Determining LowPass, BandPass, and HighPass filters

Thread Starter

iONic

Joined Nov 16, 2007
1,654
OK, let me guess, the middle filter is a BandPass.
Now, which is the HighPass and LowPass filters?

HPBPLP.PNG
 

LvW

Joined Jun 13, 2013
1,339
Your "guess" is correct - however, it is not necessary to "guess" because you can see (via optical inspection) why it is a bandpass:
* Because of the capacitors C1 (C4, C6) no DC component can enter the amplifier; very low frequencies can produce a negligible output only:
* The series connection of both capacitors (each filter) causes full negative feedback for very high frequencies (resulting in zero gain for inverting configurations);

Hence, only frequencies in the "middle" range (between the mentioned extremas) will cause an output with a maximum that can be computed or measured.
 

Thread Starter

iONic

Joined Nov 16, 2007
1,654
OK, all three are band-Pass filters. Let me rephrase my question. Which one is "passing" high freq, & which one is "passing" low freq. audio....given the input is the audio spectrum.
 
Top