Joule Thief

[dasimpson]

just wonted to ask were can i buy the $1 goldmine toriods so i then know i am using exactly the same style rather then trying to guess

[dasimpson]

i just found these and thoght they be ideal easy to get and once we have the mods for them on here every one can have the units very easy instead of all the different boards we get
ah damn and blast it we have a $50.00 minimum order (plus shipping) to all Foreign Countries (except Canada).
no way id be spending that much mind you the supercaps have been calling me just need to save lol

[dasimpson]

my led draws 25ma from 3 aa batterys in series to get 3.6 volt at 2500mah.
what i would like to do is limit the max current that can be drawn from a single aa battery to 25ma.
so any jt i build wont be able to use more then that.
i tried to do the maths many times but i just end up lost.
what risistance would i need to put in series with the battery to limit the current to 25ma.
i am hopeing that i can build a jt that can light the single led the same as 3 batterys would with out haveing to keep worrying about the current it is drawing if i can do that then i can wire the batterysw in parallel for 7500mah and get 3 times the time out of the batterys but still have the same light output.

[dasimpson]

ty for gerhard for making it possible for me to do this.the first unit works very well the second needs the cfl touching to make it work. i do have to other units but they are no good for this one recharges every time the flash is clicked and the other has 3 transistors on and hard to work out. but im happy with these.the second one seems to put out 120vac. i tested this by putting a diode infront of a cap then charging the cap then swapping the wire round both ways give a reading of 120v when ran into a neon both sides lit.the first one give me a about 300v also into my arm at one point lol.`heavy handed no shock the moment im been carefull zap a few choice words were said i can tell you the cfl is a 14watt one may try the 4 watt one i have about

[xee2]

for those who can not find a toroid:

no toroid Joule thief video >>>>  http://www.youtube.com/watch?v=q8XeS4dxAxE&feature=mfu_in_order&list=UL

also see >>>>  http://www.youtube.com/user/Lidmotor#p/a/u/0/BCevexBP26M