is it 4.7Kohms and 2.7Kohms, respectively?
>>>Thanks,
>>>Mike
>>
>>Silly affectation among europeans and audiophools. Pay it no mind.
>>
>>John
>
>Yep, But it lessens the errors due to losing the decimal point on
>schematic prints.
>
I've had no problems with honest, solid American decimal points. Maybe
the ones in europe are flimsier. Besides, I thought they were actually
supposed to do 4,7K and like that.
See: . how could you miss that?
John
qrk
4M7 = 4.7Meg
470K = 470K
47K = 47K
47K5 = 47.5K
4K7 = 4.7K
47R = 47
4R7 = 4.7
Popuarized in European and Japanese schematics some decades ago. The
main benefit is the decimal point isn't lost when you have a 3rd
generation copy or looking at a D-size schematic printed on A paper.
Mark
Charles DH Williams
John Larkin <jjla...@highlandSNIPtechTHISnologyPLEASE.com> wrote:
> I've had no problems with honest, solid American decimal points. Maybe
> the ones in europe are flimsier.
They are not flimsier, they are 'more elegant'.
Charles.
Rene Tschaggelar
Copy that paper 3 times and make it smaller ...
Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net
John Larkin
wrote:
Paper? What's that?
John
Paul Burridge
<inv...@invalid.invalid> wrote:
>On Fri, 05 Dec 2003 18:39:29 -0800, John Larkin
><jjla...@highSNIPlandTHIStechPLEASEnology.com> wrote:
>
>>On 5 Dec 2003 17:51:41 -0800, vale...@yahoo.com (Mike V.) wrote:
>>
>>>I was wondering about certain notation i see on schematics when it
>>>comes to resistors.
>>>
>>>What does 4K7 or 2K7 mean? Is it 4.7Kohms and 2.7Kohms, respectively?
>>>Thanks,
>>>Mike
>>
>>Silly affectation among europeans and audiophools. Pay it no mind.
>>
>>John
>
>Yep, But it lessens the errors due to losing the decimal point on
>schematic prints.
Naturally, Jim. British ingenuity at full stretch. :-)
--
"I expect history will be kind to me, since I intend to write it."
- Winston Churchill
Rene Tschaggelar
You never print a schematic ?
I always have the schematics printed while eg soldering the components.
I can have more schematic on paper as I can have on screen. When my protel
want a huge A2, my 600dpi laser still prints it on A4. It becomes rather
dense and requires me to wear reading glasses. Well, I'm wearing reading
glasses for soldering the tiny stuff anyway.
Yes, I'm componentizing from the schematic, not from the toplayer print
out.
JeffM
>>>>Silly affectation among europeans and audiophools. Pay it no mind.
>>>>John
>>>Yep, But it lessens the errors due to losing the decimal point on
>>>schematic prints.
Yup. The junctions in wires
in those 8th generation photocopies of schematics
were difficult to follow too.
I always hated those guys who did this
| |
| | instead of this.
----+---- --+-+--
| |
| |
John Larkin
wrote:
Actually, I confess, I *draw* schematics. On big sheets of D-size
blue-grid vellum, with pencils (Berol Turquoise F). My schematic-entry
design automation consists of an electric eraser and an electric
pencil sharpener. I just can't *design* on a screen. My CAD guy enters
the schematic into PADS for me, and I check his work by reviewing a
B-size (11x17 inches) laser printout, often running to 20 sheets or
more. We don't have problems with decimal points, though.
Wouldn't 4 7K look funny anyhow?
Reading glasses are helpful for the medium-size stuff. But a US-8 or
(horrors!) a chip-scale package needs serious optics, no matter how
old you are.
John
Michael
It's easier for speaking too,
"four kay seven" , is one less noise to make than "four point seven kay".
qrk
<jjla...@highlandSNIPtechTHISnologyPLEASE.com> wrote:
[snippage]
>Wouldn't 4 7K look funny anyhow?
Only looks funny on a fixed width font. On a proportional spaced font,
the space would be much narrower. It is a problem.
Mark
Syd Rumpo
It should, of course, be 4k7 or 2k7 using a lower case k for kilo -
upper case K is Kelvins. A small point, perhaps, but worth getting
right.
--
Syd
John Larkin
wrote:
Maybe for amateurs who work from bad copies of magazine schematics.
Heck, most of the schematics in the popular mags have plenty of
problems worse than this.
Professional electronics manufacturers usually work from an assembly
drawing, derived stuff like pick-and-place programs, and a bill of
materials. The BOM specifies the stock number of each part, and that
in turn is related to a materials control database that specifies the
allowed manufacturers and mfr part numbers that are acceptable for
each part. A schematic is a *reference* drawing that does not control
how a thing is built.
In most companies, various versions of a product may be assembled
("dash numbers"), with different parts loaded or not, and with
different values for the parts that are loaded; each assembly has its
own BOM. So the schematic is not necessarily "correct" anyhow.
Why don't mechanical drawings have dimensions like "25mm4" ? Why isn't
cheeze priced at 7$99 a pound?
John
qrk
<jjla...@highlandSNIPtechTHISnologyPLEASE.com> wrote:
John, it appears that you haven't been out of the lab/office in a long
time. I have no problem with "4.7K" notation when dealing with stuff
in the lab when I have control over my schematics. When your out in
the field in low-light conditions, cramped quarters with 90 to 100 deg
F temperatures and you have to pour thru documentation with coffee
stains, hydraulic fluid stains, boot prints, worn and torn pages,
silverfish eaten pages - you appreciate the "4K7" notation.
In the field, you don't have the luxury of having all the wonderful
assembly documentation and version control documentation, especially
when the equipment is manufactured by others.
Oh, another place proportional fonts are used are hand drawn
schematics. Still come across those when dealing with old or
industrial equipment. Last hand drawn schematic I dealt with was the
navigation lighting system on a ship a couple years ago. Sucks when
your out in the middle of the ocean without your stbd. running lights.
Mark
Boris Mohar
wrote:
Hmmm....
http://whatis.techtarget.com/definition/0,,sid9_gci499008,00.html
Syd Rumpo
wrote:
>On Tue, 09 Dec 2003 11:47:33 +0000, Syd Rumpo <sydr...@notthisclara.co.uk>
>wrote:
>
>>On 5 Dec 2003 17:51:41 -0800, vale...@yahoo.com (Mike V.) wrote:
>>
>>>I was wondering about certain notation i see on schematics when it
>>>comes to resistors.
>>>
>>>What does 4K7 or 2K7 mean? Is it 4.7Kohms and 2.7Kohms, respectively?
>>>Thanks,
>>>Mike
>>
>>It should, of course, be 4k7 or 2k7 using a lower case k for kilo -
>>upper case K is Kelvins. A small point, perhaps, but worth getting
>>right.
>
> Hmmm....
>
>http://whatis.techtarget.com/definition/0,,sid9_gci499008,00.html
Hey! Someone just made up some stuff and put it on a WebSite! It's
still not 'correct', though. Big K ain't kilo; it's pretty unlikely
to confuse, but best to get it right just in case it's your arse that
needs covering. Shame really, 'cos big letters >1, small letters <1
would've been tidy.
Next thing, people will be writing mHz for megahertz. Couldn't happen
here, Shirley?
...and the sooner we all start using Ki for 2^10 &c. the better, IMO.
--
Syd
John Larkin
wrote:
Well, all of our stuff is high-density surface-mount, which nobody
would ever try to fix to component level in the field. But I used to
work on engine control systems on steamships, and would often be
inside the back of a console (or, worse, lying on the asbestos padding
on top of a live throttle valve) with an old D-size blueline in hand,
but I never had a problem with decimal points. This was, of course,
before the silly 4K7 affectation hit. I guess we had better decimal
points in the good-ole days.
In engineering school, we had to take Engineering Drawing, and we had
to make big, juicy decimal points. Most of the brats graduating from
school now can't draw or print at all.
John
John Woodgate
wrote (in <684etvk8q75kvl6bm...@4ax.com>) about 'Resistor
Notation on Schematics?', on Wed, 10 Dec 2003:
> Hmmm....
>
>http://whatis.techtarget.com/definition/0,,sid9_gci499008,00.html
>
It doesn't say that hard drive capacities are expressed in decimal
powers, not binary, so your 40 GB drive is smaller than you think.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!
John Woodgate
<sydr...@notthisclara.co.uk> wrote (in <sr7etvse6f9rr9s57lmog2u1j329pi6
q...@4ax.com>) about 'Resistor Notation on Schematics?', on Wed, 10 Dec
2003:
>...and the sooner we all start using Ki for 2^10 &c. the better, IMO.
Committees can never change people's language habits and I'm really
quite surprised that they even tried.
Syd Rumpo
<j...@jmwa.demon.contraspam.yuk> wrote:
>I read in sci.electronics.design that Syd Rumpo
><sydr...@notthisclara.co.uk> wrote (in <sr7etvse6f9rr9s57lmog2u1j329pi6
>q...@4ax.com>) about 'Resistor Notation on Schematics?', on Wed, 10 Dec
>2003:
>>...and the sooner we all start using Ki for 2^10 &c. the better, IMO.
>
>Committees can never change people's language habits and I'm really
>quite surprised that they even tried.
You're probably right (Mibi, Mibi not), but I have seen it used in a
couple of places and use it myself. If it's queried, I've found that
mumbling things like 'standard nowadays' combined with its great
utility lead to rapid acceptance.
--
Syd
Paul Burke
>
>
>
> Well, all of our stuff is high-density surface-mount, which nobody
> would ever try to fix to component level in the field. But I used to
> work on engine control systems on steamships, and would often be
> inside the back of a console (or, worse, lying on the asbestos padding
> on top of a live throttle valve) with an old D-size blueline in hand,
> but I never had a problem with decimal points. This was, of course,
> before the silly 4K7 affectation hit. I guess we had better decimal
> points in the good-ole days.
>
>
Far more difficult to explain to the techies is the surface mount
component value system. I mean, a 100 ohm resistor is labelled 101,
whereas a 1k is 103 or 1002 depending whether it's E12 or E24. And a
100nF capacitor is sort of brownish, whereas a 100pF is greyish
off-white (I think). Now how do you put THAT on the drawing?
And yes, they DO need to know, otherwise they can't do a visual inspection.
Paul Burke
Christian HOSTELET
>On 5 Dec 2003 17:51:41 -0800, vale...@yahoo.com (Mike V.) wrote:
>
>>I was wondering about certain notation i see on schematics when it
>>comes to resistors.
>>
>>What does 4K7 or 2K7 mean? Is it 4.7Kohms and 2.7Kohms, respectively?
>>Thanks,
>>Mike
>
>470K 470K
>47K 47K
>47K5 47.5K
>4K7 4.7K
>47R 47
>4R7 4.7
>
>Popuarized in European and Japanese schematics some decades ago. The
>main benefit is the decimal point isn't lost when you have a 3rd
>generation copy or looking at a D-size schematic printed on A paper.
>
>Mark
An other benefit was that these silly americans not using comma as the
decimal separator, were still able to read and understand the japanese
and european schematics.
So, in fact
4M7 4,7 M
4K7 4,7 K
4R7 4,7
Christian
John Larkin
wrote:
>Far more difficult to explain to the techies is the surface mount
>component value system. I mean, a 100 ohm resistor is labelled 101,
>whereas a 1k is 103 or 1002 depending whether it's E12 or E24. And a
>100nF capacitor is sort of brownish, whereas a 100pF is greyish
>off-white (I think). Now how do you put THAT on the drawing?
>
>And yes, they DO need to know, otherwise they can't do a visual inspection.
>
I wonder why nobody seems able to laser-print values on capacitors?
They can do most everything else. My QC people catch incorrect
resistor values, but all the caps pretty much look the same.
John
John Larkin
4,7 is pronounced "four...uh...seven."
John
Michael A. Terrell
>
> Far more difficult to explain to the techies is the surface mount
> component value system. I mean, a 100 ohm resistor is labelled 101,
> whereas a 1k is 103 or 1002 depending whether it's E12 or E24. And a
> 100nF capacitor is sort of brownish, whereas a 100pF is greyish
> off-white (I think). Now how do you put THAT on the drawing?
>
> And yes, they DO need to know, otherwise they can't do a visual inspection.
>
> Paul Burke
I have never had a problem reading surface mount parts values. Even
the chip caps from some vendors have a two character code to indicate
the value. On the other hand, if you can't read the code, use a
capacitor meter to verify the stock number matches the stated value.
--
14 days!
Michael A. Terrell
Central Florida
Michael A. Terrell
There is a faint marking on one side of a lot of surface mount caps.
SMD assemblers seem to have an uncanny ability to mount them ALL upside
down.
Greg Neff
<jjla...@highlandSNIPtechTHISnologyPLEASE.com> wrote:
(snip)
>
>I wonder why nobody seems able to laser-print values on capacitors?
>They can do most everything else. My QC people catch incorrect
>resistor values, but all the caps pretty much look the same.
>
>John
>
Capacitor manufacturer can and do mark capacitors, but they consider
it a "value added" service. This means extra cost and meeting minimum
order requirements from the factory. It would be interesting to figure
out the history of why the OEMs expect chip resistors to be marked,
but allow chip capacitors to be unmarked.
Parts are getting so small that we will all need electron microscopes
to see the markings anyway. Murata just introduced 01005 (0.4mm x
0.2mm) chip caps. I don't like using anything smaller than 0603...
================================
Greg Neff
VP Engineering
*Microsym* Computers Inc.
gr...@guesswhichwordgoeshere.com
John Woodgate
wrote (in <fllhtvkbps333nbj9...@4ax.com>) about 'Resistor
Notation on Schematics?', on Thu, 11 Dec 2003:
>I don't like using anything smaller than 0603...
I can't SEE anything smaller than 0603. (8-(
Peter Bennett
wrote:
>Far more difficult to explain to the techies is the surface mount
>component value system. I mean, a 100 ohm resistor is labelled 101,
>whereas a 1k is 103 or 1002 depending whether it's E12 or E24.
Shouldn't be a problem - it is just the normal resistor colour code,
but written in numbers, rather than colours. Same coding is used on
through-hole ceramic capacitors (value in pf), and on some
through-hole precision resistors.
--
Peter Bennett, VE7CEI
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John Woodgate
(in <br99pg$otkh$1...@ID-128611.news.uni-berlin.de>) about 'Resistor
Notation on Schematics?', on Thu, 11 Dec 2003:
>Far more difficult to explain to the techies is the surface mount
>component value system. I mean, a 100 ohm resistor is labelled 101,
>whereas a 1k is 103 or 1002 depending whether it's E12 or E24.
If a 100 ohm is coded 101, a 1k must be coded 102, not 103.
Paul Burke
> I read in sci.electronics.design that Paul Burke <pa...@scazon.com> wrote
> (in <br99pg$otkh$1...@ID-128611.news.uni-berlin.de>) about 'Resistor
> Notation on Schematics?', on Thu, 11 Dec 2003:
>
>
>>Far more difficult to explain to the techies is the surface mount
>>component value system. I mean, a 100 ohm resistor is labelled 101,
>>whereas a 1k is 103 or 1002 depending whether it's E12 or E24.
>
>
> If a 100 ohm is coded 101, a 1k must be coded 102, not 103.
Quite right. Just testing ;)
Paul Burke