_{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.