Joule Thief

[hazens1]

@Hazens...

Absolutely awesome coil you got there --> wound so nicely. I think I might make the same one as you have described there after a small JT (plans from other people) just to get the feel for it... 211V rect. pretty cool!

ScienceMan

Edit: Hazens... Where is the load on this circuit? and when you say you are drawing 75mA - what is drawing that?

ScienceMan

Thanks!

That is the draw with no load. Any load put on the pickup coil causes the amp draw to drop. The more I load it, the more the amp draw drops. I wish I had some led string lights to test with. I tried an unmodified CFL with a very faint flickering of the bulb. I don't have any spares to cannabalize to try straight to the tube. I can drop the load on the battery to 10ma by upping the resistor to a 10k ohm and I still get 80v rectified. When I tune the coil for best voltage using a pot set to about 500 ohm I get 235v and you can clearly hear the toroid singing. I tried 2 AA rechargeables in series for about 2.5v input and I I got 340v rectified using a TIP31 Transistor with a 125ma no load draw on the battery. Still have lots to try. Still need to compare the other toroid with the same wind. Once I decide which toroid I like the best, I'm going to try different winds. So much to do, so little time...

@jeanna
I'll try modifying the turns when I get a chance to see what happens. I have 2 of those toroids as well as 5 of the others.

TYGER

.

[Pardon]

Hello @all I was just wondering if anyone has tried to use either a 150 Lumens 4 w led or a 100 Lumens 3 w led with a JT.

also i just salvaged a real nice green toroid from a pwr suply. works without rewinding but i may wind it the mk1 way.

[altrez]

 

@ALL

Success!!! I got the Pickup coil to work FINALLY!!!! Once I put it on my breadboard and took the time to test EVERY part of the circuit it worked perfect! I have a BIG list of THANK YOU'S to EVERYONE who helped me.

Thank you @jeanna @MK1 @TheNOP  @jadaro2600 @electricme @Pirate88179 @slayer007 and for all the people I left out I am sorry I will go back and check all the posts and add your name.

One thing I did notice is that the transistor gets HOT is that normal for the 2n3904?

I will post pics soon. I am so happy! I am not sure what I was doing wrong before as it would always light an LED but now it lights the LED at least 20 times brighter! From a PICKUP COIL!

THANKS!

[jeanna]

Beautiful job.

No, the transistor should not get hot. (tell her to put the hulahoop away for a while!  )

Maybe you should raise the resistor value. Part of its function there in between the transistor base and the base winding is to protect the transistor. If it is in the right place and the resistor is 1k, I dunno. Mine never get hot. corse it is chilly where I live. (the air in the room is a heat sink.)

congratulations!!!

jeanna

[TheNOP]

One thing I did notice is that the transistor gets HOT is that normal for the 2n3904?

what is your base resistor ?
you might want to use a more resistive one and/or use a heat sink if the heat become an issue

now it lights the LED at least 20 times brighter! From a PICKUP COIL!

be carefull not to blow it/them out.
adjust the voltage by removing turns on the pickup coil or add more leds in series until it match your output voltage.

ex: 3 volts for single led or multiple leds in parallel.
      9 volts for 3 leds in series or  multiple 3 leds in series in parallel.

you can also add more pickup coils tune to the voltage you need