Superposition formulas

[cabby]

Could someone take a look at the example at the bottom of the attached? I am not confident that the example they worked out at the bottom for superposition actually is correct. I believe the equation at line 50 for the first ckt should read Vx= Vo/R1 + (R1+(1/R2 + 1/R)^-1)

If someone could give me a sanity check I would appreciate it.

thanks,

 

[benbo]

Could someone take a look at the example at the bottom of the attached? I am not confident that the example they worked out at the bottom for superposition actually is correct. I believe the equation at line 50 for the first ckt should read Vx= Vo/R1 + (R1+(1/R2 + 1/R)^-1)
If someone could give me a sanity check I would appreciate it.

thanks,

I think I get the same answer as them.

Let Rp = 1/(1/R + 1/R2) so 1/Rp = 1/R+1/R2

Nodal equation =

(Vx-Vo)/R1 + Vx/Rp = 0

Vx/R1 + Vx/Rp = Vo/R1

Vx* [ 1/R1 + 1/Rp ] = Vo/R1

Vx = (Vo/R1) * 1/ [ 1/R1 + 1/Rp}

Vx = (Vo/R1) * 1 / [1/R1+1/R+1/R2]

I hope I didn’t make a mistake.

I’m not sure if your answer equals out to this. It’s easier with numbers. Maybe you could try some..

 

[cabby]

thank you Benbo. I will rework and see what I get with some numbers.

thanks