Joule Thief

[jeanna]

and Jesus responded with this picture.

PS My transistors were the @N type (American)

Bill

Thanks bill,

I saw that when he posted it. I missed the line with the code letters, somehow!!!

thanks to you for reposting and jesus for the original pic.

@xee2

I will check what I can. My meter doesn't have the good resolution.

I left my milliamp capable meter hooked up to a stubblefield battery under a tree for a week - ON - And it rained.  Pretty not nice thing to do to a very nice meter... It was also the meter that could read the Hfre of a transistor.    .

Thanks for this excellent information -- again!

@MK1

I see -- open ended.

I still haven't put the bridge in yet!!


jeanna

[WilbyInebriated]

@ All:

I just received a suggestion from my friend Hans Vonlieven, whom I suspect many of you know.  His idea is kind of similar to what Jesus has been working on, with a twist.  Hans suggested using a decent (but inexpensive) solar cell to replace our AA battery in the circuit.  Many of these are available form places like electronics goldmine for under $5.00.  Then, using our superultrabright leds, (like my 2 265,000 MCD units) we feed back into the solar cell this high intensity light output.  It may not be enough to run itself, although, if done right, I suspect it might be close, but think of the increase in duration we might get?  I am not even thinking of trying this outside.  I am already thinking about "jump starting" the circuit with an AA battery and then, somehow, switch over to the LEDs/solar cell for the main input power.  This could easily be done by using one or more supercaps.  (I knew these would come in handy)

So, we fire this thing up, and shine the LEDs directly into the solar cell.....and see what happens.  This thing might run for weeks and weeks....who knows?  I think what makes this all very possible is the advent of the very high output LEDs and the new supercaps.

I will try this as soon as I can get some cells delivered here.

Thanks Hans!

Wait, I can almost hear Jesus thinking........hey what if we did this AND hooked this up to a Bedini motor??
The possibilities are endless my friends.  I don't believe in OU so I don't think it will do that but, it may actually be able to close the loop and "self run".  Maybe?

Bill

this works bill. i did this about a year ago, however i could not get it to self run, but i did not reflect all the light from the led back to the solar cell, nor did i use 25000 mcd or 20 leds as some are running. i used a crappy solar garden light from harbor freight. it came with a joule thief circuit, no torroid, it used the little plastic coated inline inductors. basically i put the led(s) shining directly up and the solar cell about 4 inches above them supported by a clear plastic top from a dvd 50 pack, this lets some of the light out and gives some to the solar cell.

[timmy1729]

@Bill

http://www.exploratorium.edu/square_wheels/modulated_led.pdf

I was looking up how well solar cells work when powered by LED's and I came across this. It is transmitting audio using an LED and solar cell. How cool is that? 

[Freezer]

@ All:

I just received a suggestion from my friend Hans Vonlieven, whom I suspect many of you know.  His idea is kind of similar to what Jesus has been working on, with a twist.  Hans suggested using a decent (but inexpensive) solar cell to replace our AA battery in the circuit.  Many of these are available form places like electronics goldmine for under $5.00.  Then, using our superultrabright leds, (like my 2 265,000 MCD units) we feed back into the solar cell this high intensity light output.  It may not be enough to run itself, although, if done right, I suspect it might be close, but think of the increase in duration we might get?  I am not even thinking of trying this outside.  I am already thinking about "jump starting" the circuit with an AA battery and then, somehow, switch over to the LEDs/solar cell for the main input power.  This could easily be done by using one or more supercaps.  (I knew these would come in handy)

So, we fire this thing up, and shine the LEDs directly into the solar cell.....and see what happens.  This thing might run for weeks and weeks....who knows?  I think what makes this all very possible is the advent of the very high output LEDs and the new supercaps.

I will try this as soon as I can get some cells delivered here.

Thanks Hans!

Wait, I can almost hear Jesus thinking........hey what if we did this AND hooked this up to a Bedini motor??
The possibilities are endless my friends.  I don't believe in OU so I don't think it will do that but, it may actually be able to close the loop and "self run".  Maybe?

Bill

Check this video out Bill.  This guys using imhoteps radiant oscillator powered by a 1.8w solar panel, lighting up a 40w.  I also have a small 1.8w cell and will later give it a try with the camera circuit.
http://www.youtube.com/watch?v=WkheAYI2udQ

[jeanna]

I do think you should be measuring the AC voltage across the secondary leads when the circuit is running but the leads are not connected to anything except the voltmeter. You will find that this voltage sets the limit for how many LEDs in series will light when put across the secondary leads.

Another useful measurement is the AC ma current between the secondary leads while the circuit is running and the leads are only connected to the meter. This will give the maximum current available to drive the LEDs.

The volrage and current used by your LED array will always be less than these values.

I get 1.3 VAC across those secondary leads with the array unconnected.

My meter stonewalls me on the mA, as usual. bad fuse, no doubt.

Thanks,

jeanna