Is joule thief circuit gets overunity?

[ltseung888]

Why would a 0.4V rechargeable  AA battery continue to light the LED for 3 full days?

More experiments needed???

The spikes on all Boards tested on the Atten showed crossing 0 ref line.  Could that be the explanation???

[Void]

This is getting rather ridiculous, don't you think?

Are you really looking for, and trying to reproduce, some kind of OU evidence that only shows up with the cheapest possible DSOs used incorrectly? With absolutely NO concurrent validation (a technical term meaning evidence of OU from some OTHER experimental or measurement technique running alongside the Atten measurements)?

Note again, that after all this time, the definitive experiment is still not being done. Charge a known capacitor to a known voltage. Then you know precisely the energy available for whatever. Use this capacitor to run the JT circuit while monitoring its voltage and the time accurately. Monitor the output power in your favourite manner. When the capacitor has dropped by a known voltage increment, you will KNOW just how much energy you have put into your circuit, and you will KNOW for how long.... thus you will KNOW, not guess or interpret, just how much input ENERGY you are dealing with during that time. This figure can be directly compared to the output power, or more precisely to the integrated output power over the time interval concerned (the output ENERGY).

It will do no one any good if I do this measurement. It must be done on several boards that Lawrence claims do show OU behaviour, preferably by Lawrence himself, but anyone who has an "approved" board, an oscilloscope, a stopwatch, an accurate voltmeter, and a bunch of capacitors can do the work in a day or two with enough runs for statistical significance to result IF there is anything to see.

When you see that every capacitor you try results in efficiencies of under 100 percent, then you can start resorting to your special pleading that "the robust and confirmed OU effect only happens with batteries. No, not those batteries, or those, not just any batteries, but only rechargeable batteries of specific chemistry and manufacturer, and only when they are between 0.341 and 0.351 volts".... and only when they are pointed northeast, on Tuesday mornings, when the weather is clear......

Whatever, dudes.

Relax Tinselkoala. You are not stating anything that is not already obvious to me, anyway. At this point I have agreed to test a couple of Lawrence's boards to see what shows up in my own measurements. I make no assumptions at all in regards to what is happening in Lawrence's boards. Once I get a couple of boards to test with, I will make measurements and see if there is anything unusual going on there. I will report all my results back here anyway. Anyone who has any concerns with my measurements will be free to provide whatever feedback they like. The world is still safe.

[Void]

Why would a 0.4V rechargeable  AA battery continue to light the LED for 3 full days?
More experiments needed???
The spikes on all Boards tested on the Atten showed crossing 0 ref line.  Could that be the explanation???

I was thinking more about this and here is something you could try to see if this is just a normal discharge characteristic of your particular type of rechargeable battery:

Take the exact type of rechargeable battery (or, if possible, the exact same battery which you used in your test that you described here) and connect, say, a 220 ohm resistor across it terminals. Start with the battery fully charged. Place your scope probe across the battery's plus and minus terminals and monitor what happens when the battery discharges down to 0.4V. See if the battery shows the same sort of slow discharge characteristic at 0.4V with just a resistor for its load. If the discharge pattern is similar to what you saw when connected to your joule thief circuit at 0.4V, then it is likely just a characteristic of how that type of rechargeable battery discharges when it gets to around 0.4V (for a comparable load). For example, once the battery drops to about 0.4V, observe if the battery discharges at about the same rate with just the 220 ohm resistor connected, as it did with the joule thief circuit connected over a period of three days.

Important:
I am just using 220 ohms above as an example, which will give you an input current of 1.8mA when the battery is at 0.4V. If your input current when connected to your joule thief circuit was less than 1.8mA at 0.4V input, then you should use a larger value resistor for the test. You would want the input current draw at 0.4V with the resistor to be about the same as it was when the joule thief circuit was connected with 0.4V input. So, if your input current was closer to 1.2mA at 0.4V input, then use a 330 ohm resistor for the test. If you are not certain, then try using the 330 ohm resistor.

[Void]

Lawrence, I think I see how you may be getting that ringing now on your input current waveform. I connected a super capacitor charged to just over 0.4V as the input voltage source for my joule thief circuit, and at 408mV input voltage I am starting to see some ringing on the input current waveform with a little bit of zero crossing. This sort of ringing on the current waveform would not be unusual in itself when you are driving an inductive load with a capacitor. The combination of capacitance and inductance can certainly produce ringing, so that in itself certainly does not imply anything unusual or imply over unity. However, it will be interesting to conduct tests to see if this ringing does reduce power consumption or increase efficiency at all, and if so, by how much.

I have attached a screen shot of the ringing on the input current waveform (blue trace) that I am seeing using a capacitor as my DC power source for my joule thief circuit. The capacitor is currently at 408mV. You can see a little bit of zero crossing on the larger negative peaks of the ringing pattern. Again, the ringing pattern seen would not be unusual in a circuit with capacitance and inductance, and the zero crossing certainly doesn't necessarily imply that there would be an increase in efficiency or over unity. Measurements of input and output power at different input voltages with a capacitor used as the input voltage source could be used to see if efficiency increases by any measurable amount when this sort of ringing with zero crossing occurs at some given input voltage, as opposed to say using a regulated DC power supply set to the same input voltage, if no ringing occurs on the input current waveform when using the regulated power supply. If possible, I will try to run some tests of this sort to see if the ringing has any measurable effect on performance.

[ltseung888]

Lawrence, I think I see how you may be getting that ringing now on your input current waveform. I connected a super capacitor charged to just over 0.4V as the input voltage source for my joule thief circuit, and at 408mV input voltage I am starting to see some ringing on the input current waveform with a little bit of zero crossing. This sort of ringing on the current waveform would not be unusual in itself when you are driving an inductive load with a capacitor. The combination of capacitance and inductance can certainly produce ringing, so that in itself certainly does not imply anything unusual or imply over unity. However, it will be interesting to conduct tests to see if this ringing does reduce power consumption or increase efficiency at all, and if so, by how much.

I have attached a screen shot of the ringing on the input current waveform (blue trace) that I am seeing using a capacitor as my DC power source for my joule thief circuit. The capacitor is currently at 408mV. You can see a little bit of zero crossing on the larger negative peaks of the ringing pattern. Again, the ringing pattern seen would not be unusual in a circuit with capacitance and inductance, and the zero crossing certainly doesn't necessarily imply that there would be an increase in efficiency or over unity. Measurements of input and output power at different input voltages with a capacitor used as the input voltage source could be used to see if efficiency increases by any measurable amount when this sort of ringing with zero crossing occurs at some given input voltage, as opposed to say using a regulated DC power supply set to the same input voltage, if no ringing occurs on the input current waveform when using the regulated power supply. If possible, I will try to run some tests of this sort to see if the ringing has any measurable effect on performance.

@Void

The Zhou Boards showed much ringing - heard by the many young ears.  (I could not hear any but that was probably due to my poor hearing.)  I shall use different time scale to show the ringing waveforms.

I noticed that the display of your DSO is exactly like Atten.  That will make our communication much easier.  You can use the save/recall button to save the CSV file on the USB.  I can analyze one of your measurements for you (both Input and Output) as sample.  You do not need to rely on Vrms values any more.  You can use the vigorous Instantaneous Values.