Is joule thief circuit gets overunity?

[picowatt]

TK,

Before you make too many changes, consider trying to duplicate the waveforms of your reply #522.

PW

[TinselKoala]

TK,

Before you make too many changes, consider trying to duplicate the waveforms of your reply #522.

PW

Yes, I have tried, both with the original transistor and the new one, using the same battery too, and I can't seem to do it. The traces always stay below the zero line. I am starting to wonder if I inadvertently set that channel to AC-coupled for that trace. It is barely possible that I flipped the channel coupling switch the wrong way after checking the baseline at "ground" coupling. I am having a hard time believing I would do that, though, since I did check the trace several times.

Awww... does that mean my little PCB JT isn't OU after all? I'm crushed.

[picowatt]

Yes, I have tried, both with the original transistor and the new one, using the same battery too, and I can't seem to do it. The traces always stay below the zero line. I am starting to wonder if I inadvertently set that channel to AC-coupled for that trace. It is barely possible that I flipped the channel coupling switch the wrong way after checking the baseline at "ground" coupling. I am having a hard time believing I would do that, though, since I did check the trace several times.

Awww... does that mean my little PCB JT isn't OU after all? I'm crushed.

TK,

That would be my guess.  Its one of the hazards of doing late night 'scoposcopy...

PW

[TinselKoala]

Well, the first place I generally try to look, to explain any anomalous results, is for my own errors. Thanks for suggesting that I try to reproduce that trace. I'm still not convinced that I actually did that silly mistake, though, so I am going to keep on trying. My own preferred suspect is a DC balance/offset error in the scope's internal calibration. Still, if that were the explanation I should have been able to reproduce the trace.
It's a good thing that Lawrence's scope shows the channel coupling right on the screen; sometimes he has used AC coupling deliberately, but at least he won't be using it accidentally without any way to tell, like on my scope.

[ltseung888]

Well, the first place I generally try to look, to explain any anomalous results, is for my own errors. Thanks for suggesting that I try to reproduce that trace. I'm still not convinced that I actually did that silly mistake, though, so I am going to keep on trying. My own preferred suspect is a DC balance/offset error in the scope's internal calibration. Still, if that were the explanation I should have been able to reproduce the trace.
It's a good thing that Lawrence's scope shows the channel coupling right on the screen; sometimes he has used AC coupling deliberately, but at least he won't be using it accidentally without any way to tell, like on my scope.

I value my Atten Scope more now.  Just repeated the Input Waveform capture on Board 80.  You can draw the zero axis yourself.  It definitely shows current crossing the axis.....