Hello everyone, I'm new here, but I'd like to ask a question if it's not too much trouble.
As part of a homework assignment I've been instructed to build a bandpass filter with the specifications: f = 1kHz and Q = 6.
This part went off without a hitch, but the second part of the problem instructs me to us "an external amplifier to create a notch". And this is where I've been stuck for the past three days.
Here's what I've tried:
1. Attaching an inverting amplifier to the output of the bandpass filter.
2. Attaching a differential amplifier to the output of the bandpass filter.
3. Attaching a summer to the bandpass filter (wherein I attempt to subtract the input voltage from the bandpass output.)
None of these work and seem to just reproduce the bandpass. Below is my current schematic:
Uploaded with ImageShack.us
The resistor values of the summer are just random numbers I've plugged in. Here's the resulting output:
Uploaded with ImageShack.us
In all honesty, I don't know what's going on. In fact this is the solution that my professor proposed, but it doesn't work.
Can someone help? It would be greatly appreciated.
As part of a homework assignment I've been instructed to build a bandpass filter with the specifications: f = 1kHz and Q = 6.
This part went off without a hitch, but the second part of the problem instructs me to us "an external amplifier to create a notch". And this is where I've been stuck for the past three days.
Here's what I've tried:
1. Attaching an inverting amplifier to the output of the bandpass filter.
2. Attaching a differential amplifier to the output of the bandpass filter.
3. Attaching a summer to the bandpass filter (wherein I attempt to subtract the input voltage from the bandpass output.)
None of these work and seem to just reproduce the bandpass. Below is my current schematic:
Uploaded with ImageShack.us
The resistor values of the summer are just random numbers I've plugged in. Here's the resulting output:
Uploaded with ImageShack.us
In all honesty, I don't know what's going on. In fact this is the solution that my professor proposed, but it doesn't work.
Can someone help? It would be greatly appreciated.