Joule Thief

[gnino]

OK, I've reproduced the circuit as best I could with parts on hand. I used a 2n3055 transistor (thanks Bill!) and a 5-filar random toroid from an old PC PSU. Since I only have 5 windings I just eliminated one of the windings to the right of the bright bulb in your schematic. I used car tail-light bulbs, the lower-resistance filaments of the 2 in the bulbs. Other parts are as specified in the schematic.

The circuit works as I thought in the above post. It is "running" on the pulses drawn at high current, short duration, from the 4700 uF cap, which is being kept charged by a "trickle" of constant current through the dark bulb.

Ok thanks ,you look Whit the scope on it?

Ciao Luca

[TinselKoala]

Video:

http://www.youtube.com/watch?v=sLmQwtlqKWk

[TinselKoala]

Ok thanks ,you look Whit the scope on it?

Ciao Luca

After lunch.

[tinman]

OK, I've reproduced the circuit as best I could with parts on hand. I used a 2n3055 transistor (thanks Bill!) and a 5-filar random toroid from an old PC PSU. Since I only have 5 windings I just eliminated one of the windings to the right of the bright bulb in your schematic. I used car tail-light bulbs, the lower-resistance filaments of the 2 in the bulbs. Other parts are as specified in the schematic.

The circuit works as I thought in the above post. It is "running" on the pulses drawn at high current, short duration, from the 4700 uF cap, which is being kept charged by a "trickle" of constant current through the dark bulb.

I must be looking at the wrong circuit,as i only see a 120nf cap,and a 1uf cap?-no 4700uf cap,which would indeed change things to how you stated TK.

[TinselKoala]

I must be looking at the wrong circuit,as i only see a 120nf cap,and a 1uf cap?-no 4700uf cap,which would indeed change things to how you stated TK.

Confursed again? Have n't found the Louvre in Madrid, using your London map?

Tesla bifilar coil 512,340
Giving a schematic that does not show the correct component values, parts count and transistor part number,  is like giving a person in Madrid, a London subway map and expecting them to find their way to the Louvre.
Transistor mje13007
680 ohm resistor
0.1k 400volt capacitor across resistor
25 volt 4700 Uf buffer capacitor
Inductance unknown
Number of turn unknown old toroid maybe 30

in post 16380 above. My bad, I should have said "other parts in gnino's list" rather than "in the schematic". Except I see now that I used a 1K resistor, maybe that's why my lit bulb isn't brighter.

ETA: Yep, I changed to a 680R (actually about 700, tolerances you know) and the lit bulb is significantly brighter.