Andy's thread- Don Smith Device

[andy]

Why is Smith's trumpet wave growing exponentially and my not?

I think one reason is that I measured it on charging capacitor - and charging only by voltage from pulsating source.
See this picture
   

 
And now I found something simmilar in Bennet's doubler tested by Antonio Queiroz
here https://www.coe.ufrj.br/~acmq/bennetd.html but today available for me only here
https://web.archive.org/web/202106150234...nnetd.html
   

In one document Mr. Queiroz states:

"The amplification factor also increases with time because of the nonlinear diode capacitances".

Maybe this is important factor for exponentially trumpet wave - nonlinear capacitance?

[andy]

Interesting video with capacitors charged by nearby energy field


Looped Capacitors as an Electricity Trap by Milan Mancic




And scheme of his capacitor connection:
   

[Shylo]

Interesting
I don't understand why the led array didn't drain the caps after the globe was shut off?
He shorts them with the screwdriver.

[andy]

Impedance (Resistance) at resonance becomes zero #2

I probably found correct meaning of Don Smith's words about "resistance ... becomes zero"
   

So I must correct this my post
https://www.mooker.com/thread-31-post-441.html#pid441
and the image
   
where it shows serial and parallel LC circuit - with HIGH resistance and another with LOW resistance.

Don Smith talks about impedance (resistance) inside the LC. Inside. This impedance on resonance is LOW - near zero - inside the LC circuit, regardless of parallel or serial. In both cases it becomes zero.

[lfarrand]

Yes at resonance inductive and capacitive reactance cancel out and you’re just left with DC resistance. Don Smith then suggests that at radio frequency (>20kHz) the DC resistance becomes zero since the electrons are dancing above the wire, so aren’t subject to ohmic losses in the conductor. I’m not sure how true the last bit is, but certainly inductive and capacitive reactance are cancelled in resonance.

[andy]

Offtopic for me only

Columbus Egg by Fernandez
describes two phaseshifted coils using Lenz to increase magnetisation for adding to output.

Principle of this is found in Tesla On Light And Other High Frequency Phenomena

   

   

[andy]

Smith's Negative Resistance #2 and Trumpet Wave

   

Yesterday's post on OUR by lfarrand made me think. He posted link to Super-Regenerative Receivers (thanks for it @lfarrand)

Smith talks about negative resistance. And here is something similar:

In LC tank circuit ... "By the use of reaction, r (resistance) can be reduced to zero and even made negative. What happens then is that any voltage, however small or short-lived, starts oscillation at the natural frequency of the tuned circuit, and the oscillation continues to grow, in the manner shown" (citation from beforementioned website)

Reaction = Regeneration = Positive Feedback. Why?

"A regenerative circuit is an amplifier circuit that employs positive feedback (also known as regeneration or reaction)."
 S. W. Amos, R. S. Amos, Newnes Dictionary of Electronics, 4th ed., London, U. K.: Newnes, 1999, p. 265, 269"

   


And from https://en.wikipedia.org/wiki/Regenerative_circuit

"The gain ... can be increased by feeding some of the energy from its output back into its input in phase with the original input signal. This is called positive feedback or regeneration"


By negative resistance Smith means "adding":
Negative resistance = adding something to the LC circuit.

In Wiki https://en.wikipedia.org/wiki/Armstrong_oscillator is written
"the feedback signal ... is magnetically coupled into the tank inductor"

   


So conclusion for me:
Probably correct trumpet wave is made by negative resistance, which means that some energy is still added to LC circuit.
This can be added by magnetic coupling. And maybe some small feedback coil can be used for this.
And probably feedback coil frequency can be division of main coil frequency (made by spark gap or another way).

[lfarrand]

Yes, Andy, that's it! Someone is finally on the same wavelength as me Guests cannot see images in the messages. Please register at the forum by clicking here to see images.

I've been harping on about positive feedback and regenerative receivers for a few months now, but no one else has seen the significance of it until now.

Let me state it clearly: negative resistance = positive feedback

Positive feedback can be done either magnetically (wireless) or galvanically (wired, via isolation transformer).

[andy]

Experiment - to charge capacitor from 12V battery to bigger voltage only by switching to ground ?

Is this possible?

   

Try falstad simulation circuit here 
https://tinyurl.com/2cezqkxe

I will try it this week.

[lfarrand]

Experiment - to charge capacitor from 12V battery to bigger voltage only by switching to ground ?

Is this possible?



Try falstad simulation circuit here 
https://tinyurl.com/2cezqkxe

I will try it this week.

It will work, but the switches you are using in Falstad are 'ideal' switches with instant on and off time and no resistance etc, so the simulation result will not be the same as what you might achieve in the real world.