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Basic Electronics » LM34 R-C Damper

March 19, 2010
by Ralphxyz
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The spec sheet suggest using a 75 ohm resistor. I do not have a 75 ohm resistor but I do have a 100 ohm resistor.

What difference would the extra 25 ohms make? What would it do?

mongo in a prior thread, [multiple LM34 temperature sensors] (http://www.nerdkits.com/forum/thread/621/), had suggested using a capacitor to sink any noise

R-C Damper this is from the spec sheet.

Thanks for the help, I know so little but I certainly am learning.

Should the R-C Damper be at the LM34 or at the breadboard?

Ralph

March 24, 2010
by Ralphxyz
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Does no one know the answer to what affect substituting a 100 ohm resistor for the 75 ohm resistor illustrated in the spec sheet will have?

I know a larger resistance will slow the "charging" of the capacitor but I do not know what that means.

Thanks for the help and setting me straight.

Ralph

March 24, 2010
by BobaMosfet
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Yes, the difference is approximately 25uS. You can use the 100 Ohm resistor without worries.

BM

March 24, 2010
by Ralphxyz
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Excellant thank you so much.

I know that was a really trivial question but I just didn't know the answer.

Could you post the formula that determines the speed of a capacitor charging?

This is just for my learning, nothing that I specifically need.

Ralph

March 24, 2010
by BobaMosfet
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It is approximately thus:

t = R * C

t = time in seconds
R = Ohms
C = Farads

BM

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