
Home  Forums  Rules  Articles  diyAudio Store  Gallery  Wiki  Blogs  Register  Donations  FAQ  Calendar  Search  Today's Posts  Mark Forums Read  Search 
Everything Else Anything related to audio / video / electronics etc) BUT remember we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools...... 

Please consider donating to help us continue to serve you.
Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving 

Thread Tools  Search this Thread 
8th October 2011, 10:02 AM  #1 
diyAudio Member
Join Date: Nov 2009
Location: Ghaziabad (Delhi NCR)

Transfer Funtion of the given circuit ?
Hi,
Please give me the transfer function of the following circuit. Where R1,R2,R3,R4 and R5 are not equal.
__________________
Regards, Sameer Dhiman 
8th October 2011, 01:00 PM  #2 
diyAudio Member
Join Date: May 2007

How many marks will your teacher give me for the answer?

8th October 2011, 04:42 PM  #3 
diyAudio Member
Join Date: Jun 2002
Location: USA, MN

You should check out a neat little program called sapwin
__________________
Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. Carl Sagan Armaments, universal debt, and planned obsolescencethose are the three pillars of Western prosperity. —Aldous Huxley 
8th October 2011, 05:20 PM  #4 
diyAudio Moderator

Just remember that the voltages at inverting and noninverting inputs are equal, that the current flowing into the inverting and noninverting inputs is zero, and it will be pretty easy to set up the basic equations to solve for Vo/Vi.
__________________
“A philosopher is a blind man in a dark room looking for a black cat that isn't there. A theologian is the man who finds it.”  Mencken 
8th October 2011, 09:57 PM  #5 
diyAudio Member
Join Date: Feb 2003
Location: ..

it actually "safer" to explicitly include op amp gain "A" and derive the equations
you can always take the limit as A goes to infinity later  but by assuming it from the start you may save a term or two in the calculations or you may have your solution "blow up" from the infinity you are implicitly carrying around the op amp Howland current source is a favorite nasty problem set for those not understanding the "null injection" implicit infinity 
8th October 2011, 10:24 PM  #6 
diyAudio Member
Join Date: Mar 2011
Location: St Louis, Mo

What method do you think is best for solving this problem, and how far along did you get?
Dale 
10th October 2011, 04:48 PM  #7 
diyAudio Member
Join Date: Nov 2009
Location: Ghaziabad (Delhi NCR)

@DF96
I am not a student in any institute so do not expect any Marks. @SY, jcx Thank you, I solved it using superposition theory. R1 and R2 forms voltage divider for NonInv voltage. R3RD forms Rg and R4 forms Rf. So NonInv, Inv output voltage will be Vninv = V1*[R2/(R1+R2)]*[1+{R4/(R3RD)}] Vinv = V1*(R4/R3) Vout = Vninv + Vinv
__________________
Regards, Sameer Dhiman 
10th October 2011, 06:22 PM  #8 
diyAudio Member
Join Date: Oct 2006
Location: Charlotte, NC

Would you not want Vout in terms of V1 ?

10th October 2011, 06:49 PM  #9  
diyAudio Member
Join Date: May 2007

Quote:
I'm not certain that your result is correct. I would expect to see two simultaneous equations involving Vin and Vout, which you then invert to get Vout in terms of Vin. What is RD? 

10th October 2011, 08:17 PM  #10 
diyAudio Member
Join Date: Nov 2009
Location: Ghaziabad (Delhi NCR)

Sorry, R5=RD (In practical circuit R5 will be variable resistor e.g. JFET or LDR)
I've verified the equation with LTSpice. If you any other equation/solution please post that.
__________________
Regards, Sameer Dhiman 
Thread Tools  Search this Thread 


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Getting transfer characteristics  lcsaszar  Tubes / Valves  1  13th August 2008 12:14 AM 
Need transfer software for my Ipod!!!  michael9827  Instruments and Amps  3  14th June 2008 05:02 PM 
transfer function  jenks  Solid State  31  24th April 2008 09:28 PM 
Transfer Function  jclouse  MultiWay  22  1st July 2006 02:19 PM 
Transfer functions?  oracel  MultiWay  15  23rd October 2004 02:34 PM 
New To Site?  Need Help? 