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Passive Frequency Filter with Cut-off negative part of the sine wave

PeterB

Jun 7, 2017
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Jun 7, 2017
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Hey there, im relative new to electronics and i am having a probably stupid question right now to which i cant really seem to find an answer.
I am doing a small project where i want to only let through a specific area of frequencies (band pass filter) in a pretty low frequency range (between 1 and 2khz). A passive filter would be the simplest choise, but hence my project has nothing to do with audio i dont have a normal sine wave as an input. Instead i have a "sine wave" with no negative voltages (the entire negative part of the wave is 0V instead). So basically looks like a sine wave going through a single diode.
Would this actually work at all since the entire negative part is missing?

Thank you for you time.
 

duke37

Jan 9, 2011
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Jan 9, 2011
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A clipped sine wave will contain a lot of harmonics. The filter will select some of them. If this is audio, it will sound ORRIBUL.
You could simulate it in LTspice.
 

Audioguru

Sep 24, 2016
3,650
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Sep 24, 2016
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A bandpass filter does not select the band of frequencies you want and block the frequencies you don't want. It selects the middle of the band at full level then reduces the edge frequencies a little. The frequencies above and below are reduced, only when the frequencies are fairly distant from the band that are passed then they are reduced very low.
 
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