Joule Thief

[resonanceman]

I am posting  a couple pictures of  the  core  I am using before I fried it .

I was  getting  about 450 V  from   one set of pins.

I removed the  wire ......  I kept  the E core and the plastic  spool that fits over it .......with attached  pins for  connections .

First  try  10 wraps bifilar  ( cat5 wire )   
I got  46 V  out  JT LED position ....no  secondary
I am powering it with 12 V

I  noticed that   when the  E core halfs are placed together   there is a gap in the  middle  section .
I cut  3 pieces  of sheet metal  to fill  that gap .
I was thinking that  with the gap filled  I should get  higher  voltage .
It  dropped to 3.6 V  with 1 piece of metal in the gap .
3.3 V with 2 pieces.
3.2 V with all  3 pieces .
With  all  three pieces   the  gap  is  filled  as well as I have the ability to fill it .

What I wonder is  if the lower  voltage  means  the core is  acting like it is  higher  permeabillity .....or  is it lower ?
I will check  voltage   with a full set of  windings  once  I get this thing finished.

gary

This  core lights up my 90 LED array to full  brightness  with only 46 V   
When   I  read  the voltage across the  output  it reads only 4 V
WIth one of those metal  pieces in the  gap it reads  3.1 V   the  array is  maybe 1/4 power at best .
with 2 of the metal pieces in the gap .....  2.5 V  the  array is  barely  lighting .
With all 3 pieces 2.1 V  the array  is  almost  out .

gary

[resonanceman]

@gary

The hole in the core is to make sure the core doesn't saturate ...

when you add the metal in the hole it changes the core operating freq...


Hello everyone !

Mark

Thanks Mark

I had heard that  with a JT   you want to reach saturation .
Do you know  if adding metal to the gap would raise or lower the frequency?

My idea was to make  the core as close to acting like a toroid  as possible ......


gary

[Mk1]

@gary

Using 12v , will most likely saturate a core faster then a 1.5 volt input , i believe this is the reason your output goes up when your battery drains .

Filling the gap in the core , makes it (saturable) that makes the core slower to respond , i think it should lower the freq .

Mark

Keep the good work !


edit  you could try a pot on the battery and monitor the output ...

[Pirate88179]

Mark:

Good to see you.

Bill

[innovation_station]

WELCOME BACK MARK... 

READY FOR BLISTERS AND SORE FEET ? 

LOL

SEE IF WE CANT SHRINK A QUATER OR SOMETHING ... 

IST!

IF WE PUT A TOONEE IN THE SHRINKER .. THINK THE CENTER WILL POP



MISS YA BRO ..