B.E.A.M.
BEAM is an acronym standing for :
Biology, Electronics, Aesthetics and Mechanics
last updated Mar 27, 2007

White LED : Make a Joule Thief

Parts list :

1 White led	ferrite ring : recycled from my junkbox	enamelled wire, 1meter : from hobby motor
1K resistor	NPN 2N3904 transistor	1.5 V battery (dead or brand new)

6 items :-)

Test drive the circuit on Breadboard  June 22, 2002

	First thing first. Kindly ask your hobby motor to donate his enamelled wire. There are 3 windings on each motor, unwind one of them : that should give you 1 meter of wire. This is great ! The hobby motor finally do something good for you :-)
	This ferrite ring was sitting in my junk drawer for decade !! I don't know why I saved it the first place :-) Fold the 1 meter wire in half, and thread the ferrite ring as shown 20 turns should be enough Scotch-tape the loose ends  (2 inches sticking out), then cut the wire to give you 4 ends (2 wires) file the ends lightly and solder pin onto the end (for breadboard use) mark the ends A1, A2, B1 and B2
	Circuit is here using 2 of 2.2K resistors in parellel to simulate 1.1K resistor white led 2N3904 +ve : coil A1 and 1.1K resistor -ve : 3904E and white led coil B2 goto 1.1K resistor coil B1 goto 3904B coil A2 goto 3904C 3904C also goto white led.......ready to go.......
	That's it :-) I do have a box full of "Dead" battery : AA, AAA and 9V !! Using 0.82V "Dead" AAA battery and the white led is "on" !!
	Using 1.583V "Brand New" AAA battery

Headlamp conversion      July 9, 2002

Major components : ferrite bead, white led, 2N3904 and 1K Ohms resistor	Oh, thanks to Mr. cheap motor for the donation of the enamelled wires (3*1m)
	I set the transistor, ferrite bead and resistor side by side. And it fits perfectly into my really cheap headlamp.
	Fold the 1 meter wire in half, and thread the ferrite ring for 20 turns, that should be enough
	The all sit into the little "seat" :-)
	not mega-bright for this one, but it is good enough to play with.

Basic concept :
Circuits quoted from :
http://www.emanator.demon.co.uk/bigclive/joule.htm
http://edusite10.tripod.com/led3/onetran/single_tran.html

9V battery with white leds

Constant Current Circuit @ 20mA for White led

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