PECO switch motor noise

Discussion in 'FAQs' started by Cactus, Apr 8, 2002.

  1. Cactus

    Cactus Member

    I recentlly purchased a couple of PECO PL-10 switch machines, and mounted one of them several days ago.

    I'm working in N-scale, using PECO turnouts. I mounted the PL-10 directly to the turnout as in the instructions.

    Power for the machine is 16V AC, as the instructions specify. I'm using Rix momentary contact switches to activate the machine.

    Well, all works fabulously... except that the PL-10 is much noisier than I had anticipated. I knew that it would be louder than the sound of the turnout itself, but I expected an unobtrusive "snick" as the machine moved the turnout. Instead, there's a loud Buzz. It's short in duration (momentary contact switches, after all), but the decibel level is akin to my Atlas motorized turntable -- i.e. loud.

    I'm not unhappy, but I'd like to know if anyone has either:

    1. a suggestion that the buzz isn't normal, with advice on how to correct it, or

    2. a suggestion that the buzz is normal, with advice on how to soundproof it, or

    3. a suggestion that the buzz is normal, with the advice that everyone simply accepts it and so should I.


  2. Matthyro

    Matthyro Will always be re-membered

    It's not only the buzz but the load click as the armature moves. One way to reduce the noise is to use one of those momentary high voltage capacitor switch units but that dosn't get rid of the "THWACK" I don't use them anymore.
  3. billk

    billk Active Member

    Is it possible that any noise (buzz, thwack, hum, ding-dong) is being amplified by the mounting method you're using for the PL-10s?
  4. kettlestack

    kettlestack Member

    The buzz is normal when ac is used to power the machine. The loudness of it is probably because it is mounted on the trurnout which in turn is firmly mounted on the roadbed.... all acting as a sound board.

    A problem using ac through a pushbutton is that eventually, because of the high surge current the pushbutton can stick in the "Pressed" position resulting in the machines frying in 2 to 3 seconds! :( .

    Solution is to use a transistorised Capacitor Discharge unit. This is a simple device which supplies high current to the machines for a fraction of a second, then the transistor limits the power to a level that cannot possibly fry the machine (Even if the push button remains pressed indefinately. You will also get that beloved "snick" you expected to hear :) :) .

    Here is a circuit you can build yourself for just such a Capacitor Discharge Unit. Have fun (and peace of mind).


    Attached Files:

  5. shamus

    shamus Registered Member

    Hi Bill,
    Get a Capacitor Discharge unit to throw your pl10's, I expect you have placed your turnout with PL10 onto Plywood/Chipboard with just a cork underlay. If so then the "CRACK SOUND" is amplified by the board. I use these PL10's, and can only just hear them sometimes.

  6. Cactus

    Cactus Member

    Thanks all.

    The layout is built on 4 inches of extruded styrofoam with cork roadbed. It's the buzz that worried me, and it looks like I ought to buy/build a capacitor discharge unit -- both to reduce the buzz and to protect the switch machines.

    It looks simple enough. I'll do that.


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