here are some links including one for a $6 float switch (no need to make it yourself for that price http://www.floatswitches.net/floatswitch.html?src=overture http://www.automationsensors.com http://www.naugatuckmfg.com/gallery/?cid=2 http://www.almegcontrols.com/multi-level_large_size.htm ----- Original Message ----- From: "Peter van Hoof" To: Sent: Wednesday, June 09, 2004 12:02 AM Subject: Re: water level detection, how? > Usually this is done with a reed contact/switch in a hollow tube (stainless > with closed bottom) and a round float with hole in the center around this > with a magnet in it when the magnet drops far enough it will activate the > reed contact. your pump has to stop. > > for this kind of application there would be two stops a bottom one to > prevent the float from falling of the tube > a top one to limit the floats top position so it just activates the reed > contact (and not allows it to go past it ) > > Hope this helps > > Peter > > > ----- Original Message ----- > From: "John Waters" > To: > Sent: Tuesday, June 08, 2004 11:35 PM > Subject: [EE]: water level detection, how? > > > > Hi All, > > > > I have a tank with a submersible pump inside, I want to stop the pump from > > running dry when the water level is too low, what sort of sensor could I > > use? I'm thinking of using a float with a magnet attached, the magnetic > > field will trigger a relay to turn off the power, does anyone get > experience > > in building this kind of thing and would like to share the experience with > > me? > > > > Thanks in advance! > > > > John > > > > _________________________________________________________________ > > Tired of spam? Get advanced junk mail protection with MSN Premium > > > http://join.msn.com/?pgmarket=en-ca&page=byoa/prem&xAPID=1994&DI=1034&SU=http://hotmail.com/enca&HL=Market_MSNIS_Taglines > > > > -- > > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body > > > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu