Joule Thief

[jeanna]

I think,
we must find the best cheap transistor or MOSFET to switch
very fast the primary current on and off in a JT.
This will give us the best secondary induction voltage and it seems,
the higher the induction voltage is, the better will be the light output
from fluorescent bulbs and CCFL bulbs and LED chains.

So what would be the fastest switching standard cheap transistors or MOSFETs to use
for this ?

Hi Stephan,
Some of us have been working on many of these elements you speak of.
The ferrite toroids have a lower limit to their frequency.
As the frequency of a joule thief goes down, the voltage goes up, so, to light a cfl, it is necessary to have one that will vibrate at 1khz-12khz.
I have not found the lower limit yet, but certainly, 50khz will bring the overall voltage down to the point where the cfl will no longer light.
In a higher frequency toroid, it will be necessary to start with a higher voltage to light the cfl.

This is the reason that the little toroid found in a cfl is not good for use in lighting a cfl from 1.2v battery and a joule thief. [because it was designed to start from 110 volts or 220 volts.]

hack these and enhance them.
They are also pretty cheap and have a great
ferrite transformer in them.
These put out also around 30 Khz 600 Volts spikes.

Thank you for this information. You just saved me a lot of time  as this was next on my list.

jeanna

[jeanna]

I am doing as bill asked me to.
I tried to dissuade him, but to no avail.

Bill has left this forum.


jeanna

[jeanna]

Poynt has been made moderator and can therefore remove all interesting posts at his whim.
I am very sorry to have to report this.

I am hoping it was a bluff that poynt made to bill, but if poynt is really moderator, I will not have my posts moderated by him either.

I will give it some time, however.

jeanna

[Mk1]

Big bros Is taking over ?

He edit comments (removing parts ), and post them in other treads , Make people look like aXX , anyone with half a brain can see that...

i should start a new forum , for those of us really working hard , a safe place like this site use to be .

Believe me if this doesn't change , gadget , jeanna , bill , stprue , wilby , jesus, jonny , ist, i really forget many of you now but you will be welcomed  !


Everyone will have freedom to express them self , free from a holessss ....


I will start learning the blog software , and think of a name ...

[innovation_station]

i agree with you bros !

bill is a great member ! 

and pony only trys to cover it up as he has no true understanding as to why ...

however ... so be it!

if you build it they will come ... 

w