Joule Thief

[mscoffman]

I just want to show you all that it really IS possible to get a real amount of light from a jtc light.

I have 2 pictures of the same lamp with the same UNmodified LoA light bulb. They are very close in brightness. The transistor I used was a TIP31c and the whole circuit is in the box, as you can clearly see it being lit by the light itself. I have turned off all other lamps and closed the door.

Jeanna;

This is a good comparison but you should include a reference light fixture operated
from utility power in both photos as your cammera may compensate for differences
in illumination using an AGC automatic gain control. I believe what you are saying
though. Saves a lot of wondering.

:S:MarkSCoffman

[crowclaw]

/quote]
Hi stprue,
Yes... may be that accounted for the doubled up photo's!! can also confirm that the results are fairly consistant using a Whisky bottle... before and after.
If the experiment doesn't work out for any reason I can guarantee you'll feel very warm inside.
BTW it works just as well without the bottle of course. Thanks for the reply.

[xee2]

@ ist

What other parts are needed?

[xee2]

the magnet ..

Where does the magnet go? Should I make it a small cube magnet, a disk magnet, something else?

[jeanna]

Jeanna;

This is a good comparison but you should include a reference light fixture operated
from utility power in both photos as your cammera may compensate for differences
in illumination using an AGC automatic gain control. I believe what you are saying
though. Saves a lot of wondering.

:S:MarkSCoffman

Well, this is the same light powered by the 2 different sources.
I cannot do another light without adding a lot more variables.
In fact this is a great suggestion but at $10 a pop for the lamp shade of any material I went for the silk and the best brightness, but there was only one silk one the other day.

I figure the camera compensates in the same way for each situation since it is the same bulb and I assume the IR from the same bulb will not change from the jtc and the wall, but um....
Even with extra light in the room the camera can compensate.

The picture where the lamp is plugged into the wall outlet (utility power)  is a little brighter which you can see best by looking at the underneath side of the bulge in the green lamp. There is more ambient glow from the room that is reflecting back in that shadow.
That is about it, however.
The 2 lamps on 1 plug are showing what is probably the maximum light possible from that circuit, since it is brighter all together, yet each is dimmer than if either bulb is on alone.

Thanks for the suggestion.
When I go back with a pocketful of change, I will be getting another silk shade for the matched thrift store lamp. Hopefully this style has not been discontinued!

jeanna