Akula eternal lantern 4

[hartiberlin]

This was the input current into a Newman coil measured at a 1 or 10 Ohm shunt resistor and the coil was pulsed by a mechanical relay..

[d3x0r]

Ground deformation(deform) could cause a false-off... be interesting to see the signal on the emitter too at the point the collector spikes.
Probably the current gets up high enough that it's able to cause a slight positive on the emitter, which lowers the gap between the base and emitter, which causes a false-off.


When my power supply has issues with back spikes, I just add some diodes and a cap... so the power supply never gets the back pulses... the cap does, but the diodes keep the currents from the power supply in the correct direction.


Well I must say that's all less than encouraging

[Void]

Here is an old scopeshot from my. newman research.
http://www.overunity.com/newman2/myspike3.jpg

It only showed these large negative going spikes at the 2 lowest
Volts/div settings...
Strange...

Yeah, well it seems it can happen with various scopes then.
I guess one more potential problem area to keep an eye out for when using scopes.... 

[Void]

Well I must say that's all less than encouraging

It is not looking like Akula's explanations in his lantern 4 video are holding up too well,
even though we have replicated some of the strange waveforms he showed in the video.
After doing a lot of testing, I as yet don't see at all where Akula is getting the extra power from to make
it a self runner...

[TinselKoala]

Some very interesting scoposcopy going on here, I like to see this. I hope you don't mind too much if I put in my two pfennigs worth.

First, I concur that the Atten/Siglent scopes are causing the weirdness somehow. Void's experiment with the resistor instead of the coil would seem to indicate that the scope/probe combo is doing something strange when it sees the reactive load. I would like to see one other experiment done if it's not too much trouble: Deliberately decompensate the probe by "reverse setting" the capacitor. That is, have the probe make the "worst" square wave when connected to the calibrator output. Then try the 2v/5v settings again and see if that weirdness changes at all. Also see if there is any difference between AC-coupled and DC-coupled, and see what happens if you hook both probes to the same point, to display the same signal on both channels.
I have long thought that the Atten/Siglent line are the preferred scopes for OU research .....    This, and the nonadjustable DC offset issue we noted with LTseung's scope, which was also repeated at the electronics store on other Atten scopes, IIRC.... would lead me away from recommending these scopes.

The strange soft turn-off in the middle of the drive pulse ...hmm... I'd like to see some more comparisons between mosfets and BJTs before I stick my neck out on that one but I'm thinking maybe just not enough current, although one would think the drive voltage would sag in that case. Another possible culprit would be core saturation, since it seems to be related to the gap in the core.

Power supply output filtering: Yes, absolutely. Sometimes it doesn't work though. I think I managed to weld a range-switching relay in my Topward PSU by fooling around too much with weird circuits demanding strange power input, and it has some degree of built in input protection, obviously not enough. Choke in series, cap in parallel, good idea.

ETA: One other thing: I see some effects very much like that on my old HP180a scope, on one channel at three mid-low settings of that channel's attenuator. Not the lowest setting. In my case I  know this is because there is some fault in the attenuator circuit at the switch itself, or sometimes I suspect that the attenuator has been deliberately altered by the previous owner (Lawrence Livermore laboratory) to be more sensitive on those settings by about 10x.