Is joule thief circuit gets overunity?

[ltseung888]

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,

The reason why I used the "strange way" is to cater for the possible 4 CH scopes and the Tektronics from Poynt99.  Please use the same convention so that we can compare easily.  Thank you.

[bryanwizard]

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

may i see your video. post the link

[Void]

@Void,
The reason why I used the "strange way" is to cater for the possible 4 CH scopes and the Tektronics from Poynt99.  Please use the same convention so that we can compare easily.  Thank you.

Hi Lawrence. I can repeat the power measurement test on board 119, and measure the input current with the Ch2 scope probe leads reversed like you have been doing, if you like. I will do this as soon as I can get a chance.

[poynt99]

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,
Technically speaking, one of either the current or the voltage needs to be inverted when measuring input power. The input source power when measured always produces a negative (unless you have an OU device) wattage. Go around the circuit loop and notice the electric field is in opposition to all the voltage "drops" in the circuit.

Anyway, it is only a technicality, as the only difference in the end is the sign of the measured power, the magnitude will be exactly the same.

[poynt99]

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.

Could you try it please?

Also try to see if you can then apply a "mean" auto-measurement of the resulting p(t) math trace.

Thanks,

.99