# Laplace transform and z transform

Discussion in 'Electronics Homework Help' started by ElectronicsR, Apr 28, 2016.

1. ### ElectronicsR

72
1
Mar 23, 2016
Hello,
What is the purpose and use of both technique??

2. ### Harald KappModeratorModerator

11,162
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Nov 17, 2011
Welcome to EP.

Both are used to transform signals and computing algorithms from the time domain (V=f(t)) into another domains (V=f(s) or V=f(z)) to make certain computation easier.

A common application is the design of filters. Instread of dealing with integrals and differentials, filters can be comparatively easily designed in the "s" domain (Laplace transform) where multiplication and division can be used due to the properties of the transformation. Often a Fourier transform is used instead of a Laplace transform.

The "z" transform is afaik mainly used in the design of digital filters where you deal with discrete (digital) signals, not continuous (analog) signals.

To learn more about these transforms and how to use them you need to read some training material (find it on the internet using your favorite search engine).

3. ### ElectronicsR

72
1
Mar 23, 2016
Please tell in this 2nd question

4. ### Harald KappModeratorModerator

11,162
2,550
Nov 17, 2011
This is obviously some kind of homework. Therefore you will not receive complete answers. It is forum policy to guide you in that case to find the answer by your own - only that way you will learn´to deal with this kind of task.

Some rather theoretical information on the Laplace transform can be found here.
The important thing is to treat the capacitors as frequency dependend impedances X(s)=1/(s*C). You can the solve the equations (using e.g. Kirchhoffs laws) for the network shown to arrive at the transfer function V2(s)/V1(s).

72
1
Mar 23, 2016
6. ### Harald KappModeratorModerator

11,162
2,550
Nov 17, 2011
Look up the training material you've been given - surely you won't be asked this kind of question without prior teaching. You may also use your favorite search engine to look up information using e.g. the keywords 'laplace transform tutorial'. These immediately will turn up a lot of useful information.