Make a Joule Thief
Windell Oskay of Evil Mad Scientist Laboratories joins me to show you how to make to squeeze the life out of your dead batteries by making a simple circuit called the Joule Thief!
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27 thoughts on “Make a Joule Thief”
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Hate it when people bend transistor leads so close to the case.
You should always leave at least 1/8″ of lead straight. Bending them too
close to the case makes the metal leads very weak.
Hello thank you so much for sharing, I never though I could make one, I had
a TV the I did not really use and I took it apart and got me the parts and
copied the way you did it. I made one and it works, thank you so much.
I feel smarter
Hilarious when watching at 2X speed :)))
Using a very small toroid and 2 AA batteries (3 volt input), i had an
almost 5 volt output. Great tutorial guys, thank you.
So, it’s like a mini transformator…
The values of Joule Thief is
Q1=e.g 2n2222 2n3904 (Do not use 90xx transistors because the gain of the
transistor is high and will drive over the Joule Thief and will not work.
R1=350-5000 ohms
D1= LED [Vfwd=3v]
Vceo=30v p-p
Vbeo=0.7v
Would love to try this thing someday. It is such an amazing trick to use
stuff that was assumed to be useless.
Aaa aaaaahahahaha u guys rock good video thanks for th idea preciate cha
how to get toroids plz I need help
+Shaminder Brar you can find one in a fluorescent bulb !
how to get the NPN transistor..????
+sasmita champati3 any old radio should have both toroid and transistors
within.
how to get the Transistor ?
is there any substitute for toroids ???
Mine worked thanks!!! This will come in handy!! I don’t think an official
team will lie about something like this
Love the sound fx and stuff
Even though this video is posted 7 years ago there are people still showing
this technology like they found something new. Well let me tell you what..
Sony had this technology back in 1980’s and they build WM-GX series Walkman
played cassettes had dual band FM radio and also WM-GX650 and higher models
had a headphone with remote control digital display on it. Guess what? All
driven by a single AA size not 1.5 Volt but 1.2 volt rechargeable battery.
Yes back in 80’s they accomplished a 1.2 Volt rechargeable battery not
just run LED light but run a motor in Walkman to play cassettes and power
the radio with it.
+Seani Rankeen
It isn’t. I just wanted to say that I don’t understand why the TO meant
it’s pointless…
?
+M USTI Yeahr, therefore it is forbidden to use the Joules Thief.
Now we know how to put one together.
So, it would be nice to explain how it works and why the LED light works
now.
Thank you for the explanation.
+tiffany martin Secondary winding works better than bifilar center tapped
winding.I changed the transistor to TIP31 power transistor and works very
efficiently.
The Toroid boosts power up to a useable voltage that the LED can be lit
with! The transistor is like a valve and it will only open when the current
is strong enough, so “juice” flows through the toroid until the transistor
opens. RimstarOrg has a great video explaining how this works, OH and Jeri
Ellsworth has a Amamzing video, explaining it too!!!!
can it be a square ferrite core?
yes
can’t you make joule thief for 3 watt led with 700mA. with 2 battery AA can
be perfect !!