Joule Thief

[gadgetmall]

Wow. all i can say is WOW. now you all got me started again . I am winding a new coil !

[NickZ]

   Quote:
   " I worked all day off the grid in there and saw all the same effects using an antenna connected to my shed roof".

   Is your solar panel system also disconnected? 
   What current reading are you seeing. Is this just a voltage reading with no current?

   NickZ

[Magluvin]

How much voltage lives in the 10,000 uf cap during these disconnected operations?

Mags

[TinselKoala]

@lasersaber..... I'm not sure just what I've got! I hope you don't mind, I've named your circuit the "GhostLight" because of the way the LED will stay on dimly for so long with stuff disconnected, and how the circuit seems "haunted" sometimes. Spooky noises and everything, weird vibrations, tingling spines
.
I am using this term to refer to the schematic Stefan posted yesterday, with the bridge and the extra wire....

I still can't seem to find the HV but I did get all the other effects, as I noted before.

And also, my transformer is different so that might be why no HV for me... yet.

After I saw scratchrobo's video and thought about Hoppy's post a bit, I went ahead and removed the bridge from the GhostLight circuit and made another change or two... and got the thing working well as a low-voltage JT... but with a twist.

I've blown 2 x 2n2222 transistors and a white LED since starting with this thing, but not the 3055 yet. Have had some hot transistors when running on the 5v supply, but now  I think I've got this version stable.

Next will be to try to get a transformer more like the spec, and keep searching for the HV that is in there somewhere.

Here's a video I just shot..... a gang of thieves!
Still uploading, will be done in a few minutes.
http://youtu.be/LQe0In73pbY

[TinselKoala]

@Mags.... last night when I was getting the disconnected "ghost light" effect with the Earth ground and the dim LED for a long long time, I finally determined that there has to be some charge on the cap for it to work. If the cap is discharged by making some other contact somewhere, the light goes out and can't be brought back until some charge is put back on the cap. I think the energy in the cap is powering the light and the energy "from the Earth ground" is "enabling" or triggering the base current enough to start oscillations and drain the cap thru the LED.
I think in my case that it's the very small current between the Earth ground and the EM field of the house line wiring, coupled capacitatively thru my  body.
I don't know how big this cap voltage must be because when I try to meter it, it kills the effect, and because of the interaction with the house wiring I can't even scope it properly.

I have not taken things outside yet, but I'd have to go pretty far to get away from ambient fields, I'm in the middle of a residential 'hood with wires everywhere.

Now all of this has to be taken with a grain of salt because my transformer isn't right yet. But I definitely get the Ghost Light.