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Author Topic: Is joule thief circuit gets overunity?  (Read 600491 times)

poynt99

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Re: Is joule thief circuit gets overunity?
« Reply #510 on: April 09, 2013, 04:27:13 PM »
I am in phoenix until apr 16, but I am following along.

TinselKoala

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Re: Is joule thief circuit gets overunity?
« Reply #511 on: April 09, 2013, 06:50:52 PM »
@PW:
The sequence of events you have described is exactly why I have asked Lawrence to provide the input and output Voltages on one scope, and the input and output Currents on the other scope. This will allow "us" to observe the time sequence, the relationship between the input and output pulsations. We cannot see this in Lawrence's present data, with input and output data on separate instruments. A 4-ch scope will of course show these relationships in real time, but Lawrence only has the two 2-ch scopes to work with.

Another bit of data that would be quite instructive to "us" would be some actual measure of LED light output. This doesn't have to be quantitative, just synchronous. This would allow "us" to observe the relationship between the actual _illumination_ of the LED and the pulses coming from the various parts of the circuit. Again, there are not enough channels available to see this in real time, but an experimental session could be devoted to showing, say, the input or output voltage or current trace on one channel, and the trace from a photovoltaic cell taped to the LED on the second channel. This will answer the question of "when" the LED is actually ON, in relationship to the input and output signal pulses.

I have found in the past in pulsed circuits that people sometimes believe that a component is "on", when in fact it is "off".


@PW, .99:
In Lawrence's recent scopeshots of Board 80, the one that I have edited to show the _true_ baseline for the CH2 current measurement.... note that the scope is reporting + 40.00 mV RMS for that signal...... which barely ever actually goes positive, never even reaching 40 mV positive that I can see, and extending deeply negative during its spikes.  RMS, of course, is mathematically always a positive value..... so how are we to interpret a _positive_ RMS value for a signal that is actually almost always, if not strictly always, negative? The RMS value gives the wrong direction for the current being measured in this channel, doesn't it?
Lawrence has explained that the RMS boxes are a "legacy" from his early work. I hope it's clear now that these values are not relevant and may even be confusing the issue, due to things like the positive RMS value for a clearly negative-average signal. They should not be displayed at all. If the scope has a simple "average" parameter available, that might provide some rough and useful information. An artificially positive RMS value does not.

@Lawrence:
Once again.... I ask you to provide Input and Output Voltages on ONE SCOPE, and the Input and Output Currents on the OTHER SCOPE, so that we can see the TIMING relationship between the input and output pulses. I am NOT suggesting that you always do it this way; what you are doing normally is proper for your power measurements. But we need to see at least one set of screens taken with input and output voltages on one scope, and input and output currents on the other, for the timing relationships.

This TIMING relationship is what PW has described in detail above, and what I have greatly simplified when I said that the dips in the battery voltage trace are due to the LED turning on.
As PW has explained there are a couple of intermediate steps in that process, and the light from the LED is probably not happening at the exact same time that the dips in the battery voltage are happening. Nevertheless, the dips represent power being drawn from the battery, and this power eventually is mostly dissipated in the light from the LED. We really would like to see some traces of INPUT and OUTPUT on the SAME scope screen at the SAME time, so that these relationships can be made clear.

If you can arrange it, a photovoltaic cell (solar cell) simply taped in a stable manner to your board's LED will provide a voltage signal when the LED is actually ON, and can be simply hooked to a scope channel probe directly. This measurement should be done with the FLEET board's _Input_ Battery Voltage on one channel and the Photovoltaic output on the second channel. You can get a photovoltaic (solar) cell very cheaply by taking apart one of those self-charging garden lights that cost a couple of dollars -- and you'll also get a couple of white LEDs. A bargain however you look at it. Or, a simple photoRESISTOR in series with a power source like a battery can be used to provide a signal that is on when the LED is on. There is also a photoresistor inside many types of garden lights, but some simply use the PV cell itself to detect day/night.

TinselKoala

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Re: Is joule thief circuit gets overunity?
« Reply #512 on: April 09, 2013, 07:16:13 PM »
An even better, temporary, arrangement that might work to show the time relationship between the LED output and the circuit's pulsations, would be to use an optoisolator chip's input stage as a substitute for the board's LED. Then one can simply use the phototransistor output from the optoisolator to monitor the actual "LED" turning on and off. This method doesn't have the potential to actually measure the board's LED light output, though, but it will give the most accurate timing data, I think.

The H11Dx series of optoisolators is cheap and robust. I think I have an H11D4 that's not in use, I can try this on my 2n2222 JT test bed to see if it will work. The phototransistor output stage can be powered by a separate battery or power supply for the few moments the testing will take.

TinselKoala

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Re: Is joule thief circuit gets overunity?
« Reply #513 on: April 09, 2013, 08:01:58 PM »
Some oscilloscopes, like my venerable HP180a with the 1821a horizontal timebase/delay generator, have a trigger _output_ that can be used to synchronize other instruments.
It would be nice if the Attens had a trigger output. Then you could use the trigger out from one to trigger the other one, and achieve "manual" synchrony that way and reassemble a "4-channel" set of traces in the spreadsheet.

TinselKoala

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Re: Is joule thief circuit gets overunity?
« Reply #514 on: April 09, 2013, 08:18:30 PM »
Sorry to make so many posts in a row, but I'm having my coffee and thinking hard about this, also warming up my scopes.

By the way, Lawrence, even DSOs should be "warmed up" for a few minutes and allowed to stabilize before taking quantitative measurements.  Believe it or not, we have actually encountered.... persons.... who will turn the scope on, and as soon as it passes its internal self-test they make a measurement and then immediately turn the scope off, to .... save power or something. Then to make the next measurement, they turn the scope back on...... '

But the point of this post is to request that Lawrence select ONE "good" performing JT / FLEET board for his own testing and reporting purposes here, so that we can always refer to that board's performance traces in our discussions. This jumping around from board to board, with their individual differences, is not helping to clarify matters in the question of OU performance very much.
But it might also be helpful to have the WORST performing of all the boards to use as a control or comparison, as well.

picowatt

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Re: Is joule thief circuit gets overunity?
« Reply #515 on: April 09, 2013, 10:34:46 PM »
TK,

If you look at the B2 trace for Board 80, the LED is on during the narrow (c.a. 70us) positive going peaks during which time the LED is turned on.  As the LED turns off (because the voltage across it is dropping below its turn on V), the current indicated by B2 drops to zero.  This causes the rate at which the voltage is falling on B1 to slow down, hence the somewhat exponential rolloff.  As soon as Q1 turns on again, the voltage at B1 rapidly falls to zero (actuallyit falls to Q1's Vce).

Looking at the waveforms for Pin and Pout for Board 80, it looks like the circuit is 75 to 85% efficient or there abouts.

PW

TinselKoala

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Re: Is joule thief circuit gets overunity?
« Reply #516 on: April 09, 2013, 11:22:57 PM »
@PW:
You are confusing me with your "B"s, I don't have the diagram constantly in front of me, so I like to refer to the four possible traces as "input battery voltage", "input current", "output voltage" and "output current". The A1A2A3A4B1B2B3B4 assignments can be read from the schematic when they are needed, as long as we all agree to use the same schematic and the same probe orientation as given.

I've made a short video showing the response of an NPN phototransistor (NTE3037) coupled to the LED of my PCB 2n2222a JT. I verified the output of the phototransistor by also using a photovoltaic cell to show that the PV gives the same kind of waveform as the PT when stimulated by the LED, just at lower amplitude.

I've compared the phototransistor response to both the "input battery voltage" and the "output voltage" taken at the normal points as indicated on the schematic. The deepest part of the valley or dip in the Input Battery Voltage trace coincides with the moment of LED turn-on, and the LED, with a depleted battery, isn't at constant brightness during its "on" time, as evidenced by the nonhorizontal tops of the positive going narrow peaks in the output voltage trace.

This isn't a quantitative measurement, of course.... that would take some calibration effort but is clearly possible. This is just designed to look at the timing of the events. I've been meaning to do this step for some time, to verify just where in the LED light curves, the peaks and valleys of the electrical signals occur.

The video is processing and uploading now and should be viewable in half an hour or so. It will be at:
http://youtu.be/E4k2bsyca4I

ETA:Golly... I've just finished writing the notes/description, and the thing has already had three views. Please, be sure to read the description again, there might be additions that you've missed, whoever you are out there in the audio radiance.



ltseung888

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Re: Is joule thief circuit gets overunity?
« Reply #517 on: April 09, 2013, 11:41:06 PM »
I am in phoenix until apr 16, but I am following along.
@poynt99,
 
While we wait for your results, I shall go to Shenzhen and see if I can borrow some 4-Ch Oscilloscopes.  Hopefully, I can get their experts to calibrate and do the actual hook-ups for me.  PhysicsProf has the 2-CH Atten Scopes.  He will be able to double check my results in the latest corrected way.  I am sure that I can have Mr. Zhou use his many different models of Osilloscopes to display his results (Board 101-200).
 
My plan is to get the Hong Kong Universities, especially their Physics and Electrical Engineering departments involved again.  They have better scopes and most probably the high-end 4-Ch scopes.  It will take them a few minutes to hook up any one of these "guaranteed OU" boards and record the waveforms and perform the oscilloscope analysis as described.  (I shall update and provide the latest procedure to avoid confusion).
 
My job is to sow seeds.  We now have the Boards and Procedures that appear to show OU.  We should have more experts join the game.  They will know their oscillocopes better.  They will be able to produce better JTs including better toroids, more layers, more LEDs etc.  Some will no doubt use the 2n3055 with the higher power so as to work above the noise level.
 
In October 2013, my filed patent with BSI Hong Kong will be published.  In the patent, many conceptual applications are described.  However, I believe many researchers will think of same or similar applications before that date.  The floodgate is open.  With your expected results (and those from PhysicsProf) and others, I feel that much more resources will pour into this lead-out energy research. 
 
Thank you to you, Tk and others for spending so much time and energy to make such progress.  God Bless.

TinselKoala

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Re: Is joule thief circuit gets overunity?
« Reply #518 on: April 10, 2013, 12:23:30 AM »
Well, I appreciate the acknowlegment, but what are you going to do "if" we find that your circuit isn't OU after all, nor is it even especially efficient? (I believe that PW's estimate is "ballpark" accurate.)

Meanwhile I realized that I haven't shown the test point locations on my PCB JT. Except for the use of a metal can 2n2222a, this circuit, even including the toroid windings and material, is, as far as I can tell, the exact same as your boards (without the capacitors). I'm using a battery that is even less powerful than a depleted AAA, though.
Anyhow, FWIW here are the locations of the test points, corresponding to the letter-number system used on Lawrence's most recently posted schematic.

Legend:
A2A3, B2B4 == common circuit reference point, all scope ground leads go here
A1 == input battery voltage
A4 == input current (inverted probe, so negative means "conventional" current flowing)
B1 == output voltage
B3 == output current

picowatt

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Re: Is joule thief circuit gets overunity?
« Reply #519 on: April 10, 2013, 12:46:14 AM »
@PW:
You are confusing me with your "B"s, I don't have the diagram constantly in front of me, so I like to refer to the four possible traces as "input battery voltage", "input current", "output voltage" and "output current". The A1A2A3A4B1B2B3B4 assignments can be read from the schematic when they are needed, as long as we all agree to use the same schematic and the same probe orientation as given.

I've made a short video showing the response of an NPN phototransistor (NTE3037) coupled to the LED of my PCB 2n2222a JT. I verified the output of the phototransistor by also using a photovoltaic cell to show that the PV gives the same kind of waveform as the PT when stimulated by the LED, just at lower amplitude.

I've compared the phototransistor response to both the "input battery voltage" and the "output voltage" taken at the normal points as indicated on the schematic. The deepest part of the valley or dip in the Input Battery Voltage trace coincides with the moment of LED turn-on, and the LED, with a depleted battery, isn't at constant brightness during its "on" time, as evidenced by the nonhorizontal tops of the positive going narrow peaks in the output voltage trace.

This isn't a quantitative measurement, of course.... that would take some calibration effort but is clearly possible. This is just designed to look at the timing of the events. I've been meaning to do this step for some time, to verify just where in the LED light curves, the peaks and valleys of the electrical signals occur.

The video is processing and uploading now and should be viewable in half an hour or so. It will be at:
http://youtu.be/E4k2bsyca4I


T,

Really, you can't manage A1=Vin, A2=Iin, B1=Vout, B2=Iout with the A3-4 and B3-4 being the scope grounds connected to the bottom of the input CSR?

OK, I'll quit usig them.

Your video shows that the LED is on when the voltage at Vout is hi, which can only happen when Q1 is off.  that is as I stated previously.

Regarding the second part of the video showing the Vin ripples and Vout:

As Q1 turns off, and Vout subsequently goes hi, the current draw on the battery is switched off.  Vin immediately begins to rise as the battery recovers from the load applied when Q1 was turned on.  This battery (Vin) recovery is the rising portion of the "apparent" negative peak during your Vout "hi" time .  The positive most portion of Vin is the maximum recovered battery voltage.  When Q1 turns on again, Vout is pulled lo.  At the same time, currejt is being drawn from Vin which slowly discharges the battery, hence the slow downward ramp on Vin until Q1 again turns off releasing the load on the battery and again allowing it to recover.

Again, if you look at the second part of your video, you will see that Vin begins to drop as soon as Q1 turns on (and Vout goes lo) and immediately begins to recover as Q1 turns off (and Vout goes hi).  So, actually, the poitive going portion of the Vin ripple coincides with Q1 turning off, Vout going hi, and the LED turning on.  The negative going portion of the Vin ripple, which is much slower and drawn out in time, coincides with Q1 being on, Vout being lo, and the LED being off. 


Your waveforms don't look as sharp and "spikey" as Lawrence's.  What do your Vin and Iin traces look like?

PW

TinselKoala

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Re: Is joule thief circuit gets overunity?
« Reply #520 on: April 10, 2013, 12:53:50 AM »
For comparison with Lawrence's Board 80 Output slide, I have here taken corresponding traces from the PCB JT. Here I am powering it from a partly depleted AA battery that measures 1.304 volts unloaded, on the Simpson digital voltmeter. I don't usually use this much input power, but this is more comparable to Lawrence's input.
The top trace is the Voltage Output at B1, the bottom trace is the Current Output at B3. The top trace is set to 2 volts per division, the bottom trace at 100 mV per division. (The top trace is using the center horizontal graticule line as the baseline, not the line indicated by the number "1" to the right. The lower trace is using the baseline indicated by the "2".)  I am showing only a single pulse to make the point that the waveshapes are the same, except that my "60 MHz" analog scope isn't displaying the spike amplitude.... but I assure you that it is there.

picowatt

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Re: Is joule thief circuit gets overunity?
« Reply #521 on: April 10, 2013, 01:12:35 AM »
For comparison with Lawrence's Board 80 Output slide, I have here taken corresponding traces from the PCB JT. Here I am powering it from a partly depleted AA battery that measures 1.304 volts unloaded, on the Simpson digital voltmeter. I don't usually use this much input power, but this is more comparable to Lawrence's input.
The top trace is the Voltage Output at B1, the bottom trace is the Current Output at B3. The top trace is set to 2 volts per division, the bottom trace at 100 mV per division. (The top trace is using the center horizontal graticule line as the baseline, not the line indicated by the number "1" to the right. The lower trace is using the baseline indicated by the "2".)  I am showing only a single pulse to make the point that the waveshapes are the same, except that my "60 MHz" analog scope isn't displaying the spike amplitude.... but I assure you that it is there.

T,

Your Iout trace drops off as a fairly linear ramp.  Board 80's Iout drop looks more exponential.

I don't believe your scope BW is the issue here regarding the "less spikey".  More likely your PCB has less interconnect inductance so the waveforms are more heavily damped.

You don't have the BW limit on do you?  (Just kidding)

PW   


TinselKoala

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Re: Is joule thief circuit gets overunity?
« Reply #522 on: April 10, 2013, 01:16:08 AM »

T,

Really, you can't manage A1=Vin, A2=Iin, B1=Vout, B2=Iout with the A3-4 and B3-4 being the scope grounds connected to the bottom of the input CSR?

OK, I'll quit usig them.

Your video shows that the LED is on when the voltage at Vout is hi, which can only happen when Q1 is off.  that is as I stated previously.

Regarding the second part of the video showing the Vin ripples and Vout:

As Q1 turns off, and Vout subsequently goes hi, the current draw on the battery is switched off.  Vin immediately begins to rise as the battery recovers from the load applied when Q1 was turned on.  This battery (Vin) recovery is the rising portion of the "apparent" negative peak during your Vout "hi" time .  The positive most portion of Vin is the maximum recovered battery voltage.  When Q1 turns on again, Vout is pulled lo.  At the same time, currejt is being drawn from Vin which slowly discharges the battery, hence the slow downward ramp on Vin until Q1 again turns off releasing the load on the battery and again allowing it to recover.

Again, if you look at the second part of your video, you will see that Vin begins to drop as soon as Q1 turns on (and Vout goes lo) and immediately begins to recover as Q1 turns off (and Vout goes hi).  So, actually, the poitive going portion of the Vin ripple coincides with Q1 turning off, Vout going hi, and the LED turning on.  The negative going portion of the Vin ripple, which is much slower and drawn out in time, coincides with Q1 being on, Vout being lo, and the LED being off. 


Your waveforms don't look as sharp and "spikey" as Lawrence's.  What do your Vin and Iin traces look like?

PW
One thing you must realize is that those traces were done with the tiny hearing aid battery that is mostly depleted. Here are some traces from this board for comparison to Lawrence's traces, that I just made with an alkaline AA battery that reads 1.304 volts unloaded... that is, it too is fairly well depleted.

I don't usually use this much input power, but this is more comparable to Lawrence's input.

In the first shot, Output, the top trace is the Voltage Output at B1, the bottom trace is the Current Output at B3. The top trace is set to 2 volts per division, the bottom trace at 100 mV per division. (The top trace is using the center horizontal graticule line as the baseline, not the line indicated by the number "1" to the right. The lower trace is using the baseline indicated by the "2".)  I am showing only a single pulse to make the point that the waveshapes are the same, except that my "60 MHz" analog scope isn't displaying the spike amplitude.... but I assure you that it is there. Timebase is at 10 microsec/div and the delay function is used to bring a pulse onto the screen window.

The second shot is the Input, the top trace is the Input Battery Voltage at A1 and the lower trace is the Input Current at A4. The top trace is at 500 mV per division and is using the center horizontal graticule marker as its baseline, not the number to the right. The lower trace is at 100 mV per division, is using the numbered graticule line "2" as its baseline, and clearly and repeatably shows values both above and below the baseline. No "invert" is used and the probe is positioned just like Lawrence's is wrt current direction. Timebase is at 50 microsec/div.

So you can presumably see clearly that, if Lawrence's board is OU.... then mine must be too, since it gives the same instrumental readings when powered and probed in the same way that his is..... excepting the appearance of the high-frequency spikes.

And your detailed explanation seems to concur with what I said: the LED turns on at the bottom of the valleys, at the point where the slope reverses, and the power represented by the decreasing voltage slope to that point is the power that is pulsed into the LED.

picowatt

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Re: Is joule thief circuit gets overunity?
« Reply #523 on: April 10, 2013, 01:55:17 AM »
One thing you must realize is that those traces were done with the tiny hearing aid battery that is mostly depleted. Here are some traces from this board for comparison to Lawrence's traces, that I just made with an alkaline AA battery that reads 1.304 volts unloaded... that is, it too is fairly well depleted.

I don't usually use this much input power, but this is more comparable to Lawrence's input.

In the first shot, Output, the top trace is the Voltage Output at B1, the bottom trace is the Current Output at B3. The top trace is set to 2 volts per division, the bottom trace at 100 mV per division. (The top trace is using the center horizontal graticule line as the baseline, not the line indicated by the number "1" to the right. The lower trace is using the baseline indicated by the "2".)  I am showing only a single pulse to make the point that the waveshapes are the same, except that my "60 MHz" analog scope isn't displaying the spike amplitude.... but I assure you that it is there. Timebase is at 10 microsec/div and the delay function is used to bring a pulse onto the screen window.

The second shot is the Input, the top trace is the Input Battery Voltage at A1 and the lower trace is the Input Current at A4. The top trace is at 500 mV per division and is using the center horizontal graticule marker as its baseline, not the number to the right. The lower trace is at 100 mV per division, is using the numbered graticule line "2" as its baseline, and clearly and repeatably shows values both above and below the baseline. No "invert" is used and the probe is positioned just like Lawrence's is wrt current direction. Timebase is at 50 microsec/div.

So you can presumably see clearly that, if Lawrence's board is OU.... then mine must be too, since it gives the same instrumental readings when powered and probed in the same way that his is..... excepting the appearance of the high-frequency spikes.

And your detailed explanation seems to concur with what I said: the LED turns on at the bottom of the valleys, at the point where the slope reverses, and the power represented by the decreasing voltage slope to that point is the power that is pulsed into the LED.

TK,

I still think Board 80's waveforms look a bit different than yours.  Not just that the spikes are missing, but the general slopes on the tops of bothe the V and I waveforms appear to have a different rate.

As with regards to your last sentence above, I agree that the LED turns on at the bottom of the input voltage valleys, at the point where the slope reverses, BUT, I would state: the power represented by the decreasing voltage up to that point is the power being drawn from the battery and stored in the toroid (and as well disipated in Q1, the input CSR and the battery's Rint).

The LED turns on when no current is being pulled from the battery (Q1 is off).  As well, if there is any battery recharging from the collapse of the toroid, it is occurring during the rising portion of the Vin waveform from just past the most negative peak when the LED is on.  During that period (whilst the waveform is rising) the LED is on and current must flow thru the LED, output CSR, Input CSR, input battery, and the toroid to complete he circuit.  The collasing toroid acts as an additional battery in series with, and with a voltage higher than, the input battery.  The polarity is such that the current thru the LED and toroid tends to raise the terminal voltage of the input battery slightly during the LED on time.  So, if anything, the battery is actually recovering a bit of its charge when the LED is on.

The internal R of the input battery will affect the amount of ripple seen on Vin, and the amount of battery depletion determines the battery internal R.

What happens to your circuit with a fresh alkaline?

PW

TinselKoala

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Re: Is joule thief circuit gets overunity?
« Reply #524 on: April 10, 2013, 02:06:37 AM »
T,

Your Iout trace drops off as a fairly linear ramp.  Board 80's Iout drop looks more exponential.

I don't believe your scope BW is the issue here regarding the "less spikey".  More likely your PCB has less interconnect inductance so the waveforms are more heavily damped.

You don't have the BW limit on do you?  (Just kidding)

PW
You are probably right about the spikes, I withdraw my assurances. I just checked with a higher-bandwidth scope and I can't resolve the spike.
No, no bw limit on.

The I drop difference is probably because of the source battery, I should think. But I'm not so sure it is that different.