CMOS Tri-State-Indikator (akustisch)

The disadvantage of most wind direction meters is the need for complicated mechanical drive systems which are necessarily prone to wear. The unit described here is intended to offer a solution to this problem. A disc which contains a number of slots is attached to the spindle of the weather vane. A light source is mounted above the disc, and a row of 3 light dependent resistors (LDRs) is situated below the disc -as shown in figure 1. Which LDRs are illumina-ted will depend upon the position of the disc, and therefore upon the direction of the wind.