Joule Thief

[gadgetmall]

@IST your going to have to build the switch . you need a tiny 3 volt relay or just replace the led with a tiny relay that had the photo cell circuit on it .

[TheNOP]

This one says high permeability. I don't know if that is good or bad for this. Nobody answered my question on that yesterday, so I guess nobody else knows either.

Permeability is the inductance per unit length.
In general, permeability isn't a constant, as it can vary with the position in the medium, the frequency of the field applied, humidity, temperature, and other parameters. In a nonlinear medium, the permeability can depend on the strength of the magnetic field.
In ferromagnetic materials, the relationship between B and H fields exhibits both non-linearity and hysteresis: B is not a single-valued function of H, but depends also on the material.

in short, the more permeable a material is the more flux you can pass trough it.
high permeability mean higher current can pass trough the material before saturation.

current is limited by the size of a core and material type.
higher frequencies can core saturate faster too.



@slayer007
unless the frequency at witch your jt operate is really high, all toroid with a secondary coil will work.
even with a nail you should see some voltage out the secondary coil.
it might not be as effective due to its permeability, but you should get something there.

it will make a difference layered as it will pick up the other half .. on the back wind no?

in term of volts you will see at the output, it does not matter.
in term of self inductance and self capacitance, there are differences with the way you wind your coils.

[Pirate88179]

@ MK1:

Yes, that is , or was, a good command to print the screen but, ever since I obtained service pack 3 for XP, it no longer works.  I can hit those commands 100 times and.....nothing.  So, now I use this.  But, you are correct, it was the way to do it. (at least for me)  What ohm pots are you using?  I have tried 3 that I salvaged from different devices and I can't get them to make much of a difference.  They range from 10 ohm, to 25 and then 50.  I have looked online at various electronics sites and the selection of pots seems rather limited.  What is a good number to look for?  Also, I thought that when turned the one direction, the resistance either went to 0 or went to the full amount of the pot rating.  I have tested these using my meter and....yes, the resistance changes but goes nowhere near 0 on either side of the knob turning.  I know I need to get the "correct" pots but have no idea what to get or their ratings.  Thanks.

Bill

[TheNOP]

Sorry double post , PC issue , I am going down,lol , messenger down, internet half dead , this side takes like 3 minutes to load a page then try logging in , just got a new one explorer opened about a thousand pages, crap.

disable activex and scripting for internet zone (IE settings/Security)
set trusted site zone to medium and add the sites URLs you wish to permit script applet to run to the permition list.

for maximum security, also disable third party extentions, install on demand "other" and java(advanced setting)

[Pirate88179]

disable activex and scripting for internet zone (IE settings/Security)
set trusted site zone to medium and add the sites URLs you wish to permit script applet to run to the permition list.

for maximum security, also disable third party extentions, install on demand "other" and java(advanced setting)

I agree except, for maximum security, use Firefox.  I have not used IE for 1.5 years and I do not miss it one bit.  I know all browsers piggyback on explorer to some extent but, Firefox has worked very well for me.....so far.

Bill