Joule Thief

[resonanceman]

Just  after  I posted   that last post it hit me what went wrong.

I was looking  for  problems  with my circuit .

I  did not focus enough  on other things .

I have  a capacitive  charger  on  my 12V battery .
Just  a  cap and a bridge .
It works  great for  reconditioning  lead  acid batterys

I connected   to this  charger  because it was already hooked up to the battery .
I did not  check the battery switch .    It was off .
Usually  I unplug the charger  after  I charge up the battery ... last time  I just turned it off  but  didn;t unplug it .



If this  kind of charger  is not hooked up  to the  battery  the voltage will  go up to  line voltage .
As  it turns out ... I hit my  transistor  with 108V
The 108 V also explains  why I saw a spark when I  connected the power .
I saw the  108  but misread  it as 10.8 .......  I thought my battery was not holding  a charge very well.


so .....more than likely  my circuit is fine  .......and should work once I lower my input  voltage by   a little over 100 V   



I am out of time tonight ..............tomorrow  I  will have to change  my  transistor and  try it again

gary

[freepow]

  Hi everyone, I'm back, I am happy with my experimenting, I have got finally resonably high AC-volts !
My scope measures around 134 volts AC  or with NEON it measures around 92 volts AC.
I am happy, and will be trying to get higher AC-volts,  My joule thief only has 8 turn bifilar with 30 turn secondary on it.  Has anyone got this many AC-volts with this small amount of turns that i have ??

[xee2]

@ freepow

Hi everyone, I'm back, I am happy with my experimenting, I have got finally resonably high AC-volts !
My scope measures around 134 volts AC  or with NEON it measures around 92 volts AC.
I am happy, and will be trying to get higher AC-volts,  My joule thief only has 8 turn bifilar with 30 turn secondary on it.  Has anyone got this many AC-volts with this small amount of turns that i have ??

I think that is as good as anyone has gotten with a 30 turn pickup. But, what do you mean by AC output. Most JT output pulsed DC which looks like this photo from video by Yucca. This was taken at the collector, but I think the pickup coil looks the same. I do not have a scope so I can not be sure. Can you post some scope photos of your pickup coil output?

[resonanceman]

Hi everyone, I'm back, I am happy with my experimenting, I have got finally resonably high AC-volts !
My scope measures around 134 volts AC  or with NEON it measures around 92 volts AC.
I am happy, and will be trying to get higher AC-volts,  My joule thief only has 8 turn bifilar with 30 turn secondary on it.  Has anyone got this many AC-volts with this small amount of turns that i have ??

Freepow

Great work   

One question I have is  have you tried less than 8 turns on your bifilar primary ?
It seems  like 8 turns is alot ....unless you have a very high permeability toroid.




Xee

As I understand it the output has alot to do with the kind of  primary windings .....some  are mostly pulsed DC some  are much closer to real AC.


Freepow

When you light up  your neon  ..... does  it light  both  sides of the neon  equally?
If so  it is  AC .......if it lights mostly one  side it is mostly DC.

gary

[xee2]

@ freepow

When you light up  your neon  ..... does  it light  both  sides of the neon  equally?
If so  it is  AC .......if it lights mostly one  side it is mostly DC.

Good point. You need to look carefully. It is sometimes easy to be fooled by the reflection of the lit electrode on the unlit electrode.