Joule Thief

[electricme]

@MK1
Hi Mark, thank you for posting this very interesting link, it holds several keys within its information.

http://www.nuenergy.org/alt/page_36_from_harnessing_cosmic_energy.htm

I would recomend this to all, but you will have to do a google name search to locate a indepth item.

jim

[xee2]

@ electricme

Nice photos. Here is a little annotation.

EDIT: Can you use the same circuit and take a scope shot with a capacitor across the base resistor to see what that does?

[electricme]

@Xee2
Sure can xee, I already tried this a while ago, lets see.

@ electricme
EDIT: Can you use the same circuit and take a scope shot with a capacitor across the base resistor to see what that does?

OK I took 4 more snap shots.

Switch is in ON
0796.jpg = Top view of the JT, capacitor is seen accros resistor. Switch is in ON/Closed position.
0797.jpg = Waveform is the same as I took in photo 0783.jpg.
Green LED is bright

Switch is OFF
0798.jpg = Top view again, showing switch in OFF position, capacitor is out of circuit.
0799.jpg = Waveform is now much different, bottom of trace is flat, whilst top is curved.
Green LED is Dull.

The probe was connected to the transistors emittor.

I next connected the probe to the BASE of the transistor, photos I will do before next post, the surprises continues ha ha.

jim

[jeanna]

Wow, awesome everybody!!
Thank you Jim for giving Bill a hand.

Nice pics, Bill. Isn't this fun?

Jim, after the switch broke, I thought you kind of put that biggo away. I am glad you will bring it out again.

Altrez,
This is very cool. I think you are using one big toroid for all this. Is this correct?
Mine should be here soon, I hope. If I remember right, the biggest one I ordered was 2 1/2 inches.
I will get that pic for you in a day or so. I went into the garden today and well, it is what I did today.

Bill, Try this:
Wrap a secondary of about 10 turns of 30 gauge wire around your joule thief and instead of using the battery for ground, clip the clip on one wire end and the probe on the other wire end. (that is, both ends of the secondary pickup)

I think you will see (literally) what is so exciting about the secondary pickup on these jt circuits.

Now unwrap 5 of the turns and make this little pickup go back and return to where it started. And look. It is really different.

Once you make a MK1 style, you will 'see' why they are so excellent especially compared to a single direction secondary.
AND, unlike me (and altrez) , you can really share this with the group here.

What a great day everyone!

jeanna

[electricme]

@Xee2
@all
These following tests are to compliment the last tests Xee2 asked me to do for him which was the signal on the Emittor of the transistor.

This series is for the signal to the BASE leg of the transistor.

Here is a set of tests/photos I just ran, they show what occurs when the capacitor is inserted in the circuit and what happens when it is left out of the circuit.

0800.jpg = Probe tip on transistors base leg

Switch is OFF (NO CAP)
0801.jpg = All you can see is a continous streem of pulses about 1/5th of a volt.
               My cro is only 10MHz so a 20MHz cro or higher would be needed to see further in this streem of pulses.

Switch is ON (CAP in Circuit)
0802.jpg = The waveform can be seen showing the pulses entering the transistor base leg.
0803.jpg = This is the closest I could get to showing the bottom of the pulse itself. this is where the transistor has turned off, the wave has collapsed, and recovery is beginning.
0804.jpg = Similar to 0802.jpg, but showing just 1 pulse cycle.
0805.jpg = This is the pulse streem entering the transistor base as seen by the cro.

Everyone, please remember that these cro shots reflect what is happening with my JT, as we all have different JT replications, different wire sizes, different toroids etc, these waveforms of mine will only be good for an indication, to allow you to understand what is actually going on.

jim
 
I forgot to mention the transistor is a 58050 I took from a solar light.
The cap is a ceramic 102k (tiny looking flat brown disk thingie)