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Author Topic: Joule Thief  (Read 6276916 times)

nievesoliveras

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Re: Jule Thief
« Reply #30 on: November 23, 2008, 02:46:57 PM »
@spinner

Hmm, this circuit (a very basic transistor oscillator with an inductive coupling) is called "The Joule Thief"? Lol,  I can assure you it's more like a "Joule waster"...

Yes, it works with only a few (easy to get or make) components, but that's about all it can do...
It actually works as a (quite inefficient) DC to AC/frequency converter, wasting at least half of the Energy available.

Maybe it's the rather low input voltage where LED is still working that fascinates you?

There are serial (three/four pin "transistor like") components on the market, which allows you >85% efficiency (DC/DC chips, usually needing only a few external low-tech components to work). They all beat this circuit (in efficiency) at least by the factor of two... And they're still not Unity.

Joule Thief? Yeah, sure...

I built a joule thief circuit " http://www.overunity.com/index.php?topic=6123.msg139345#msg139345 "
And as today it is still working.  It lights 4 leds with a 1.5v battery that only has 0.35volts left.
also if I connect a 0.00v AA battery, it charges it by increments of 0.01v every three hours.

Just build it and see for yourself. The schematic is included.

Jesus

Yucca

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Re: Jule Thief
« Reply #31 on: November 23, 2008, 03:19:36 PM »
Hmm, this circuit (a very basic transistor oscillator with an inductive coupling) is called "The Joule Thief"? Lol,  I can assure you it's more like a "Joule waster"...

Yes, it works with only a few (easy to get or make) components, but that's about all it can do...
It actually works as a (quite inefficient) DC to AC/frequency converter, wasting at least half of the Energy available.

Maybe it's the rather low input voltage where LED is still working that fascinates you?

There are serial (three/four pin "transistor like") components on the market, which allows you >85% efficiency (DC/DC chips, usually needing only a few external low-tech components to work). They all beat this circuit (in efficiency) at least by the factor of two... And they're still not Unity.

Joule Thief? Yeah, sure...

I would agree that although it operates on low voltages it burns more current in the coil chargeup than is captured as BEMF by the LED, but I think if you make the coil out of very thin wire then more efficiency can be had, the coil gauge will need to be matched to the load. Basically up the gauge until the LED stops getting brighter. Or maybe make a very high impedance coil with exceptionally fine wire and many more turns and have a high voltage and incredibly low current light the LED, a bit like a Stiffler SEC. In this scheme the trigger coil ratio will need to be lowered so as not to upset the transistor base.

But it is in it's current form a bit of a Joule waster as you put it, but as I see it plenty of room for improvement.

I think the circuit is a good thing to play with because it helps the experimenter gain a more intuitive understanding for electronics than just buying a 80% efficiency DC-DC converter. The DC-DC converter packages you speak of can any of them operate down to 0.3V input voltage?

Yucca.

spinner

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Re: Jule Thief
« Reply #32 on: November 23, 2008, 05:31:13 PM »
Quote
I built a joule thief circuit " http://www.overunity.com/index.php?topic=6123.msg139345#msg139345 "
And as today it is still working.  It lights 4 leds with a 1.5v battery that only has 0.35volts left.
also if I connect a 0.00v AA battery, it charges it by increments of 0.01v every three hours.

Just build it and see for yourself. The schematic is included.
Jesus
Ok, empty batteries still have some juice left (chemical potential) before they're really dead. (as no output current).
The internal resistance of the battery rises tremendously, while the electrolyte decayes...

Measure the voltage of your battery in circuit. Measure unloaded battery with a DMM. Any difference? Use scope to see the waveforms in the circuit,... Digital V-meter is a nice instrument, but has some limitations... You cannot measure pulses of any kind...

You can try using a charged el. cap instead of the battery. Or, use a (low ohm) resistor divider connected to a good battery () and try your circuit (setting up the output at 0,35V). Add filter cap,...

Ah, I see. This circuit "sucks energy" from otherwise "dead" batteries (the ones considered empty after the normal use). So it actually is a Joule Thief...


@Yucca
Any component in this circuit is lossy. Especially semiconductors. Therefore, this circuit cannot be OU.
But it's interesting and educational to play with, indeed.
It may pump the energy from somewhere...  ;)

Yes, DC/DC circuits need much more than 0,35V.  This circuit, too. Transistor cannot operate with CE voltage that low, but with suitable inductive coupling and a voltage superposition while oscillating it obviously works...


I'll leave all the practical and useful solutions to you, guys!
Cheers!

WilbyInebriated

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Re: Jule Thief
« Reply #33 on: November 23, 2008, 05:39:17 PM »
Hmm, this circuit (a very basic transistor oscillator with an inductive coupling) is called "The Joule Thief"? Lol,  I can assure you it's more like a "Joule waster"...

Yes, it works with only a few (easy to get or make) components, but that's about all it can do...
It actually works as a (quite inefficient) DC to AC/frequency converter, wasting at least half of the Energy available.

Maybe it's the rather low input voltage where LED is still working that fascinates you?

There are serial (three/four pin "transistor like") components on the market, which allows you >85% efficiency (DC/DC chips, usually needing only a few external low-tech components to work). They all beat this circuit (in efficiency) at least by the factor of two... And they're still not Unity.

Joule Thief? Yeah, sure...

ummm... thanks Captain Obvious....

the serial component you speak of are not more efficient, and for sure not by a factor of 2, as tested here...
http://www.talkingelectronics.com/projects/LEDTorchCircuits/LEDTorchCircuits-P1.html

all that aside, my JT lamp uses 3x2 led's 3.3V 19mA each. 310mA drain @1.5V (81%)
now if you buck it instead of boost, and feed the "extra" V back to the smoothing capacitor, gets you closer to 90% efficient.
« Last Edit: November 23, 2008, 06:22:31 PM by WilbyInebriated »

nievesoliveras

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Re: Jule Thief
« Reply #34 on: November 23, 2008, 06:46:18 PM »
@all

I put a capacitor 2200uf 50v to the circuit and after an hour it was filled with 2.44volts. The thing is that it gets empty again somehow and it start it all over again.

The strangest thing is that it is filled with the same battery and circuit. The battery now oscillates between 0.35 and 0.44 volts. I peeled the battery cover to diferenciate it from the other batteries I have.

When I put it back to the circuit, it took about 10 seconds to light the four LDs again without the capacitor.

?????

Jesus

innovation_station

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Re: Jule Thief
« Reply #35 on: November 24, 2008, 12:13:19 PM »
Hmm, this circuit (a very basic transistor oscillator with an inductive coupling) is called "The Joule Thief"? Lol,  I can assure you it's more like a "Joule waster"...

Yes, it works with only a few (easy to get or make) components, but that's about all it can do...
It actually works as a (quite inefficient) DC to AC/frequency converter, wasting at least half of the Energy available.

Maybe it's the rather low input voltage where LED is still working that fascinates you?

There are serial (three/four pin "transistor like") components on the market, which allows you >85% efficiency (DC/DC chips, usually needing only a few external low-tech components to work). They all beat this circuit (in efficiency) at least by the factor of two... And they're still not Unity.

Joule Thief? Yeah, sure...


fool yea sure...  i bet u are   do you get paid to do what you do? :D

it works and whos fault is it if YOU DONT UNDERSTAND!!!   WHY IT WORKS.... :D :D :D

lieing through your teeth  EH!!

you can run on for a long time ......  run on for a long time ........  sooner or later gotta cut you DOWN!  ;)

 ;D

IST!

well i guess i will have to make a little test ...... 8)

i have 2 24 led rings....   they run off 4 aa batteries each....    i will install a jt in 1 unit  and we will mesure the run time from 1 battery......

and we will in the other unit just let it run with 4 batteries  and see how long it runs ....

as tesla stated time is gained.....   DOES THAT MEAN RUN TIME..... ;D

 ;D

spinner

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!
« Reply #36 on: November 24, 2008, 01:06:28 PM »
ummm... thanks Captain Obvious....
???
Quote
the serial component you speak of are not more efficient, and for sure not by a factor of 2, as tested here...
http://www.talkingelectronics.com/projects/LEDTorchCircuits/LEDTorchCircuits-P1.html
Yes they are.  ;D
Why would they (manufacturers) lie about it? Take, for instance, PR4401. It's efficiency is declared under certain conditions, and it can provide a continuous power at #82% (ENERGY EFFICIENCY)!. Try to adopt the circuit discussed in this thread to the same conditions (add rectifying/smoothing, etc..), and see how it will perform....

Or, take a two identical supercaps charged to the same Voltage, and see how long the LEDs will work  with both circuits.... Or, find an equivalent serial ic circuit with a PWM output capability... Or,... Whatever...
You're aware that we're comparing a +50 years old electro-tech components against a few years old? I'm sure there's at least some improvement being made....

BTW, Thanks for providing the link... It is a good text, telling a lot about LEDs and suitable LV driving circuits...

As you may have noticed, the author never claims OU. And the only efficiency he's talking about is based on a "personal" light intensity perceptions (not correct measurements). Need I say more?

Quote
all that aside, my JT lamp uses 3x2 led's 3.3V 19mA each. 310mA drain @1.5V (81%)
now if you buck it instead of boost, and feed the "extra" V back to the smoothing capacitor, gets you closer to 90% efficient.

Thanks.. Can you provide a circuit schematics and description/details of a measuring procedure?
The "extra smoothing cap" ALWAYS lowers the combined circuit efficiency... Voltage without current cannot do much work...

OK, i admitted before that we're "not looking through the same glasses"...

Cheers!

innovation_station

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Re: Jule Thief
« Reply #37 on: November 24, 2008, 01:40:50 PM »
i appolige spinner

i dont mean to be rude bro

i want my point across properly ... 

this is one of the simplest cavatition devices....   ever


 ;)

once understood

well

ist

spinner

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Re: Jule Thief
« Reply #38 on: November 24, 2008, 01:41:27 PM »

fool yea sure...  i bet u are   do you get paid to do what you do? :D

it works and whos fault is it if YOU DONT UNDERSTAND!!!   WHY IT WORKS.... :D :D :D

lieing through your teeth  EH!!

you can run on for a long time ......  run on for a long time ........  sooner or later gotta cut you DOWN!  ;)

 ;D

IST!

well i guess i will have to make a little test ...... 8)

i have 2 24 led rings....   they run off 4 aa batteries each....    i will install a jt in 1 unit  and we will mesure the run time from 1 battery......

and we will in the other unit just let it run with 4 batteries  and see how long it runs ....

as tesla stated time is gained.....   DOES THAT MEAN RUN TIME..... ;D

 ;D

Ahh...Ohh.. Geee, thanks, IST!

I feel honored, I finally got attention from the top FE scientist, and the most productive inventor of all times!

Yes, majesty?

Oh, please please please, let me understand....
 ::)

innovation_station

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Re: Jule Thief
« Reply #39 on: November 24, 2008, 01:49:25 PM »
Ahh...Ohh.. Geee, thanks, IST!

I feel honored, I finally got attention from the top FE scientist, and the most productive inventor of all times!

Yes, majesty?

Oh, please please please, let me understand....
 ::)


now your being an ass

why?

do you think this sh!t dont work....   

hummmm   i must laugh .... 

how much power do you want  ;) :)

lol lol !!!


ist

walk the path .....   or pave your own....  im still walking.... my path :)

nievesoliveras

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Re: Jule Thief
« Reply #40 on: November 24, 2008, 02:40:07 PM »
@all

The circuit is just an efficient way to spend the energy left on an almost dead battery. It is not overunity.
It is still working, but the light is very dim now.
I connected it to an air energy receiver I built and the energy receiver only gets now 0.24v connected to the joule thief.
It does not turn the LEDs on.

Thank you all!

Jesus

innovation_station

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Re: Jule Thief
« Reply #41 on: November 24, 2008, 03:32:26 PM »
@all

The circuit is just an efficient way to spend the energy left on an almost dead battery. It is not overunity.
It is still working, but the light is very dim now.
I connected it to an air energy receiver I built and the energy receiver only gets now 0.24v connected to the joule thief.
It does not turn the LEDs on.

Thank you all!

Jesus

there is only 1 way this can be proven true or false ....

a run time test ....  2 batteries...  power 1 led how long?   brand new....  and 2 batteries of the same brand new with a joule theif power a led how long?? 

not rocket sience here ....

someone please do the test...   is time gained?

ist

spinner

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Re: Jule Thief
« Reply #42 on: November 24, 2008, 04:02:20 PM »
now your being an ass
why?
do you think this sh!t dont work....   
hummmm   i must laugh .... 
how much power do you want  ;) :)
lol lol !!!
ist

walk the path .....   or pave your own....  im still walking.... my path :)

Ist, I'm sorry I was acting like an ass... OK, Bro?  ;D
I've accepted your apology, now I'm going to smoke a peace pipe... :D

We can always agree to disagree, and I think there's nothing wrong with that...
Cheers!

@Jesus
Thanks for the report!

Paul-R

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Re: Jule Thief
« Reply #43 on: November 24, 2008, 04:37:57 PM »
Ok, empty batteries still have some juice left (chemical potential) before they're really dead...
...remembering that if you put them in a charger, they often charge up again, whatever it
says on the side of the battery.

Freezer

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Re: Jule Thief
« Reply #44 on: November 24, 2008, 08:10:27 PM »
...remembering that if you put them in a charger, they often charge up again, whatever it
says on the side of the battery.

http://www.hammacher.com/publish/75357.asp