# Capacitor notation

Discussion in 'Electronic Basics' started by Peter Hucker, Jul 16, 2006.

1. ### Peter HuckerGuest

I have two capacitors lying here, with the following inscriptions:
http://www.hucker.plus.com/temp/caps.jpg

One is blue and circular and reads:

B
102K
2KV

The other is green and a rounded rectangular shape and reads:

104K100V

The blue one reads approx 1nF on my meter, the green one reads approx 100nF.

This makes sense if you take the three numbers (102 or 104) read the same way as resistors - 1, 0, then 2 (or 4) zeroes. I.e. 1000 or 100000, and the units to be pF. So what does the K mean? I originally thought it was a multiplier (1000), but it seems unnecessary, unless the units without the K are in fF!

Also, what is the B on the blue one? I asssume it's not to indicate the colour ;-)

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

Jack and Jill went up the hill
And planned to do some kissing.
Jack made a pass, and grabbed her ass
Now two of his teeth are missing.

Peter Hucker, Jul 16, 2006

2. ### Don KlipsteinGuest

In article <op.tcso87uowabk2w@blue>, Peter Hucker wrote:
>I have two capacitors lying here, with the following inscriptions:
>http://www.hucker.plus.com/temp/caps.jpg
>
>One is blue and circular and reads:
>
>B
>102K
>2KV
>
>The other is green and a rounded rectangular shape and reads:
>
>104K100V
>
> The blue one reads approx 1nF on my meter, the green one reads approx
> 100nF.
>
> This makes sense if you take the three numbers (102 or 104) read the
> same way as resistors - 1, 0, then 2 (or 4) zeroes. I.e. 1000 or
> 100000, and the units to be pF. So what does the K mean? I originally
> thought it was a multiplier (1000), but it seems unnecessary, unless the
> units without the K are in fF!

K means 10% tolerance. J means 5% tolerance.

No tolerance code usually means 20% tolerance but can be worse. For
example, ceramics with Z5U and similar dielectrics usually have tolerance
of +80/-20% at 25 degrees C and the value varies greatly with temperature
- generally decreasing as the temperature goes much away from 25 C in
either direction.

>Also, what is the B on the blue one? I asssume it's not to indicate the
>colour ;-)

That I don't know.

- Don Klipstein ()

Don Klipstein, Jul 16, 2006

3. ### John PopelishGuest

Peter Hucker wrote:
> I have two capacitors lying here, with the following inscriptions:
> http://www.hucker.plus.com/temp/caps.jpg
>
> One is blue and circular and reads:
>
> B
> 102K
> 2KV
>
> The other is green and a rounded rectangular shape and reads:
>
> 104K100V
>
> The blue one reads approx 1nF on my meter, the green one reads approx 100nF.
>
> This makes sense if you take the three numbers (102 or 104) read the same way as resistors - 1, 0, then 2 (or 4) zeroes. I.e. 1000 or 100000, and the units to be pF. So what does the K mean? I originally thought it was a multiplier (1000), but it seems unnecessary, unless the units without the K are in fF!
>
> Also, what is the B on the blue one? I asssume it's not to indicate the colour ;-)
>

I could translate these for you, but you should have a crack at them
yourself, first. See:
http://www.twysted-pair.com/capidcds.htm

John Popelish, Jul 16, 2006
4. ### EeyoreGuest

Peter Hucker wrote:

> I have two capacitors lying here, with the following inscriptions:
> http://www.hucker.plus.com/temp/caps.jpg
>
> One is blue and circular and reads:
>
> B
> 102K
> 2KV
>
> The other is green and a rounded rectangular shape and reads:
>
> 104K100V
>
> The blue one reads approx 1nF on my meter, the green one reads approx 100nF.
>
> This makes sense if you take the three numbers (102 or 104) read the same way as resistors - 1, 0, then 2 (or 4) zeroes. I.e. 1000 or 100000, and the units to be pF.

That's it.

> So what does the K mean? I originally thought it was a multiplier (1000), but it seems unnecessary, unless the units without the K are in fF!

K is 10% tolerance.

> Also, what is the B on the blue one? I asssume it's not to indicate the colour ;-)

Manufacturer's mark.

Graham

Eeyore, Jul 16, 2006
5. ### HKJGuest

HKJ, Jul 16, 2006
6. ### JamieGuest

Peter Hucker wrote:

> I have two capacitors lying here, with the following inscriptions:
> http://www.hucker.plus.com/temp/caps.jpg
>
> One is blue and circular and reads:
>
> B
> 102K
> 2KV
>
> The other is green and a rounded rectangular shape and reads:
>
> 104K100V
>
> The blue one reads approx 1nF on my meter, the green one reads approx 100nF.
>
> This makes sense if you take the three numbers (102 or 104) read the same way as resistors - 1, 0, then 2 (or 4) zeroes. I.e. 1000 or 100000, and the units to be pF. So what does the K mean? I originally thought it was a multiplier (1000), but it seems unnecessary, unless the units without the K are in fF!
>
> Also, what is the B on the blue one? I asssume it's not to indicate the colour ;-)
>

lets see, i'll take wack at it.
0.001 Uf at 10% ?
that's just a guess,. i just ordered some caps the other day, the K
was on the top of me head.

--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

Jamie, Jul 17, 2006
7. ### Peter HuckerGuest

On Sun, 16 Jul 2006 19:56:00 +0100, Don Klipstein <> wrote:

> In article <op.tcso87uowabk2w@blue>, Peter Hucker wrote:
>> I have two capacitors lying here, with the following inscriptions:
>> http://www.hucker.plus.com/temp/caps.jpg
>>
>> One is blue and circular and reads:
>>
>> B
>> 102K
>> 2KV
>>
>> The other is green and a rounded rectangular shape and reads:
>>
>> 104K100V
>>
>> The blue one reads approx 1nF on my meter, the green one reads approx
>> 100nF.
>>
>> This makes sense if you take the three numbers (102 or 104) read the
>> same way as resistors - 1, 0, then 2 (or 4) zeroes. I.e. 1000 or
>> 100000, and the units to be pF. So what does the K mean? I originally
>> thought it was a multiplier (1000), but it seems unnecessary, unless the
>> units without the K are in fF!

>
> K means 10% tolerance. J means 5% tolerance.

Ah I see. Thanks.

> No tolerance code usually means 20% tolerance but can be worse. For
> example, ceramics with Z5U and similar dielectrics usually have tolerance
> of +80/-20% at 25 degrees C and the value varies greatly with temperature
> - generally decreasing as the temperature goes much away from 25 C in
> either direction.

Ouch - are those things much use?

>> Also, what is the B on the blue one? I asssume it's not to indicate the
>> colour ;-)

>
> That I don't know.
>
> - Don Klipstein ()

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

Anybody who claims that marriage is a fifty-fifty proposition doesn't know a damned thing about women or fractions.

Peter Hucker, Jul 17, 2006
8. ### Peter HuckerGuest

On Sun, 16 Jul 2006 20:04:17 +0100, John Popelish <> wrote:

> Peter Hucker wrote:
>> I have two capacitors lying here, with the following inscriptions:
>> http://www.hucker.plus.com/temp/caps.jpg
>>
>> One is blue and circular and reads:
>>
>> B
>> 102K
>> 2KV
>>
>> The other is green and a rounded rectangular shape and reads:
>>
>> 104K100V
>>
>> The blue one reads approx 1nF on my meter, the green one reads approx 100nF.
>>
>> This makes sense if you take the three numbers (102 or 104) read the same way as resistors - 1, 0, then 2 (or 4) zeroes. I.e. 1000 or 100000, and the units to be pF. So what does the K mean? I originally thought it was a multiplier (1000), but it seems unnecessary, unless the units without the K are in fF!
>>
>> Also, what is the B on the blue one? I asssume it's not to indicate the colour ;-)
>>

> I could translate these for you, but you should have a crack at them
> yourself, first. See:
> http://www.twysted-pair.com/capidcds.htm

Christ, what a mess! Rather ambiguous when the third number COULD be a multiplier.

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

Politicians are like diapers.
They should both be changed frequently and for the same reason.

Peter Hucker, Jul 17, 2006
9. ### Peter HuckerGuest

On Mon, 17 Jul 2006 04:54:20 +0100, Jamie <> wrote:

> Peter Hucker wrote:
>
>> I have two capacitors lying here, with the following inscriptions:
>> http://www.hucker.plus.com/temp/caps.jpg
>>
>> One is blue and circular and reads:
>>
>> B
>> 102K
>> 2KV
>>
>> The other is green and a rounded rectangular shape and reads:
>>
>> 104K100V
>>
>> The blue one reads approx 1nF on my meter, the green one reads approx100nF.
>>
>> This makes sense if you take the three numbers (102 or 104) read the same way as resistors - 1, 0, then 2 (or 4) zeroes. I.e. 1000 or 100000, and the units to be pF. So what does the K mean? I originally thought it was a multiplier (1000), but it seems unnecessary, unless the unitswithout the K are in fF!
>>
>> Also, what is the B on the blue one? I asssume it's not to indicate the colour ;-)
>>

> lets see, i'll take wack at it.
> 0.001 Uf at 10% ?
> that's just a guess,. i just ordered some caps the other day, the K
> was on the top of me head.

I wish I knew of a place in the UK that had their components organised better on their websites. Maplin are almost impossible to use, Farnell are getting close.

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

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Peter Hucker, Jul 17, 2006
10. ### Phat BytestardGuest

On Mon, 17 Jul 2006 12:13:55 +0100, "Peter Hucker" <> Gave
us:

>Christ, what a mess! Rather ambiguous when the third number COULD be a multiplier.

The third digit IS ALWAYS a multiplier.

If it is expressed in 3 digit form, it is in picofarads to the order
of magnitude given in the third digit.

A nanofard part declaration is two significant digits with the lower
case "n" designation in the place where the third digit would be.

That was a greta page BTW. Nothing ambiguous at all.

Phat Bytestard, Jul 18, 2006
11. ### Peter HuckerGuest

On Tue, 18 Jul 2006 02:51:42 +0100, Phat Bytestard <> wrote:

> On Mon, 17 Jul 2006 12:13:55 +0100, "Peter Hucker" <> Gave
> us:
>
>> Christ, what a mess! Rather ambiguous when the third number COULD bea multiplier.

>
> The third digit IS ALWAYS a multiplier.
>
> If it is expressed in 3 digit form, it is in picofarads to the order
> of magnitude given in the third digit.
>
> A nanofard part declaration is two significant digits with the lower
> case "n" designation in the place where the third digit would be.
>
> That was a greta page BTW. Nothing ambiguous at all.

http://www.twysted-pair.com/capidcds.htm shows a 150nF capacitor with "150". If the third digit was a multiplier, that would be 15 x 10^0 = 15nF, yet the site claims it is a 150nF cap.

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

If quizzes are quizzical, what are tests?

Peter Hucker, Jul 18, 2006
12. ### PhilK

Joined:
Sep 16, 2009
Messages:
1
0
Location:
Mount Airy, MD, USA
Kfj

I believe it is:

M = 20%
K = 10%
J = 5%
...
F = 1%

Ref: on the http : // WorldWideWeb (www)
wjoe.com
/capacitorinfo2.htm

PhilK

PhilK, Sep 16, 2009