Author Topic: What Voltage is used to calculated capacitor charge?  (Read 560 times)

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Offline implorTopic starter

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What Voltage is used to calculated capacitor charge?
« on: November 24, 2019, 02:29:27 pm »

Is there a standard that say what voltage to use when determine a capacitors capacitance?

Example:

you have a 1uF rated at 50V capacitors.

is that 1uF at 50V?

C = Q/V




 

Offline Kleinstein

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Re: What Voltage is used to calculated capacitor charge?
« Reply #1 on: November 24, 2019, 02:36:08 pm »
In most cases capacitors are quite linear and it does not really matter which voltage to use.
The normal way is to use a small voltage (like 1V) - so the same instrument can test all most capacitors.
Especially with some MLCCs (class 2) however this can matter and the capacitance values given are for low voltage with no bias.
 

Offline implorTopic starter

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Re: What Voltage is used to calculated capacitor charge?
« Reply #2 on: November 24, 2019, 02:55:49 pm »
Sound logical ;).

the confusion is because i'm thinking of Capacitance as Energy but it's not.

I was thinking about how using a high voltage rated capacitor would impact the amount of stored energy. Example 50V MLCC vs 25V MLCC (ignoring derating)

But when I'm now doing some math I see it's only dependent on the accentual applied voltage and not the maximum rating.

W = (C*V^2)/2

Thanks for the reply  :-+
 


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