1+ 2+ 3 LED Throwies
By Graffiti Research Lab
Make and toss a bunch of these inexpensive little lights to add color to any
ferromagnetic surface in your neighborhood.
You will need:
10mm diffused LED, any color(s) 20 cents each from HB ½"x1" NdFeB disc magnet, Ni-Cu-Ni plated
Electronic Components ( hebeiltd.com.cn). 25 count for $13 from Amazing Magnets
1" strapping tape ( amazingmagnets.com).
One roll will make many throwies. Conductive epoxy (optional)
CR2032 3V lithium batteries Weather-resistant alternative to tape. Available from
25 cents each from CheapBatteries.com. Newark InOne ( newark.com).
1. Test the LED.
Pinch the LED’s leads to
the battery terminals,
with the longer lead
(the anode) touching
the positive terminal
(+) of the battery, and
the shorter lead (the
cathode) touching nega-
tive (-). Confirm that the - +
LED lights up.
3. Tape the magnet
to the battery.
Place the magnet on the
positive terminal of the
battery, and continue
to wrap the tape tightly
until it’s all done. The
magnet should hold
firmly to the battery.
That’s it — you’re ready
to throw (or make a few
dozen more). Throw it
up high and in quantity
to impress your friends
and city officials.
2. Tape the LED to the battery.
Tape the LED leads to the battery by cutting off a 7"
piece of strapping tape and wrapping it once around
both sides of the battery. Keep the tape very tight
as you wrap. The LED should not flicker.
NO TE: The battery’s
positive contact surface
extends around the sides
of the battery. Don’t let the
LED’s cathode touch the
positive terminal, or you’ll
short the circuit.
Throwies naturally chain
together in your pocket,
making multi-segmented
throwie bugs, which will
also stick to metal surfaces
if they aren’t too long.
A throwie will shine for about 1-2 weeks, depending on
the weather and the LED color. To get one off a ferromagnetic surface, don’t pull it, or it may come apart.
Instead, apply a lateral force to the magnet base, and
slide it off the surface while lifting it with a fingernail
or tool.
Graffiti Research Lab ( graffitiresearchlab.com) is dedicated to outfitting graffiti artists with open source technologies for
urban communication.
