Materials
Mini breadboard6 candle-flicker LEDs (2 red and 4 yellow)6 100-ohm resistors2 NPN transistorsInfrared phototransistor5-kilohm resistorJumper wires3 AAA battery box with switch3 alkaline AAA batteries
Tools
Side-cutting pliersWire strippers
Instructions
This article originally appeared in the October 2015 issue of Popular Science, under the title “Build a Flameless Hack-o’-Lantern.”
