Joule Thief

[Pirate88179]

Mark:

Great point.  I shoot all of my videos on auto settings as well as my photos.  In the videos, you can see for a brief moment that my leds, or whatever, look very bright, but them they appear to dim.  This is just the camera compensating and adjusting the settings.  In some of my videos, I refer to this as ramping down.

It would be good to have a standard.  Someone suggest hundreds of pages ago that we use a light meter of some kind.  I didn't even know they made those any more.

Iam sure with all of the smart guys, and gal, here, we can come up with a good common standard.

Bill

[Mk1]

@bill

Even a LUX METER would need to be at a set distance and same ambient  light , it would be preferable to eliminate the last variable , so in the dark only.

But the cost of the equipment is prohibitive .

[jeanna]

OK,
While you have been discussing these things, I have been as well, but with a camera.
I first covered the screen of my computer, them stood the same distance away (as well as I could) then took these shots.
I was wanting to see-show the differences in brightness between the 34 leds in my (really mine) circuit, and the golden torus light (my replication of the one lidmotor gave my name)
There is a big difference in the quality of light as we know.

In one, I actually stepped away so we could see the amount of glow produced by the fluoro as contrasted with the leds. Some of the 34 leds are at full brightness and some are with the 10 ohm resistor at the battery stopping the amount of volts the jt has to work with.

Multi secondary full brightness
multi secondary 10 ohm brightness
the 'golden torus light' aka JLJL
jeanna's 2 lights = this is the one that shows the different amount of glow.

jeanna

[Mk1]

@all

The cheap way would be to compare the cfl to him self , with same camera  settings , and distance .

Cost would be reduced to buying a second bulb.

[Pirate88179]

Mark:

That is a brilliant idea! (no pun intended)  So, you are saying, we have the light in question hooked to a JT and next to it in the same photo, same camera, same settings, same time, we have the same cfl using line power at it's rated output?

I don't think we could find a better comparison that that without buying some equipment.

I will do as you suggest on my test of my Jeanna Light when I get it built.

Elegant solution Mark, well done.

Bill