Water alarm sensor

Jimbo · 08-10-2002, 04:02 PM

Hi all,

Found this water alarm sensor. You could hook your main pump to it via a Normally closed relay (recommend solid state) and it would shut off your main pump if it goes off.

http://www.allelectronics.com/cgi-bi...108&type=store

http://www.allelectronics.com has alot of cool stuff including fans ect...

Hope this helps

Doug1 · 08-10-2002, 04:06 PM

As I read it the alarm goes off if water is detected, how would one redo it to alarm or shut off if no water was in the return chamber ?

Jimbo · 08-10-2002, 04:39 PM

You use a normally closed relay (NC) most relays have have NC and NO (normally open attachments). So if the relay is not being powered it will supply voltage to the pump. If the relay is activated it will shut off power to the pump. Solid state relay's don't need much juice to turn them on/off so you could probally hook it right to the sensor attachment to the speaker. You could also use an inverter ic LS7417 to invert the voltage, So if the circuit was normally off you could invert that to 9v and power a solid state relay. This relay should work with the circuit though.

http://www.allelectronics.com/cgi-bi...415&type=store

I still recommend a solid state relay and that you power the water sensor with a external power supply. Most solid state relay's only come with a NO connection so you will need to invert the voltage with an inverter chip.

http://www.allelectronics.com/cgi-bi...-10&type=store

-If you need more help let me know. I can supply a schematic for the circuit you need.