# LTspice simulation distortion function

Discussion in 'Circuit Simulation & PCB Design' started by gilmanli, Sep 28, 2010.

1. ### koolguyActive Member

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At the emitter, why 2 resistance & capacitor // connected??
& What is this E12, E24.... ,i have seen many time as in 555 Calculator.

2. ### audioguruWell-Known MemberMost Helpful Member

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The total of the two resistors is for the DC biasing and the unbypassed resistor is part of the AC gain calculation.

Standard 5% resistors have 24 values per decade (E24). I haven't used 10% resistors for about 47 years so maybe they had only 12 values per decade (E12).

3. ### koolguyActive Member

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Last edited: Jan 8, 2011

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5. ### ericgibbsWell-Known MemberMost Helpful Member

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hi,
In decimalisation, a decade is a power of 10, increase or decrease in value. eg: 470R, 4.7K, 47K, 470K...etc

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6. ### koolguyActive Member

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I find this circuit in my old electronics book, it is oscillator.

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7. ### ericgibbsWell-Known MemberMost Helpful Member

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What shape would the waveform be from that oscillator...????

I thought you wanted a Sine wave.?

8. ### koolguyActive Member

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There is no waveform shown.

9. ### koolguyActive Member

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In this waveform how to find angle of shift??

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10. ### ericgibbsWell-Known MemberMost Helpful Member

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So do a LTspice simulation as see what you get.!

After all you say want to learn, the best way a learn a subject is to get down and do it...

11. ### ericgibbsWell-Known MemberMost Helpful Member

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Its a start, but its incomplete.!

Place name labels on the signal point on the circuit, so that plots can be identified.

So thats a plot of Vs in and Vout...

BTW:
When you post a LTspice plot, please post your *.asc file so that we can try it.

Last edited: Jan 9, 2011
12. ### koolguyActive Member

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Is this is the *.asc file.

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13. ### audioguruWell-Known MemberMost Helpful Member

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A decade is 10 times. A decade of resistance values starts the decade at 1k and goes 1.1k, 1.2k, 1.3k, 1.5k, 1.6k, 1.8k, 2k, 2.2k etc up to 9.1k. The next decade starts at 10k and goes up to 91k.

It is designed by sombody who knows nothing about electronics because it is not an oscillator. An oscillator has positive feedeback. This transistor does not have positive feedback, instead it has negative feedback at high frequencies.
Also the transistor is poorly biased by only one resistor from the positive supply so it is turned on all the time.

I guess the low level is the output because a highpass filter attenuates the signal. The frequency is too low at 1kHz so the attenuation is high and the phase-shift appears to be almost 90 degrees. The phase-shift will be 60 degrees and the attenuation will be less at a higher frequency.

14. ### koolguyActive Member

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How to find exact angle??

15. ### ericgibbsWell-Known MemberMost Helpful Member

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Use the two cursors on the plot is one way.

This shows a 2kHz sine wave, note its not exactly 60degs shifted, you figure out that part.
Use the phase shift formula I posted yesterday.!!!

The *.ASC file is attached.

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• ###### Draft48.asc
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16. ### koolguyActive Member

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Hi, i am still unable to find Angle b/w them?

How??

Last edited: Jan 9, 2011
17. ### audioguruWell-Known MemberMost Helpful Member

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180 degrees is half-way around.
90 degrees is a right angle.
60 degrees is 1/3rd of half way around.

Simply design a phase-shift oscillator the has three RC filters that have exactly the same R and C values. Then each RC filter produces a phase-shift of 60 degrees. It is easy if you use an amplifier with a high input impedance like a darlington transistor or two opamps.

18. ### RMMMNew Member

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How far is the END??

19. ### koolguyActive Member

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\
I don't Know.

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I can tell.

21. ### koolguyActive Member

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HI ,AG i have seen your many post but don't get, how to get beta for any transistor??

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