Controlling a solenoid valse using 9V battery

Discussion in 'The Projects Forum' started by sajdisaiyed, May 5, 2016.

  1. sajdisaiyed

    Thread Starter New Member

    May 5, 2016
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    Hi,
    I am attaching the datasheet of the valve that I want to control.
    The valve will need to open and close for a few milliseconds only. eg. In a single run, it will open two times like this:
    - Open for 80ms - remain closed for 50ms - then open for 80ms and then close.

    This process can repeat for say about 100 times in whole day. Not more than that.

    Do you think that using 9V battery to control this is a good idea?

    I know that ideally I should use 12V AC with 1A voltage. But since the usage is so low and for such small fraction of second, I was wondering if I can save the hassle of cable clutter by using 9V battery instead.

    Concerns I am looking at are:
    1. Will the battery or valve heat up a lot?
    2. Will the battery die too soon?
    3. Will there be any loss of valve performance?

    Any suggestions are appreciated.
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    bad idea for all concerns stated above..
     
  3. sajdisaiyed

    Thread Starter New Member

    May 5, 2016
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    Thanks for your reply.
    But I am only talking about a few triggers of milliseconds.

    Would that still be a problem?

    I am currently using it to trigger the valve and havent seen these behaviours in the battery or the valve, but I I wanted to mass produce this kit and hence am interested to know if this could be a big concern or not.
     
  4. crutschow

    Expert

    Mar 14, 2008
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    It's not a good idea to run a 12V solenoid (the lowest voltage I see listed) with only 9V.
     
  5. sajdisaiyed

    Thread Starter New Member

    May 5, 2016
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    Will Duracell 12V A23 batteries work?
     
  6. crutschow

    Expert

    Mar 14, 2008
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    Those are too small to handle the current.
    How much room to you have for the battery?
     
  7. sajdisaiyed

    Thread Starter New Member

    May 5, 2016
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    I have a case that can hold 9V battery.
     
  8. crutschow

    Expert

    Mar 14, 2008
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    I suppose this is a silly question but why did you allow room for only a 9V battery to drive a 12V solenoid? :confused:
     
  9. sajdisaiyed

    Thread Starter New Member

    May 5, 2016
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    But tell me something, I am currently using a 9V battery to trigger the circuit and everything works fine.
    My use-case is very simple.
    The valve has a water reservoir connected to it. Whenever I trigger the circuit, the valve opens and closes twice ( for 80ms).
    This lets the valve release two tiny water droplets that fall out.

    I have been running my test circuit and have not seen any of the above problems.

    The reason why I raised this question was to take an expert opinion because i read in another thread that 9V is OK if the valve opens for a few second but not good if I want to run the valve continuously for longer duration.

    So just wanted to cross validate that what I am doing is OK? because so far there are no practical problems but theoretically, can this be done?
     
  10. sajdisaiyed

    Thread Starter New Member

    May 5, 2016
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    There is an option for me to have a12V cable adaptor but because the valve worked fine as described above, I went for 9V housing.
     
  11. Papabravo

    Expert

    Feb 24, 2006
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    That makes you a wishful thinker instead of an engineer. Why continue to defend your decision after asking for help? Listen to us or don't listen to us it's all the same to us.
     
  12. sajdisaiyed

    Thread Starter New Member

    May 5, 2016
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    I think if I was just wishful thinker I would not be discussing it here.
    Once I learned that the way I am using 9V is not right, I came here in search for help.
    What I am now trying to figure out is is there a possible way to still work with DC power and not have to connect an additional 12V adapter.

    I hope thats fair??
     
  13. Papabravo

    Expert

    Feb 24, 2006
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    Using anecdotal evidence is what marks the difference between wishful thinking and engineering.

    "...because the valve worked fine as described above, I went for 9V housing."
    Your words not mine. Part of being an engineer is to recognize your mistake; and then take steps to fix it. At least you're trying to get other opinions, and that's not nothing.
     
  14. sajdisaiyed

    Thread Starter New Member

    May 5, 2016
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    That statement was in reply to the question asked to me "why did you allow room for only a 9V battery"

    I am definitely trying to fix the problem here.
     
  15. crutschow

    Expert

    Mar 14, 2008
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    Okay. Even if it works in your test with a 9V battery, the next one you test may not.
    If it's designed for 12V then that's what you should use.
    On option is to bump up the voltage with a small boost converter to charge a capacitor.
    A 9V alkaline battery has about 400mA hours of capacity or 4 W-Hrs of energy.
    The valve will use 6.5W * o.16s = 1.04 W-sec per dual 80ms operation. This would allow for about 4*60*60 / 1.04 ≈ 14,000 operations with 100% efficiency. So even if you assume no more than 50% efficiency in conversion to the 12V, you should still get about 7,000 operations from the battery.

    Does adding such a boost circuit sound like something you would want to do?
     
  16. sajdisaiyed

    Thread Starter New Member

    May 5, 2016
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    That sounds like a good solution.
    Meanwhile, I have asked the supplier to let me know if they have the same valve with 9V power.
    In that case, I might not have to do this extra bumping up or adding an adapter.

    Thanks for confirming my doubt that the current solution is not right.
     
  17. crutschow

    Expert

    Mar 14, 2008
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    Note that a 9V battery is not good at supplying such a high current (over a half amp) so you should had a large capacitor across the battery to help supply the current pulse.
    It should be at least 10,000μF, 16V such as this.
     
  18. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Since the battery voltage will drop with use and with temperature, have you established what is the minimum voltage which will operate the valve?
     
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