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: Joule Thief 101  (Read 926776 times)

MileHigh

  • Hero Member
  • *****
  • Posts: 7600
Re: Joule Thief 101
« Reply #2685 on: July 12, 2016, 12:42:25 PM »
Brad:

Where is your model for the battery coming from that has the decreasing source voltage?  Is it your own invention from this recent discussion or is it something that you have seen and used before?  I have never seen it before myself.  Can you show any references for that model?

Right now I am assuming that model is yours, but I will see what you have to say.

You are playing quite a bit of the "ignore game" over the past few days, haven't you?  I have pointed out several key points that you just try to "waive" but perhaps people are noticing them.

You can't ignore this:

There is a tragic flaw in your model.  If when the battery is outputting 1.0 volts and you measure a 10-ohm output impedance, then having your variable voltage source set at 1.0 volts and the output impedance resistance set at 10 ohms will not work.  The reason it won't work is that the variable voltage would have to be at 1.0 volts plus some unknown delta so that the final voltage after the resistor is 1.0 volts.

Do you get that?  You might need the variable voltage to be 1.15 volts with a variable resistance of 10 ohms to give you 1.0 volts after the variable resistor.  This will always be a function of the resistance of the load itself.  For a different load you might need the variable voltage to be 1.20 volts with a variable resistance of 10 ohms to give you 1.0 volts after the variable resistor.  From what I can see your model is unworkable.

Quote
And continue to learn the past?

No, more like getting up to speed with the present.  Wouldn't you like to reduce the number of ridiculous gaffes you make?  You need to read some electronics books.

Quote
Like you would of heard about a J/FET

I heard a story about a JFET being shoved up your ass.  Is it true?

Quote
At T=5 seconds,MHs device explodes.
I am yet to see any reason posted why the CEMF is also not ideal.
This means that it will also take an infinite amount of time before current start to flow
If you did(theoretically),the current would rise instantly to an infinite value.
If R = 0,which id dose,as the inductor is ideal,then no current flows through the ideal inductor.
This results in an instant current rise to an infinite value.
If the voltage increases,then it is not an ideal voltage,as an ideal voltage dose not change in time.
This also shows that MHs question cannot be answered,as it cannot exist.

That was brought out for your Bizarro World debate fans.  It gets them all excited, they even start taking warm up swings with their frying pans but they don't make contact.  You fans love the fact that when talking about the ideal inductor and voltage source question you kept on going back and forth between no-current infinite-current no-current infinite-current like some poor hapless pinball being banged back and forth between the bumpers of a pinball machine.  They absolutely love your early work and it gets them all excited and pumped up.

MileHigh

Grumage

  • Hero Member
  • *****
  • Posts: 1113
Re: Joule Thief 101
« Reply #2686 on: July 12, 2016, 12:50:21 PM »
I can see you have about as much imagination and creativity as lumpy gravy.  I guess that you are just a drone in The Grand Parade of Lifeless Packaging.

For the grand parade of lifeless packaging
All ready to use
The grand parade of lifeless packaging
I just need a fuse

Got people stocked in every shade
Must be doing well with trade
Stamped, addressed in odd fatality
That evens out their personality

With profit potential marked by a sign
I can recognize some of the production line
No bite at all in labor bondage
Just wrinkled wrappers or human bandage

Grand parade of lifeless packaging
All ready to use
It's the grand parade of lifeless packaging
I just need a fuse

"We are now in our manufacturing phase. Your interest is important to us but due to overwhelming demand we have temporarily suspended accepting orders at this time."

Bad MileHigh...... Bad.

You dare to bring a poor defenceless lamb into this debate, what about it's " Mama "?

The " Ripples " caused might just go on till " Suppers ready " !

For your " Nursery cryme " I sentence you to a week in the " Colony ".

Los Endos...... Grum.  :)

minnie

  • Hero Member
  • *****
  • Posts: 1244
Re: Joule Thief 101
« Reply #2687 on: July 12, 2016, 12:51:07 PM »



  tinman you don't seem to have much of a grasp of basic concepts.
  I don't know if you can get it in your part of the world but the BBC
  does a series of programs called "In our Time" with Melvyn Bragg.
  There are a whole lot of interesting science programs to choose
  from with things like the photon, negative numbers,quantum gravity
  and loads more. Enjoy,
                   John.

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Joule Thief 101
« Reply #2688 on: July 12, 2016, 01:18:43 PM »
 author=MileHigh link=topic=8341.msg488321#msg488321 date=1468320145]







That was brought out for your Bizarro World debate fans.  It gets them all excited, they even start taking warm up swings with their frying pans but they don't make contact.  You fans love the fact that when talking about the ideal inductor and voltage source question you kept on going back and forth between no-current infinite-current no-current infinite-current like some poor hapless pinball being banged back and forth between the bumpers of a pinball machine.  They absolutely love your early work and it gets them all excited and pumped up.

MileHigh
[/quote]

Quote
I heard a story about a JFET being shoved up your ass.  Is it true?

LMAO
Sorry MH,but sometime's-even when you are being rude and perverted--you are funny.
I did have a laugh at that lol ;D
And because you made me laugh,i will let it slide. ;)

Quote
Where is your model for the battery coming from that has the decreasing source voltage?  Is it your own invention from this recent discussion or is it something that you have seen and used before?  I have never seen it before myself.  Can you show any references for that model?

Right now I am assuming that model is yours, but I will see what you have to say.

You are playing quite a bit of the "ignore game" over the past few days, haven't you?  I have pointed out several key points that you just try to "waive" but perhaps people are noticing them.

You can't ignore this:

There is a tragic flaw in your model.  If when the battery is outputting 1.0 volts and you measure a 10-ohm output impedance, then having your variable voltage source set at 1.0 volts and the output impedance resistance set at 10 ohms will not work.  The reason it won't work is that the variable voltage would have to be at 1.0 volts plus some unknown delta so that the final voltage after the resistor is 1.0 volts.

Well first up MH,your model was a power supply set at 1.5 volt's,and a VR in series with the power supply and load. This just dose not simulate a real battery simply by increasing the VRs resistance over time.

My model that simulates a real battery running a JT is as follow's,when wanting to use a super cap as the power source. As we all know(except you it would seem) the batteries voltage will drop as the energy value stored in that battery reduces. We also know at the same time,the impedance (internal resistance) will go up in that battery. All three things happen at once MH,and these are facts you cannot ignore.
So ,as the voltage drops in the super cap-(as it will with a battery),we increase the resistance of the series VR to mimic the increase of impedance that would take place in the battery.
So with your model,the inductor will always have 1.5 volts across it at T=0,where as using my model,the inductor will have the actual voltage of the battery,and will show the drop in voltage over time,as we get with a battery--where yours will not.

Below in the first diagram,i show your model as you describe it should be.
In the following scope shot's,i show the value of the VR that is to mimic impedance of a battery.
You can clearly see,that no matter what the impedance value,at T=0,the inductor always has your set 1.5 volts across it.

So ,unfortunately for you MH,your model dose not replicate an actual battery running a JT,as the voltage across the coil at T=0 will always be a set value,and dose not show a batteries voltage dropping as we would see with an actual battery.

Next i will show you the JT running on a super cap,and then after that,i will show you the JT running on a battery. We will then use my model-the super cap and VR,and look at both that model and an actual battery at various voltages,and see who's model is correct.
So even after half an hour running MH,your model will still show a peak voltage across the inductor of 1.5 volt's,and we all know that that would not be the case with a real battery. ;)

Quote
No, more like getting up to speed with the present.  Wouldn't you like to reduce the number of ridiculous gaffes you make?  You need to read some electronics books.

Says the man that dares not take up the challenge ;)--even with the help of others lol.


Brad

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Joule Thief 101
« Reply #2689 on: July 12, 2016, 01:20:42 PM »


  tinman you don't seem to have much of a grasp of basic concepts.
  I don't know if you can get it in your part of the world but the BBC
  does a series of programs called "In our Time" with Melvyn Bragg.
  There are a whole lot of interesting science programs to choose
  from with things like the photon, negative numbers,quantum gravity
  and loads more. Enjoy,
                   John.

If you agree with MH because these programs say he is correct,then i think i will give them a miss thanks.
Perhaps you would be better sticking with the animal picture's--they seem to make more sense ;)


Brad

MileHigh

  • Hero Member
  • *****
  • Posts: 7600
Re: Joule Thief 101
« Reply #2690 on: July 12, 2016, 01:21:11 PM »
Bad MileHigh...... Bad.

You dare to bring a poor defenceless lamb into this debate, what about it's " Mama "?

The " Ripples " caused might just go on till " Suppers ready " !

For your " Nursery cryme " I sentence you to a week in the " Colony ".

Los Endos...... Grum.  :)

Let's even get more classic with a great musical interlude.

Cheers

https://www.youtube.com/watch?v=SD5engyVXe0

MileHigh

  • Hero Member
  • *****
  • Posts: 7600
Re: Joule Thief 101
« Reply #2691 on: July 12, 2016, 01:46:34 PM »
Brad:

This time I have to compliment you for doing a nice set of tests with the progressively increasing output resistance with the properly labelled scope captures and the properly labeled schematic with properly labeled test points.  That is a real breath of fresh air compared to some of your earlier presentations.  It's actually not stressful to look at that data, which is a really nice change.

If the voltage source is fixed at 1.5 volts and you have a variable resistor only, then you are going to see 1.5 volts at the inductor when the transistor initially switches on just like you say.  The real question is is that significant or not.  It's not easy to know when to ignore things, and I am not necessarily saying that it can be ignored in this case.  But it is very important as a general principle to know when to ignore things and when not to ignore things and that has to be learned.  It's a combination of science, skill, experience, and art.

With respect to a battery model that is adapted specifically to a Joule Thief arrangement, perhaps just the standard model that I am stating with some kind of simple low-pass filter on the output would be satisfactory.  When your VR is 33 ohms, you see a sawtooth for the battery voltage waveform.  I am pretty sure in reality if you had a depleted AA cell with a 33-ohm output impedance driving a 10 kHz Joule Thief, you would not see as dramatic a sawtooth waveform for the battery voltage.  You would simply see a low DC voltage with a tiny amount of ripple superimposed on it.  In other words, it would look like the sawtooth had passed through a low-pass filter.

Anyway, I look forward to seeing what you and TK generate in terms of results.

MileHigh

minnie

  • Hero Member
  • *****
  • Posts: 1244
Re: Joule Thief 101
« Reply #2692 on: July 12, 2016, 01:52:23 PM »



   I've learned a lot about inductors and CEMF from MH questions.
  What have I learned from tinman? Answer, a Fisher & Paykel is
  a damn good motor.
   What use is a joule theif or a pulsed motor anyway??


           John.

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Joule Thief 101
« Reply #2693 on: July 12, 2016, 01:55:23 PM »
Brad:

This time I have to compliment you for doing a nice set of tests with the progressively increasing output resistance with the properly labelled scope captures and the properly labeled schematic with properly labeled test points.  That is a real breath of fresh air compared to some of your earlier presentations.  It's actually not stressful to look at that data, which is a really nice change.

If the voltage source is fixed at 1.5 volts and you have a variable resistor only, then you are going to see 1.5 volts at the inductor when the transistor initially switches on just like you say.  The real question is is that significant or not.  It's not easy to know when to ignore things, and I am not necessarily saying that it can be ignored in this case.  But it is very important as a general principle to know when to ignore things and when not to ignore things and that has to be learned.  It's a combination of science, skill, experience, and art.

With respect to a battery model that is adapted specifically to a Joule Thief arrangement, perhaps just the standard model that I am stating with some kind of simple low-pass filter on the output would be satisfactory.  When your VR is 33 ohms, you see a sawtooth for the battery voltage waveform.  I am pretty sure in reality if you had a depleted AA cell with a 33-ohm output impedance driving a 10 kHz Joule Thief, you would not see as dramatic a sawtooth waveform for the battery voltage.  You would simply see a low DC voltage with a tiny amount of ripple superimposed on it.  In other words, it would look like the sawtooth had passed through a low-pass filter.

Anyway, I look forward to seeing what you and TK generate in terms of results.

MileHigh

Thank you MH.

Perhaps we could put the guns away,and work together as we use to ?

Anyway,below is some scope shots,where we are using a 50F super cap as the power supply,and the VR is set to 0 ohms for all three scope shot's,that show 3 various voltages across the capacitor,that drop over run time. As we can see here,the super cap having very low internal resistance-regardless of voltage,dose not represent a batteries behaviour as the voltage drops in that battery.

You might also notice the big difference in the frequency jumps between using the PSU and VR to that of using a super cap with very little impedance. I think you would agree that there is a big difference there,and that may give you some answers as to why TKs circuit 2 was more efficient than circuit 1 when using the power supply,and then it swapped around when he switched to the super cap.

Next i will post an actual battery,and we will see what the voltage trace looks like across our battery/inductor.


Brad

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Joule Thief 101
« Reply #2694 on: July 12, 2016, 02:25:49 PM »
Below is two scope shot's,where the circuit now has a battery.
The two batteries were of a different brand,but both alkaline batteries.
The voltages can be seen on the scope shots.

This is at very low current draw levels,and as the JT is made to work harder,the battery voltage drop during the on time is made more apparent.
But this is with my JT in standard trim,with the base VR set at the full 1k.
Reducing the base resistance results in a higher current draw,a larger sawtooth wave form across the battery,and higher light output,along with a decrease in frequency.


Brad

MileHigh

  • Hero Member
  • *****
  • Posts: 7600
Re: Joule Thief 101
« Reply #2695 on: July 12, 2016, 08:55:27 PM »
Brad:

I am probably jumping off the bus pretty soon.  This whole ordeal started when Smoky2 said he was going to coach you and Magluvin to make a "resonant Joule Thief."  He claimed that something really special was going to happen with the "tuning" and his brother had some "resonant Joule Thieves" that ran "permanently."  I said the whole thing was complete and utter crap, remember?  Then that started the discussion about resonance and the whole nine yards.

You need a foil like me, because without that you and the boys (no gurus participating) create this "enabling" environment were "everything is awesome" and you deceive each other by never having the guts to correct each other.  That's why you learned very little over the past six years and with me being your foil you kept on being stung in the ass and it was good for you, no matter how upset and angry you got.  Without a foil like me to upset the awesome party, ultimately that's why you and many of the other boys couldn't solve for a simple circuit consisting of a power supply and one single solitary component.  Or you had all been discussing resonance for years but couldn't properly define it or answer two simple questions about it even through you were given a month and a half to answer the questions.  That's comfortably awesome numbness.

Ultimately, I don't really care.  You guys do whatever the hell it is that you want to do.  It's just such a pain to see all of this sleepwalking going on sometimes.

For example, when I look at most of your recently posted Joule Thief scope captures, the current waveform is a saw-tooth or triangle waveform.  To me it appears that that's not normal Joule Thief operation.  It's still lighting the LED of course but it looks to me like the Joule Thief operation has broken down and resembles a generic oscillator more than a Joule Thief.  I have a feeling that there is a very good chance that that didn't even occur to you.

I am perfectly content to just sit and watch what you and TK produce.

MileHigh

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Joule Thief 101
« Reply #2696 on: July 13, 2016, 01:22:30 AM »
 author=MileHigh link=topic=8341.msg488361#msg488361 date=1468349727]


Quote
I am perfectly content to just sit and watch what you and TK produce.

MileHigh


Quote
I am probably jumping off the bus pretty soon.  This whole ordeal started when Smoky2 said he was going to coach you and Magluvin to make a "resonant Joule Thief."  He claimed that something really special was going to happen with the "tuning" and his brother had some "resonant Joule Thieves" that ran "permanently."  I said the whole thing was complete and utter crap, remember?  Then that started the discussion about resonance and the whole nine yards.

I would have to agree that the whole resonant thing went south,but i think Smoky2 was hoping that we could find or design that resonant JT,and see what the outcome was.

Quote
For example, when I look at most of your recently posted Joule Thief scope captures, the current waveform is a saw-tooth or triangle waveform.  To me it appears that that's not normal Joule Thief operation.  It's still lighting the LED of course but it looks to me like the Joule Thief operation has broken down and resembles a generic oscillator more than a Joule Thief.  I have a feeling that there is a very good chance that that didn't even occur to you.

There is a reason for the saw-tooth wave form MH,and perhaps you may have noticed when the transition took place from that of a current wave form that would be seen on a normal JT.
The circuit being used is your JT circuit (circuit number 1). But in saying that,the current trace is not really that different to what my other JTs show--see pic below.
The only change i notice,is that the waveform in the latest scope shot's is more !crisp!,where the trace rises and falls in a much more linear way.

I will do some comparison tests tonight--as soon as the light box is completed,and post the relevant scope shot's,and efficiency data.

Brad

MileHigh

  • Hero Member
  • *****
  • Posts: 7600
Re: Joule Thief 101
« Reply #2697 on: July 13, 2016, 02:07:22 AM »
Well you can see in your latest scope capture that the current is rising and falling in an exponential-type waveform which is what you expect to see for a Joule Thief.  You can also see a little tell-tale signature of a switching event in that current waveform, suggesting that the Joule Thief is switching normally.  You don't normally expect to see a saw-tooth or triangle waveform for a normally operating Joule Thief.

<<<  I am going to qualify the above paragraph for when it comes to watching what happens when a fresh battery transitions to a depleted battery when powering a Joule Thief.  I don't really have a handle on how the current waveform will change as the output impedance of the battery starts to slowly creep up.  >>>

When looking at the latest capture, the unexplained vertical spike noise on the older current waveform captures stands out even more and requires investigation.

You are back to your bad habits again and you are not showing where the test points are for that latest scope capture.  Weren't you embarrassed when you posted a scope capture a few weeks back and Picowatt told you that he couldn't make head or tail of it and asked you for the corresponding schematic?

If you don't at least sample what the waveform looks like at the base resistor input (bottom of L2) every time you fiddle with a new Joule Thief configuration then you are making a mistake.  Same thing applies for the transistor collector waveform to see if you are getting clean switching or not.

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Joule Thief 101
« Reply #2698 on: July 13, 2016, 06:16:33 AM »
Well you can see in your latest scope capture that the current is rising and falling in an exponential-type waveform which is what you expect to see for a Joule Thief.  You can also see a little tell-tale signature of a switching event in that current waveform, suggesting that the Joule Thief is switching normally.  You don't normally expect to see a saw-tooth or triangle waveform for a normally operating Joule Thief.

<<<  I am going to qualify the above paragraph for when it comes to watching what happens when a fresh battery transitions to a depleted battery when powering a Joule Thief.  I don't really have a handle on how the current waveform will change as the output impedance of the battery starts to slowly creep up.  >>>

When looking at the latest capture, the unexplained vertical spike noise on the older current waveform captures stands out even more and requires investigation.

You are back to your bad habits again and you are not showing where the test points are for that latest scope capture.  Weren't you embarrassed when you posted a scope capture a few weeks back and Picowatt told you that he couldn't make head or tail of it and asked you for the corresponding schematic?

If you don't at least sample what the waveform looks like at the base resistor input (bottom of L2) every time you fiddle with a new Joule Thief configuration then you are making a mistake.  Same thing applies for the transistor collector waveform to see if you are getting clean switching or not.

MH
The test points for the latest scope capture are clearly shown in the attached schematic,so i dont know what you are talking about.
CH 1 is obviously inverted,when you take note of scope probe polarity on the attached schematic.

We will sort out the two differing wave forms for the current trace soon enough,and the same go's  with the base trace. You seem to be back to that bad habbit of wanting everything all at once,but i can only do so much each working night-friday and Saturday nights  i get a bit more time.


Brad

MileHigh

  • Hero Member
  • *****
  • Posts: 7600
Re: Joule Thief 101
« Reply #2699 on: July 13, 2016, 07:02:23 AM »
No Brad, the test points are ambiguous.  I don't see a definitive ground connection.  I don't see any probe colours matching the scope channel colours like I am used to seeing before.

Here is the bloody point:  Every time I look at a scope capture with a provided schematic from you I don't want to have to play a guessing game and spend 90 seconds figuring out what is what.  I don't give a damn if you say it is "obvious."  It is pretty straightforward in this case but I still don't give a damn.  It's a pain in the ass.

I literally just saw the text "CVR 1 trace" in the upper right quadrant of the image after staring at the image about 20 times.

You took the trouble to stitch together your scope capture with the schematic using an image editing program.  You couldn't be bothered to spend just one minute while you were in the image editing program to label where the scope channel was connected in a clear and unambiguous manner.

Look at the attached image.  I updated your graphic.  I can look at that graphic and in 1/2 second I see exactly what is going on, no muss, no fuss, no bullshit looking at "options."