# Analog Electronics Help?

Discussion in 'Homework Help' started by conclusionof, Nov 11, 2008.

Nov 11, 2008
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2. ### Firestorm Senior Member

Jan 24, 2005
353
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What part do you not understand on this problem. Just break the problem up. This is a inverting op-amp, so use that formula. You can combine V1 and V2 with addition. If you have a more specific question, please don't hesitate to ask.

3. ### mik3 Senior Member

Feb 4, 2008
4,846
63
Vo=-Vin*(R2/R1)

if you take R1 as Z1 and R2 as Z2 then

Z2=R and

Z1=R+jωL

thus

Vo=-(V1+V2)*[R/(R+jωL)]

4. ### conclusionof Thread Starter New Member

Nov 11, 2008
4
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I dont understand how to add V1 and V2 up since one of them in sinus function while other is in cosinus form.

Also can we use here phasor method ? (Though I know it is not proper to use phasor if the frequencies are not same)

5. ### mik3 Senior Member

Feb 4, 2008
4,846
63
If the frequencies are different you cant use phasors to add them. Just use trigonometric identities to add them or expand each sin or cos in a series form, take the most important bits and add them.

What exactly V1 and V2 equal to?

6. ### Firestorm Senior Member

Jan 24, 2005
353
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You can convert the cos function to a sine function by adding a $\pi$/2 to the sine function:

Ex:
sin(A) = cos(A+$\pi$/2)