Joule Thief

[Mk1]

@all

[Mk1]

@all

First test on the prototype 5 , it works , i did not do all my usual testing yet .

But you can see if light 24 led in parallel on four and a half turn secondary.

I got the same light from 0 to 300 ohm (value of the pot) so i am not even close to the sweet spot...

[Rosphere]

Well done... did you use the same dimensions for your former etc? I have also run this up at around 25 volts using an IGBT (cross between a mosfet and transistor. The distance increases as does the voltage amplitude!

I used a jacketed 3-wire construct of about 3/16" diameter that I had on hand.  Two of the three wires are stranded and insulated, (one white one black,) while the third is stranded, tinned, and uninsulated.

Because I did not want to tear into the jacketed wire construction, the number of base windings is equal to the number of collector windings.  The number of windings is 15.  The coil profile shape is an equilateral triangle.  A photo would be helpful here, (sister-in-law is still 'borrowing' my camera.)

The inside diameter is 11 inches.  The outside diameter 12.5 is inches.  The height is 0.9 inches.  (I wound it on a 'Knifty Knitter' that Dansway advised me to purchase years ago--finally got some use out of it.)

I made three identical coils, held together with electrical tape.  With three wires each, I have nine total coils to play with.

measured inductance      
top white   0.128   mH
top black   0.128   mH
top tin   0.126   mH
mid white   0.127   mH
mid black   0.127   mH
mid tin   0.126   mH
low white   0.126   mH
low black   0.126   mH
low tin   0.124   mH

measured resistance      
top white   0.45   Ohms
top black   0.5   Ohms
top tin   0.4   Ohms
mid white   0.45   Ohms
mid black   0.45   Ohms
mid tin   0.4   Ohms
low white   0.45   Ohms
low black   0.4   Ohms
low tin   0.4   Ohms

measured capactance      
top white-black   0.002   Î¼F
top white-tin   0.004   Î¼F
top black-tin   0.004   Î¼F
mid white-black   0.002   Î¼F
mid white-tin   0.004   Î¼F
mid black-tin   0.004   Î¼F
low white-black   0.002   Î¼F
low white-tin   0.004   Î¼F
low black-tin   0.004   Î¼F

I was able to reproduce your results using only two of the three coils.  Two wires from the mid-coil were connected in JT fashion using a TIP41A NPN, a 50K POT, and a AA battery.  One wire from the top coil was connected to two white LEDs.  The further I separated the two coils from one another, the dimmer the LEDs became.

Since I was using clip leads to connect everything, after I reproduced your results I was able to play around with the extra coil and the extra wires; like using the extra wire in parallel with the collector-the LEDs glow a little brighter, etc.

Again, thanks for posting.  That was cheap fun for the weekend, (I only had to purchase the white LEDs and I intended to get some sooner or later anyway.)

[innovation_station]

mk

75 ohm 3vdc  4 " ring  7hz wobble it ...

: )

W

if you cant get wobble it is the transistor ... 

if you hit it right on BOOM  go the switches ...  less they can handle it ...

[Rosphere]

MK1, nice bright results on your JT-agentgates combo.  Maybe I will have a go next weekend.

(How is your "new soul" working out for you today?) lol