Joule Thief

[jadaro2600]

Well, this is just what's accumulating if I put a diode on the collector to a capacitor.  The actual voltage when there's an LED on it is different.

The inductors are some sort of ferrite.  They're attracted by a magnet.  They came from a DSL filter.  ( an older one ) ..there are four of them in each filter.

[xee2]

@ jadaro2600

Each spike on the collector coil will add charge to the capacitor until its voltage reaches to peak spike voltage. With the neon across the capacitor, when the capacitor voltage gets to about 100 volts the neon turns on. If the net current coming into the capacitor is less than the neon current, then the neon will discharge the capacitor until the voltage drops to under 90 volts and the neon turns off and the process repeats. If the current coming into the capacitor is greater than the neon current, then the capacitor keeps increasing in voltage until it reaches the peal spike voltage.

The spike voltage will be limited to the capacitor voltage while the capacitor is charging.

[jadaro2600]

I fried the switching diode in the picture.  I'm now using a different transistor and diode all together.  The setup is now putting out 170 volts - I still can't get it to light up this CFL though, I think the thing need just a little bit more voltage.

[xee2]

@ jadaro2600

The transistor spec you need to be concerned about is the max Vceo. If you can find data sheets on internet for your transistors you can select the one with the highest Vceo and use it.

I reccommend 1N4007 diodes.

[jadaro2600]

I'm getting a few 1800 volt capacitors soon.  There are a few transistors also.  I have the worst luck with these components.

Everything is a mess!  I need to order more diodes and more relevant transistors.  This inductor thing is turning out to be funny - with the neon connected, I can move the inductors apart and watch the neon flash, with them closer together the neon stays lit.

The odd thing is that the inductors will work when put 90 degrees to one another.

In the diagram, the colored paths... it's either one or the other.

*edit: added new circuit diagram