THE LAB
LED Tossers
Having a house party and in need of some cool decorations? Need to jazz up
your bedroom? Then here is a bright activity idea for you… literally! These
“tossers” are a great way to decorate any metallic surface.
Materials:
•
•
•
•
10mm Diffused LED – You can get them in all sorts of colours so mix
and match: red, blue, amber, green and white. Try to get diffused
rather than clear lights
CR2032 3V Lithium Batteries
1-inch wide Strapping Tape
1/2" Diameter x 1/8" Thick NdFeB Disc Magnet, Ni-Cu-Ni plated C
What’s a LED light anyway?
LED is an acronym for Light
Emitting Diode.
LEDs are semi-conductor
diodes which allows current (electricity) to flow from the negative (anode)
end to the positive (cathode) end. The colour of the emitted light depends
on the composition and condition of the semiconducting material used (for
more information on LEDs, check out the article on the movie Click, in The
Studio section)
Instructions
First thing is to make sure that your LED works. To do this, pinch the LED
leads (the wires coming out of the light), to the ends of the battery. You will
notice that the LED has a longer lead
LED Light
(anode) and this should touch the positive
end of the battery. The shorter lead
(cathode) should touch the negative end of
the battery.
The positive side of the battery actually
has a larger contact surface than the
negative end. This is because the positive
end extends around the sides of the
battery. Be careful that the cathode lead of
the LED doesn’t touch the positive end of
the battery or it will create a “short”,
causing the LED to function improperly.
Short Lead
(cathode/positive)
Long Lead
(anode/negative)
+
3V Battery
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THE LAB
Next, cut off a piece of tape (about 1 inch wide and 7 inches long) and tape
the LED leads to the battery. Make sure that you wrap it around tightly a few
times leaving some of the tape for the next step.
Then, place a magnet on the positive
side of the battery. Continue to
tightly wrap the tape around to hold
the magnet and battery in place.
The LED tossers are ready to be
(gently) tossed onto a ferromagnetic
(i.e. a normal magnetic) surface –
like a fridge, car wheels, walls, etc…
Your tosser should last around 1 -2
weeks.
Magnet
3V Battery
Some special notes: Remember to keep the magnet away from common
storage devices like hard drives and credit cards.
Why?
ATM cards, credit cards and hard drives are magnetic storage devices (in
fact, that black strip on the credit cards that you run your card through the
machine is actually called a magnetic strip). They store information based on
a pattern of magnetic particles. When you place another magnet near by, it’s
magnetic field (moving electrical charges that attract and repel one another)
disrupts the order of the magnetic particles, causing the data to be
destroyed.
References:
CLICK on Science ...The Workings of a Remote Control, CRAM Science
http://www.cramscience.ca/es.php?a=46
Holiday Shopping...The Science of Debit Cards, CRAM Science
http://www.cramscience.ca/es.php?a=93
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…fill your mind.