AC solenoid sluggish

Discussion in 'General Electronics Chat' started by oidium45, May 8, 2012.

  1. oidium45

    Thread Starter Active Member

    Apr 24, 2010
    130
    8
    Hello,
    I have an 120vac solenoid that has a sluggish start. Once it has recessed about 1/4 the way through it works just fine. If you do not help it get started it will just sit there and hum. (This seems to be only periodically)

    My question is...
    Can you use a capacitor to give the solinoid an initial burst upon startup similar to a motor start capacitor?

    I understand this is a pretty general questin but i do not have the solenoid information with me at this time.
     
  2. paulktreg

    Distinguished Member

    Jun 2, 2008
    611
    120
    Can you fit some sort of bracket to get the plunger into a reliable starting position?
     
  3. strantor

    AAC Fanatic!

    Oct 3, 2010
    4,302
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    check your connections. The only thing I can think of that (electrically) would make a solenoid work, but work weakly, is if there is resistance in series with it. The problem may not be electrical. May be there is crud inside it.
     
  4. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,750
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    How many connections are there to operate the solenoid.
     
  5. crutschow

    Expert

    Mar 14, 2008
    13,000
    3,229
    A large AC capacitor could be put in series to resonate with the solenoid inductance and increase the solenoid current. You'd have to know the inductance of the solenoid to determine the required capacitor value for that.
     
  6. P-MONKE

    Member

    Mar 14, 2012
    83
    5
    This ^

    Some solenoids have an extra tap on the coil: The full winding is powered to initially energise the solenoid. Once actuated, an end of travel switch toggles the current to the smaller "holding" part of the winding only, meaning that much less current is required to maintain actuation. This also means that less power and heat are dissipated.

    Sometimes this switch can get misaligned or damaged and only the holding part of the winding ever receives power, making the solenoid operation weak and unreliable.

    BTW, this configuration is common in electromechanical amusement machines - are you working on something interesting?
     
  7. P-MONKE

    Member

    Mar 14, 2012
    83
    5
    Sometimes we wonders why we bothers, precious...

    I don't know how you regular guys keep doing this. ;)
     
  8. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    come again !.
    Are u saying what I think you are saying ?:D
     
  9. P-MONKE

    Member

    Mar 14, 2012
    83
    5
    OP asks a question, so someone goes to the trouble attempting to answer it, only for OP to not bother replying.

    I'm new here, as you can tell, and my electronics knowledge is rusty and full of holes like my first car but I try to help if I can. But I still find it a bit depressing when people can't be bothered with simple manners.

    Kudos to the stoics - your efforts border on the heroic :)
     
    Last edited: May 11, 2012
  10. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,750
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    Ur electronics may be full of holes, but did u know my English is full of holes too.

    There are some things I do not understand.
    U need to stop beating around the bush when I am involved in a thread.

    What I mean to say is just say it direct. Which I tend to do.
    What to do, English is not my mother tongue. :(
     
    P-MONKE likes this.
  11. P-MONKE

    Member

    Mar 14, 2012
    83
    5
    I'll remember that, R!f@@
     
  12. shortbus

    AAC Fanatic!

    Sep 30, 2009
    4,004
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    @P-MONKE, most of the regular posters here, and I'd be willing to bet on most forums, are about learning. And helping. Even the "hit and run guys" help the rest of us to learn. We discuss the problem and learn from each other and then apply it in some way some other time. This is what makes this place the best of the Web!!! Welcome to the best. :)
     
    P-MONKE and gerty like this.
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