Joule Thief

[Mk1]

@all

This has nothing to do with the joule thief, but its a must see , it will challenge your mind.

http://video.google.ca/videoplay?docid=1285345463618889531&ei=umZCS-K-D4balQex0ODRDw&q=lloyd+pye&hl=en#

It is 2 hour but really worth it !

[crowclaw]

@ Jeanna

At 1.5volts probably a lot less voltage as it stands... it was only a quick hook up  for further trials depending on received interest. Mosfet devices have different operating characteristics as you are probably aware, as an example a BC547 small signal transistor gave an  output of 100volts at 40Ma for 1.5volts input using this same toroid. Mosfet devices are ideal in power circuits due to their very low turn on resistance so less heat generation at higher currents. Perhaps another thread is required for ideas using alternative circuit ideas, devices and supplies?? 

[jeanna]

Perhaps another thread is required for ideas using alternative circuit ideas, devices and supplies??

Well, I do not think so unless the basic elements are changed.
The single battery is one and the center tapped primary (the bifilar ) winding is another.
Using pulses to create volts is an underlying element in a joule thief.
Experimenting with other types of transistors, adding, subtracting caps etc is all within the range of the joule thief topic. afai think anyway.
(I personally want to keep this as utterly simple as possible.)
At the moment it IS very simple.

Since we are not powering our houses and running motors, there is room for more.

Thanks for the contribution, and also,
thank you for the numbers you got with a single battery.

100v on the C-E junction is quite high.
I usually see about 10v.
So with 10 times the output at only 40m amps draw this is impressive.

I wonder how a secondary will do.
Did you ever make the secondary and look at it?

thank you,

jeanna

[xee2]

@ crowclaw

See photo's.

Nice pulses. I think they are more usable than the rather sloppy JT pulses. I can think of a lot of things you can do with that output. It looks like positive and negative currents are well balanced, so it should drive a voltage multiplier. I would suggest adding a pickup coil to see what voltage you can get. And also see if it will run on 1.5 volys.

I assume you just replaced the JT transistor with the fet, but a diagram would still be good.

[xee2]

This is a circuit I posted on the New Jewel Thief "Resonate LCR Circuit" Much less energy draw.... thread started by sirmikey1. There is more information there about it.

This circuit uses only 0.1 mA to blink a neon or LEDs. A 1.5 volt "D" cell flashlight battery is rated at 12,000 mA-hr. Dividing 0.1 mA into 12,000 yields a run time of 12000/.1/24/365 = 13.7 years . Of course the battery will probably leak before that. If using LED also use a 1N4007 diode in series with the LED to prevent the LED from being damaged by the reverse voltage.

Three videos of this circuit on YouTube at:

http://www.youtube.com/watch?v=uKEPhnCxsqw
http://www.youtube.com/watch?v=xc_PGdwTTEc
http://www.youtube.com/watch?v=TpMmvY4JOpE

NOTE: It is not really a Joule thief, it is actually a relaxation oscillator.