Joule Thief

[the_big_m_in_ok]

freepow said:

I am attaching two joule thiefs that i,ve tried, both of these I used 2-AA i think, I could only measure just under 1 VAC with my digital multi-meter, should,nt it measure a good high VAC ??
I want to light a 240v - 4 watt fluoro with 1-AA, I dont want to use a disp-camera-circuit, any help with diagrams would be much appreciated, thanks.

Welcome freepow,
I recognise you transistor arrangement as a darlington transistor pair, thus:

http://en.wikipedia.org/wiki/Darlington_transistor
These are used as one transistor which act to increase current gain in an amplifier.  Good use of components.

For 4 watts from and AA battery, you might try taking a lot of 1:1 toroids with one side at 5-12 volts paralleled, and then wire the opposite sides in series to give 240VAC outright.  Adjust frequency for resonance as needed.  You might need that many toroids, or the feeble AA might not even light the lamp.

--Lee

[Mk1]

@all

I may have went a bit crazy here .

[freepow]

 :)Thankyou to every one for your help !
I have onle a few LED's so i dont know how many i can light, but with one JT of mine with a small toroid out of a CFL, I wound 6 turns bifilar on it and I get around 60 VDC, but I have not been very good with producing AC-Voltage as yet, I would like to use my ferrite toroid which is about one and a half inches diameter and use the transistors that i only have - which is a 2n3904 or a bc547 or 2n2222, and if someone can show me how to wind a primary and especially a SECONDARY on the toroid, so I can get some decent
AC-voltage from it, but i need the JT to work of course.
With one of my JT that have shoen yesterday on this sight, the LED only flicked on and off when i connected the battery, but when i added a wire from one side of the secondary and ran it to the collecter or base-cant remember which one, well I got it to light brightly, but the multi-meter only still read
AC-voltage of around 0.73v, i cant seem to get a nice 100 VAC or more, can someone suggest something with the transistors that i have and also the toroid that i have ?
Thanks to everyone.
Oh, also I cant find MK1's description of a way to measure your AC !
And i can get nice high volts of DC with that 1.5 inch toroid, but i need high AC so I can light my 4watter fluoro.
thanks for the nice photos and diagrams great stuff !!!
Hope to get some replys and diagrams thanks heaps.

[stprue]

@Stprue, first, I will ask a few questions.

You have 4 separate pickup wires made for each pickup. I mean instead of wrapping tha red pickup with 4 turns you wound it separately 4 times?
I am not sure why there are so many except they might go in opposite directions?

Also, you are not using the transistor base as a switch but instead you are using the emitter. Is that right?
I mean there is no resistor on the base of the transistor so there is no switch control at the base.
Instead you are controlling the switching at the emitter. I guess this will shut down the transistor in a similar way.

I will need to make and tune a big toroid for this.
Making it in the MK2x way.
I do not have one like that at the moment.

I also do not have those caps or that bridge.
I suspect you are getting a lot of your effect from this part of your circuit.

It is strange that it can light a neon but doesnot immediately blow a led.

jeanna

I have 4 total pickup wires maybe 6'' or 7'' long.  Each one is going in the same direction and wraped around the torroid 2 turns each.  As for the transistor I am using it to the best of my knowledge the regular way but I'm make 2 extra connections.

You should be able to use other bridges and get very similar results but you are right aobut the caps, especially the small ones! Very important!!!

P.S. I'm not killing the led beacuse my neon is attached and I'm connecting the led after the neon which blocks the cap surges.

[stprue]

:)Thankyou to every one for your help !
I have onle a few LED's so i dont know how many i can light, but with one JT of mine with a small toroid out of a CFL, I wound 6 turns bifilar on it and I get around 60 VDC, but I have not been very good with producing AC-Voltage as yet, I would like to use my ferrite toroid which is about one and a half inches diameter and use the transistors that i only have - which is a 2n3904 or a bc547 or 2n2222, and if someone can show me how to wind a primary and especially a SECONDARY on the toroid, so I can get some decent
AC-voltage from it, but i need the JT to work of course.
With one of my JT that have shoen yesterday on this sight, the LED only flicked on and off when i connected the battery, but when i added a wire from one side of the secondary and ran it to the collecter or base-cant remember which one, well I got it to light brightly, but the multi-meter only still read
AC-voltage of around 0.73v, i cant seem to get a nice 100 VAC or more, can someone suggest something with the transistors that i have and also the toroid that i have ?
Thanks to everyone.
Oh, also I cant find MK1's description of a way to measure your AC !
And i can get nice high volts of DC with that 1.5 inch toroid, but i need high AC so I can light my 4watter fluoro.
thanks for the nice photos and diagrams great stuff !!!
Hope to get some replys and diagrams thanks heaps.

You should be able to light your floro with hight voltage DC also.