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Author Topic: Joule Thief  (Read 6275721 times)

gadgetmall

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Re: Jule Thief
« Reply #15930 on: December 13, 2012, 04:40:44 PM »
Hi Guys and Merry Christmas to Each and every one of you . I hope you and yours  get what you want for Christmas .
As for me i am getting this LCF meter after years of wanting one and i will make good use of it to find out why some of my circuits work and some don't . Here is a link for this China Jewel . It can measure Frequency to 500 mhz as well as inductance and capacitance and this will tell exactly how and why several circuits are charging higher than the supply of the modded crossover . There is one other person who has replicated this exactly so i am not alone in this one . http://www.ebay.com/itm/300731799625

this is less than 40 dollars and will be a much needed coil winders tool This is bare Bones and will fit In a small box enclosure i have .

L8r 

Gadget

drodenbe

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Re: Jule Thief
« Reply #15931 on: December 14, 2012, 11:53:24 AM »
BS2012

If you leave the base lead open which normally would go to the positive terminal and install a resistor of about 1k in series with about a 20k pot and connect them between the base and the positive you have a basic Katcher circuit.  I don't know if you have ever worked with them but they produce a large output.  I lit 200 leds off of the last one I built.  I have never tried with toroid core ,But I will today may be interesting.  By the way I have built a joule thief coil that has been working for a couple of days and it charges the battery and I have a 2600F supercap that it charged up from 1.5 volts to 4.8 volts overnight.  I have an HP3490A 6 digit multimeter that I monitor my circuits. I picked it up second hand I think a must when working with these circuits.  It reads 4 and 5 places right of decimal point.  The coil I wound is a E core configuration with 500t on both primary and secondary.  The cores are separated by 2mm gap.  Pop cycle sticks work great.  On one of the windings I wound a 10 turn coil with #22 wire.  The 500t coil is #24.  I use one winding as joule thief.  If you have two grounds from outside as I do you should run the positive side of the battery to one ground and hook the other to the plus side of the circuit.  I have tried the same hookup only using the negative side but the plus side works better.   I am experimenting with different windings to see if I can improve the charge rate.  Also I want to add that with the gap between the other winding It doesn't load the primary coil.  This is a plus in its self.  Have not had time to check out the possibilities with the second winding.  Well I guess I have spent my two cents.  Have fun playing with circuit if you like. 

drodenbe

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Re: Jule Thief
« Reply #15932 on: December 14, 2012, 12:02:06 PM »
gadgetmall

I bought one of the LC meters you are talking about.  I have had it for a couple months and it is great.  I have two other different kinds, I bought earlier and I hate them.  won't measure most of what I hook them up to.  But this one is great.  I am so happy with it I am going to give it a new home inside a nice utility box.   

TinselKoala

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Re: Jule Thief
« Reply #15933 on: December 14, 2012, 12:10:35 PM »
Those meters are so cool.... I just used my Arduino and a few other parts to build a little circuit to measure inductance. A little more work and it becomes the LC and Freq meter too, but for now it's just inductance. It's amazing how versatile the Arduino is. This morning it made my breakfast in the TKSousDuino PID temperature controlled crockpot, and tonight it's measuring my stray inductors, and doing it better than my "ProsKit" LCR meter.

http://www.youtube.com/watch?v=S6N8ys8FiA4

Links to the source of the project and the program sketch are in the video description.

TinselKoala

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Re: Jule Thief
« Reply #15934 on: December 14, 2012, 02:04:34 PM »
I thought you might like to see a scopeshot of how these meters do their thing.

This is it measuring a 1 milliHenry coil: The top trace is the pulse response from the comparator circuit and the bottom is the stimulus pulse to the coil and its ringing response. The Arduino sends a short pulse and the inductor rings, and the Arduino reads the frequency of the upper trace and then calculates the inductance, according to the known capacitance value of the tank circuit. It's a pretty thing to watch on the scope.


xee2

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Re: Jule Thief
« Reply #15935 on: December 14, 2012, 07:37:47 PM »
gadgetmall

I bought one of the LC meters you are talking about.  I have had it for a couple months and it is great.  I have two other different kinds, I bought earlier and I hate them.  won't measure most of what I hook them up to.  But this one is great.  I am so happy with it I am going to give it a new home inside a nice utility box.


What is the smallest inductance and capacitance it will measure?

gadgetmall

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Re: Jule Thief
« Reply #15936 on: December 14, 2012, 08:46:15 PM »

What is the smallest inductance and capacitance it will measure?
The minimum resolution: 0.01 pF
* Inductance measuring range: 0.001 uH - 100mH
* Big inductance measuring range: 0.001 mH - 100H

xee2

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Re: Jule Thief
« Reply #15937 on: December 15, 2012, 12:57:33 AM »
The minimum resolution: 0.01 pF
* Inductance measuring range: 0.001 uH - 100mH
* Big inductance measuring range: 0.001 mH - 100H


Thanks. That is a great deal.

TinselKoala

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Re: Jule Thief
« Reply #15938 on: December 15, 2012, 08:50:31 AM »
0.001 microHenry, that is, one nanoHy? Sorry, I don't believe it. The display might display 1.000 milliHenry at the low range but this is false precision.

What is the inductance of one inch, straight,  of #27 magnet wire?

It is over 26 nanoHy, more than 26 times your instrument's stated lower limit.

So you are telling me that instrument can measure accurately..... the inductance of two millimeters of wire.

http://www.consultrsr.com/resources/eis/induct5.htm

verpies

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Re: Jule Thief
« Reply #15939 on: December 15, 2012, 08:43:15 PM »
What is the inductance of one inch, straight,  of #27 magnet wire?
It is over 26 nanoHy,
This guy claims that for helixes of large pitch, a coiled wire has less inductance than a straight wire!
Don't take my word for it - read it.

gadgetmall

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Re: Jule Thief
« Reply #15940 on: December 16, 2012, 02:19:40 AM »
Tk i just copied and pasted from the meter ad  8) I could not find what kind of chip is on it but it has good reviews . Do you think it is an adreino ?

Drodenbe Thanks and good to know !

TinselKoala

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Re: Jule Thief
« Reply #15941 on: December 16, 2012, 10:53:44 AM »
Tk i just copied and pasted from the meter ad  8) I could not find what kind of chip is on it but it has good reviews . Do you think it is an adreino ?

Drodenbe Thanks and good to know !
I don't know, I doubt if it has a full Arduino in there,  but it could be the same microprocessor. Can you see the main chip? Is it an Atmel or ATmega 328?

I'm pretty sure it will use the same technique for getting the inductance though: send a quick pulse to the inductor, use a comparator to track the zero-crossings of the ringdown waveforms , and read the frequency of the comparator's output, like my scopeshot shows.

But it doesn't matter how it does it really.... it is just that it is very hard, using any technique, to measure tiny inductances... since the test leads themselves have much greater inductance than 1 nHy and at those low values, even the positioning of the leads can have a great (relative) effect.

Hey, it's still a very cool meter, and a bargain for what it does. And it inspired me to do it with Arduino! Thanks..... !

I just made another JT vid showing an interesting effect using a loopstick variable inductor, with an extra winding, for the transformer. It will be up in an hour or so, and I'll post a link then.

TinselKoala

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Re: Jule Thief
« Reply #15942 on: December 16, 2012, 10:59:23 AM »
This guy claims that for helixes of large pitch, a coiled wire has less inductance than a straight wire!
Don't take my word for it - read it.

I can believe it. A lot of time you will see commercial inductors wound with helical-type or herringbone windings... the loopstick I just experimented with is an example. I think this is done to use a lot of wire to get the DC resistance up, without raising the self-inductance much. Then the loopstick has a good ferrite adjustable core, to get the inductance back up to useful values.

electricme

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Re: Jule Thief
« Reply #15943 on: December 29, 2012, 08:13:07 AM »
Hi Guys, just popping in to say G'day from the land Down Under.
An update, havent been ignoring, OU in t5he back of my mind right now.
Things got too much for me with the floods two years ago to the day, still repairing my house, then my wife of 36 years passed away two months ago.
I'm battling on, will get back in here eventually when it's not so full on here.
Keep up the good work.
Happy new year to everyone.
Jim

WilbyInebriated

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Re: Jule Thief
« Reply #15944 on: December 29, 2012, 09:14:54 AM »
Hi Guys, just popping in to say G'day from the land Down Under.
An update, havent been ignoring, OU in t5he back of my mind right now.
Things got too much for me with the floods two years ago to the day, still repairing my house, then my wife of 36 years passed away two months ago.
I'm battling on, will get back in here eventually when it's not so full on here.
Keep up the good work.
Happy new year to everyone.
Jim
howdy jim, good to hear from you!
i am very sorry to hear of your loss. hold tight to memories of love shared for comfort, lean on your friends for strength, and always remember how much you are cared about.

the best things in life aren't things...