Lab 13: The Response of an RC Circuit
- Validate the R-C response for a partially and fully charging/discharging capacitor.
- Check the validity of Kirchhoff’s Voltage Law for an R-C circuit.
Consider the Thévenin RC circuit with the square wave voltage input. The time dependent voltage across the capacitor is:
What determines whether a capacitor is partially or completely charged is the pulse width (pw) of the square wave input. Two cases will be considered:
- pw = 5τ and
- pw = 2.
For a pulse width of 5τ or greater, the capacitor will have enough time to completely charge up and completely discharge.
For a pulse width of 2τ, the capacitor will not have had enough time to completely charge up or completely discharge. It will require 5 cycles of the constant square wave input to reach its final steady state value. The repeated application of the complete response for a constant input for these 5 cycles will ultimately achieve the final steady-state value that is observed experimentally on the oscilloscope.
Part 1: Setting up the Function Generator