Is joule thief circuit gets overunity?

[picowatt]

@PW,

You probably missed it with the hugh number of posts.  See reply 552.  It contains the full DSO analysis for Board 80.  The first sheet is the Output.  The second sheet is the Input.  The various wavforms such as Voltage, Current and Power are also displayed.  The saved BMP files are included for comparison.  The COP was calculated to be 1.41 at the end of first sheet.

@All,

I also tried to get CH2 Vavg to 0V by adjusting the DC Power Supply.  The readings were fluctating and I could not get a perfect steady reading.  However, when CH1 Vrms was at 680mV, CH2 Vavg fluctuated between 4mV and -2mV.

Lawrence,

I have looked at the DSO Analysis.xls attached to post 552 several times.  It appears to be only the output data calculated for average output power, but no where do I see the input power data or calculation.

It should not be this difficult to communicate.  A while back you posted Board 80's screen captures as slide 12 and slide 13 in your post 503.  You said those captures indicated OU.  I have asked several times for the input and output power calculations from the data captured during that same test and represented by slides 12 and 13.  The calculations in post 552 appear to be from slide 13, but no where have I seen the slide 12 input power calculations. 

Actually, to date, I have not been able to find any posts wherein you provide input AND output power calculations from input and output data collected at the SAME time during any given test you have presented.  With some tests you post your output calculations, with others you post input calculations.

PW 

[Pirate88179]

Lawrence,

Although your Board 80 input current trace does show some excursion above the zero ref line, overall, there is much more area under the zero ref line.  Everything under the zero ref line is current being drawn from the battery.  Looking at that board's input and output power captures demonstrates an efficiency of about 75 to 85%.

TK's reply 522 definitely looked like it was OU by a significant amount.  The apparent equal area above and below the zero ref line on the input current trace made me wonder, however, if he had inadvertantly switched to AC coupling.  Although the jury may still be out on that completely, it is the most likely explanation for that anamalous capture.

PW

I still stand with my original prediction made  March 31, 2013, 02:53:13 PM,  partially quoted below:

" I want to make a prediction here.  I believe that .99's tests will show somewhere between 60 and 69% efficiency.  Not bad for a simple JT circuit but no where near 100%, much less 200%+ as has been discussed."

Those toroids are not the best ones to use and he is losing a lot of energy to those resistors as heat.  No way is it COP  of 1,221.  We will see if I am close to being correct.

Bill

[picowatt]

I still stand with my original prediction made  March 31, 2013, 02:53:13 PM,  partially quoted below:

" I want to make a prediction here.  I believe that .99's tests will show somewhere between 60 and 69% efficiency.  Not bad for a simple JT circuit but no where near 100%, much less 200%+ as has been discussed."

Those toroids are not the best ones to use and he is losing a lot of energy to those resistors as heat.  No way is it COP  of 1,221.  We will see if I am close to being correct.

Bill

Bill,

My "eyeball" guesstimate of efficiency for board 80 in post #503 slide 12 and 13 is tad bit better than your estimate, but not a COP of 1,221...

PW

[Pirate88179]

Bill,

My "eyeball" guesstimate of efficiency for board 80 in post #503 slide 12 and 13 is tad bit better than your estimate, but not a COP of 1,221...

PW

Stefan should start a contest to see who gets the closest, ha ha.  We could all agree to go by .99's numbers when they come in.  I guess we will just have to wait and see.  I thought I was guessing on the high side but...oh well...we will see.

Bill

[Groundloop]

The oscilloscope analysis for Board 107.


Average Output Power
12.05105778 watt
Average Input Power
0.009865636 watt

COP = 1221.52

This Board 107 will be carefully studied and preserved.

ltseung888,

Please post a photo of this board.

GL.