Discussion in 'Homework Help' started by kahafeez, Jan 16, 2009.
hi plz help me with the described problem.....
I'm not sure what the problem is? You want to reduce the output voltage to ¼ of it's original value?
yes thats right, but i'm afraid that by attaching two resistors the oscillations might die as well....
Why would it? Op amps have extremely low output impedance, so that shouldn't be a problem. This is homework, so I won't give the answer, but you have way too much attenuation on that voltage divider.
I agree with Bill that this looks like classwork for a course. I have moved it to the homework forum.
The Wien Bridge Oscillator needs a gain of 3.
If the pot is set to a little more than 4.3k (close to half) then the gain is perfect.
A voltage divider at the output of a 10k resistor in series with a 3.3k resistor will have 0.248 times the output across the 3.3k resistor if the load current is zero.
AG, I think your mental calculator has failed you. The pot needs to be set to 8.6k for a gain of 3.