10000uF (coupled) frequency responce!

[whiz115]

does anyone knows the frequency responce for a 10000uF capacitor
when it is coupled? also where can i find a table which demostrates the frequency responses for typical capacitors when they are coupled?

i only know that a 10000uF capacitor has zero ohm reactance at 3184Hz
and 15.92ohm reactance at 1Hz. what's the reactance after 3184Hz?
it can pass any frequency without blocking it?! no upper limit?

thank you!

 

[j.p.bill]

Do you mean using the capacitor as a coupling capacitor between amplifier stages? That's and outrageously large value for the function. More like a big filter capacitor on a bridge rectifier.

The formula T = RC will give you the charge time for the capacitor and the input resistor. Use F = 1/T for the frequency below which there will start to be signal attenuation. Unless you're coupling signals at a fraction of a Hertz, 10,000 uF is overkill.

Yes, Xc decreases with frequency. Hard to get smaller than zero.

 

[audioguru]

An electolytic capacitor has its internal foil and insulation wound around and around which makes it inductive at high frequencies. So it resonates with a high impedance at a certain not very high frequency.

If you like deep bass and accurate high frequencies then use a DC-coupled amplifier.

 

[whiz115]

well...

somebody told me that i can't use large capacitors to pass high frequencies...
because there is a limit which a capacitor has "cut off" for both high and low frequencies...

i tought that capacitors tend to cut off lower frequencies and not higher!

 

[audioguru]

i thought that capacitors tend to cut off lower frequencies and not higher!

Read what I said about how big capacitors are inductive and are a high impedance at their resonant frequency.

 

[whiz115]

i was explaining why i did the initial question...

so it's the induction that limits a big electrolytic capacitor to pass high frequencies...does induction limits also small ceramic capacitors to pass a whatever value of high frequency we want?

 

[mneary]

Yes, all electronic devices have some inductance. Typical ceramic capacitors begin to "look" inductive at frequencies between 10 MHz and 100 MHz, depending on their physical dimensions, internal construction, and capacitance.

 

[audioguru]

A ceramic disk capacitor with short leads and small so its capacitance is 2000pf or less performs very well up to microwave frequencies.

 

[johnnitwenty]

is this a homework?
this link is useful:
http://www.ecircuitcenter.com/Circuits/cmodel1/cmodel1.htm

 

[mneary]

A disk capacitor may perform very well at microwave frequencies, but its reactance has shifted + (inductive) at hundreds of MHz, even for small values.
**broken link removed** The lead length is usually the limiting factor.

 

[whiz115]

thanks guys! now i think i understand what my friend wanted to say...

 

[Hero999]

That capacitor will probably have an inductance of about 2:mu:H, therefore it will have a resonant frequency of just over 1kHz which is useless for AC coupling.