Signal and system summing opamp math calculation support argument

Discussion in 'Homework Help' started by majdi, Sep 11, 2014.

1. majdi Thread Starter New Member

Jun 22, 2011
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Hello and good day all, i need advice on this question. At least keyword or url so i can study more. For electronic calculation i successfully calculate gain, -vout and else. But this type i not really understand when input in x1(t), x2(t) the vout in y(t).

2. ericgibbs AAC Fanatic!

Jan 29, 2010
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hi m,

Mathematical functions are usually expressed as: y =f(x) .
E

Jun 22, 2011
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4. ericgibbs AAC Fanatic!

Jan 29, 2010
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As its a Inverting Summing amp, its purpose is to add together the x1(t) and x2(t) signals together, and give the Sum as y(t),, the same as you would do adding two numbers,
Consider what effect the 'Inverting' within the amp will do to the polarity of y(t).

So your first, y(t)= x1(t) + x2(t) equation is correct, but include the inversion.

E

5. majdi Thread Starter New Member

Jun 22, 2011
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i). Time-varying or Time-invariant

y1(t-t0) -> corresponding to x2(t)
x2(t) -> x1(t-t0)
x2(t) -> coorresponding to y2(t)
y1(t-t0) = y2(t) Is not true. Which mean this is Time-Varying System.

ii). Linear or Nonlinear
-y(t) = x1(t)+x2(t)
The system is in linear system because the condition is in additive or superposition property.

iii). Instantaneous or Dynamic
The system is Dynamic System, this is because the output y(t) response at any instant t depend not only on the present value of input, but also on the past values of the input which is the value before t.

iv). Causal or Non-causal

This is Causal System because -y(t) = x1(t)+x2(t), which mean y(t) to the input does not depend on future values of that input, x1(t-t0) and x2(t-t0) but only on the x1(t) and x2(t) present and or past values of the input, x1(t-t0) and x2(t-t0).

v). Open-loop or Close-Loop

Last edited: Sep 12, 2014
6. ericgibbs AAC Fanatic!

Jan 29, 2010
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There is negative feedback via Rf [10k] from the Output to the Input of the amp, so would you say its Open or Closed loop.?

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7. majdi Thread Starter New Member

Jun 22, 2011
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Close-Loop, since close loop perform operation with feedback. So this how signal and system related. Thank you ericgibbs