Joule Thief

[jeanna]

Hi jeanna,

i did it also except that i have about 25 to 30 turns around the core. that is really surprising for me. and look how many LED's. i will let it so till tomorrow morning. i used the wire from a LAN cable.

Norbert

Excellent!!
I did cut a big enough piece to make more winds. I will try to get 20-30 and see. Now, just to be sure, are you running these many lights as primary jt lights?

By primary jt lights, I mean is it a stack of leds in parallel to each other hooked up between the C and E of the transistor?

Or are they running off a secondary that is added to the copper coil with 25-30 turns? (I think not since you did not mention a secondary, I just want to hear it from you.)

I read beyond this post I quoted and see that the rectified voltage is 9 volts from a 1.1v battery pack. good stuff.

Did you measure the amp draw?


Thank you,

jeanna

[innovation_station]

i just built my first mk8 ....  looks like it turned out well ... 

i have not fired it yet tho i used the same cores ...   so my tuneing and winding config  should not change ...   i did add a few more turns on the pickups i have 10 up and 10 back both sides 30 ga magnet wire 8 strands twisted x2  ...   

i have started the MK HV! coil   its out put is high voltage over 1000v... 

ist!

i will add pics soon aswell we will list thease kits to the page ....   

back to work  ......     

[jadaro2600]

I'm getting very poor results with a floral wire core.  - I get better results out of a linear transformer.  It seems as though the iron wire I'm using is stifling the whole process.  I've tried my configuration shorted out and disconnected.

[jeanna]

OK renseak,

I just made 30 turns around this all copper ring. I made it as described in the video and after finishing 5 times around using 24gauge tele wire continued to make 30 turns around that core. Then I twisted it beginning of one to end of the other wire and set it up like a jt.

The light is fair. It is bright. but not as bright as the 2 lights working off a secondary that I took the battery from.

And the amp draw is 29.5mA
The light should be much brighter for that draw.

I cannot get another light to light in parallel to this one either. It puts out the first one and takes a minute or so to light that first one again.

I am wondering if I have hurt the breadboard or something. I cannot get the result you have. Darn.

jeanna

[TheNOP]

In the inner workings out our blocking oscillators - the things which ultimately turn the transistor on and off at high frequency - isn't there fly back voltage created in the coil-to-base when the transistor is turned. ...isn't this what turns the transistor off?  ...creating the oscillations in the first place.

my understanding of it is that it create both: inrush current and back emf.

when the transistor close, the flow to the base cease, opening the transistor back as the current is taking the less resistance path.
when the base feed get back high enough, either feeded by the back emf or the normal emf, the transistor close again.

well, i am not sure at this point if it is the bemf or its induced current in the other jt coil, Lenz's law.


@Mk1
speaking of Lenz's law, just an idea.
putting the jt coils between each pickup coils, one or 2 turns each.