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mdzafar
Joined: 30 Oct 2006
Posts: 28
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 23 Jun 2008 15:47 help requir in Very basic problem |
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Hi
Please help in following very basics Questions..
1)anyone could tell me about the existing of any linear or non-linear Signal in the world??? or i need concept of linear and non linear signals ,if it exist??
2) If the System is non linear , and input to the sysytem is linear what should be the Output of system ?? Explain your ans please
Regards
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bulx
Joined: 07 Aug 2004
Posts: 163
Helped: 23
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| 30 Jun 2008 17:03 Re: help requir in Very basic problem |
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AFAIK, there is nothing like a "linear signal". Perhaps one could call a signal that can be represented as y(t) = a*t + b as "linear", but even thats not usual.
However, there are plenty of linear systems. It only mean that if the response of a system to a signal x0 is y0, and to a signal x1 is y1, then the response to the signla x0 + x1 will be y0+y1. It doesnt say anything about the actual transfer function of the system.
So knowing that the input to a system, and that the system is linear, there is nothing much you can say about the output.
-b
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drabos
Joined: 03 Jan 2006
Posts: 431
Helped: 26
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| 30 Jun 2008 17:32 help requir in Very basic problem |
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| hmm, linear system doesn't make new frequencies, non-linear system does it. So, from the input you know the frequency components at the output if you have a linear system ...
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LvW
Joined: 07 May 2008
Posts: 684
Helped: 132
Location: Germany
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| 30 Jun 2008 18:43 Re: help requir in Very basic problem |
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I donīt want to confuse anybody, however, to be exact it is important to know that in reality NO system is linear. In the analog world each transfer characteristic is more or less nonlinear - but it is a normal procedure to use a bias point around which the characteristic can be regarded as "quasi-linear" with minor errors. This is called "linearization".
Example: Each good audio amplifier can be regarded as "linear" as long as the the signal amplitudes are low enough. And this sounds "good" since the THD is small enough. But when the "volume" is increased the signal quality rapidly goes down because many strong harmonics are generated. And this can be heard !
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xulfee
Joined: 27 May 2008
Posts: 204
Helped: 25
Location: Pakistan
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| 01 Jul 2008 9:39 help requir in Very basic problem |
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| linearity is property of system (super position & homogeneous),this term is not used for signals,if u provide a linear signal to a nonlinear system it will behaves according to systems frequency responses.
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