Low pass filter 20kHz

[spasmous2]

I am looking for a low pass filter around 20kHz to smooth a voltage
before passing it to an oscilloscope. The power requirements are
nominal and the transition region is not very important, Bessel, Cheby-
whatever, doesn't matter as long the general effect is to squish the
high frequencies above, say, 20-30kHz.

I was hoping there would be a simple component like a feed-thru
terminator I could buy off-the-shelf for around the same price (~$20)
but I can't seem to find a vendor. Anyone know of one?

 

[Eeyore]

spasmous2 wrote:

I am looking for a low pass filter around 20kHz to smooth a voltage
before passing it to an oscilloscope. The power requirements are
nominal and the transition region is not very important, Bessel, Cheby-
whatever, doesn't matter as long the general effect is to squish the
high frequencies above, say, 20-30kHz.

I was hoping there would be a simple component like a feed-thru
terminator I could buy off-the-shelf for around the same price (~$20)
but I can't seem to find a vendor. Anyone know of one?

The frequency is so low that it doesn't 'feed through' type construction.

Why not build your own ? A first order filter just needs one resistor and one
capacitor.

Graham

 

[Lost in the Wasteland]

spasmous2 wrote:

I am looking for a low pass filter around 20kHz to smooth a voltage

http://www.muzique.com/schem/filter.htm

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[Otto, Matt]

The secondary of most 12 VDC transformers will squash just about
everything. Otherwise try Radio Shack. They have a selection of
inductors...

-----Original Message-----
From: Lost in the Wasteland [mailto:Lost@there.com]
Posted At: Saturday, July 28, 2007 8:48 PM
Posted To: equipment
Conversation: Low pass filter 20kHz
Subject: Re: Low pass filter 20kHz


spasmous2 wrote:

I am looking for a low pass filter around 20kHz to smooth a voltage

http://www.muzique.com/schem/filter.htm

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