Solenoid valve help!!!

Discussion in 'The Projects Forum' started by helloiamkat, Jun 18, 2010.

  1. helloiamkat

    Thread Starter New Member

    Jun 17, 2010
    5
    0
    Hi,

    This is my first post here and I hope I explain this correctly.

    I am seeking to make a solenoid valve switch on and then off (for oil) after a given interval of 2 hours. It is AC powered, it will be activated by a light sensing circuit. I have been advised to look at relay circuits and driver circuits.

    Any clues as to what I should be looking at?

    Thanks in advance.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Hello Kat.
    Welcome to AAC. Don't be afraid of making bonehead mistakes; they're made regularly around here (and I've made a lot of 'em) but try hard to give some decent scoop now and then.

    What AC voltage are you having to deal with? We tend to shy away from directly mains-powered topics on this board.

    Tell us more about your project. Is it activated by light, or by time, or either/both? I am sort of confused by your description of the problem.
     
  3. helloiamkat

    Thread Starter New Member

    Jun 17, 2010
    5
    0
    It is mains-powered unfortunately. 220VAC to be exact. It was the only solenoid valve I could find, the rest were to expensive.

    The plan is to use LDRs and LEDs as the sensing part. Once the LDR senses the light from the LED the solenoid valve would be activated until another LDR circuit tells it to return to its original state.

    I am really confused as to what I should do first. Thanks.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    A low DC voltage circuit that controls the AC to the solenoid through a solid state relay would be much safer. The control might be as simple as an LDR and a voltage comparator.
     
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  5. someonesdad

    Senior Member

    Jul 7, 2009
    1,585
    141
    An adjustable time delay relay would work and a DC input one could use some low control voltage like beenthere suggested. Then your circuit would probably not be much more than the LDR, a wall wart for the DC power, and the relay. Might need a transistor to switch the relay though. But it will be simple and safe; the only hazardous stuff will be wiring up the 220 V stuff, so make sure you ask for instructions if you've never done that before. I'd recommend a 2 pole relay.

    The same thing can be built with a standard relay and a 555 timer circuit, but it will take more work (but will also be more interesting).
     
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  6. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,172
    397
    A Is solenoid a single coil?
    B Does it self reset when power is removed?
    C Is each leg of AC pwr hot ref. to earth?
     
  7. helloiamkat

    Thread Starter New Member

    Jun 17, 2010
    5
    0
    okay thanks, i'll look into all of your suggestions.

    to bernard: im not sure if the solenoid is single coil and if the leg of the AC power hot ref to earth. however, it does self reset when power is removed.

    thanks. :)
     
  8. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    kat, do you have a model number of the solenoid you are using?

    That would lead to the datasheet. And THAT would help us tremendously.
     
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