A throwie is a small LED attached to a coin battery and a rare earth magnet.
In quantity, they are used for creating non-destructive graffiti and light displays.
Singly or in small quantities they are just fun.
You use them by throwing individual LEDs onto (ferromagnetic) metallic objects.
By throwing LEDs onto an object, the object itself acts as a canvas.
Throwies usually consist of a CR2032 or pair of CR2016s with an LED held across the battery with tape and a strong magnet. Very simple, no current limiting resistor, easy for kids to assemble. Lots of fun.
What are the properties for a good throwie LED?
Good things, possibly in order of importance:
- Safe (no exploding or burning batteries, LED can withstand being thrown, etc)
- Omnidirectional light
- Different colors
- Lasts a long time (days great, a few hours minimum)
While I know there is no right answer, I'd like to know the properties to look for and a range of the values that would make a good throwie.