How I would try this is to use an infrared thru beam (if this is possible) and measure duty cycle , use a lookup table to convert to degrees. Peter van Hoof ----- Original Message ----- From: "Marcel Duchamp" To: "Microcontroller discussion list - Public." Sent: Wednesday, November 17, 2004 6:04 PM Subject: Re: [PIC] All PIC problems solved ? ...hmmm, here's one > Jinx wrote: >> I need to measure the variable angle (19-32deg) of a turbine >> blade in real time. Turbine is spinning at ~ 3000rpm. > > -snip- > >> Any other suggestions ? > > One way of doing this is to fix a reflective surface on the moving > element. Then a beam of light is used to reflect off the surface and > measure displacement which when calibrated can be an indication of blade > angle. Careful calibration is a must but it does work. In the case of a > rotating blade, you will get a chopped signal but that's something for the > signal conditioning electronics to work out. > MD > _______________________________________________ > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > _______________________________________________ http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist