Akula eternal lantern 4

[itsu]

But; the physical layout of the board... the variable capacitor is not near the mosfet... and there's a resistor in parallel with it...

You are right, my mistake, it does seem that the variable capacitor is not near the transistor/MOSFET.
It looks more like it is used for tuning the frequency/duty cycle of the 7414 instead.

Regards Itsu

[Void]

... it does seem that the variable capacitor is not near the transistor/MOSFET.
It looks more like it is used for tuning the frequency/duty cycle of the 7414 instead.
Regards Itsu

Yes, my impression from watching the lantern 4 video is that Akula adjusted the variable capacitor to
increase the pulse width.

[d3x0r]

and may not be of too much significance at all in regards to the
'ferromagnetic resonance' which Akula is talking about, but I am not certain.

In general I'd agree.... but the pulse goes to a LOW voltage... below ground in akula's....


I did some research on various magnetic effects... ferrimagnetic vs ferromagnetic


http://en.wikipedia.org/wiki/Ferrimagnetism  (Ferrimagnetism is exhibited by ferrites and magnetic garnets.)
http://en.wikipedia.org/wiki/Ferromagnetism


http://en.wikipedia.org/wiki/Giant_magnetoresistance (would seem to apply to the conductivity of the thing, as opposed to an external effect)
http://en.wikipedia.org/wiki/Colossal_magnetoresistance (larger resistance; "Initially discovered in mixed-valence perovskite manganites in the 1950" )


perovskite - "Perovskite (pronunciation: pe'ɹovskaɪt) is a calcium titanium oxide mineral species composed of calcium titanate, with the chemical formula CaTiO3. The mineral was discovered in the Ural Mountains of Russia by Gustav Rose in 1839 and is named after Russian mineralogist Lev Perovski (1792–1856"


maybe the adjustable capacitance is before the PNP/NPN driver.. with a resistor across that... still haven't really identified all the parts... the color bands are obscured by the video encoding
--
Edit: Vertical lines on second pictuture I was trying to recreate the vertical division marks.
horizontal line is 0 level

[d3x0r]

You are right, my mistake, it does seem that the variable capacitor is not near the transistor/MOSFET.
It looks more like it is used for tuning the frequency/duty cycle of the 7414 instead.

Regards Itsu

then the schematic is still wrong
Maybe that's on the gates of the NPN/PNP drivers... I don't think it's part of the 7414
The effect is to extend the duty cycle.... and could be any number of places I suppose.
But there's only 2 adjustments; the variable resistor (frequency) and the variable cap (minor duty cycle extend)...
the schematic has 2 variable resistors... but they're not represented in any of the images....



Edit: I guess from relative positions at the top they are the same timescale...

[d3x0r]

Hmm... and the NPN/PNP are backwards... otherwise the emitter of the NPN will float and false-turnoff...
Edit: NEvermind; I guess they have to be that way...

maybe the point between them can buffer a negative voltage.