1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Potential Divider

  1. Apr 29, 2007 #1
    1. The problem statement, all variables and given/known data

    Why is a potential divider required in a sensor circuit?

    2. Relevant equations

    V_out = r1/(r1+r2)*V_in

    3. The attempt at a solution

    Firstly you can get the required voltage across the sensor by changing the resistance of r2 (if r1 is the sensor).

    Apparently, though, using a potential divider also increases the sensitivity of the sensor. ie. a small change in resistance causes a larger change in output, but I don't see how this works. could someone explain?

    Thanks
     
  2. jcsd
  3. Apr 29, 2007 #2
    any ideas?
     
  4. Apr 29, 2007 #3

    Mentz114

    User Avatar
    Gold Member

    Your answer seems logical - i.e.to get the correct voltage drop across the sensor.

    You can work out the sensitivity by calculating d v_out/dr1 where r1 is the sensor resistance, as a function of r1 and r2.
     
  5. Apr 30, 2007 #4
    ah thanks! a bit of calc shows that you have maximum sensitivity when r1=r2...
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook




Loading...
Similar Threads for Potential Divider Date
Potential Divider Circuits (resistor + LED) Mar 30, 2017
Potential Divider Circuits Mar 24, 2017
Potential divider question Sep 4, 2016
Finding the emf of a cell Nov 13, 2015
Potentiometer position problem Jan 8, 2015