Joule Thief

[oscar]

.... Tesla lectures ....

He says that it is not so much the frequency itself (in a certain application) but the rate of change of the frequency that makes the big difference - or big something.
.........
Still not sure what he meant.
Does anybody know?

Hi jeanna,

thanks to you and the other experimenters in the tread for your work.

No, I don't know (= am not sure) what Tesla means if he makes a distinction between "rate of change" and "frequency".

But I think that by "rate of change" he means the "speed of the change".

An example: the change between day and night repeats its cycle every 24 hours.
I would say that is a good comparison for a frequency.

But note that the "rate of change" is highest/fastest at dusk and dawn, since this is when the change from darkness to light actually happens.

So in spite of a slow frequency of a certain process, the "rate of change" can be quite high, if the change as such happens in a short timespan.
I sum it up:
"High (=quick) rate of change" for our purpose would consist in a "disruptive charge or discharge" which one could also call an impulsive change (as opposed to a gradual change for which the best example is a sine wave).

[gadgetmall]

this is an idea of mine that uses a new type of ceramic light tile . It Glows Bright Blue for 10-40 hours after it is exposed to light for 30 minutes. I bought a hundred of these glass ceramic  tiles from turkey called Curtisium and have them in every cfl and windowsill and even a few on the patio as walk lights . I might sell them if there is an interest ..the  blur is cause i forgot to turn the stabilizer on  in My camera .
. They all produce a Nice bright Blue light after you turn off the lights Makes it easy to see in the bathroom or bedroom lab .... . To My Knowledge they are not available now  unless you buy 800 dollars worth .
Gadget

[xee2]

@ adgetmall

this is an idea of mine that uses a new type of ceramic light tile . It Glows Bright Blue for 10-40 hours after it is exposed to light for 30 minutes. I bought a hundred of these glass ceramic  tiles from turkey called Curtisium and have them in every cfl and windowsill and even a few on the patio as walk lights . I might sell them if there is an interest ..the  blur is cause i forgot to turn the stabilizer on  in My camera .
. They all produce a Nice bright Blue light after you turn off the lights Makes it easy to see in the bathroom or bedroom lab .... . To My Knowledge they are not available now  unless you buy 800 dollars worth .
Gadget

Great info. Thanks. One inch square tiles are being sold for 50 cents each at this web site.

http://www.batterystation.com/curtisium.htm

[Pirate88179]

Gadget and Xee2:

Thanks for bringing these to my attention.  I HAVE to get some of these.  The website posted said....1 minute exposure to light gives up to 40 hours of light?  This sounds way more efficient than solar!  Maybe not all that bright 20 hours later but still.  Imagine a room tiled with these buggers.  Flip on a light for 1 minute, or open the blinds for the sun...and poof.....all the light you need for the next 20-40 hours.  Holy crap!  I need these.  Thanks.

Bill

[Pirate88179]

Gadget:

I just had an idea! (maybe)  Get a bunch of these and superglue a small magnet on the back.  Folks that go camping can stick a shitload of them on the car roof while traveling to the campsite.  Leave them on the roof until dark and then, have all the light they need the rest of the evening!  I imagine like 30 of these in a tent would be some pretty good light.

Bill