Joule Thief

[jeanna]

This is just a bit more. inspired by what ist just said, although I am not sure what ckt the comment was about??

I just changed the cap on the base resistor which is now 2.2k down from 4.7k (but it is the same for the following:)

Using 100pF the lights of the secondary dimmed a little, but easily seen change.

Using 10,000pF, the lights of the secondary brightened BUT the cost!! The amperage went up 10 times!

@Gadgetmail, you said there was some tuning involved and you ended up with the 68pF. The closest Radio Shack had to 68  was the 100pF and my next larger size is100 times greater and the use was 10 times greater.

The change went from 2.5mA with 100pF (it sez 101) across the base resistor, to 23.6mA with the 10,000pF (it sez 103)

With more amps there was more light. (I don't think 10 times more though) I think I will shut up for a while and wind a new toroid so I can make some planned changes. syl.

thank you,

jeanna

[Mk1]

@all

http://www.google.com/patents?id=srNUAAAAEBAJ&pg=PA1&dq=2548049&source=gbs_selected_pages&cad=0_1

This can be done on 2 toroid.


http://www.vias.org/eltransformers/lee_electronic_transformers_09_06.html

[gadgetmall]

OK I am glad you corrected me. Here is what happens.

On the secondary circuit (checking amperage when the lights are coming only from the secondary,) the amperage draw goes down with the cap across the battery.

I was playing around with some of xee's ideas last night and he had the light in the primary spot.

With the leds in the primary spot of the jt ckt, and the cap across the battery the amperage goes up. - or at least it did with the caps numbers I was working with.

I really want to keep the lights coming off only the secondary. This is where the free ride is, IMHO.

thank you,

jeanna

ok Jeanna > i got your Circuit with cap across the input 10volt cap ,tiny .. and it has been lit for 11 days now running 2 whites 4 reds one green and three rainbow Leds .. Its My Bedside Nightlight .   NOW  i also have My new Circuit with the larger 10volts cap drawing .81 ma running 4 white Brights .. running for  some 4 days now still bright and still running off a dead battery .  Ie (.90 ).. . So . I guess it really matters about the Uf . what Uf are you using  and what voltage .? It mat take a few minutes for it to stabilize by the way . mine didn't but during some cap input test if they are to low it takes a long time to charge to the battery level and thus heavy current draw .

[TheNOP]

Looking at the Fugi it looks like there is a heavier  gauge wire wrapped around the transformer about 10 or 11 turns // I want to get a toroid to do what that transformer Does  and do it with a JT . Then I want to Help Mk1 and IST on the mag amp cause what i see is it needs a pure dc source like a fugi charged cap circuit maybe  and an ac source like a Darlington circuit  JT  maybe .. .. Ramblings of a Mad Scientist   Maybe ?

get the resistance between each pins of your transformer, measure the wires size.
those values can be use to calculate the turns.

http://www.cirris.com/testing/resistance/wire.html

you can calculate the ratio too.
measure volts on primary then measure on the secondary.
divide secondary value by the primary value.

in the case of the Fuji transformer keep in mind that one of the coils is center taped.

the Fuji is not the only source for those kind of transformer.
you can find them in almost every electronic appliance.
computer PS, some printers, etc...
size and specifications change but you can always use the trick above to know how many turns are used in them.

[slayer007]

@MK1

I allso found this on yahoo about Mag-Amp Magnetic Amplifiers.

http://www.butlerwinding.com/elelectronic-transformer/mag-amp.html