# transfer function help

Discussion in 'Homework Help' started by jstrike21, Nov 11, 2009.

1. ### jstrike21 Thread Starter Member

Sep 24, 2009
104
0

I got Vo/Vi= R/(R1+Ls+R)

Vi is on the left and Vo is on the right

My question is: At what frequency will the magnitude of H(jw) be maximum?
I know at low frequencies it will be maximum but is that what i put for my answer?

2. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
790

At any frequency greater than ω=0, the output is less than that at ω=0. So ω=0 would my answer.

3. ### jstrike21 Thread Starter Member

Sep 24, 2009
104
0
when finding corner(cut off) frequency do I take

R/(R1+R),, which is the max value of H(jw), divided by square root of 2 and set that all equal to the transfer function?

4. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
790
I would think the corner frequency is ω=(R+R1)/L rads/sec

5. ### jstrike21 Thread Starter Member

Sep 24, 2009
104
0
now I have the same circuit but the is a capacitor instead of an inductor.

Vo/Vi=R/(R1+(1/jw)+R)

2.) What frequency will the magnitude of H(jw) be maximum?
As frequency goes to infinity?

3.) What is the maximum value of the magnitude H(jw)
R/(R1+R)?

6. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
790
$Vo/Vi=\frac{R}{R1+\frac{1}{j\omega C}+R}$

2. Yes
3. Yes