Akula eternal lantern 4

[d3x0r]

Well... I was searching for 'flyback pulses' and various similar things... 'transformer gap pulse' but found no images that relate (except the one I posted on this thread )


The first pulse comes back while the base is on... and there's a definate dip in the voltage on the base as a result of the pulse...


Duty cycle will have to be longer than 20us

[d3x0r]

Just setup with my flyback core and mobius coil to see if I could replicate; I was only getting a large pulse when the base turned off... change back to a mpsa18 and had to make the pulse longer than 20-30us to get a pulse while the base was still on... but no negative dip

[d3x0r]

https://www.youtube.com/watch?v=G_fd9mk15rE

[itsu]

Well... I was searching for 'flyback pulses' and various similar things... 'transformer gap pulse' but found no images that relate (except the one I posted on this thread )


The first pulse comes back while the base is on... and there's a definate dip in the voltage on the base as a result of the pulse...


Duty cycle will have to be longer than 20us

Not sure why you are calling them  'flyback pulses'  as in the diagram in reply #65 i understand you (and i) are only using the primary
coil with the secondary not connected to anything (i did load it sometimes with 470 Ohm resistor to get rid of the many ringing signals)

Allthough i have wound the prim./sec. coils on a flyback core, to my understanding, there is no flyback like action going because we have no diode etc. connected to the secondary.

Regards Itsu

[d3x0r]

Not sure why you are calling them  'flyback pulses'  as in the diagram in reply #65 i understand you (and i) are only using the primary
coil with the secondary not connected to anything (i did load it sometimes with 470 Ohm resistor to get rid of the many ringing signals)

Allthough i have wound the prim./sec. coils on a flyback core, to my understanding, there is no flyback like action going because we have no diode etc. connected to the secondary.

Regards Itsu

Well... I don't know what else to call them....
In my video i didn't have a secondary on the core... just the primary...
I also tried for 'melnichenko pulse'
but it didn't seem to matter if the core was closed(no gap) or open.


It's kinda a chicken and egg.  Although when I zoom in it seems the base starts to go low, and the collector goes high... so I dunno maybe it's the inductance of the 2-3inch wire I have to the emitter (base?)....
was testing at 4.0V.


... so looking at details of akula's board... he has the power supply with a long wire soldered to a large-ish capacitor...
Hmm schematic must be wrong... the pulldown(1k) and variable(0-.22n) cap must be on the other side of the 10ohm&10n to the base...
*sigh* and there's 2 transistor things that aren't represented...


(image 5) at the chinese demo, he got rid of what was labeled C28 is replaced with a diode
going to work on this sketch a little more; in the beginning clip he didn't have the diodes...