Author Topic: Identifying box caps by the little numbers on top  (Read 3980 times)

Bret608

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Identifying box caps by the little numbers on top
« on: September 21, 2012, 07:33:25 AM »
Hi everyone,

How do you read the numbers on top of our old friend the box capacitor? I've got five of them going onto a Wolfshirt board this afternoon, and want to make sure I've got it right. So I've got a specific task here, but since I'll surely use this knowledge many times after, I thought this would be the right place for the thread.

So for example, here are the numbers on the caps and what I think they mean after looking at the BOM:

104J100: 100n?
102J100: 1n?
473J100: 47n? (subbing for the 50n cap)
332J100: 3n?

Thanks in advance for the help as always!

Bret

culturejam

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Re: Identifying box caps by the little numbers on top
« Reply #1 on: September 21, 2012, 07:58:38 AM »
You have it right on the values.

It breaks down like this:

Value | Tolerance | Voltage Rating

104J100


104 = 100n  (10 + 4 zeroes, in picofarads)

J = 5% tolerance

100 = 100v rating


For more reading:
http://www.electronics2000.co.uk/data/itemsaf/capmarks.php

Bret608

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Re: Identifying box caps by the little numbers on top
« Reply #2 on: September 21, 2012, 08:04:03 AM »
I appreciate it! This site looks to be a great resource.

Guitafuzz

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Re: Identifying box caps by the little numbers on top
« Reply #3 on: September 21, 2012, 09:21:16 AM »


   Hi Bret this table can be useful too together with the explanion of culturejam.

   

DutchMF

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Re: Identifying box caps by the little numbers on top
« Reply #4 on: September 21, 2012, 01:34:39 PM »
You have it right on the values.

It breaks down like this:

Value | Tolerance | Voltage Rating

104J100


104 = 100n  (10 + 4 zeroes, in picofarads)

J = 5% tolerance

100 = 100v rating


For more reading:
http://www.electronics2000.co.uk/data/itemsaf/capmarks.php

Good stuff CJ, thanx! I knew a lot of this in bits and pieces, but seeing it like this in one concise post is always a pleasure!

Paul
"If you can't stand the heat, stay away from the soldering iron!"

culturejam

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Re: Identifying box caps by the little numbers on top
« Reply #5 on: September 22, 2012, 11:31:26 PM »
Here's another handy chart for converting between the various multipliers of values:
http://www.justradios.com/uFnFpF.html