Joule Thief

[xee2]

@ resonanceman

I made another non   toroid JT  today
It is just  a coil  of  cat5 cable ......I am guessing  about 150 ft
I  am using  one pair as  primary
I have all the  other pairs in series  as a secondary
With  my Jesus charger  and  3055  I am getting  68 V with no load.
My LMs  take  well over 100 V  to light  the array this bright

It seems to me that another  coil of cable or 2 placed  near  this one would act as   secondarys .

Here is a simple trick you may want to try with your non-toroid JT. You could problably get the same performance with one transistor and a heat sink, but this will let you push more amps without a heat sink. The advantqage of no toroid is that you can use a lot of amps without worrying about the core saturating (since there isn't one).


EDIT: voltages are wrong (they are actually less than half value shown - due to voltage divider error).

[Artic_Knight]

Mark

I spent several  hours trying to  get this thing to  download videos

I am giving up for now .

Thanks for  all the suggestions .   
I am planning on  trying that player  when I can

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I made another non   toroid JT  today
It is just  a coil  of  cat5 cable ......I am guessing  about 150 ft
I  am using  one pair as  primary
I have all the  other pairs in series  as a secondary
With  my Jesus charger  and  3055  I am getting  68 V with no load.
My LMs  take  well over 100 V  to light  the array this bright

It seems to me that another  coil of cable or 2 placed  near  this one would act as   secondarys .




gary

something that should be known, magnetic conductors such as ferrite torroids are fantastic when they are properly paired in operational frequency however they are used on things like monitor cables and good usb cables to eliminate high frequencies. this coil you made is a air coil and does not have any "magnetic storage" or other properties to damage the signal thus you are most likely using a higher frequency than currently seen on this thread (unless someone else posted a air core) cores like what we use are typically used when someone wants a "magnetic capacitor" of sorts, not only would it be able to step up or down the current passing through it but it also it stores some of that current. the origional plain joule thief was designed to store 1.5 volts and combine that with 1.5volts from the battery to light a led but it also was designed to run from a lower than average battery of .7v typically. now heres something interesting i noticed. the battery might read .7 volts but if you bridge a cap in parallel it reads 1.3v! maybe i had a funny battery when i did this but try it and see if you can do the same! anyways the JT was designed to take advantage of several of the properties of magnetism in these cores.  what this group has started to do in its applications honestly warrant something other than a JT. thats not to say what is needed for best performance will be much different but i think the ferrite is holding back the performance. when you provide some measurments we may know for sure.

great work.

great work everyone.

[resonanceman]

Hi Gary,
I agree with jesus.
Is ther any difference in this except the non toroid?
The reason I am wanting to know, is that a long time ago jadaro made a non ferrite coil and I made a copy and really nothing happened.
They (jadaro's and mine) were much smaller than this cat5 cable coil

Jeanna
Yes The  primary   simply  a twisted pair  connected  start of one with the end of the other .

All the other pairs  are  connected   start to end .......I  checked  the voltage every connection to make sure  it was  right .
Smaller was probably the problem
I think that the  flux is  less dense without a core ......so  you need more wire to make equil  flux

This is how I am envisioning this.

You take the blue and orange colored wires in the coil.
You put the beginning of one and the end of the other together and connect that as the center tap into the pos battery rail. The other 2 ends go into the collector and base at the end of the base resistor.
Is the pot with the red cap the base resistor pot? I am assuming so.

Yes that sounds right
Yes  the  red thing is  a  knob on  the  pot   it is 100K

Did you have any trouble getting the 2N3055 to begin oscillating?

Havn't  had that problem yet

What is the amps draw?

Sorry .......I was to busy playing  to  pay much attention to the amps .



I remember  .1A   but  not  sure if that was full brightness .
I will put it back together and   take a few more readings tomorow

I tried  adding  some LMs   for flyback and feedback .....didn't work to well .
I am thinking  there is an impedance mismatch or something .
It  might  be  easier  to use more  coils that are similar  for the flyback.

This is cool.

I have another question for you about the LM1.

You mentioned to me that (was it ) Slayer or lidmotor? had simply used 2 spools from the radio shack 3 spool set as the primary bifilar. The added resistance from the thinner wire gave something to it and more...

Is that what you are using now?

If someone made a diagram for you could you talk them through the changes needed? Or, is it the same diagram, just a different kind of coil?

Thank you,

jeanna

I have  made a couple  JTs   with a single separate  winding  each on their own spool
They can work  but I have not  got  any real power out of them yet .
My last try was to   put  a 2 spool   primary  made with sewing machine  bobbins  in one of my LMs  and   drive the LMs  with it .......I did  get a couple of volts ......but  that is all

The  schematic  for this  would be a basic  JT with a secondary
The only  difference is  materials

edit add

I meant to include this.

I did a scope test on an old stubblefield generator last week. I posted some pics at the time, but I want to put the results together here because it relates.

I had made the generator with a straw between the iron bolt and the windings so if I ever wanted to take the core out I could. So, here it is with and without the bjtl and with and without the core.
I just plunked thi into one of my jt circuits I had on a breadboard.

I am as always taking readings off the secondary.
Except for the final one ,the secondary is a step down thick wire unknown count.

With core
no light
10.73v   57.1KHz

with BJTL
3.63v 41.6KHz

NO CORE
with bjtl
4.5-5v  7.57KHz

NO CORE
Secondary is a full spool of red RS magwire
35.9v  2.77KHz

So, what I am seeing is that this can very definitely be done without a core.

(NOT LazyMan, however!  )

I will help with a drawing if it is different and needs one.

jeanna

Looks  good



now  all we have to do is get rid of that   transistor 



gary

[TheNOP]

now heres something interesting i noticed. the battery might read .7 volts but if you bridge a cap in parallel it reads 1.3v! maybe i had a funny battery when i did this but try it and see if you can do the same!

?
are you sure that the reading you got was not .13 volts instead ?

unless you are talking of with a jt connect to the battery, you probably made a mistake somewhere.

[resonanceman]

something that should be known, magnetic conductors such as ferrite torroids are fantastic when they are properly paired in operational frequency however they are used on things like monitor cables and good usb cables to eliminate high frequencies. this coil you made is a air coil and does not have any "magnetic storage" or other properties to damage the signal thus you are most likely using a higher frequency than currently seen on this thread (unless someone else posted a air core) cores like what we use are typically used when someone wants a "magnetic capacitor" of sorts, not only would it be able to step up or down the current passing through it but it also it stores some of that current. the origional plain joule thief was designed to store 1.5 volts and combine that with 1.5volts from the battery to light a led but it also was designed to run from a lower than average battery of .7v typically. now heres something interesting i noticed. the battery might read .7 volts but if you bridge a cap in parallel it reads 1.3v! maybe i had a funny battery when i did this but try it and see if you can do the same! anyways the JT was designed to take advantage of several of the properties of magnetism in these cores.  what this group has started to do in its applications honestly warrant something other than a JT. thats not to say what is needed for best performance will be much different but i think the ferrite is holding back the performance. when you provide some measurments we may know for sure.

great work.

great work everyone.

Thanks  Artic_Knight

I agree that   the frequency might be higher

My interest in  non  toroid  JTs  started when   I was looking for  a source   for larger toroids
In  general   large   and low permeabilty do not go together except in some  RF applications  so   in my opinion   the  toroid  became the weak link in being able to scale   these things up .

I do not think that the  cat5 cable is the way to go ............but it was a convenient  test 
I think that it may  be pointing the way .
I  was surprised  when it lit my array .
I almost didn;t try it  because  I was  only getting 68 V   with my LMs  I am not even sure that would  give even a  hint of light .

I will  try to get  some  numbers posted tomorow

I think I am  about  done for the night




gary