Storing Cookies (See : http://ec.europa.eu/ipg/basics/legal/cookies/index_en.htm ) help us to bring you our services at overunity.com . If you use this website and our services you declare yourself okay with using cookies .More Infos here:
https://overunity.com/5553/privacy-policy/
If you do not agree with storing cookies, please LEAVE this website now. From the 25th of May 2018, every existing user has to accept the GDPR agreement at first login. If a user is unwilling to accept the GDPR, he should email us and request to erase his account. Many thanks for your understanding

User Menu

Custom Search

Author Topic: Is joule thief circuit gets overunity?  (Read 602762 times)

ltseung888

  • Hero Member
  • *****
  • Posts: 4363
Re: Is joule thief circuit gets overunity?
« Reply #855 on: May 16, 2013, 01:27:50 PM »
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

  • Hero Member
  • *****
  • Posts: 2333
Re: Is joule thief circuit gets overunity?
« Reply #856 on: May 16, 2013, 03:46:38 PM »
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

  • Hero Member
  • *****
  • Posts: 2333
Re: Is joule thief circuit gets overunity?
« Reply #857 on: May 16, 2013, 04:17:26 PM »
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.




« Last Edit: May 16, 2013, 06:26:36 PM by Void »

Void

  • Hero Member
  • *****
  • Posts: 2333
Re: Is joule thief circuit gets overunity?
« Reply #858 on: May 16, 2013, 04:52:37 PM »
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

  • Hero Member
  • *****
  • Posts: 4363
Re: Is joule thief circuit gets overunity?
« Reply #859 on: May 16, 2013, 10:27:09 PM »
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.

Void

  • Hero Member
  • *****
  • Posts: 2333
Re: Is joule thief circuit gets overunity?
« Reply #860 on: May 17, 2013, 12:13:52 AM »
@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.

Yes, your boards seem to show a lot more ringing than my circuit, and they also show some unusual pulses/noise superimposed on the waveforms as well, which may be just due to electrical noise of some sort, but I don't know. It might be something else causing those pulses. My super capacitor is actually 3000 Farads nominal value, so it is going to take a fair bit of time for the input voltage to drop down much below 0.4 volts. :) It is the only super capacitor I had available however. My joule thief circuit has been running all day and the input voltage is still at 400mV from 408mV yesterday evening. :) It might be a day or two before the voltage has dropped down much below 400mV. The ringing that can often be heard on a joule thief circuit is generally due to the frequency of oscillation being in the audio frequency range, which causes the ferrite to ring at that frequency for some reason, and probably not so much to do with the type of ringing pattern that can be seen on the input current waveform. My joule thief circuit seems to operate mainly above the audio frequency range, at least at the lower input voltages I have been testing it at, so I don't hear any ringing noise from my ferrite toroid. I will see if I can get the data logging working on the weekend. If I can do it using a USB flash drive, I would prefer that because hooking up to a laptop will likely increase the electrical noise in the test circuit. Laptops and their switching power supplies tend to produce a fair bit of electrical noise.


Pirate88179

  • elite_member
  • Hero Member
  • ******
  • Posts: 8366
Re: Is joule thief circuit gets overunity?
« Reply #861 on: May 17, 2013, 05:08:47 AM »
@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.

Lawrence:

If your students can hear the ringing, then your JT's are operating under 20,000 cycles/sec.  (Possibly a little higher, but not much)  Some of the JT lights I have built made that annoying high pitched buzz so I simply placed a small neo on the ferrite toroid and it raised the HZ above my hearing level...and also made the lights a little brighter.

Note that Void's frequencies are much higher and that is why he can't hear them.

Just my 2.1175 cents.

Bill

ltseung888

  • Hero Member
  • *****
  • Posts: 4363
Re: Is joule thief circuit gets overunity?
« Reply #862 on: May 17, 2013, 07:45:24 AM »
Analyzing the Noise.  Look at the following 5 slides.  The noise is relatively systematic.
 
What can it be???

Void

  • Hero Member
  • *****
  • Posts: 2333
Re: Is joule thief circuit gets overunity?
« Reply #863 on: May 17, 2013, 02:11:33 PM »
Analyzing the Noise.  Look at the following 5 slides.  The noise is relatively systematic.
What can it be???

I am not sure, as your input current waveforms look a lot different from mine.
Would you mind showing a scope shot with everything else still connected the same,
but with one of the input power wires disconnected, or with the power turned off?
This will give an indication of what kind of electrical noise the circuit is picking up
when the circuit is turned off, so we can see what sort of noise remains.



Void

  • Hero Member
  • *****
  • Posts: 2333
Re: Is joule thief circuit gets overunity?
« Reply #864 on: May 17, 2013, 02:26:39 PM »
Here is a scope shot of the input waveforms of my joule thief circuit with the super cap now at about 384mV.
The input current waveform still looks fairly similar to the way it looked at 408mV, but the frequency
slowly increases as the input voltage drops. The frequency is now around 294kHz at this input voltage.


TinselKoala

  • Hero Member
  • *****
  • Posts: 13958
Re: Is joule thief circuit gets overunity?
« Reply #865 on: May 17, 2013, 02:38:12 PM »
Here is a scope shot of the input waveforms of my joule thief circuit with the super cap now at about 384mV.
The input current waveform still looks fairly similar to the way it looked at 408mV, but the frequency
slowly increases as the input voltage drops. The frequency is now around 294kHz at this input voltage.
Channel 2 is the current trace? Is your current trace display inverted, or are you using different probe positions than are given in the last complete diagram?

I see you have also overlapped the baselines of the two traces, putting them both on the center graticule marker. And you are using bandwidth limiting on the current trace.

(Edited, Channel 2 is the greenish one).

TinselKoala

  • Hero Member
  • *****
  • Posts: 13958
Re: Is joule thief circuit gets overunity?
« Reply #866 on: May 17, 2013, 02:49:19 PM »
Lawrence, it should be clear to you by now that the term "ringing" has two different meanings. First, the common meaning, an audible tone like a high-pitched bell ringing, that your students with young ears can hear. This is caused by loose windings on the toroid and perhaps the toroid itself, vibrating at the frequency of oscillation of the JT circuit, which as we know is a function of voltage as well as the toroid and transistor characteristics. When the oscillation frequency is in the range of human hearing you hear the parts vibrating.
The second, more technical meaning is the _inductive ringdown_ and this can be seen very clearly in your last, highest-speed scopeshot. This is the "bounce" in a signal that is seen when some energy is sloshing  back and forth between an inductor and a capacitance. As you can see, I hope, from careful examination of that last scope shot, this energy sloshes back and forth (the ringing) and dissipates (the decrease in amplitude of the cycles during each ring) but most importantly: IT AVERAGES TO ZERO, or slightly below zero since there is always a little bit of current flowing in addition to the ring. The frequency of this inductive ringdown is very high, as you can see, and is clearly out of the range of hearing. The inductances and capacitances participating in this high-frequency ringing are simply the wires and spacings in your circuit. This is why tight construction and short wires are used in high frequency circuit layout: to reduce this kind of ringing noise, which usually is considered detrimental to circuit performance.
Another feature to note from your series of shots is the difference between the first and second shots. You can clearly see that the first shot is missing a lot of the action, due to the "picket fence" effect of sampling and display rates and resolutions.  The first shot looks like random noise. The second shot is beginning to resolve the transistor's switching frequency (the potentially audible ringing). By the time you get to the last shot you are able to resolve the ringing of the inductances and capacitances of the wiring and layout themselves, far above the range of human hearing.... and acting as a purely dissipative mechanism for heating up the components concerned, as you can see from the fact that each cluster of ring oscillations decreases in amplitude over time.

(And you _still_ aren't putting your baselines directly on a graticule marker. See the little arrows on the left side of the display? Please use your vertical positioning knobs to put these little arrows _exactly_ on one of the horizontal graticule lines, unless there is a specific and clear reason for not doing so. You have no such reason, and the lack of accuracy in your scope setup is making it unduly difficult for observers to interpret your scope traces. I have mentioned this issue to you several times now. The reason for those wiggly lines on a scope display is so that they can be interpreted. The numbers in boxes that you seem to rely upon do not tell the whole, or even the most important story that an oscilloscope can tell. Proper management of the display of the traces is an essential part of scoposcopy. PLEASE PUT THE CHANNEL BASELINES EXACTLY ON HORIZONTAL GRATICULE LINES in all your future scopeshots unless you have a good, conscious and articulatable reason for not doing so. But congratulations on setting your trigger a bit better.)

TinselKoala

  • Hero Member
  • *****
  • Posts: 13958
Re: Is joule thief circuit gets overunity?
« Reply #867 on: May 17, 2013, 03:06:22 PM »
The triggering point on the Atten and the similar scope that Void is using is indicated by several features of the display. Of course the trigger voltage and channel and edge are displayed as a "number in box" at the lower right of the screen. But on the trace display itself, the trigger voltage is indicated by a "T" and arrow, in the color of the channel selected, on the left edge of the display along with the channel baseline markers. The trigger TIME is indicated by the white arrow at the top of the display, and this is normally set at the center vertical graticule marker. SO the intersection of the lines defined by the "T" and the white arrow is where the scopes are triggering (or should be).

In Void's scopeshot this can be clearly seen: the trace triggers the scope at the intersection, right in the center of the screen horizontally and at the set trigger voltage vertically.

In Lawrence's scopeshots... not so much.  In the last one particularly, the trigger point has been moved off the screen to the left with the horizontal positioning control and we are seeing a "delayed" display, and it's unclear just where the scope is triggering and on what signal, since the trigger point is off the screen. In many other scopeshots from Lawrence, there doesn't seem to be anything happening at the trigger point on the display, yet the scope is triggering anyway.

ltseung888

  • Hero Member
  • *****
  • Posts: 4363
Re: Is joule thief circuit gets overunity?
« Reply #868 on: May 17, 2013, 03:08:41 PM »
If the "ringing pulse" represents current crossing the 0 ref line, then we must have positive and negative power in the circuit.  (Input Volotage is all positive.  Output Voltage and Output Current are all positive.)
 
What does that mean?  How can current flow forwards and backwards in a DC environment?
 
*** Look at the theoretical explanation again.  If there is a "hidden" pulsing source, the above is possible.  That is Lead-out energy.  So long as there is crossing of the 0 reference line - either the main Current or the spikes, there is lead-out energy.  Amen.
 
*** It is a matter of producing the circuit to achieve this crossing the 0 ref line behavior.  The Zhou Board is only one example.

Void

  • Hero Member
  • *****
  • Posts: 2333
Re: Is joule thief circuit gets overunity?
« Reply #869 on: May 17, 2013, 03:11:17 PM »
Channel 1 is the current trace? Is your current trace display inverted, or are you using different probe positions than are given in the last complete diagram?

I see you have also overlapped the baselines of the two traces, putting them both on the center graticule marker. And you are using bandwidth limiting on the current trace.

Hi Tinselkoala. My probes are oriented the same as I have shown in the schematic I posted previously. Yellow(Ch.1) is the input voltage waveform, and blue(Ch.2) is the input current waveform. The input current waveform should not be inverted. Yes, I have both waveforms vertically set at the center line. I like to set them that way.

Regarding the bandwidth limiting on channel 2, my scope turns this on automatically at low volts per division settings, and I am not able to turn it off. There seems to be some auto routine there that flips this on maybe as the signal gets a certain percentage of noise on it. My input current waveform is starting to get close to the noise level at this input voltage. I don't know what frequency the scope limits the bandwidth to when the BW Limit feature is turned on. The user manual for my scope seems to have been written by a grade four student. The PC interface software that comes with my scope also seems to have been written by the same grade four student. :) The scope itself however seems at least passable, so far.