Joule Thief

[Artic_Knight]

does anyone have a link to that SEC group?

[jeanna]

Hi everybody,
Last week I dug my old iMac out of a box and as of today I have a working running debian linux system!!! Whew. well, a few things are running right. I still have challenges, but I am so pleased.

@Gadgetmail, I noticed, finally!, that you are using a PNP transistor. I bought a few of those a couple of years ago but never used them. Is there some reason that you use PNP? or is it because it is a germanium transistor that you use it?

@Arctic Knight,
5 years ago I made a dozen little single led "candles" which I made with 47 ohm resistors and 2 NiMH batteries. They ran for 30 days. The first week to 10 days they were bright enough that it was hard to say they were using anything. I just want to caution you about conclusions, here. Leds are very interesting things, they actually TAKE less from the battery as there is less to take. Anyway, it makes making comparisons really hard.

[BTW there is a commercial fake candle made with 2 batteries but it uses a transistor to make a fake flicker. I have some of these which I got out of curiosity. They run very low in a week. They really only last Monday to Friday.  ]

@Slayer, Do you suppose you could put your scanner on a diet? I would like to see that all in one page. Please?

@IST, those are really nice looking coil wheels.
Did you put a wire through the center of the individual coils on their way to the larger ring?

thank you,

jeanna

[jeanna]

@all
here is an experiment i am doing using a very large toroid wound 4 20 t = 80 turns . battery is .90 volts it was drawing 11ma lighting all 4 leds . i put a capacitor across the pot i am using to adjust the Bias to base of germanium transistor and the current dropped to less than 3 ma doing the same job of lighting all 4 leds bright So now i have 4 leds running at 2.85 ma with a dead battery .just by adding a capacitor in this circuit .I can adjust the current draw to 1 ma and all 4 leds are lit approx 20 % bright . Very Interesting . I don't know of anyone who has a circuit that can light 4 white leds bright at less than 3 ma

Gadgetmai,

I have a couple of questions about this - not about the cap, but the coils.

Do they reverse at the 1/2 way mark? I can't tell from the pic. I think on this one you might have said it was center tapped, but not in the text of the page (p 200)

The other thing. Your circuit only draws 11 mA. The thing I kept noticing with the circuit was that there was about 23 mA draw no matter how many leds were being lit off the secondary.

So, I assume you will see the same effect. But your string is only drawing 11mA. I think your circuit is way more efficiect or powerful at less draw. I don't have a big toroid like yours, but I want to make a copy to find out what in your circuit has made it draw only 11mA?

the PNP?
the germanium?
The large diameter?
The 40 turns?

that is 4 things I can ask about. I guess the question about how you wound them is another.

thank you,

jeanna

[electricme]

@ gadgetmall
Nice circuit there, now lets see, you have what I think are 2 identical oscillators, the juice arrives at C3, which is refined by R3, the output Hz - frequency, is fed into another identical circuit, the output goes via to the base ot T1, the collector now hits the torrid with  frequency.

The 30 turn coil now picks up the collapsing magnetic field, and the "juice" is sent to the LEDs

Your circuit I think, but not sure is a beat frequency oscillator.

One frequency is beating against the other frequency.

jim

[electricme]

@ Gadgetmall
I got it, your riddle, ha ha good one.

Answer, his horses name is friday, as you said in the post, ie he rode in on friday.


jim