Akula eternal lantern 4

[itsu]

@Void and Itsu, just use an LC lowpassfilter after your power supply , so your Powersupply will basically just see a DC load and will not be affected.. an 1 Henry and 10.000 uF lowpassfilter should do it...

Thanks Stefan,

i was meaning to make something like that because i hate it when the PS does that.

Ok,  so we are back to square 1 i guess.

Perhaps we need a better translation of the video in which Akula explains the effect, i personally had problems following the tekst 


Regards Itsu

[Void]

The question is now , if these exponential rising flanks are really there or not....hmm..

Itsu,  also strange to hear from you that this center spike is still there without the core ??

I guess these exponentially rising slopes only occur , when the pulse is so short that it also affects the basis pulse as shown by you Itsu...when you made the pulse duration very short...

I suspect that those exponentially rising pulses are not there. It may be due to
some change in capacitance when switching between 2V/div and 5V/div. I think the Atten
scopes have the same insides as my Siglent scope, at least for certain models anyway,
so that might explain why Akula got the same strange looking waveform on his scope.
If the strange looking waveform is just an artifact of the scope, then what was Akula talking about?

Also, yes. If Itsu gets the same odd pulses when using an air core coil, then it seems it is not
related to some characteristic of ferrite. So then, what exactly causes those strange pulses?
Could it be just random short duration noise spikes on the base or gate causing the switching to occur?
Wait, no, I guess not, because the pulses Itsu and Akula are getting seem to be very stable and consistent...

[Void]

@Void and Itsu, just use an LC lowpassfilter after your power supply , so your Powersupply will basically just see a DC load and will not be affected.. an 1 Henry and 10.000 uF lowpassfilter should do it...

Yes, I have already tried a large value choke with not much change, but maybe
including the large filter cap as well will help. I have found however that the power supply regulator
is OK at lower pulse frequencies if I keep the pulse widths short.

[itsu]

I suspect that those exponentially rising pulses are not there. It may be due to
some change in capacitance when switching between 2V/div and 5V/div. I think the Atten
scopes have the same insides as my Siglent scope, at least for certain models anyway,
so that might explain why Akula got the same strange looking waveform on his scope.
If the strange looking waveform is just an artifact of the scope, then what was Akula talking about?

Also, yes. If Itsu gets the same odd pulses when using an air core coil, then it seems it is not
related to some characteristic of ferrite. So then, what exactly causes those strange pulses?
Could it be just random short duration noise spikes on the base or gate causing the switching to occur?
Wait, no, I guess not, because the pulses Itsu and Akula are getting seem to be very stable and consistent...

I just used my other scope (200MHz OWON PDS8202), but also there no difference in the drain/collector 2 or 5V/div. settings.


Yes i think its a (false) switching of the transistor/MOSFET due to the low gate/base (well, not really on the base) input signal, allthough my Tektronix scope "sees" no spikes or noise on that gate/base signal.

Regards itsu

[hartiberlin]

Hi Istu and Void,
Where are you measuring exactly the yellow gate (base) signal ?

Directly at the Function generator output or
directly at the basis of the transistor ?

If you still have 10 Ohms parallel with 10 nF in series at the output of the
FG before going into the base , this RC could really be
Responseable for the sudden switch off or spike in the circuit
As it could ring itsself with its stray inductance by being energized by a pulse...
So please only directly show the signal at the base..