Joule Thief

[WilbyInebriated]

regarding the sealant or wire insulation, super corona dope works great, covers all the bases.
http://www.web-tronics.com/sucodo554.html

[altrez]

@ScienceMan

Hey I am new here as well Try starting out with a basic JT to get the feel for the device. You can also try the fuji mod. So far I can light a 4 watt tube with 1 AA battery.

Take Care and good luck!

[TheNOP]

Hi Guys

I want to do a JT for a science project for school.

I'm slowly reading this thread from the end to the beginning to try and get an idea of the best JT to use for my project... 

Any suggestions for which circuit and what winding config. could be used to light up fluorescent tubes using the smallest possible battery (to give a contrasting appearance between supply and output)?

Any help would be much appreciated.

SciMan

if you want to build yourself.

what you will need:
-1 core, 1 inch toroid will do. (you are not limited to just toroids)
-1 transistor, 2n2222 and 2n3904 are mostly used but most camera's flashes ones are proven to work very well.
- wires, 22 gauge for the jt coils, 30 gauge or less is recommended for the pickup coil.
-1 capacitor, 47 uf will do. (optional)
-1 diodes bridge. to take measurement, not need in the final device.
-1 potentiometer, 10k ohms will do
-1 protoboard(breadboard) is recommended but is optional.
-1 voltsmeter


-put a temporary coil on your core, about 10 turns will do.
it is for tuning your jt coils

-put the joule thief coils at 90 degree on each side of your temporary coils.
that make it so your jt coils are 180 degree appart.
make them 10 turns each but keep long enough of wire to be able to add at least 10 more turns.

-hook the diodes bridge to the temporary coil, + and - pins goes to your voltsmeter.

-make the jt connections as per the schematic, see below.


now you are ready to tune the jt coils to your core.

1 -sweep the potentiometer slowly from one end to the other, while keeping an eye on your voltsmeter.
   get it to the highest voltage it can go, mark down the measurement.

2- compair the measurements, if this is the first measurement go to step 3.

a - if voltage get higher than previously do step 3

b - if voltage is lower remove the last turn you made, you are done with the tuning.

c - if this is the second measurement and it is lower go to step 4

d - you had to many turns and now voltage is lower, redo the last turn, you are done with the tuning.

3 - disconnect the battery, add one turn on the coils that have less turns, or pick one if this is the first measurement.
     reconnect the battery and do step 1

4 - you have to many turns.
do step 3, but keep in mind you must remove instead of adding during the remaining of the procedure



tuning is now done.

-remove the temporary coil and add the true pickup coils, between the jt coils.
the number of turns is dictate by the application you want to use your jt for.


for cfls application:
the transformer of the fuji camera is known to be able to light cfls.
they have around 2000 turns in them.
this can get a bit troublesome at that high number of turns.
so i suggest Mk1 way of doing it, multiples coils.

the figure here is a mk1 coils:
http://www.overunity.com/index.php?topic=6942.msg162320#msg162320

an mk8 (16 coils, 8 coils on each side of the jt coils, is sayed to light cfls)
but an mk4(8 coils) or mk6(12 coils) might work too.
connect all pickup coils in series.

note: the the pickup coils can also be tuned.
        but that is an other procedure than the one above.
        it involve volt per turn measurements.

have fun. 


P.S. for those who can see errors in this post, or see it can benifit from additional informations.
       please feel free to copy, make the needed changes, then repost it.

[hazens1]

1/2 inch toroid wrapped 22 turns x 2 bifilar Green 26 gauge magnet wire. 88 turn Red 30 gauge Tertiary. N2222 NPN transistor. 461pf 1kv capacitor and 10k resistor parallel. Running on 1.2v 2100mah rechargeable AA. Puts out 18v rectified from 1.3v load. Current load is 8ma.

Edit: Tertiary is actually 88 turns, not 44. Sorry..

[Goat]

1/2 inch toroid wrapped 22 turns x 2 bifilar Green 26 gauge magnet wire. 44 turn Red 30 gauge Tertiary. N2222 NPN transistor. 461pf 1kv capacitor and 10k resistor parallel. Running on 1.2v 2100mah rechargeable AA. Puts out 18v rectified from 1.3v load. Current load is 8ma.

@hazens1

Nice presentation of your JT using only 8 mA, congradulations 

I noticed that you mentioned the JT coil was 22 turns x 2 bifilar Green 26 gauge magnet wire while the 4 turn Red 30 gauge Tertiary is exactly double the number of turns.

How was the Tertiary wound in relation to the JT primary?

It looks like it's all wound at the same time to me but please elaborate if you can, it looks different than the MK JT coils at 180 degrees which is ok as you seem to have a greater output with low power consumption than the original  JT circuit

Regards,
Paul