Is joule thief circuit gets overunity?

[poynt99]

Yes, I can.

Give me a couple hours to get that uploaded.

[picowatt]

.99

Post #264 on page 18 is a better capture shot from lawrence regarding board 33.  Still  bit noisey and much more "spikey" than what your seeing.

PW 

ADDED:  Sorry, that was for board 38, never mind.  My prior posts are for board 33 however.
Did not have the reading glasses on...

[TinselKoala]

@.99.... beautyfull! You gotta love the new Tek scopes. The Digital Phosphor idea really makes for a nice looking display.
Two of those probes together cost more than what my car is worth!
Do you by chance have a differential voltage probe and a current probe for it?

I think that scope can probably do two live math traces, so you could display input voltage and current, instantaneous power, and the integral of the power all on one screen.

I also think that it's pretty clear that there is a DC offset issue happening with the Atten scopes at this very high sensitivity setting. 12 mV isn't much and wouldn't show up in most cases.... but there has to be a reason why there's nearly a two orders of magnitude price differential between Atten and Tek, too.

[poynt99]

Lawrence,

3 uploads; 001 is for an Input Voltage of about 0.5V, just as the circuit began oscillating. 002 is for an Input Voltage of about 1.00V, and 003 about 1.36V.

Happy crunching.

[picowatt]

@.99.... beautyfull! You gotta love the new Tek scopes. The Digital Phosphor idea really makes for a nice looking display.
Two of those probes together cost more than what my car is worth!
Do you by chance have a differential voltage probe and a current probe for it?

I think that scope can probably do two live math traces, so you could display input voltage and current, instantaneous power, and the integral of the power all on one screen.

I also think that it's pretty clear that there is a DC offset issue happening with the Atten scopes at this very high sensitivity setting. 12 mV isn't much and wouldn't show up in most cases.... but there has to be a reason why there's nearly a two orders of magnitude price differential between Atten and Tek, too.

TK,

Yes, but if one knew the low cost scope well, and compensated for its offset and any DC gain error after making a few cal tests, one could still acheive some accurate results (at least better).

I believe I read there was a firmware update for the Atten scopes regarding the "cal on power up" hanging during offset correction.  Don't quote me, but I believe I bumped into that while searching for the DC specs.

But that Tek sure makes pretty outputs...  And at only $9G used...  (probes, taxes, dealer prep, wash wax and a tank of gas not included)

PW