Mathew Lippincott <[email protected]> wrote: > you can measure the capacitance of a wire to determine depth. here are > some plans, this device uses the changes in a 555's R/C circuit to measure > the capacitance change. > http://njhurst.com/electronics/watersensor/ > > here's some notes on replicating and simplifying that circuit to just > sample the output of the 555 directly (work in progress). > http://publiclab.org/notes/laurenrae/11-24-2014/don-explains-the-theory-behind-the-depth-sensor-for-the-riffle
I worked for a automotive vendor years ago that made fuel gauges, some of which used capacitance. However, most of their units used magnetic reed switches wired in parallel w/ resistors on a long tube-mounted circuit board. The float had a magnet that triggered the reed switches. The output is a step function but apparently accurate enough for most truck gauges. The nice thing about the design is it can be adjusted to account for irregularly shaped tanks. Magnetic reed switches at HobbyLinc: http://www.hobbylinc.com/htm/bra/bra3530.htm _______________________________________________ dorkbotpdx-blabber mailing list [email protected] http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber
