Homemade Easter Egg Anemometer:  In any wind generator installation, it's critical to be able to measure wind speed. That gives you a baseline against which to measure your machine's performance, and anemometers respond much more quickly to changes in windspeed than do wind generators. Commercial anemometers are very expensive and the operational concept is pretty simple, so we decided it would be cheaper (and MUCH more fun) to build our own! Plastic Easter Egg halves made ideal (and very colorful) cups.   (Circuit / schematic design added 6/06)

Low cost anemometer fights dust:  08/30/2001 EDN - Design Ideas / (Electronic circuit added 10/03)  As higher levels of power dissipation underscore the need for cooling, more and more fans are finding their way into small electronic enclosures. The dust that fans pull into these enclosures can, however, cause major problems for high-reliability systems. By coating heat sinks and electrically charged components, the dust acts as a blanket that raises the effective thermal impedance betw... .

Low-Cost Anemometer Fights Dust:  App Note 844: Maxim IC  (Circuit / schematic design added 6/06)

Self Heated Transistor Digitizes AirfLow:  03/14/96 EDN-Design Ideas / (Electronic Schematic / circuit added 4/02)  

Transistor and FVCs Make Linear Anemometer:  09/26/96 EDN-Design Ideas / (added 11/05) The basic operation of this front-end sensor is identical to that of the earlier circuit. Q1 is the self-heated airflow sensor; Q2 senses ambient temperature. Zero-adjust resistor R2 sets the zero-airflow quiescent bias currents for Q1 and Q2. With proper adjustment of R2, the temperature rise of Q1 from its collector power dissipation reduces its VBE (at a rate of 2 mV/8C) to just slightly below the sum of Q2's VBE plus the drop across R1. Comparator IC1A then has a noninverting input whose voltage is slightly less positive than the inverting input. Its output, therefore, goes low, holding C1 discharged and multivibrator IC1B reset, with its output high. This condition produces a 0V output in switch S3 and, consequently, the output of IC2....