Joule Thief

[jeanna]

@ jeanna 

Photo is real. The AAA battery is a bit old by now.

Just straight off the battery? If so, what is the reason for using this flash circuit??

Just follow my last set of instructions. That is how mine is built. One of the leads to the large cap goes to the negative battery clip, so you might want to use that instead of the clip if you are not using a separate battery holder.

I will look for your last set. It prob. only 10 pages back or so. 
I will take note of the neg cap lead.
And is yours still working? If so how long? or is THAT what the picture is?

Did you get another 2 hours out of battery, or just the 2 hours you got last night?

I got a small response this morning on last night's battery. The neon flashed for 2 minutes. Then it stopped and I wasn't able to start it up.

One of the leads on I think the transformer was bent down and touching something next to it, and by the time I discovered and fixed it, I had changed to a fresh battery. 1.29V NiMH. This is what ran for 2 hours today with the diode and the trigger each shorted. The battery is at the same voltage. I think I broke something. I was fooling around and touched the xenon got a spark - the thing died. I cannot see anything wrong. The transistor has readings that look normal. But they may not be. I may have fried that transistor, I hope not.

jeanna

[xee2]

@ jeanna

The photo is with the AA Fuji board (using an AAA battery instead of the AA battery) with one of the leads to the tube removed.

Another building tip: If you do not have leads with small clips it is hard to clip to the diode lead. If you remove the insulation from a small diameter solid wire then loop about a 1 inch piece around the diode lead and twist it tight then you can clip to the wire. If you don't have a wire to use, you can use the wire from the twist-ties used to close bread wrappers.

[Pirate88179]

@ AbbaRue:

I tried another single wire test tonight after work.  I had already done the 100 led test so I tried for the entire 300.  They would not light.  I then tried 200 and they lit, although I would have to say at about (subjective) 30% brightness.  I have no idea what this means or does not mean but, that is what happened.  On all the tests I had to have my hand near the battery otherwise there was no light.  Also, I tested for polarity and it made a difference as well.  The LEDs would only light using the single wire from the pin on the transformer, not the lead from the clipped diode.  I hope this helps.

Bill

[jeanna]

@Timmy,

I must concur with jesus. As it happens I fried my joule thief torroid today. (I didn't even use the stove as Abba Rue did  ) but it was my opportunity to change the led to white from red.

I went through the whole thing changing the light and transistor checking polarity all the while. aargh it didn't work as a joule thief.

I had used the 3904. I forgot it doesn't work.

Well, I took out a 2222 and replaced this no good transistor with it. So, I had to do it all over again, this time with the 2222 that I traded with a 3904 on a breadboard. (I was afraid I didn't have one.- but I did.)

So, in the end I too have a new torroid joule thief with a 2222 and white LED. Ah such accomplishment!



jeanna

[Pirate88179]

@Timmy,

I must concur with jesus. As it happens I fried my joule thief torroid today. (I didn't even use the stove as Abba Rue did  ) but it was my opportunity to change the led to white from red.

I went through the whole thing changing the light and transistor checking polarity all the while. aargh it didn't work as a joule thief.

I had used the 3904. I forgot it doesn't work.

Well, I took out a 2222 and replaced this no good transistor with it. So, I had to do it all over again, this time with the 2222 that I traded with a 3904 on a breadboard. (I was afraid I didn't have one.- but I did.)

So, in the end I too have a new toroid joule thief with a 2222 and white LED. Ah such accomplishment!



jeanna

I am using the 3904 on all my JTs with the toroid and all of them light up one or more 10mm superbright white leds. (28,500 mcd's)  All of them work using dead batteries as well.  Maybe you guys used too heavy of a gauge of wire? (I used 22 ga. on a 1" OD toroid)  I have read that this makes them hard to start without the use of a magnet to help it get going.  The 3904 is fine for these and I will see how many superbright whites I can light from one later tomorrow.

Bill