Joule Thief

[jadaro2600]

@TheNOP, haha..picture looks like it says "to puke generator".

..thanyou all for the information about the diagram.  It did seem a little strange.

Now, for another question, ..I have a DMM, and it has a diode checking mechanism ..which, when placed across the appropriate leads on a diode, gives me a number ( usually a less than one as a decimal, such a 0.671 ).  Is this number the voltage drop I can expect to see across it?

[jeanna]

@ jeanna

Congratulations. Isn't 100 volts the highest you have gotten?.

Thank you.
Yes, it is. I am on my way to making a hand wound fuji ckt.
yeay!!

I suspect he just has a better 2N2222 than you do. The 2N2222 has a large variation in performance from unit to unit. I recommend 2N2222A which is sorted for better performance and is usually only a penny more.

In fact mine are 2N2222A. I was being lazy skipping the A.

But I see Hazens has clarified. a TIP31 3amp transistor. I will need to look up what that is. I have some mosfets, but I am under the impression they will not start with the low voltage of a AA battery. Could try though...

Did you adjust the base resistor value for highest voltage?

Yes.
Mine is best at about 250ohm

A 100 volt output is close to lighting a neon. They usually need a little over 100 volts to turn on and then will run with only 90 volts once they are on. Just connect the neon between the two leads of the secondary coil. No rectifier or cap is needed. It works both ways

.

Thank you xee,

All this helps a lot.

btw, when jadaro asked for a pic of the wave across emitter and neg bat. I just touched the emitter leg. It was there I saw ??8 or so volts in a little ripple. And that is when I touched the base leg and saw 4.4volts.

Xee,(or anybody)  isn't this going to kill my transistor?  Why is it still OK?

thank you,

jeanna

[jadaro2600]

btw, when jadaro asked for a pic of the wave across emitter and neg bat. I just touched the emitter leg. It was there I saw ??8 or so volts in a little ripple. And that is when I touched the base leg and saw 4.4volts.

Xee,(or anybody)  isn't this going to kill my transistor?  Why is it still OK?

thank you,

jeanna

This is exactly what I've been worried about - ..the flyback is causing spikes which could theoretically damage the transistor.  In most industrial situations, the transistor is controlled with a cmos clock and is specifically timed to work as it should - we're mostly working without all of the control circuitry..

This isn't the case with the resistor moved between the coil and the base - in this case it's minimized, however, there's still fluctuations.

Removing the resistor all together is how I got my inductance driven transistor to work - whenever the energy flow from the positive to the collector attempting to get to ground, the co-wound coil has an induction in it, which activates the base, the basae turns on and then there power flowing through the coil to the collector and it's turned off - flyback in the other direction - it gets turned off, etc.  No need for and path from positive through to the base... here is a diagram, and a picture of it in action.  This isn't using a 2n222, I'm now using a more resistant NTE210.  There are two configurations shown - either works.

[jeanna]

Hmm,Jadaro,

What am I missing?

I cannot see a difference in the 2 pictures. I expected the cap to be in different places, but, I am not seeing any difference.

thank you,

jeanna

[TheNOP]

looks like it says "to puke generator".

it say "to pulse generator" for me. 

I have a DMM, and it has a diode checking mechanism ..which, when placed across the appropriate leads on a diode, gives me a number ( usually a less than one as a decimal, such a 0.671 ).  Is this number the voltage drop I can expect to see across it?

it is the resistance of your diode.
you can use your DMM on ohms settings to test if i am right.



@jeanna
4.4volts to the base is ok



@All
this give a fairly good understanding of transformers.
http://www.scribd.com/doc/9659415/Practical-Transformer-Handbook
take note of the differences between what is sayed to be "the appropriate way" and the way it is use in a jt.
those differences are crucial and are what make a jt work like it does.