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Author Topic: How to identify smd ceramic cap values.  (Read 7664 times)

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Offline SmAsHTopic starter

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How to identify smd ceramic cap values.
« on: August 23, 2009, 12:09:22 AM »
Does anyone know of a way to work out the capacitance of a smd ceramic capacitor?
I have a tonne of them sitting in a tray and would like to know if anyone has a way i could identify them.

Thanks in advance,
SmAsH
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Offline fiflak666

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Re: How to identify smd ceramic cap values.
« Reply #1 on: August 23, 2009, 02:28:10 AM »
unfortunately it isn't simple  :-\

I know only one way to find it out (as I know the only one)

You have to use multimeter able to measure capaticance (like this IMAGE) and somehow connect it to your small capacitor (for example solder thin piceces of wire - taken from resistor - to soldering pads of capacitor)

to avoid situation like this - next time write on the tray value of capaticance (it should be done at the moment of buing - in the electronic shop)
« Last Edit: August 23, 2009, 02:32:01 AM by fiflak666 »

Offline SmAsHTopic starter

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Re: How to identify smd ceramic cap values.
« Reply #2 on: August 23, 2009, 02:31:07 AM »
damn, i guess im screwed for a while then...
my old fart of a multimeter doesn't measure capacitance :P
someday ill get a new one... someday...

thanks for that fiflak666 :)
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Offline Truckstop

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Re: How to identify smd ceramic cap values.
« Reply #3 on: August 23, 2009, 03:02:34 AM »
youll need to make a cheet sheet when you measure them. i diddent even think of using them befor reading this post. heres some values i had laying around and what they measured out at...

# on cap        --    Measured value
     101       ---              100pf
       10       ---              0.01pf
     224      ---              220pf
     475     ----             47pf

Yes a good multimeter is worth its weight in gold. i have one such as the one pictured, as well as a desktop multimeter that has way too many functions...  hope the values help, they should be accurate, i tested at least 2 of each value,(2 of the ones labled 475, 4 of the ones labled 101, 3 of the 10's and 5 of the 224's. written values are average not exact.

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Offline SmAsHTopic starter

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Re: How to identify smd ceramic cap values.
« Reply #4 on: August 23, 2009, 03:08:07 AM »
were those ones tantalum or ceramic?
i cant find any writing on my ceramic ones...
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Offline fiflak666

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Re: How to identify smd ceramic cap values.
« Reply #5 on: August 23, 2009, 09:34:06 AM »
you won't find any writing because there are any  :P

producent doesn't put any additional signs on smd capaticor because it would change its capacity

Offline Truckstop

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Re: How to identify smd ceramic cap values.
« Reply #6 on: August 23, 2009, 12:39:19 PM »
they are the rectangular surface mount caps. yes the smaller ones usually dont have writing on them but the larger ones do...

truckstop
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Offline Soeren

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Re: How to identify smd ceramic cap values.
« Reply #7 on: August 23, 2009, 02:03:10 PM »
Hi,

There are several ways of measuring the capacitance.

Either use a capacitance bridge (cheap) or setup an oscillator (a 555 astable would do) with Cx as the frequency determining component and measure frequency - then calculate the value of Cx.
Calibrate either with caps of a known value.
Regards,
Søren

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