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Author Topic: Joule Thief 101  (Read 926841 times)

resonanceman

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Re: Joule Thief 101
« Reply #75 on: January 26, 2010, 07:09:43 PM »
;D100 spiky volts?
That is nice to know.
I think I will pick up one of those next time I am in wallmart. I need another plaque, so that might be soon.


Jeanna

No..... not spiky volts......normal volts
From my experience  the reading on a meter  with spiky voltage  means  very little
With the meter  connected  across the  LED array I have  lit the array pretty brightly with as much as 250V  and  as low as less than  one volt
How brightly the array lights seems to be dependant more on the power  level that the circuit can deliver more than the voltage.

About this array .......was out of the first Light of America floodlight that I ever bought.
I use it as  my general purpose  load for my circuits.
It is great because it lights a little with almost any application of power.
With very low power  just a few LEDs will glow purple .

The  new flood  lights  do not  react like this.......they require much more power to turn on........when they come on they are nice and bright.

Another thing to think about ........ my first flood lights  were VERY easy to take apart ......but each new generation  has gotten harder to take apart
The last  one I took apart  was a real pain ........I had to CUT the reflector around  the circuit board  then  pull  the board out.
The back  of the array was also coated with some kind of glue.......effectively making it about twice as thick.

Because of these  things  I do not plan on buying more  floodlights  to  take apart to get the arrays .

You might look for the  light in the picture below.
It is a little smaller........  and  cheaper......
If I remember right it has  24 LEDs  but it is almost  as bright  as my 90 LED array because  these seem to be straw hat  LEDs
I have  bought  several  of these.........the electronics  burns out fast .......but the LEDs  are still good.........and  quick and easy to get to.


Quote


I might try to get that much from the little one.
I just made a bunch of turns and it seemed good at 50-60v at 470r, but with less resistance or more turns or both 100v is probably possible.
I was addressing the cfl. I do not think that is possible with the tiny toroid.
I made one at the end of the summer from my 3/4 inch toroid that lit a 4 inch 4watt tube, but it fizzled. I think there were so many turns, that they must have shifyed and choked it.

I notice xee2 has re-wound his that got choked and he is getting good HV from it.
I completely agree.


This is something like the russian pictures from the other day.

I also had good results by winding the base coil around one toroid, and the collector coil around both. This gave me 2 toroids with similar voltage output, but if I remember, different shape.

I find it interesting to light a cfl, but it is not necessary nor very bright. Certainly using a bunch of leds is the brightest way.




My goal with the Little torids was for lighting  a LED array .......I finally replaced my  Dewalt 18 V batterys ........ Now I have  an 18 V light to convert to LEDs
I plan  on using some feedback....... the original bulb only lasts around 4 hrs per charge........I am shooting for  a week or 2 with LEDs .......
A  LOA 60 LED flloodlight  array just  barely fits  into the place the  reflector  used to be.


You got me wondering  if it is possible  to light a CFL with the little  toroids  ........  I wonder  of it is possible   to put the toroids both in series and parallel like we do  with LEDs
So far with my candy cane coils the series coils only seem to add power not voltage.

Just maybe....... the base coil  can be " shortened " by not putting it though all the toroids......... that might  change the transformer ratio.

gary


jeanna

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Re: Joule Thief 101
« Reply #76 on: January 27, 2010, 12:29:55 AM »
Thanks gary, I have seen those. I will try one next time.

=====
I want to give a follow up picture of this tiny toroid as a finished lamp. With 42 leds, it is only marginally brighter than the 24led one, similar to itm which is a surprise, and may relate to very low amps per led. I turned the cluster and it got brighter, so I might just need to play with the directions of the leds.
I tried to make the lights face outward in a hemispherical way. You can see I was not successful, and I may be able to improve this light by carefully bending the led wires. I put hot glue on the legs so shorting won't be an issue.
1- the cluster run by the tiny toroid in place and on.
2- a piece of plastic bag (!) wrapped around the cluster to give an even diffusion.
3-all put together and on.

jeanna

b_rads

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Re: Joule Thief 101
« Reply #77 on: October 04, 2010, 06:13:16 PM »
Thanks to ALL for the great info on this wonderful circuit.  I built my first basic Joule Thief this weekend and it worked as advertised.  In reading this thread, I created a guide from the posts here and have made it available in the download section.  It helped me and it might help others.  Thanks again to ALL.
http://www.overunity.com/index.php?action=downloads;sa=view;down=441
Joule Thief 101.pdf

tikbalang

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Re: Joule Thief 101
« Reply #78 on: December 15, 2010, 04:28:01 PM »
i am not getting optimum brightness from the leds.

i built the circuit from the 3rd post of this thread combined with jeanna's instructions on page 5 of this thread.

i tried 4 sets of coils, with CFL toroids:

A. 3T+3T/8T (default CFL winding)
B. 5T+5T/5T (cat5 wires)
C. 9T+12T/10T (jeanna's, #24 magnet wire)
D. 8T+8T (no secondary, cat5 wires)

my output is 1 led at the collector or 5 leds in series at the secondary coil. the leds light up but not as bright as when driven with 20ma constant current source.

the first 3 did not differ much in terms of brightness, both for 1led and 5led config. the last one seemed just a tad brighter but i could not fit anymore windings.

is it ok to jumble up the wires? can we establish a ratio to the windings? is it ok to use thinner wires to fit in more windings?

resonanceman

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Re: Joule Thief 101
« Reply #79 on: December 16, 2010, 04:33:02 AM »
i am not getting optimum brightness from the leds.

i built the circuit from the 3rd post of this thread combined with jeanna's instructions on page 5 of this thread.

i tried 4 sets of coils, with CFL toroids:

A. 3T+3T/8T (default CFL winding)
B. 5T+5T/5T (cat5 wires)
C. 9T+12T/10T (jeanna's, #24 magnet wire)
D. 8T+8T (no secondary, cat5 wires)

my output is 1 led at the collector or 5 leds in series at the secondary coil. the leds light up but not as bright as when driven with 20ma constant current source.

the first 3 did not differ much in terms of brightness, both for 1led and 5led config. the last one seemed just a tad brighter but i could not fit anymore windings.

is it ok to jumble up the wires? can we establish a ratio to the windings? is it ok to use thinner wires to fit in more windings?


tikbalang

I made a  similar misstake
the windings you have tried look to me like they are for a ferrite toroid.
The CFL toroids are not ferrite .....they are probably powered iron.

Powdered iron requires more primary windings.

My best CFL toroid JT was made with 20 windings  of #30 magnet wire  4 strands  twisted together and wrapped on the toroid as one .

2 of those wires are used as primary  2  as secondary
Both sets of wires are connected start of one  to the end of the other.

This setup only puts out 1.6V according to my DMM but they seem to be very spikey volts......... by that I mean that the  impulses are very strong and the JT can do more than its indicated voltage would indicate.

This JT will light a 1W LED pretty bright.
It also lights a MR 16 light with 32 LEDs pretty bright.
This light also was all its original electronics.
This light will not light at all with 9V DC

gary

jeanna

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Re: Joule Thief 101
« Reply #80 on: December 30, 2010, 09:48:05 PM »
i am not getting optimum brightness from the leds.

i built the circuit from the 3rd post of this thread combined with jeanna's instructions on page 5 of this thread.
.........

is it ok to jumble up the wires? can we establish a ratio to the windings? is it ok to use thinner wires to fit in more windings?

Yes,  most of the time, it is OK to jumble the secondary wires, but be careful not to get them too close to the primary. It can choke the system if you do.

No, we cannot establish a windings ratio.
The numbers relate to the ferrite core and each one is different.

Yes, thinner wire is great.
Just be careful not to scratch the insulation. It is brittle on the thin wire and will break out and cause spark damage and the jtc will stop working. It will first work fine then inexplicably stop when this happens.

btw, the brightness never seems the same when using the high frequency as compared to the 20mA straight through.
If they are almost as bright, then this is the real deal.

Good job, keep going!

jeanna

tikbalang

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Re: Joule Thief 101
« Reply #81 on: January 02, 2011, 03:36:37 PM »
Quote
No, we cannot establish a windings ratio.
The numbers relate to the ferrite core and each one is different.

i was hoping there was some way of quantifying something in this circuit that can be adjusted to get a similar result over and over. can the windings compensate for a bad toroid? to what extent? how to tell if the windings were not enough? or too much?


Quote
Yes, thinner wire is great.
Just be careful not to scratch the insulation. It is brittle on the thin wire and will break out and cause spark damage and the jtc will stop working. It will first work fine then inexplicably stop when this happens.

i can confirm this. it happened to me on several experiments and the solution was to rewind the coil with new wire and to coat the toroid with nail polish.

btw, before i started painting over the toroids, i get a reading of 15kohms  to 30kohms between the toroid and the wires. it should be infinite, right?


Quote
btw, the brightness never seems the same when using the high frequency as compared to the 20mA straight through.
If they are almost as bright, then this is the real deal.

then i may already have been successful with a 1led joule thief circuit. i have built a few that were blindingly bright when LOOKED AT but can't illuminate anything useful at more than 4ft.

i did a few experiments before the holidays and one of the more successful coils were from a spool-type inductor salvaged from a CFL. the inductor itself broke so i took about 6ft of the fine wire, doubled it over to two strands of 3ft then jumble-wound it on a sharpie pen. i'll re-create it and post pics later. i'm mentioning it here because it took me a while to hunt for toroids when they were not needed at all, newbies take note!

some pre-built coils that failed: am coils with ferrite rods from two different walkman-type radios and an isolation transformer from a crt monitor.

surprisingly, CFL toroids work as-is with varying degrees of successes. i assumed they would be of the same quality since they practically have the same purpose in the CFL circuit. the plain black unpainted toroids seem to be bad performers. i found a yellow one similar to jeanna's that i will work on later with more windings, it already is bright as-is. there are a few reds and blues that i have yet to test.

CFL toroids come in different sizes and colors but the windings are more or less the same: 2T+2T/6T or 3T+3T/8T (that's "primary base+primary collector/secondary" in joule thief lingo.

i tried mixing it up with 3T+8T for a 1led jt but the difference is negligible.

thanks resman and jeanna, i'll come back later for pics and more results.

jeanna

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Re: Joule Thief 101
« Reply #82 on: January 02, 2011, 10:42:46 PM »
@tlkb...

Have you seen this?

http://www.youtube.com/watch?v=ZnNQrYy_Bw4

I used the toroid from a cfl and took a hint from the existing turns on it, and made this light that has 42 leds.
I am able to see and if I were younger I could read by it because it is a good brightness.
There are umm 7 parallel rows of 6 series wired leds =ing 42.
I have decided that it really is no brighter than 24 leds and I suggest 6 or 7 might be good enough.
I wanted a light that would shoot in all directions (and, also I wanted to see if it could be brighter than 24 leds.)

jeanna

shylo

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Re: Joule Thief 101
« Reply #83 on: January 03, 2011, 03:00:03 AM »
Hi Jenna ,You seem to to be the go to person for questions on this subject,..I was wondering about the transistors used, I just salvage parts from old pcb's,... does the heat from my soldering gun cause damage to the components?, because I've tried making a jt with several different transistors , none of the 2222 though, all different #'s, I just can't get it to work for me ,the torrid is out of a microwave,roughly the size of a quater but thicker.....I guess I need to know if you can re-use old components or do you need to buy new?...thanx .....shylo

resonanceman

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Re: Joule Thief 101
« Reply #84 on: January 03, 2011, 07:26:06 AM »
Hi Jenna ,You seem to to be the go to person for questions on this subject,..I was wondering about the transistors used, I just salvage parts from old pcb's,... does the heat from my soldering gun cause damage to the components?, because I've tried making a jt with several different transistors , none of the 2222 though, all different #'s, I just can't get it to work for me ,the torrid is out of a microwave,roughly the size of a quater but thicker.....I guess I need to know if you can re-use old components or do you need to buy new?...thanx .....shylo

shylo

ALot of people use recycled parts for JTs.
I tried pulling transistors out of old  equipment but I didn't have much luck with most of them.
There are tons of different kinds of  transistors alot of them require 5V for the base.

I choose to buy transistors
it is just one less variable that I have to worry about .

Old monitors have some great parts
The flyback trnasformer works great as a JT
I save all the ferrite core transformers I find in the monitor.
There should also be some high voltage caps in there too
Just make sure you know how to ground the picture tube........it can hold a lethal  charge for years.

have you been reading the joule ringer thread?
If you want to salvage parts I would look for a store that will give you a few used disposable cameras.......most of the parts in them should  be good for JTs


gary

dasimpson

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Re: Joule Thief 101
« Reply #85 on: January 04, 2011, 12:31:29 PM »
Hi Jenna ,You seem to to be the go to person for questions on this subject,..I was wondering about the transistors used, I just salvage parts from old pcb's,... does the heat from my soldering gun cause damage to the components?, because I've tried making a jt with several different transistors , none of the 2222 though, all different #'s, I just can't get it to work for me ,the torrid is out of a microwave,roughly the size of a quater but thicker.....I guess I need to know if you can re-use old components or do you need to buy new?...thanx .....shylo

yes you can use scrap i do for the transistors you need to know the pinouts they are not always the same

it hertz

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Re: Joule Thief 101
« Reply #86 on: January 18, 2011, 04:40:42 AM »
Hi guys im starting to gather components for my first JT  i have downloaded the joule thief 101  PDF and it say

"The schematic shows a 1K resistor going to the base of the transistor I
recommend using a potentiometer (Pot) in place of the resistor"

What size potentiometer would i need ?
Thanx
neil

Pirate88179

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Re: Joule Thief 101
« Reply #87 on: January 18, 2011, 06:05:24 AM »
I have used a 10k but that is because that is all I had.  It usually calls for a 1k so, as long as that is in the range...it will be fine.


Bill

b_rads

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Re: Joule Thief 101
« Reply #88 on: March 11, 2011, 05:54:07 PM »
@all
I fully intended to do research last night but, instead I played with a basic joule thief and the Carbon/Copper/Zinc battery.  What great fun.  I could not light a 5mm LED directly from the two cells.  With a basic joule thief the two cells produced a very intense light.  I could light with as little as 10.7ma and the pot used at full on would consume slightly over 50ma.  I need to find the sweet spot where the cells are not stressed.

The DIY Copper Carbon Zinc document is here:
http://www.overunity.com/index.php?action=downloads;sa=view;down=460
The Basic Joule Thief 101 document is here:
http://www.overunity.com/index.php?action=downloads;sa=view;down=441

Have fun!
Brad S.

Pirate88179

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Re: Joule Thief 101
« Reply #89 on: March 11, 2011, 10:04:50 PM »
Brad:

Nice work.  Be careful that you are not sending too much voltage into those leds as you can fry them easily with a JT when running only 2 of them.  Trust me on this...ha ha.  It will be good to see how long your cells perform with this load.  You might try adding a supercap of 5 to 10 farads in parallel with your cells, that has always helped my longevity.

Bill