Have you looked into light gates? I mean they are used in mice all the time so they must be pretty cheap and if you have opaque fans they must work fine. OIf course you'll have to make a circuit and find a way to fit them onto the fans but hey its another option.
~ Boli
__________________
1800+ @ 2247 (214x10.5) - STABLE, 512MB PC3700 TwinX Cosair RAM, NF7-S v2.0, GeForce3 Ti200
Parallel BIM, 120.1 Thermochill, Eheim 1048, Maze 3, Maze4 GPU, "Z" chipset, 1/2" tubing, PC-70: 5x120mm & 9x80mm fans.
Internet Server & second machine (folding 24/7): 512MB DDR RAM, XP2000+
|