Joule Thief

[timmy1729]

@ Jeanna:

I think you just described the Darlington transistor arrangement.  Others can correct me if I am wrong but it sounds like that is what you are suggesting to hook up.  If only you thought of this 30 years earlier, it could have been named the Jeanna Transistor.  What I always wondered about the Darlington, not the ones you buy but the ones you make from 2 transistors, is why could one not make 3,4 or five transistors hooked together like this?

This just shows that you have good thinking skills Jeanna.  Good job.









Darlington transistor
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Circuit diagram of Darlington configuration

In electronics, the Darlington transistor (often called a Darlington pair) is a semiconductor device which combines two bipolar transistors in a single device so that the current amplified by the first is amplified further by the second[1]. This configuration gives a high current gain (written β, hfe, or hFE) and can take less space than two separate transistors because the two transistors can use a shared collector. Integrated circuit packages are available, but it is still common also to use two separate transistors.

The Darlington configuration was invented by Bell Laboratories engineer Sidney Darlington in 1953. He patented the idea of having two or three transistors on a single chip (and sharing a single collector), but not that of an arbitrary number (which might have covered all modern integrated circuits)[2].

A similar configuration but with transistors of opposite type (NPN and PNP) is the Sziklai pair, which sometimes called the "complementary Darlington."


Bill

@Bill
I had posted this same question a few pages back. I have used two separate 2n3904's in a Darlington config and have used a TIP-??? Darlington. The TIP gave me greater output than the separate transistors. Apparently I don't know how to make the 2n3904 produce an amplifying effect. Can anyone tell me how to do that?
I was thinking that 3 or more would produce more, but I'm not so sure since the 2-way wouldn't produce as much as the TIP.

@All
I was thinking(dangerous, I know) about using the pickup coil to run another JT, sort of. I was thinking about having a JT setup without the toroid; just the resistor, transistor, and LED. Then taking one wire from my pickup coil and hooking it to the collector spot, where one wire from the toroid would go, and hook the other wire from the pickup coil to the resistor. Would it work? Would it not work? Or would I fry some parts doing that? I just thought about giving the juice from the pickup coil a little "guidance."

Also, could I use the pickup coil as my AC power source for that "Tesla 1-wire trick" I posted last time? I don't want to mess with dangerous voltage since I don't know what I'm doing, but I'd like it to have enough juice to work if it will work.

[gadgetmall]

@all
here is an experiment i am doing using a very large toroid wound 4 20 t = 80 turns . battery is .90 volts it was drawing 11ma lighting all 4 leds . i put a capacitor across the pot i am using to adjust the Bias to base of germanium transistor and the current dropped to less than 3 ma doing the same job of lighting all 4 leds bright So now i have 4 leds running at 2.85 ma with a dead battery .just by adding a capacitor in this circuit .I can adjust the current draw to 1 ma and all 4 leds are lit approx 20 % bright . Very Interesting . I don't know of anyone who has a circuit that can light 4 white leds bright at less than 3 ma

[innovation_station]

next new coil 



i got soooo many coils i lost count 

ist!

what if ....   we made 2 in 1 

and  we made a NPN  JT  as we have been doing ..... on the ver   and  a PNP on the hoz..  and they were wound to repell 1 another


TURBINE WHAT ......    generator ?

how about this the first jt powers the second in this unit ...  could use a bit of help ...   guys... lol

hey if we did use 2 npn jt's could we not wind an alum pick up coil to pull inverted power from it ??

i just happin to have some real thick alum wire ...

kinda like first jt gets powered ... insted of the leds put output to steel wire ... then to led ... check to see that it works ... then to cap ... 

put a higher voltage cap there ... then use a 3055 off the bigger cap to power the next one wich would be the hor jt do the exact same thing with it but this time take the out from the steel wire from the inside ... feed it to the alum wire on the outside  then to your load .. 

what ya think ......

should i try it ??   

i mean i have already built it ... except the alum it only takes a min but the 3055 curcuit i could use a hand with i dont have many left ... ive been blowing them  a bit latley ... could just be a few bad ones tho ... im running low on em tho ...   

back to work ...

[timmy1729]

I bought these from a local company called "Airgas".  They are also national and on the internet.  I paid $20.00 for my carbon rod which is 1"OD x 18" long.  Or, was.  I have since cut it into 2 pieces 9" long.  let me know if you can't find them.  there may be cheaper places but last year I searched for a long time and this was the best bang for the buck.  Others wanted $100.00 for 1/2" OD x 6" long.  It pays to shop around.  these, to my understanding, are used in the welding industry as cut-off rods.  They may not be used as much as in the past which is why I had to order mine. I have also seen carbon welding rods which are copper clad.  These cost more and I think you would have to remove the copper which would be a waste.  PM me if you need a part number or website.  I don't have it handy or I would post it.  I can find it if you need it.  Actually, I think I looked it up for Timmy so maybe he can post it?  Carbon is basically pretty cheap so, do not pay too much here.

Bill

@Gadget
I'll try to remember to post the info in exactly two hours. It's exactly 9:30 and the IT dept won't let me check my gmail until 11:30. The wife was going to get me one for xmas but their online ordering was not working at the time and we ended up using the money for something else, so I still don't have it. But, she tried to order it and sent me screenshots, so I'll post the info in little while.

[gadgetmall]

@Timmy
thanks for the reply about those rods . If you get let me know . I found some 1/2 inch 1 foot long copper coated gouging rods at the local welding shop for 50 cent each . I pealed the copper off and left one inch on the top to solder wires on . I think they will do fine .. I found this place on the internet that sells packs of 100 for less than 30 bucks !you can peal the copper sheathing off .http://www.atlweldingsupply.com/Gouging-Rods_c_302-1.html