Joule Thief

[WilbyInebriated]

Perhaps take a compass in the other pocket because you want soft iron, and soft iron loses its magnetisation after the magnet moves away. So make sure the magnet sticks then when the magnet is moved away, make sure there is no pull on the compass.

I'd say if there is something that is cheap and soft iron and comes insulated go for it.

Also, Jim has mentioned nail polish several times. I think that would work too. I read in one wire brochure that there were many layers to the varnish on the mag wire.


jeanna

nail polish works well, super corona dope works good also.
http://www.mgchemicals.com/products/4226.html

[timmy1729]

@All
Well, I decided to experiment with the windings on my big toroid.I think the outer diameter of it is 1.125". I've got a pretty new spool of 18 gauge solid copper wire and some magnet wire from a kid's electronics kit(Hey, they're a good intro to the basics, even if you're 29). I fit 18 turns of the 18 gauge wire and about 38 turns of the magnet wire. I'm thinking it's like 30 gauge or something. I will make a JT of it in the morning. Right now, I need sleep and it's about 1:45am here. It's cool, though. Tomorrow is my off Friday. We get every other Friday off(80 hours over 9 days, though). So, I'll have time tomorrow to play with my JT toys 

[jonnydavro]

@ electricme.My joule thief (1st one i have ever made)is made with 10 bifilar turns off bell wire on a ferrite identical visually to one i think it was pirate was using.The voltage output off my joule thief by itself i think will be far below what some off you guys have produced its just that i am using the output i have very efficiently.The rotor i have spinning triggers a reed switch which discharges the cap through the coil which then pulses the rotor.I am not using a stepper motor.I am also collecting the bemf from the coil but have not had time to play with that yet.Another thing,the rotor which weighs over 20grams(each magnet is 5g + the mini cd)is mounted on an unconnected dc motor as the bearing,this is producing a voltage aswell so more possibilities there.
The capasitor i am using is 60000uf but you can use one a lot smaller i tried a 4700uf and it worked fine,,just not as fast and with a shorter run down time after the battery is removed so what i am saying is you don't need a massive cap to run a pulse motor if anyone else was thinking about replicating.One other thing,after making the video i left the motor running and the cap climbed up to 4.5v and the motor was nearly turning into a helicopter so i pulled the plug and the rundown time i estimate was over a minute,but i will have to time it next time as it caught me by suprise it was so long.Anyway plenty more to come from me on this yet.
                                                                                Regards jonnydavro
                                                         

[gadgetmall]

@all
It was lack of sleep.. the voltage on the battery did drop  to 2.148 this morning indicating more current in than out , sooooo I will do more test with a twin unit when the proto board comes in hopefully today along with a couple super caps. I did notice an increase in voltage with the feedback circuit of .015 volts in steps  for a brief period of 1 day .it may be that i am using one of those rechargeable Alki Eveready's recharged with a Bedini .this is evident in a replication if you do one . R1 is 10ohms r2 is 200ohms d4 and d2 are 1n4001 d3 and d1 are low power Green leds .r3 is 1 k c1 is 2200 uf 10v q1 is unmarked from a very old camera shutter circuit and u can use anything there with low power hi gain . germanium prefer and the toroid core is from PC power supply .medium size  I discussed the winding in previous posts. I will make it My part of this experiment  to further this experiment to prolong /sustain the jt with more accurate measurements of current and volt input VS  output and Time  when i get the proto board..including a Schematic  of each . as the led will light in various places as you can see.I think it is possible to decrease the current input to a point where the output windings rectified can feed more out than in . it may take more than two secondaries  at x amount of turns and X size wire or a second transformer .. Also will hook up the 555 to control the frequency ..l8r..

[electricme]

@ jonnydavro
Thankyou for the circuit and it's explination, well done.

About your UTube video (I had to go to another PC to view it) I can see the big coil, is it a single coil, or bifilar? the reason for me asking I car'nt see it on your circuit you posted.
I saw the 2 identical multimeters, that is excellent pre thought, displaying several bits of electrical info at once is wise indeed.
One can see at aglance whats happening.

I noticed you  mentioned there were magnets mounted on a mini cd, a safety flag went off in my head.

If this disk gets up to high RPM as you say, better make sure the glue used dosent let go and the magnet dosent fly off, if it did, it could do a bit of misschiff it it hit something. I suggest you get another mini CD and afix it to the top of the magnets, giving some extra support, and mabe put a steel band around the circumference to help absorb any shock from flying magnetics. If a magnet hit your big coil.......

One other thing, I know I might be harrping on safety here but I have seen the results of accidents, and I refer to a balance problem, if one magnet goes a-stray, that leaves a tremendous force trying to tear the rest of the spinning disk apart, (like loosing a lawnmower blade) it could "take off" in any direction
HEAD for da hills ha ha, wheres ma tin hat, duck unda de sofa.

I am intriged with how you are switching the back EMF and supplying this energy back into the battery, but I cannot see the reed switch you mentioned shown on your circuit, could you repost the circuit with the alterations please.

That said, how about using this modification suggestion instead.
Make a metal disk, (or use a mini cd disk) drill 4 holes (or file slots)  at every 90 degrees through this disk, then use a infrared diode and receiving diode to register pulses, feed the pulses to a MOSFET, put several 75v zenner diodes between S & D so the EMF pulse wont destroy the Mosfet.

This will take away the danger of flying magnets as trigger pionts to collapse the coil, which produces the  BEMF pulse, but I realise the phisical make and break of points is a key to making square waves, which is happening with this circuit, so I dont know..

Every old printer has these LED proxmidity devices to stop the ink cartridges from crashing into the side of the cases.

I just thought of another mod to this, get another CD motor, put it upside down on the original, (shaft buts up onto shaft) with CD between them.
How? get a  6" nail, drill right through the middle, slip the 1st motor shaft halfway in, slip the upside motor shaft in, and use locktite.
Pirate (bill) could help you with tollerances, you wil have to take my word on this.
This will give you double output, when you do get around to using the power both motors make. 

Ohhhhhh should I go to sleep tonight? This thread is awsome.

jim