Is joule thief circuit gets overunity?

[picowatt]

Lawrence,

If you are willing to perform the excel file edits, here they are.

On the output data set used for post 575 (which I believe is the same as DSO analysis.xls from post 552) perform the following edits:

First, delete all data points beyond line 7020.

Second, delete all data points between line 14 and line 736

Considering the 14 line offset in the data list, what you should have left are sample points 722 to 7006.

Perform your Pout(avg) calculations using only those sample points.

Please post the result if you will.

Thanks again,
PW

[poynt99]

Pw,
Please let me know why in your opinion the Pout computation will not be correct if done as follows:

Pout (avg)=avg ( iout (t) x vout (t))

No consideration for Q on time etc be necessary, is it?

[picowatt]

Pw,
Please let me know why in your opinion the Pout computation will not be correct if done as follows:

Pout (avg)=avg ( iout (t) x vout (t))

No consideration for Q on time etc be necessary, is it?

.99,

I now believe it is correct. 

I stared at it too long yesterday and in the midst of it all forgot that in the end, Pin(avg) is removed from Pout(avg) when the net power calculation is performed. 

PW

[picowatt]

Pw,
Please let me know why in your opinion the Pout computation will not be correct if done as follows:

Pout (avg)=avg ( iout (t) x vout (t))

No consideration for Q on time etc be necessary, is it?

.99,

As for Q on time, no, I have never considered that an issue because of the averaging.  Bill had asked about the duty cycle and the post I think you are referring to is my response to his question.

PW   

[picowatt]

Pw,
Please let me know why in your opinion the Pout computation will not be correct if done as follows:

Pout (avg)=avg ( iout (t) x vout (t))

No consideration for Q on time etc be necessary, is it?

.99

I am beginning to wonder if Lawrence's scopes need to have their input channel offsets checked.  Looking at the raw output data listing, when Q1 is on, Vout is 80mV.  At that same time, there is 12ma being indicated as the output current.  I have checked the current flow through several LED's of various "colors" and cannot find any that indicate anywhere near 1ma at that applied voltage.  Possibly his LED is different than those I have tested, but if that channel is applying a 12ma offset to all Pout calculations, that would be significant.

PW