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!

What is the importance of the upper resistor in this circuit

  1. Feb 18, 2015 #1
    The book also says you can increase the time delay by increasing the resistance of the upper resistor , why, what does it do?

    uploading images
  2. jcsd
  3. Feb 18, 2015 #2


    User Avatar
    Gold Member

    You need to study basic RC circuits. Think about this circuit with nothing but the upper resistor and the capacitor/switch pair (and a voltage applied across the two in series. What does this circuit do?
  4. Feb 18, 2015 #3


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    increasing the value of the upper resistor ( the one currently marked 22k) decreases the current flow to the capacitor
    and therefore the capacitor takes longer to charge up

  5. Feb 18, 2015 #4
    Ok the explanation is clear. Thank you very much.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook