Joule Thief

[nievesoliveras]

My apologies to everyone,

I appear to be hopelessly confused about the transistor symbols. I don't know if I will ever be able to clear it up.

Anyway, Jesus, your first drawing was correct.

The emitter goes to the neg of the battery, and the symbol is as you had it. Of course, you were right.

(In a little explanation, which none of you need, of course, it all started after the second lesson 5 years ago. I was fine with following electrons around a circuit, but, all of a sudden when the explanation started with transistors, the current was changed to conventional current and I was now supposed to follow the protons going around the circuit and the symbols and their wonderful arrow pointing the way had to be reversed  and Oh my goodness.... )

So, again I apologize.

The Emitter goes to the negative!! whatever that looks like!

jeanna

Yes, jesus, you may delete the wrong drawing.

Lady @jeanna

I left the drawing posted with a warning that if they do something wrong is not your fault, because you asked me to delete it. Because there is no harm to the circuit by inverting the collector and the emitter if the connection is to the negative.  The transistor will just let the electricity pass when is triggered by the positive input to the base.
I have used a NPN transistor to manage the positive electricity and it has worked perfectly. What it does not do is to get triggered by a negative signal to the base.

Jesus

[gadgetmall]

Yikes! I gotta catch up!

Jim, There is a website called treehugger, I think, where the good folks there used a hamster wheel connected to an induction generator to run the lights for the hamster room. pretty funny. Maybe your mice in a cage could be put to useful work? 

@jesus, Thank you for making the change and yes, it was a good idea to mark the ends. It is most likely because I am a noob at these things... I cannot find it today, but yesterday I found a site that explained that the voltage mattered more on the collector? was it? I wish I could find that reference today, but see, it makes me think it is the reason our voltage spikes from the toroid are able to do what we are finding. I think in that reference he said the E was affected by current, and the C by voltage - but I may need to edit this if I am wrong.

So, since there is a reason to believe there may be a difference, thanks for posting it as I have actually put it together.

@xee,  I  have it connected so the E is going to the neg- of the battery.

@MK1, I have a 2N2222 so I will be trying this with my breadboard circuits, and I will be back about it.

Well, if you are using the secondary to make the lights, I can. I had 30 lights where the total was 23mA so divided by 30 that is 0.76mA each. or 766uA each.

So, gadgetmail, please give a couple of details, how are they wired to be turned on? If they are a part of the original jt circuit, this is a really big difference and you are putting us another big step forward!!!! yeay!

thanks,

jeanna

But I think

OK I measured the total ma draw in series with the battery . 2.85ma   divide by  4 = 0.71 ma per led  . I used 4 windings of 20  all in series center tapped at 40 total 80 turns normal JT no secondary .. It is a Large Green Toroid . and yea i believe from what i have read that this is a step forward . it is still going . i wont touch it until it is dead but that could be a very long time as the voltage is still .90 full bright and 2.84 now . i guess its a little cold in here so the components are just a bit different . WOW . 90 Still .The only mod to the normal jt circuit that made it draw less and put out more was the little non polarized cap marked 680 ,across the variable resistor . ok the variable resistor has three legs . i use wiper and on end for adjustments and put the cap across the resistor part the two outside legs . Does this make sense ?

[TheNOP]

@resonanceman


you could try it as a replacement for the 3904 but i don't think it will start the jt.
IRF510 gate threshold is  2 volts min, 4 volts max.

you might like to try with xee2's Darlington scematic
http://www.overunity.com/index.php?topic=6123.msg153736#msg153736

just make sure the IRF510 gate is not feed more then 4 volts.

[jeanna]

@jesus,
That is a fine solution. Thank you.

center tapped at 40 total 80 turns normal JT no secondary
...
green
.....
The only mod to the normal jt circuit that made it draw less and put out more was the little non polarized cap marked 680 ,across the variable resistor . ok the variable resistor has three legs . i use wiper and on end for adjustments and put the cap across the resistor part the two outside legs . Does this make sense ?

I have to try this. I was never able to get 4 lights on my single jt without the secondary... I think, maybe I never tried. I will see in parallel I doubt it is possible in series, so you do have more in a couple of places, I think... wow!

I think you have wound many more turns as well. But you say the only thing that made a difference is the cap

oh boy, this is extra cool because of something I think N Stubblefield did. ...

So, this cap sounds like a 68picofarad cap ? 680 I think that is 68 with no zeros and measured in picos. Is that right?

excellent... stepping forward.

About the resistor, if you measure with your dmm set to ohms, one the base of the transistor and on the other place where it connects to the battery, you should be able to read exactly what the resistance is.

I am curious, what is it?

thank you,

jeanna

[innovation_station]

Lady @jeanna

I left the drawing posted with a warning that if they do something wrong is not your fault, because you asked me to delete it. Because there is no harm to the circuit by inverting the collector and the emitter if the connection is to the negative.  The transistor will just let the electricity pass when is triggered by the positive input to the base.
I have used a NPN transistor to manage the positive electricity and it has worked perfectly. What it does not do is to get triggered by a negative signal to the base.

Jesus

so should it be called npn and ppp   lol


no way you could draw it up eh?   useing to npn  trannys to switch ..  both??

would be a great help 

ist 

now were cappin the gap lol 

the old cut the input way back trick