I am designing a device that detects harmonic distortion. While playing music within musical limits(say 20hz-20khz) it will not trigger unless the frequency is outside the hearing range(over 20khz).
My highest input voltage can go upto about 200ACV(before attenuation) So I want to attenuate the input voltage with a voltage divider, then use an opamp as a differentiator to trigger an LED when harmonics develop(they develop close to clipping threshold). Can someone help me with the capacitor value, and what resistance values should be used to attenuate the input? The circuit is generally simple but I have never designed for something that has a range of say 200-300ACV RMS max. I want as little power to be wasted through the circuit as possible as I am going to use it during music play(a speaker connected and playing).
My Max ACV ratings can change to go lower some...
I realize an HPF has a slope which is why I don't want to try one because then it would be tough to design within limits due to another voltage in a different music setup having a higher voltage output(I want to be able to use it for more then one setup). Is a differentiator more dependand on frequency? I don't want to have to worry too much about designing for a max voltage value but then moving it to a higher voltage setup and now the slope isn't sharp enough, but I don't want to use inductors for a multi order filter, just something like a capacitor or few.
The speaker impedance will varry due to using a circuit for each speaker channel, 1, 2, and 4 ohms.
My highest input voltage can go upto about 200ACV(before attenuation) So I want to attenuate the input voltage with a voltage divider, then use an opamp as a differentiator to trigger an LED when harmonics develop(they develop close to clipping threshold). Can someone help me with the capacitor value, and what resistance values should be used to attenuate the input? The circuit is generally simple but I have never designed for something that has a range of say 200-300ACV RMS max. I want as little power to be wasted through the circuit as possible as I am going to use it during music play(a speaker connected and playing).
My Max ACV ratings can change to go lower some...
I realize an HPF has a slope which is why I don't want to try one because then it would be tough to design within limits due to another voltage in a different music setup having a higher voltage output(I want to be able to use it for more then one setup). Is a differentiator more dependand on frequency? I don't want to have to worry too much about designing for a max voltage value but then moving it to a higher voltage setup and now the slope isn't sharp enough, but I don't want to use inductors for a multi order filter, just something like a capacitor or few.
The speaker impedance will varry due to using a circuit for each speaker channel, 1, 2, and 4 ohms.
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