# Laplace to Time Domain Converter

Description| How it works

This app plots the step response of a system having a transfer function of the form (n1s + n2) / (s2 + d1s + d2)

.xls file (97 KB) or .zip file (27 KB)

## How to use

The use of this app is quite straightforward, simply key in the values of n1 and n2 into the cells B8 and B9 and those of d1 and d2 into cells B11 and B12. Key in the maximum time in the cell B16, this sets the range of the X-axis of the chart. The step response is shown on the chart.

For example, lets take the first order transfer function 6/(1 + 3s). To plot the step response using this app, we first note that we need a term with s2 in the denominator, and with a coefficient of 1. To get this, we multiply all the terms in the numerator and denominator with s/3.

Thus, 6/(1 + 3s) = 2s / (s2 + s/3)

Accordingly, we have
n1 =2
n2 = 0
d1 = 1/3
d2 = 0

See this screenshot showing the correct entries and the response to a step input from t = 0 to t = 20.

## Also See:

Discrete Fourier Transform

Filter Analysis and Simulation

PI Control of First Order Process

PI Control of Integrating Process