Why the is using C2 and C4 feedback capacitor in this schematic which is a speech amplifier?
Why he wanted to double integrated from the input speech by adding the said caps?
Why the is using C2 and C4 feedback capacitor in this schematic which is a speech amplifier?
Why he wanted to double integrated from the input speech by adding the said caps?
Thanks Nigel
I know that an Integrator is a Low pass filter, But I am wondering why we need to use an integartor for a speech amplifier?
Why the designer wated to filter high frequencies? What kind of high frequency you talk about?
Thanks Nigel
I know that an Integrator is a Low pass filter, But I am wondering why we need to use an integartor for a speech amplifier?
Why the designer wated to filter high frequencies? What kind of high frequency you talk about?
All you want is speech frequencies, so you filter off the high frequencies and the low frequencies, this makes speech more intelligible, and reduces the bandwidth required - absolutely crucial for radio ham use, where narrow channel spacing is used.
The resistor in parallel with the feedback capacitor makes it a low-pass filter with a -3dB rolloff frequency of 1/(2pi*RC). If there were no resistor than the circuit would be a pure integrator.