Zener Diodes and Op-Amps

• WoAiMeiMei

  2 May 09, 21:19

  All Solved

   1) Ok

  2)Ok

  3) Ok

  4) Ok

  

  http://i39.tinypic.com/vzhufd.jpg

• syncopation_music

  2 May 09, 22:34

  Your question 1 is simple

  recall what is the forward voltage of Zener ?

  then you will be able to find the answer

   

  the question 2 is zener = 0 ohm ,mean its a short ... shorted zener is just a piece of wire

  remember ?

   

   

  I graduate from Ngee Ann Polytechnic ,Dip in Electronics and Computer Engineering

   

   

   

• syncopation_music

  2 May 09, 22:36

  question 3 .. pls refer to wikipedia.com on wheatstone bridge :) suppose you forgotten the simple formulae :)

   

  just wiki on "wheatstone bridge" and the answer will be given

   

  wheatstone is the perequisite for the principle behind an Galvanometer

   

   

• syncopation_music

  2 May 09, 22:38

  question 4 is a voltage divider /integrator or differentiator circuit [ i cant exactly remember ]

  there is a simple formulae for this

   

  check them out in the Poly library

   u can check boylestad, paynter or bogart books on electronics device :)

   

  wiki i dun think can find ... becos so far no one contribute mass scale on op-amp topics

   something to help u

  http://en.wikipedia.org/wiki/Operational_amplifier

   

• WoAiMeiMei

  3 May 09, 11:12

  I don't actually study in singapore so my course curriculum would be slightly different. ie. we never actually cover wheatstone bridges but thank god for wiki! lol
  
  Q4 im still in the dark, especially when given a circuit which is not like the normal ones.
  
  When looking at Q2, if Vr = 0, would that mean our circuit comprises of just a Vs, RA and RL? Then how do we deal with the information given for Vz, And Iz (max/min)
  
  Q1) is forward V = 0.7?

• syncopation_music

  3 May 09, 14:00

  Originally posted by WoAiMeiMei:

  I don't actually study in singapore so my course curriculum would be slightly different. ie. we never actually cover wheatstone bridges but thank god for wiki! lol
  
  Q4 im still in the dark, especially when given a circuit which is not like the normal ones.
  
  When looking at Q2, if Vr = 0, would that mean our circuit comprises of just a Vs, RA and RL? Then how do we deal with the information given for Vz, And Iz (max/min)
  
  Q1) is forward V = 0.7?

  if looking at a certain way ...it mean something

  let me check first

   

   

• WoAiMeiMei

  4 May 09, 09:23

  stuck.. on the first 2 -.-

• WoAiMeiMei

  5 May 09, 06:27

  with a test this friday, gg.. ><

  every1 must be having tests and exams now

• WoAiMeiMei

  5 May 09, 13:11

  Ok, i got

  3) as R4= (R2/R1 ). R3

  1) (Vs - Vz / Ra) x Vz

   

  got 1 .. yes! lol!

• WoAiMeiMei

  5 May 09, 13:37

  Q4), first part i achieved by

  Rf / V1 = R1

  Rf / V2 = R2

  with V1 being A and V2 being B

   

  part b not sure... yet

• WoAiMeiMei

  5 May 09, 14:00

  solved it..

  :D

   

  Part B = V- = -Rf/R1 (V1)

• syncopation_music

  5 May 09, 14:01

  good ;) you are doing fine :)

   

• WoAiMeiMei

  5 May 09, 15:18

  What ive done for Q2) which is apparently wrong =.=

   

  (Vs x 0.75 )/ Lowest RL   (lowest V, lowest R)  = Current L

  Vs x 1.25 (highest V) / Current L = RA

  it's wrong, now what? :s

• WoAiMeiMei

  5 May 09, 15:40

  Q2)

   

  Given R(load) varies [min call X, max call Y] Vs[15,25] Vz= value given call Vz
  
  Iz,max=Is,max-IL,min
        =(Vs,max-Vz)/Ra - Vz/Y
  
  Iz,min=Is,min-IL,max
        =(Vs,min-Vz)/Ra - Vz/X
  
  Iz,min=0.1(Iz,max)
  use graphics calculator and the two eqn's u have from above with the unkown as Ra and out comes the ANSWER to Q2

• WoAiMeiMei

  5 May 09, 20:34

  Problem solved :D thnx