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Author Topic: Joule Thief 101  (Read 926781 times)

tinman

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Re: Joule Thief 101
« Reply #2655 on: July 11, 2016, 05:30:58 PM »
 author=MileHigh link=topic=8341.msg488258#msg488258 date=1468246723]




Quote
Well, this is turning out to be a big showcase for your powers of reasoning.  Let's have a look.

Lord knows indeed, he certainly works in mysterious ways with you.  I post a simple example to look at how two different load types with different duty cycles will affect the losses in a seven ohm internal resistance for the power source, and you talk about something totally different and unrelated in your response.  It's like you are on the Bizzaro World debating team, and you are in higher esteem the more illogical and/or non-responsive your debating points are.

I just put an end to you trying to be deceitful again.
My question was clearly stated,and we will not have you change it all around to suit your need to be correct. If you had of answered my question as asked,you would have worked out why circuit 2 is more efficient,which would mean that you were wrong--and we cant have that now,can we :D

Quote
But I was talking about a battery as the source and this test is being done with a capacitor so you can't draw any conclusions.  In addition, it makes no sense whatsoever to mention "circuit 2 slightly lower,which would indicate a slightly deeper drain of the battery" because the difference between the two final recorded capacitor voltages is insignificant.  Anybody that understands science would ignore the voltage difference in this case.  The debate attendees from Bizarro World are giving you a round of applause.

It would seem that you also need a few lessons in deep battery discharging as well.
I have clearly explained the difference in using caps to batteries to TK,and im sure he already knew that anyway. But the outcome will be the same in the end,and circuit 2 will discharge the battery,and use more of it's remaining energy to that of circuit 1.

Quote
But TK said this. "I'll be using a Nesscap 10F 2.7V rated capacitor with 30mOhm (0.030 ohm) equivalent series resistance."  Therefore the equivalent series resistance of the capacitor can be considered negligible and can be ignored.  The debate attendees from Bizarro World are giving you a another round of applause.

Well MH,it would once again seem you took a hop,skip,and face plant :D
Im guessing you !once again! did not read what i wrote to TK,regarding simulating the increasing internal resistance of a battery as the voltage drop's,when using a cap as the power supply.

Quote
Here is where you get a thunderous round of applause from your Bizarro fans for all of your "bench smarts."
You get a smattering of applause from the Bizarro Word fans.  It's not really correct to say that the internal resistance of the battery increases as the "voltage drops."  You don't necessarily see a voltage drop on a high-internal-resistance battery with a voltmeter, do you?  The internal resistance of the battery increases as the state of charge of the battery decreases.  Six years on the bench and your t-shirt looks great.

OMG MH--are you serious  :o
The internal resistance of the battery increases as the state of charge of the battery decreases.
So MH--Mr bench guru,when the battery is driving a load,and the state of charge decreases,causing the internal resistance of the battery to increase,what will happen to the voltage across the battery  ::)
You don't necessarily see a voltage drop on a high-internal-resistance battery with a voltmeter, do you?
Well im not sure what planet you came from,but here on earth-yes you do see a voltage drop as the internal resistance increases.
Feel free to show us how you can measure the internal resistance of a battery,without seeing a voltage drop across that battery,as you carry out your test :D--this should be good ;D
MH,you seem to be struggling lately,and your skill set seems to have plummeted to an all time low.
Perhaps you could tell everyone reading this thread,as to how the voltage across a battery driving a load will not decrease as that battery discharges,and the internal resistance of that battery go's up as the state of charge go's down ???.

Quote
Now you've got your Bizarro World fans really excited and they are waving their frying pans
.

What we have got,and have just seen once again MH,is you grasping for air,and coming up with some of the wackiest post we have ever seen here on this forum.

It has become very clear MH,that you are only here to derail the thread once again,and your whakadoo comments above proved just that.

MH
What ever happy pills the doctor has given you,i would stop taking.
Go back to the doctor,and tell him that they are not good for you. In fact,i would change doctors if i were you ;)


Brad

tinman

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Re: Joule Thief 101
« Reply #2656 on: July 11, 2016, 05:44:20 PM »
MH
Quote
Lets showcase your reasoning /Snip/ from bizzaro world"
end quote

I could not agree more ...you have an opportunity to get "infront" of the investigation and lead by example
and yet you chose to "lead from behind"

I have to say ,yes it is always much safer to lead from the back ....

But Quite Bizarre indeed.. if one truly expects to be taken seriously!

Our world is filled with "Monday morning quarterbacks"!

Not just one mans opinion ....

Chet K

Chet

Lets stop fooling our selves here. MH is never going to take on my challenge--not even with the help of one of the brightest minds on this forum(itsu).

Looking at his last post,i think he has lost a couple of cows in the top paddock :
It has become very clear that his mighty pen would have been no match for the bench experimenter .
The good news is that the hybrid toroid transformer has double+ the efficiency than any other JT transformer i have tried so far--and that includes some very well wound ferrite toroid cores of many shapes and sizes.

What i would like to do,is put it up against the best TK has,and see how it go's.
First i need to get my light box to the same specks as TK's,so as we are working with an even playing field.

So lets just forget about the MH challenge,as i think(still think) that the hybrid toroid coil has a lot to offer.


Brad

MileHigh

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Re: Joule Thief 101
« Reply #2657 on: July 11, 2016, 06:29:04 PM »
Brad:

Quote
In regards to a capacitor,how dose the value of internal resistance change as the voltage drops?

It's almost hopeless with you, isn't it?  You have been on the bench playing with capacitors for six years.  You have read all about capacitors and have seen them being discussed on the forums countless times.  You have seen diagrams of how they are constructed and how they work.

Yet apparently you don't have any innate sense whatsoever of what is going on inside a capacitor, and you make the most idiotic and ridiculous comment.  It almost makes it look like in your mind the true workings of a capacitor remain a mysterious, enigmatic, and amorphous grey blob.  For you a capacitor may as well be a grey blob.  In all sincerity, how else could you pose such a ridiculous question?

Quote
Perhaps a VR on the base would allow us to raise the light output for circuit 2,to match that of circuit 1.

And we talked about the Joule Thief and the base resistor in a Joule Thief over and over.  And your comment reveals, to no surprise, that you still apparently don't have the slightest idea about how a Joule Thief actually functions.  Sometimes speculations or questions posed by individuals inadvertently reveal how limited their understanding of something really is.

Your Bizarro World fans are ecstatically clanking their frying pans together in a cacophony of frying pan high fives, they are so excited.

MileHigh

TinselKoala

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Re: Joule Thief 101
« Reply #2658 on: July 11, 2016, 08:53:47 PM »
Brad, my lightbox was built when I was doing some efficiency tests for another project, to compare with results from some other researchers. This is why I used the 18 inch distance from LED to sensor. The box is 5 inches square by 18 inches long (inside dimensions) and is painted inside with gloss white paint. The Extech LT300 lightmeter sensor dome is in the center of the back end wall. The front end wall is removable for access, and has a small breadboard attached to its inner surface for mounting LEDs etc.  This puts the LED about 1/2 inch from the actual surface of the front wall. The actual distance from the LED under test and the sensor inside the dome is 18 inches, as the sensor itself is recessed a bit in its housing.

I'm using one LumiLED Luxeon 3535L surface-mount LED (part number MXA7-PW57-H001) in the center of the front wall breadboard, soldered to some pins to fit the breadboard. These LEDs have a nice wide dispersion angle and no focussing lens. They are superefficent, but are generally meant to be supplied with 100 or 200  mA  DC max (depending on exact part number). At that drive current they are blindingly brilliant (but need a heatsink), but even at 20 mA drive they are amazingly bright. I've attached the full data sheet for these LEDs below. They are great, you should order some!


Has nobody drawn graphs from my raw data yet?    :-*
 

MileHigh

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Re: Joule Thief 101
« Reply #2659 on: July 11, 2016, 10:55:46 PM »
Brad:

Quote
Yes,we could run the test this way-using super caps. But as i stated in my last post,the cap will not include the impedance/internal resistance rise that you would get with a battery.

To carry out the test correctly using a cap in place of the battery,you would have to include a series variable  resister,and increase the resistance value to mimic that of the internal resistance value of the battery as the voltage drops. You would have to get some sort of graph plot from tests carried out on an actual battery,to give you some idea as to how much the internal value increases as the voltage drops. Once you have some estimates-say at 100mV intervals,you could then adjust you VR to mimic that internal resistance when using the cap,at those 100mV intervals.

It seems that you have stepped into the Portable Logic Discombobulator (DLP) shipped directly from The Bizarro Duller Image Inc.  Remember when I mentioned about acting on thoughts without thinking a bit deeper before the premature pearls of wisdom start popping out?

The DLP is used by the Bizarro World debaters to dull their wits in preparation for a big debate.  You step into it and there are buttons for the various discombobulation settings; "Sauté," "Sizzle," and "Pan-Fry."

Would you like to super-size your fries what that?  Your supporters are rooting for you.

MileHigh

TinselKoala

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Re: Joule Thief 101
« Reply #2660 on: July 11, 2016, 11:43:27 PM »
@MH: Without my entering the debate too deeply.... Just what is wrong with the idea of equalizing the impedances of the capacitor and battery by using a variable resistance in series with the capacitor? I'm not asking whether or not this is actually necessary to make the test valid (I don't think it is necessary), I'm asking you to explain what is wrong with the idea. After all, the necessary added resistance would only be a few ohms at most. Approximating the change in battery impedance by using a fixed resistor at the average value would probably be "close enough" as they say.


Meanwhile, back at the Real Data Dude Ranch.... here is the graphed raw data from my testing of last night.  Which circuit is more efficient? Let the happy reader decide.

The total light output over the time of the test can be seen in the Lux-Seconds curves as the integration (total area) of the curves. The voltage vs. light output efficiency can be derived from the Lux-Voltage curves.

MileHigh

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Re: Joule Thief 101
« Reply #2661 on: July 12, 2016, 12:07:47 AM »
@MH: Without my entering the debate too deeply.... Just what is wrong with the idea of equalizing the impedances of the capacitor and battery by using a variable resistance in series with the capacitor? I'm not asking whether or not this is actually necessary to make the test valid (I don't think it is necessary), I'm asking you to explain what is wrong with the idea. After all, the necessary added resistance would only be a few ohms at most. Approximating the change in battery impedance by using a fixed resistor at the average value would probably be "close enough" as they say.

Let's see if Brad can figure that out first, it's his pearl of wisdom.

"'Eye sea,' said the blind man."

TinselKoala

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Re: Joule Thief 101
« Reply #2662 on: July 12, 2016, 12:36:07 AM »
MH: You may recall Mark Dansie's earlier comment about testing a circuit that was optimized for the particular power cell they are using. It turned out that this optimization included taking into account the output impedance of the power cell. One test that was performed involved substituting a capacitor charged to the nominal voltage of the power cell. This resulted in the immediate failure (smoke release) of the MarkE-designed circuit's DC-DC converter chip, due to the ability of the capacitor to deliver a lot more current at the design voltage than the original power cell could. It turns out that a proper test with a capacitor would use a series resistance (albeit very low, like 0.1 to 1.0 ohms) to avoid blowing the converter chip.

The moral of the story is that one may not neglect the output impedance of the power source arbitrarily. Now, whether or not the battery's output impedance actually matters very much in the present testing of the JT circuit efficiency.... that is another question. After all, the power dissipation of a couple of ohms at say 40 mA is... shall we say.... not very great.
I2R= .040 x .040 x 2 = a bit over 3 milliWatts.

Personally I should think that a real test of the circuit efficiencies should use as low a supply impedance as possible. Maybe PW and .99 and others might like to weigh in on this topic.
After all, many times in testing various circuits we have seen on this forum, the suggestion has been made that capacitors should be used instead of batteries. But also, we have seen cases where the battery type and condition made a big difference in performance. So perhaps the battery indeed should be considered a critical component of the JT.

Opinions? Discussions?


Meanwhile one last graph from the raw data: Voltage vs. Duration
(Note the little bump in the Blue data: this is probably due to my delay or error in recording that one data point.)

tinman

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Re: Joule Thief 101
« Reply #2663 on: July 12, 2016, 12:58:54 AM »
Brad, my lightbox was built when I was doing some efficiency tests for another project, to compare with results from some other researchers. This is why I used the 18 inch distance from LED to sensor. The box is 5 inches square by 18 inches long (inside dimensions) and is painted inside with gloss white paint. The Extech LT300 lightmeter sensor dome is in the center of the back end wall. The front end wall is removable for access, and has a small breadboard attached to its inner surface for mounting LEDs etc.  This puts the LED about 1/2 inch from the actual surface of the front wall. The actual distance from the LED under test and the sensor inside the dome is 18 inches, as the sensor itself is recessed a bit in its housing.

I'm using one LumiLED Luxeon 3535L surface-mount LED (part number MXA7-PW57-H001) in the center of the front wall breadboard, soldered to some pins to fit the breadboard. These LEDs have a nice wide dispersion angle and no focussing lens. They are superefficent, but are generally meant to be supplied with 100 or 200  mA  DC max (depending on exact part number). At that drive current they are blindingly brilliant (but need a heatsink), but even at 20 mA drive they are amazingly bright. I've attached the full data sheet for these LEDs below. They are great, you should order some!


    :-*

Thanks for the info TK,i will begin construction of a light box so as it matches your light box dimensions.
I will call into jaycar on the way home tonight,and grab a small bread board,as that sounds a great way to change out  different light globe's/LEDs

Quote
Has nobody drawn graphs from my raw data yet?

Sorry TK,i havnt had time,as i have been working on my setup.
MH seems to have much spare time  :D


Brad

poynt99

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Re: Joule Thief 101
« Reply #2664 on: July 12, 2016, 01:45:14 AM »
Personally I should think that a real test of the circuit efficiencies should use as low a supply impedance as possible. Maybe PW and .99 and others might like to weigh in on this topic.
I think I've essentially weighed in on this already with the challenge I posted. The power source was to be a bench supply set to 1.5V. It's the only way to establish a known fixed input condition. The Ro of most bench supplies should be low enough such that 100mW of power draw isn't going to drop the voltage much nor cause ripple on the output.

tinman

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Re: Joule Thief 101
« Reply #2665 on: July 12, 2016, 01:56:33 AM »
I think I've essentially weighed in on this already with the challenge I posted. The power source was to be a bench supply set to 1.5V. It's the only way to establish a known fixed input condition. The Ro of most bench supplies should be low enough such that 100mW of power draw isn't going to drop the voltage much nor cause ripple on the output.

Poynt

We are not talking about the challenge,we are talking about the two JT circuit's.
While the battery is running a JT circuit(or any load),and the voltage drops across that battery,dose not the internal resistance/impedance of the battery increase?.
If so,then is energy dissipated across this resistance?
If that is also correct,would it not be more efficient to avoid sending current through this resistance as much as possible ?.


Brad

tinman

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Re: Joule Thief 101
« Reply #2666 on: July 12, 2016, 02:04:22 AM »
Let's see if Brad can figure that out first, it's his pearl of wisdom.

"'Eye sea,' said the blind man."

I think you have forgotten much of what you have said in this thread MH.
Perhaps you should go back and review the discussion in relation to having a VR on the base,and what you said about it making no difference to light output by decreasing the base resistance,due to the internal resistance/impedance of the battery as the voltage drop's.
This may stop you from dropping your self in it again ;)

Just a suggestion ;)


Brad

MileHigh

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Re: Joule Thief 101
« Reply #2667 on: July 12, 2016, 02:58:43 AM »
I think you have forgotten much of what you have said in this thread MH.
Perhaps you should go back and review the discussion in relation to having a VR on the base,and what you said about it making no difference to light output by decreasing the base resistance,due to the internal resistance/impedance of the battery as the voltage drop's.
This may stop you from dropping your self in it again ;)

Just a suggestion ;)

Brad

I can hear the sounds of the frying pans clanking off in the distance.

I tried to repeatedly to explain to you what the base resistor was for you but you would have none of that.  I tried repeatedly to explain to you that your test that showed a limited amount of brightness change in the LED was just a distant secondary effect of changing the value of the base resistor but you wouldn't have any of that.  Just like the YouTube clip explaining how a Joule Thief works got you all confused, frustrated, and mad, you clearly have no understanding about how a Joule Thief works even though it must have been explained to you at least a dozen times.

Here is your big bamboozle moment:

The chances of TK changing the value of the base resistor in the second circuit to bring the Lux output to the same level as the first circuit while maintaining proper Joule Thief circuit operation are essentially nil.

Here is your big bamboozle moment II:

Quote
To carry out the test correctly using a cap in place of the battery,you would have to include a series variable  resister,and increase the resistance value to mimic that of the internal resistance value of the battery as the voltage drops.

Okay!  So the supercapcap drops from 1.5 volts to say one volt.  You measure the output impedance of the battery when it also has dropped to one volt driving when the Joule Thief and say for illustrative purposes the output impedance of the battery is measured as being 10 ohms.

Here is where Brad's brain is on fire!

He takes his supercap which is outputting one volt, then adds the series resistor of 10 ohms, and then connects the Joule Thief load.  "We have the technology."

Then he sets the setup off to run, and WHOOPS!, he is not measuring one volt at the Joule Thief now.  He is only measuring 0.85 volts!

What's going on?  Brad says, "I know when my supercap is at one volt I must put a 10-ohm resistor in series.  But then the voltage at the Joule Thief is 0.85 volts."  "I am confused, because I know when my battery voltage is 0.85 volts, the output impedance is 12 ohms and I am supposed to put a 12-ohm resistor in series."

"But I just put a 10-ohm resistor in place but now I have to put a 12-ohm resistor in place??"

The steaming she is a starting, the sizzling sound she is a crackling.  Get your marshmallows out!

The fans from Bizarro World start up a chant, "More discombobulator!  More discombulator!" with the clanking sound of frying pans in the background.

The moral of the story:  Avoid the Logic Discombobulator and think first before you leap into the forum.

tinman

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Re: Joule Thief 101
« Reply #2668 on: July 12, 2016, 04:28:31 AM »
I can hear the sounds of the frying pans clanking off in the distance.

I tried to repeatedly to explain to you what the base resistor was for you but you would have none of that.  I tried repeatedly to explain to you that your test that showed a limited amount of brightness change in the LED was just a distant secondary effect of changing the value of the base resistor but you wouldn't have any of that.  Just like the YouTube clip explaining how a Joule Thief works got you all confused, frustrated, and mad, you clearly have no understanding about how a Joule Thief works even though it must have been explained to you at least a dozen times.

Here is your big bamboozle moment:

The chances of TK changing the value of the base resistor in the second circuit to bring the Lux output to the same level as the first circuit while maintaining proper Joule Thief circuit operation are essentially nil.

Here is your big bamboozle moment II:

Okay!  So the supercapcap drops from 1.5 volts to say one volt.  You measure the output impedance of the battery when it also has dropped to one volt driving when the Joule Thief and say for illustrative purposes the output impedance of the battery is measured as being 10 ohms.

Here is where Brad's brain is on fire!

He takes his supercap which is outputting one volt, then adds the series resistor of 10 ohms, and then connects the Joule Thief load.  "We have the technology."

Then he sets the setup off to run, and WHOOPS!, he is not measuring one volt at the Joule Thief now.  He is only measuring 0.85 volts!

What's going on?  Brad says, "I know when my supercap is at one volt I must put a 10-ohm resistor in series.  But then the voltage at the Joule Thief is 0.85 volts."  "I am confused, because I know when my battery voltage is 0.85 volts, the output impedance is 12 ohms and I am supposed to put a 12-ohm resistor in series."

"But I just put a 10-ohm resistor in place but now I have to put a 12-ohm resistor in place??"

The steaming she is a starting, the sizzling sound she is a crackling.  Get your marshmallows out!

The fans from Bizarro World start up a chant, "More discombobulator!  More discombulator!" with the clanking sound of frying pans in the background.

The moral of the story:  Avoid the Logic Discombobulator and think first before you leap into the forum.

Lol
You are a strange man MH.


Brad

ramset

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Re: Joule Thief 101
« Reply #2669 on: July 12, 2016, 04:41:31 AM »
Would seem a med imbalance...
the auditory hallucinations should calm down in a day or two..."I can hear the sounds of the frying pans clanking off in the distance.".

Might take longer for the others to stop...["steaming Brain Fires" and such]

I suggest a few days off and  lay off the Old Star trek marathons ...

and definitely no old Pink panther marathons!!

could make the  twitching much worse !!


 :o

Oh and back to crayons for the time being no "pens" or other sharp objects.