Quote:
Originally Posted by Ether
A one-per-rev sensor may actually be a superior solution for this application.
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Here is another method for getting once per rev pulses: use a strong (rare-earth) two-pole diametrically oriented magnet as the target for a Hall effect latch sensor. One good magnet for this application is KJ Magnetics part
R424DIA. One good sensor IC is Melexis part
US1881. The typical 3-wire application circuit shown in diagram 13.1 on page 8 of the Melexis UA1881
data sheet can be implemented using a small piece of perf board, and mounted so that the sensor is about a centimeter from the target. The signal can be processed as Ether describes.
__________________
Richard Wallace
Mentor since 2011 for FRC 3620 Average Joes (St. Joseph, Michigan)
Mentor 2002-10 for FRC 931 Perpetual Chaos (St. Louis, Missouri)
since 2003
I believe in intuition and inspiration. Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution. It is, strictly speaking, a real factor in scientific research.
(Cosmic Religion : With Other Opinions and Aphorisms (1931) by Albert Einstein, p. 97)