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Step 7Winding
Now bend your magnet wire in half and wind it around your toroid.
Cut the ends and using a Ohmmeter, identify the ends of L1 and L2.
Solder the end of L1 to the begginig of L2. So polarity on L1 and L2 are oposite. (for more detail go to these link: http://www.evilmadscientist.com/article.php/joulethief)
This is how it works:
When the transistor conducts, current flows thru L1 and the the LED is off (fig. a). This creates a magnetic field on the coil and makes L2 shut off the transistor. When this happens (fig. b), the energy of the magnetic field induces a voltage on the coil called "back emf" and this ADDS up with the battery so you have 3 V or more (it like adding batteries in series).
Because this cycle occurs at high frequencies (kHz, depending on your inductor and transistor, etc), the LED seems to be all the time ON.
Cut the ends and using a Ohmmeter, identify the ends of L1 and L2.
Solder the end of L1 to the begginig of L2. So polarity on L1 and L2 are oposite. (for more detail go to these link: http://www.evilmadscientist.com/article.php/joulethief)
This is how it works:
When the transistor conducts, current flows thru L1 and the the LED is off (fig. a). This creates a magnetic field on the coil and makes L2 shut off the transistor. When this happens (fig. b), the energy of the magnetic field induces a voltage on the coil called "back emf" and this ADDS up with the battery so you have 3 V or more (it like adding batteries in series).
Because this cycle occurs at high frequencies (kHz, depending on your inductor and transistor, etc), the LED seems to be all the time ON.
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Jun 4, 2010. 9:44 PMmr smart
says:
is there a way to make this into a dc to dc high voltage transformer ?
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Jun 5, 2010. 8:20 PMunknownpocketnerd (author)
says:
Well, you'll need to do some calculations to guess the winding ratio. Or you can make a boost converter.
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