A bunch of years ago I bought a water detector type kit for a science project... It has since disappeared and I was wondering if someone has a schematic of how I could go about building such a thing. Now that I'm going to be moving to the basement I'd like a bit of advanced warning should something spring a leak.
Thanks in advance!
-Dan
A construction project years ago used one of the "TV Clothespins" that were used in TV shops to connect a TV antenna to your TV. They put an aspirin between the jaws. If it got wet it dissolved, and the jaws shorted out.
-- Michael A. Terrell Central Florida
going
Thanks for the idea.. it certainly is decidedly low-tech... the problem is that would probably require quite a bit of water.. I'd want something that even if the concrete got sufficiently damp would set off the alarm.
Thanks though :)
going
That's nearly as low tech as looking to see if your socks are wet after you have been in the cellar. Good solution though.
a
Blotting paper permeated with NaCl sitting on floor with an electrode at each end. Use the electrodes to trigger whatever.
going
I made a lawn sprinkler - rain detector some years ago. I still use it. I used a small circuit board (2"x2") with the copper removed about 1/8" down the middle. A wire connected to both sides, created the sensor which I attached to my fence outdoors. The sensor goes to a comparator (LM741) and that output pulls a small relay whose contact interupts the 24 VAC to the sprinkler valves. Works great, but I need to make new sensors every other year, they tend to corrode. I was going to try two stainless steel screws, mounted on some sort of insulator, but I never seem to fing the time! I can post the schematic if you need it.
can
Hi Scada, That would be greatly appreciated! How do you power the comparison circuit itself? I guess I'll see in the schematic.
Cheers, Dan
ps. If you can't post it on a website (since this is a non-binaries group), you can email it to: signups (a.t) rogers (d0t) com. Thanks!
Good idea, but isn't NaCl slightly hygroscopic and would either take up atmospheric moisture or fail to fully dry out after rain?
How about something that's both ionic and efflorescent? - any chemists out there?
--
Then there's duct tape ...
(Garrison Keillor)
nofr@sbhevre.pbzchyvax.pb.hx
Yeah, I remember the aspirin trick. But they must've bent the jaws somehow, because they don't normally touch, just come close. I think the one I made used two 4-40 panhead screws thru holes drilled thru the end of the clothespin.
But in reality, what good is a clothespin going to do? It sets off an alarm, and then what? You either have to start getting rid of the water, like with a sump pump, or else start moving all the stuff to a higher level or out of the basement. And there's a good chance that you or someone won't be around when the alarm goes off. :-( So the thing that makes the most sense to me is to use a pair of sump pumps, on separate electrical circuits. At least one will work if the other fails.
Reminds me of the time the plant mgr and I went up on the roof of the
4-story bldg to replace the sump pump. I walked thru the air conditioning plenum door into the plenum, and stood on a metal grate with a lotta air coming out of it. I looked down, and WHOO-HOO!! I don't like it here!! This 1 inch thick grate was all that was between us and a sheer 60+ foot drop straight down thru the middle of the bldg! Whatever you do, do NOT drop your keys here! Or anything else for that matter!-- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/electronics/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
You could use a interdigitated pattern on a PC board, and connect it to a couple transistors to boost the current. But it could have reliability problems, like when a bug crawls over the pattern and shorts out the fingers. Probably a better way is to sense a change in capacitance caused by the liquid.
-- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/electronics/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
Thats actually a good idea. Are there any capacitance detecting circuits out there that won't eat through a battery though?
Regards, Dan
Fred -
I was thinking that since the blotter paper was so inexpensive, it would be a one use throw away. As to atmospheric moisture...hmmm...I didn't really think about that :-( The only way I can weasel out of that one is that most homes (at least in the US) have the central heater in the basement so moisture in the air shouldn't be too much of a problem...I hope....I hope....I hope.
Water runs uphill where you worked? Neat trick :-)
--
Then there's duct tape ...
(Garrison Keillor)
nofr@sbhevre.pbzchyvax.pb.hx
In article , snipped-for-privacy@rogers.com mentioned...
What do you expect the output of the detector to do? If you want it to hold in a relay, then the batteries wouldn't last very long. After all, you want it to be failsafe, so if it fails, it sets the alarm off.
But there are many low power circuits out there that would do the trick, and run off a battery for a year or so. The device can be off for a minute or so, and once every minute for a few milliseconds or seconds, test to see of there's any moisture. Or else just use really low current until the moisture is detected.
-- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/electronics/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
In article , snipped-for-privacy@cerebrumconfus.it mentioned...
No, not really. Like most A/Cs, the cooling coils sweat, and the runoff has to be kept out of the ducts. So there's a big galvanized pan under the air handling unit, and a small sump pump pumps the water out of the pan and out into one of the roof drains. If he sump pump doesn't work, the pan will gather water, and I think there was an alarm float to tell when the level rises to overflow.
Really, all the basement should need is a float in the sump to tell if there's any water gathering there.
-- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/electronics/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
It'll just get hooked up to a piezo buzzer or something similar.. or heck, I could probably even tie it into the master home alarm-- so definately low draw. A sump pump isn't really an option unless its a torrential flood which is unlikely. My main concern is the dang humidifer leaking as it has done many times in the past (the float switch on those things are really tempremental), as well as if anything else should go awry. It should give me enough time to prop the furniture onto plastic blocks or something should the need arise.
So about that capacitence circuit, any ideas about one that would run on a
9v battery or something similar for a few months/years? :)Thanks, Dan
In article , snipped-for-privacy@rogers.com mentioned...
If you're not there, then who's going to hear the alarm and take action? One thing you might consider is putting a needle valve inline with the humidifier feedline. Then you can restrict the flow to a trickle just in case the float valve doesn't work. At least it'll buy you some time.
Some URLs of low power circuits you might be able to adapt to this problem.
His water alarm seems to be unsafe. Running it directly off the AC line is _not_ a very safe way!
-- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/electronics/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.