Safety water level solenoid shut off

Discussion in 'The Projects Forum' started by director87, Nov 24, 2012.

  1. director87

    Thread Starter New Member

    Nov 20, 2012
    2
    0
    I have read up on some other threads and done research on water level sensors. I have a decent idea of what I am going to do, but before I blow something up I wanted to check here. I know I'll have something wrong.

    I have a reservoir with a Reverse osmosis pumping water into it for my fish tank. I have a float valve that controls the water level, but I've been told that these go bad so, as a backup, I am installing a DIY float sensor that triggers a solenoid.

    I have these parts:



    I wanted to integrate a buzzer as well, but I'm thinking v1.00 should be simple. Am I missing any components before I start this?

    Any advice/comments would be appreciated. Thanks :D
     
  2. John P

    AAC Fanatic!

    Oct 14, 2008
    1,632
    224
    Your power supply and valve seem to be AC powered and your relay is DC. But what's the relay for, anyway? I'd have thought that the float switch could operate the valve directly with no relay. However, that depends on the rating of the switch versus the current drawn by the valve. I'd also expect to have a snubber circuit in parallel with the valve coil; this would help protect the switch contacts from sparking when the valve is turned off.
     
    director87 likes this.
  3. tubeguy

    Well-Known Member

    Nov 3, 2012
    1,157
    197
    Did you get the circuit from the float switch link?

    If yes it implies you do need a relay, because this type of float switch frequently uses a magnetic reed switch which handles a much lower current than a typical solenoid valve. (22 gauge wires imply small current also)

    As pointed out by John P you should get a 24VAC coil relay to match the AC power supply.

    Edit: Just Noticed "I have these parts" so you could get a 1N4002 100v 1 amp diode (Radio Shack) and wire it in series with the relay coil and switch to operate the coil from DC.
     
    Last edited: Nov 25, 2012
    director87 likes this.
  4. director87

    Thread Starter New Member

    Nov 20, 2012
    2
    0
    Thank you John P and tubeguy. I didn't realize that my relay was DC... completely missed that. Luckily out of all the parts that I've ordered, that's the one I did not.

    I'm going to go with this one: http://www.grainger.com/Grainger/DAYTON-Relay-1EHH6?Pid=search

    Do you think its good enough?

    Thank you for all your help
     
  5. tubeguy

    Well-Known Member

    Nov 3, 2012
    1,157
    197
    Should Work. One thing not stated in the specs for the solenoid valve is the current draw.
    The power supply is 1 amp, so when you get the parts you should make sure the voltage on the supply stays at least 24 vac when connected to the solenoid.. These supply's will usually supply somewhat higher voltage when not loaded to capacity so higher is ok, but lower is not.
     
Loading...