An online calculator to calculate and graph the voltage across a resistor of a high pass RC circuit when the input \( v_i(t) \) is a square wave.
We first give the formulas of the voltage across the resistor of the RC circuit shown below when the input is a square wave.
The formulas developed in the study of high pass RC circuit response to a square wave is presented here as it is used in the calculator.
When a square wave of period \( T \) of the form
\( \displaystyle v_i(t) = V_0 \sum_{n=0}^{n=\infty} \left\{ u(t - n\;T)- u (t-(n+1/2)\;T) \right\} \) were \( u(t) \) is the unit step function,
the voltage \( v_R(t) \) across the resistor is given by
\( \displaystyle v_R(t) = \displaystyle V_0 \sum_{n=0}^{n=\infty} \left \{ u(t-nT) \; \left(e^{- \dfrac{t - n \; T}{R \;C} } \right)
\\\\ \quad \quad \quad
- u(t-(n+1/2)T) \; \left(e^{-\dfrac{ t - (n + 1/2) T}{\; R \; C} } \right) \right\} \)
\( \tau = R C \) is called the time constant of the circuit.