Is joule thief circuit gets overunity?

[poynt99]

Void,

Are you able to get a math trace of (ch1 * ch2) on your scope?

[Pirate88179]

would be possible to used the earth battery as an input power

I already did that a few years ago.  I lit 400 leds from a JT circuit and my earth battery.  Check out my youtube videos if you like.

Bill

[ltseung888]

@Lawrence: Here are my power measurements for your JT Board # 119.
For the same input voltage (0.5VDC) using my regulated power supply, your JT board runs at a much lower frequency than my board (most probably mainly due to the different type of toroid you are using), and your board also has higher input and output currents than my JT board at the same input voltage. The switching spikes on the input voltage waveform on your board are sharper with a higher amplitude, and with less ringing than I get with my JT circuit.
The efficiency measured to be pretty close to my JT board at the same input voltage however.
Do you want to see these same type of measurements for the other boards you sent me as well?

Input Voltage:  500mV
Input Power:  5.282mW
Output Power:  3.779mW
Efficiency:  71.54%

I am attaching the scope screen shots below.
Yellow traces are the voltage waveforms, and blue traces are the current waveforms.
I am also attaching the Excel spreadsheet files showing the data samples and the resulting power calculations.
-- void --

@Void,
There is something wrong with the Input Waveform.  If you used Board 119, the waveform should be similar to the attached.  Do not use the Invert function.  The Current Waveform (CH2) should be mostly negative.  In your example, it is all positive.  Please check.

[Void]

@Void,
There is something wrong with the Input Waveform.  If you used Board 119, the waveform should be similar to the attached.  Do not use the Invert function.  The Current Waveform (CH2) should be mostly negative.  In your example, it is all positive.  Please check.

Hi Lawrence. I have explained this before. There is nothing wrong with my input current waveform measurement. The reason your input current waveform shows as negative is because you hook up your scope probe for the input current measurement in reverse, which causes your current waveform to show as inverted. Since I am using a 2 channel scope, I see no reason to not measure the input current in its proper orientation. I might try an experiment to connect my input current probe in reverse like you connect it, just to see if the input power measurement comes out the same, but just with an inverted sign. If you think about it, for your input current waveform to show as negative current, your input current waveform must be inverted.

[Void]

Void,
Are you able to get a math trace of (ch1 * ch2) on your scope?

Hi poynt99. I haven't tried the math trace feature on my scope, but according to the manual for my scope, it does have a CH1*Ch2 math trace function.