Joule Thief

[Koen1]

@IST: what are you trying to do, exactly?
I see you post a lot on some kind of photo-sensitive component
or some other like a mosfet to use as a switch...
What are you planning to do with the switch that you can't do with
a transistor?
Can't you use a Reed/Reid switch?

@all: Is there a common goal to our tinkering here, at all?
It is clear we're all playing with Joule Thief setups and variations
on the circuit, but what are we trying to do, really?
Is the goal to light as many LEDs as possible on one AA,
or is it to light as many CFTs on one AA, or is it to get one nearly
empty AA to light many LEDs, or is it to get actual OU output
from a JT variation...
... or is it just to toy around with a small transformer?

The camera mods are all roughly related to trying to light fluorescent
tubes, the classics to lighting LEDs, but then there's IST and
MK who appear to have something in mind seeing their large
numbers of posts, but it is unclear what...

Anyone for making some sense out of the jumble of sidelines here?

[innovation_station]

right now im building an out door entrance light ... powered by 6 solar units from ramma i used 1 of my led boards .. i made 6 toroides from the cfl toroides .. they will be powered by the solar unts ...  each ring will power 9 superbright leds 

for a total of  54 leds 10 mm  my pocket blinder ....    might need your shades ..  the thing is 2 " thick there bouts ..

just put it where ever you want ...    this will last more than 24 hours....   

ist

[Koen1]

Ok, so you're planning to use the solar cell during the day
to charge your caps or a battery, then use that to power
several JTs with their array of LEDs during the night?

So the gain would be in lighting more LEDs from that
solar charged battery than would "normally" be possible?

I thought you were working on an OU JT but you're
working on a solar powered JT instead...
Or did I miss something?

[sparks]

The core of the torroids material has to be matched to the frequencies employed in the circuit.  The faster the circuit the less permeable the core material needs to be.  At real high frequency just the permeability of air is needed.  Magnetic amplifiers control the permeabiltiy or when the core material will saturate.  If the ac or pulsed signal to be controlled encounters a saturated magnetic core it passes down the circuit unimpeded.  If the core is unsaturated the voltage rise and fall converts into magnetic compression and rarification of the core material and the voltage wave is said to be choked.  What is real important to understand here is that dc current flow is a collisional thing.  Electrons bumping into other electrons and so forth all the way down the wire.  These randomized collisions are very inefficient resulting in heating of the conductor proportional to the amount of collisions necessary to get the job done.  Wheras a pulsed rise and fall of voltage transmits it's power as a wave through the conductor electric field.  You can have a dc current flowing in a wire and impose on this same piece of wire an ac signal that travels right through the same electric field or conductor.   It's like if you had a pipe full of water and you need some pressure down the other end.  You can do it two ways.  Build up some pressure at the pump against an open valve.  Or just smack the end of the filled pipe.  Either way you will see the pressure gauge down at the other end go up and down.   One is an inertial wave while the other is a resisted flow.  Which is more efficient?  RESISTED flow or inertial wave.  The best part about smacking the pipe is that the wave will do it's thing down the end of the pipe and turn around and do it at the other end you smacked for quite awhile while you take a breather.

[innovation_station]

im just finishing a few things i have laying around ... will post a pic to day of this unit ... 


yes solar recharged batteries powering a array of leds .... for the purpous of light ..


next is the same unit just as a cap charger or a battery charger that is on todays list aswell

ist