5J30.10-RLC ringing

5j3010 5j3010d 5j3010c 5j3010b

Description: This demonstration shows how RLC circuits can exhibit damped harmonic oscillations in an electrical context, similar to a mechanical harmonic oscillator.


  • Oscilloscope
  • Function generator
  • Capacitor Decade Box
  • Large Solenoid
  • Audio AMP and Speaker

Setup Procedure:

  1. Clamp the speaker to a bench rod on the display cart
  2. Connect the components together according to the above circuit diagram
  3. Set the capacitors on the decade box to the above mentioned settings
  4. Set the function generator to a 1 Hz Square wave at a high amplitude
  5. Vary the position of the Solenoids Iron Core with the speaker on to test the setup

Demonstration Procedure:

  1. Turn on the function generator and oscilloscope to show the form of the input voltage signal
  2. With the iron core most of the way inside the solenoid, turn on the speaker
  3. Explain that as the inductance varies with the position of the iron core, the rate of decay of the oscillations will change according to omega = (LC)^-1/2
  4. Slide the iron core back and forth and note how the sound from the speaker changes