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Author Topic: Don Smith's Documents and reference material  (Read 106129 times)

Group: Mad Scientist
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Posts: 158
Yeah I thought that was the case from the diagrams. My brain has trouble with the concept of negative resistance.

Resistance is just impedance to DC, and impedance is derived from reactance (L and C). ;)
Negative impedance/reactance is what you really want to measure.
(sorry, there is just no way of avoiding the more painful AC math)

Negative reactance can occur when capacitance or inductance is varied with respect to time.  (This is how you would quantify the amount of energy produced in a parametric oscillator.)

Assuming a lossless circuit in the above example and with all other factors being constant, the amplitude and frequency of oscillation will increase as L or C decrease.

https://www.researchgate.net/publication/231003793_Parametric_resonance_in_a_linear_oscillator_at_square-wave_modulation

Then there's also the possibility I have no idea what I am talking about :P
« Last Edit: 2019-11-13, 02:12:04 by Reiyuki »


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Critical thinking is important, but a professional skeptic will never discover anything new.
   

Group: Tinkerer
Hero Member
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Posts: 1063
That PDF has many references to neg resistance. I now want to source some magnetron and dynatron tubes. Or I may have a go at building one :)
   

Group: Elite Experimentalist
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Posts: 1953

Hi Jim,

there is a very simple circuit which you can use to play with negative resistance, see my post #51 above:

https://www.overunityresearch.com/index.php?topic=2.msg36020#msg36020

I played with that circuit and was able to get those 3 states, kind of, see the video there.

Itsu
   

Group: Tinkerer
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Posts: 1063
Aaah thanks you. I've since read that it seems to be a non-documented feature in many 2N2222A but not all.
   

Group: Elite Experimentalist
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Posts: 1953

Hmmmm,   "a non-documented feature" he,  sounds like they deliberate made it that way then.

I thought it was a side effect of some transistors due to their specific makeup (N-P-N layers).

Thanks,    Itsu
   

Group: Tinkerer
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Posts: 1063
This is interesting reading. https://electronics.stackexchange.com/questions/357653/oscillator-circuit-with-a-negistor I should have said "property" not "feature"
   
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