Joule Thief

[Mk1]

@AbbaRue

Thank for the transformer explanation, those results are however subject to other variables like the speed of the switching transistor
and the saturating freq of the core . regular transformer works on 60 cycle 120 in specific design , i wish it would be as as counting numbers , i my self can't replicate the 120v 60 per side , the core is bigger i get 27v per side , i dropped the turns from the primary and got lower results i lost 5 volts, i tried 500 ohm resistor and got 30 volts.

[Pirate88179]

@ Timmy:

Good job on the Kodak circuit.  Be real careful when testing with your multimeter and set it way higher than anything you think you might be getting or you will fry something in the meter or blow a fuse.  The think the Fuji puts out close to 400 volts and I don't know about the Kodak but, since you got bit, you know it is something in the high voltage area.  I have been real hesitant to hook up any of my meters to the Fuji circuit's ac output.  I don't know if the meters will read that accurately anyway, maybe someone else on here will know.

@ Jeanna:

Excellent work on the longevity tests!  30 leds illuminated for over 10 hours is a lot of light for what little energy you used up.  This is very good information.  Since I am almost caught up on my video production, I have been wondering around my place looking for stuff I can try to run from the Fuji or blow up, ha ha.  You mentioned motors.  The only decent size motor I have is in a blender and I am afraid that the output from the Fuji might burn up something in there and not run.  I do have a number of 12 volt computer fans lying about, I can always wire them together and hit it for a second or two.  I have some very small motors that I will try to run when my bag of 1" toroids gets here from electronics goldmine. (maybe tonight, I hope!!)  This shipment also has my solar cells that I can't wait to experiment (play) with.

I just got in several new cases so I am going to be busy again for a while but I will do what I can when I can.  Thanks for all of your efforts Jeanna.

Bill

[xee2]

@ jeanna

Battery voltage is not a good indicator of the amount of charge left in the battery.

An ammeter is a voltmeter and a resistor. Ohms law gives current in amps = voltage across resistor divided by resistance in ohms. If you put a 1 ohm resistor in series with the battery and measure the voltage across the resistor, then the current going through the resistor in milliamps will be equal to the voltage across the resistor in millvolts.

[gadgetmall]

Hello Gang . I thought i would show you an earth battery powering 2 Joule thieves . one on a bread board and one taped up that i gave to my little girl .The Earth battery consists of a 2 foot ling piece of 3/4 inch galvanized pipe and a 1/8 inch copper gas tube about a foot long . Both are about 10 inches apart with self taping screws holding telephone wire on them . It puts out 1.08 volts and i did not see hardly any current to speak of maybe 1 ma .. anyways its enough to light 2 jts at he same time .not very bright but about 20% and for Free light that is enough to see where your going in the computer room at night .they are wound 25 turns of2 strands of solid  telephone wire and Germanium transistors ..the leds are 10,000 mcd from goldmine electronics . 

[TheNOP]

I am wanting to know how many amps I am using because I don't have an ammeter.  I thought it could be done by calculation. sorry for foggy question.

I = V / R

get the resistance of one diode then measure the voltage passing trug it, each side of it.
or
add a resistance in series with your diode(s) then measure the voltage passing trug it.

do the volts measurement with your bridge rectifier, then add 1.414 to the value you get.

the current passing in the resistance is the same for all the diodes.