Capacitance and inductance of passive filter

AI Thread Summary
Calculating values for capacitors and inductors in a passive filter requires knowledge of frequency, but current is not necessary. At 60Hz, finding suitable component values can be challenging due to limitations in available capacitor and inductor sizes. Real-world applications often necessitate active filters for low frequencies unless high-cost components are used. Various filter types, such as Chebyshev and Butterworth, can be employed depending on the desired characteristics. Online calculators can assist in determining appropriate component values, while voltage and current are primarily relevant for power handling considerations.
Idea04
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I'm having some trouble calculating the values I need for a capacitor and inductor for a passive filter. The values that I know to use are current, voltage and frequency. But I have a voltage <1 volt and a frequency of 60Hz but no current. Can someone help me figure out what value of capacitor and inductor to use.
 
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Idea04 said:
I'm having some trouble calculating the values I need for a capacitor and inductor for a passive filter. The values that I know to use are current, voltage and frequency. But I have a voltage <1 volt and a frequency of 60Hz but no current. Can someone help me figure out what value of capacitor and inductor to use.
You don't need to know the current. Just the frequency, capacitance and indunctance.
http://mysite.du.edu/~etuttle/electron/elect31.htm"
 
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Do you have an equation to figure out inductance and capacitance. If I don't have the capacitor or inductor how do I determine what the inductance and capacitance is. All I have is the frequency.
 
There is no equation; both are free parameters.
However, in real applications you need real componenents. If you take a look at what is available you will quickly realize that the range is actually quite limited; you can't buy a 100F capacitor or a 1 fH inductor. You need to find a combination of values that give you the right frequency and at the same time result in realistic values for C and L.

Which, by the way, can't really be done at 60Hz; for frequencies that low you need an active filter (unless you are willing to spend a LOT of money on the type of huge chokes used in e.g. tube amplifiers).
 
What sort of filter? For what? Low pass? Impedance? Roll off? Ultimate attenuation?

There are plenty of filter types .. Chebyshev, Butterworth, Elliptical, Constant K. These will have low passband ripple if terminated with the current i/p and o/p impedance.

There are probably on-line calculators to give you the component values.

Voltage and current only come into when considering the required power handling.
 
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