capacitor codes

[rshafi68]

i want a code table to read the right value of capacitors like pico ,nano.can anybody help me in this regard?

 

[Papabravo]

If you mean capacitor values expressed as three decimal digits. Sure the first two digits are the value multiplied by 10 to the third digit. Te result is ALWAYS in pico farads.

Examples

103 = 10 * 10^3 picofarads = 0.01 microfarads
104 = 10 * 10^4 picofarads =  0.1 microfarads
105 = 10 * 10^5 picofarads =  1.0 microfarads

474 = 47 * 10^4 picofarads = 0.47 microfarads

 

[lord loh.]

And if they are mentioned with a period, they are to be assumed as microFarads.

Ex:

.01 = .01 microFarads.

Here is **broken link removed**

Cheers.

 

[desperadogear]

Reading Capacitor Codes
Large capacitor have the value printed plainly on them, such as 10.uF (Ten Micro Farads) but
smaller disk types along with plastic film types often have just 2 or three numbers on them?
First, most will have three numbers, but sometimes there are just two numbers. These are
read as Pico-Farads. An example: 47 printed on a small disk can be assumed to be 47 Pico-
Farads (or 47 puff as some like to say)
Now, what about the three numbers? It is somewhat similar to the resistor code. The first two
are the 1st and 2nd significant digits and the third is a multiplier code. Most of the time the last
digit tells you how many zeros to write after the first two digits, but the standard (EIA standard
RS-198) has a couple of curves that you probably will never see. But just to be complete here
it is in a table.
What these numbers don't tell us is the ESR rating of a capacitor. Despite popular belief
capacitors will often still have the correct value of capacitance when they fail. To truly check a
capacitor's condition, you need a meter that measures the ESR.
milli, micro, nano, pico
1 mili Farad (or any other unit) is 1/1,000th or .001 times the unit. (10-3)
1 micro = 1/1,000,000 or 0.000 001 times the unit (10-6 )
1 nano = 1/1,000,000,000 or 0.000 000 001 times the unit (10-9 )
1 pico = 1/1,000,000,000,000 or 0.000 000 000 001 times the unit (10-12 )
Table 1 Digit multipliers
Third digit Multiplier (this times the first two digits
gives you the value in Pico-Farads)
0 1
1 10
2 100
3 1,000
4 10,000
5 100,000
6 not used
7 not used
8 .01
9 .1
Now for an example: A capacitor marked 104 is 10 with 4 more zeros or 100,000pF which is
otherwise referred to as a .1 uF capacitor.
Most kit builders don't need to go further, but I know you want to learn more. Anyway, Just to
confuse you some more there is sometimes a tolerance code given by a single letter. I don't
know why there were picked in the order they are, except that it kind of follows the middle row
of keys on a typewriter.
So a 103J is a 10,000 pF with +/-5% tolerance
Table 2 Letter tolerance code
Letter symbol Tolerance of capacitor
B +/- 0.10%
C +/- 0.25%
D +/- 0.5%
E +/- 0.5%
F +/- 1%
G +/- 2%
H +/- 3%
J +/- 5%
K +/- 10%
M +/- 20%
N +/- 0.05%
P +100% ,-0%
Z +80%, -20%
Now to be really complicate things there is sometimes a letter-number-letter (like Z5U) code
that gives information. Table 3 shows how to read these cryptic codes. A 224 Z5U would be a
220,000 pF (or .22 uF) cap with a low temperature rating of -10 deg C a high temperature
rating of +85 Deg C and a tolerance of +22%,-56%.
Table 3 Dielectric codes
First
symbol
(a
letter)
Low
temperature
requirement
Second
symbol
(a
number)
High
Temperature
requirement
Third
Symbol
(a
letter)
MAX.
Capaci
tance
chang
e over
temper
ature
Z +10 deg. C 2 +45 deg. C A +1.0%
Y -30 deg. C 4 +65 deg. C B +/- 1.5%
X -55 deg. C 5 +85 deg. C C +/- 2.2%
6 +105 deg. C D +/- 3.3%
7 +125 deg. C E +/- 4.7%
F +/- 7.5%
P +/- 10.0%
R +/- 15.0%
S +/- 22.0%
T +22%,
-33%
U +22%,
-56%
V +22%,
-82%
There are some Capacitor color codes - the last dot is the tolerance code where brown is +/-
1% red +/-2% as in the resistor color code with two exceptions black is +/- 20% and white is
+/- 10% going backward the three dots to the left of the tolerance dot form the value in pF
There will be two or three more color dots before the value but they mean

 

[heraldo]

point and line code?

--------------------------------------------------------------------------------

I find a capacitor with this value 474 (0.47 micro farads) , but how i find his rated voltage? y only see some kind of lines and points. (_._.)
Somebody know the manufacturer to seek the especifications at the official site.
Sorry for bad engllish, my first langiaje is Spanish

my capacitor present the same shape and clolor as the shown on the picture

 

[Dr.EM]

That one says at the bottom "250v", it is rated at 250 volts. The number with "v" following it will indicate the voltage rating on a similar cap.

 

[heraldo]

This is a better pic

 

[Tracy Walker]

Reading Capacitor Codes

But I have a bag of assorted capacitors from circuit city in which most of the small (in physical size) caps have just one or two numbers, ie; '1' or '10' with an underline and nothing more. What's that all about?

 

[rmn_tech]

pico farads

If the capacitor has just one or two numbers then it is probably in pico farads.

e.g 47 = 47 pico farads
3.3 or 3p3 = 3.3 pico farads

However some components are manufactured for a particular manufacturer and have a non standard marking. This makes it difficult to identify them and therefore difficult to repair unless the engineer is a registered agent. However this is rare with passive components so I think you will find that your capacitors are simply pico farads

 

[Hero999]

100nF and 220nf.

 

[fingaz]

You could try going here www.electronics2000.co.uk and downloading electronics assistant. It will help you to work out capacitor codes aswell as many other things (resistors, power, ohm's law etc etc)

And it's FREE

 

[Tracy Walker]

You could try going here www.electronics200.co.uk and downloading electronics assistant. It will help you to work out capacitor codes aswell as many other things (resistors, power, ohm's law etc etc)

And it's FREE

you need to add a zero to that URL--it's electronics2000...etc.

 

[fingaz]

yeah, sorry. . . slight typo there

 

[Dean Huster]

I don't like the tolerance listing that was posted previously. I think this one is far more correct:

B = ±0.1pF
C = ± 0.25pF
D = ±0.5pF
E = ±0.25%
F = ±1.0%
G = ±2%
H = ±2.5%
J = ±5%
K = ±10%
L = ±15%
M = ±20%
N = ±30%
P = -0, +100%
S = -20, +50%
W = -0, +200%
X = -20, +40%
Z = -20, +80%

Dean

 

[adax811]

i got 1 capacitor problem.....

who can help me about how to read a capacitor?
i got a picture here, pm me and i send u the pic.

 

[fingaz]

Read through the whole of this thread. . . it explains how to read capacitor codes. If you're still not sure, post the picture, or the code and we'll be happy to help you work it out.

 

[Richard Principal]

and I have this

TOLERANCE CODE:
B = ±0.1pF
C = ±0.25pF
D = ±0.5pF, ± 0.5%
E = ±1pF
F = ±1pF, ±1%,
G = ±2pF, ±2%,
H = ±2,5%
J = ±5%,
K = ±10%,
L = ±15%
M = ±20%,
N = ±30%
P = +100%/ -0%
R = +30% / -20%
S = +50% / -20%
Z = +80% / -20%

note the error at E & F

 

[adax811]

like heraldo had said, how to know the voltage about his capacitor? (__.__.)

 

[Hero999]

Connect it so a variable power, crank up the voltage until it explodes.

 

[fingaz]

If it doesn't state a voltage, you can only guess. . . And a guess is just that.

There's no secret, invisible writing. . . And it's not written in the dashes and dots. If it's something you need to replace, then just replace it with a higher voltage rating than you expect it to need.

All electrolytics that I've seen give the rated voltage (in V - volts or WV - working volts=same thing) And you can get ceramics rated at 4Kv, which should be high enough for most applications.

If you're replacing a particular capacitor in a specific piece of equipment, and you're not sure what to use. . . just ask on here, give as much info as possible, and I'm sure the more experienced members will be pleased to point you in the right direction. . .

Or just do what Hero999 suggested, but don't forget to note the voltage at which the cap exploded