Gopal Shenoy (Clutch & Break coils question)

Discussion in 'General Electronics Chat' started by gopal.shenoy@navneet.com, Sep 1, 2013.

  1. gopal.shenoy@navneet.com

    Thread Starter New Member

    Sep 1, 2013
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    I am facing some problem on Clutch & Break. It is used on Cutting machine when cutting command received both Clutch & break operate together hence break released & clutch engage & cutting process completes. Both coil voltage are 24 VDC. 66 watt & 65 Watt respectively. Both the coils are connected in series & 48 Volt DC is applied from controller. Now problem is when ever cutting command comes Break energies slightly late than clutch coil hence there is excess load on clutch coil. How we can operate Break coil quicker than clutch coil??
     
  2. crutschow

    Expert

    Mar 14, 2008
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    If I understand correctly, when the power is applied you need the Brake solenoid to operate (release) slightly before the Clutch solenoid is operated (engaged).

    One possible way is to add a capacitor directly across the Clutch solenoid, which will delay its operation. The proper value will likely have to be experimentally determined, as it depends upon the inductance and operating speed of the solenoids, but I would start with an electrolytic capacitor of about 1000μF rated at 50V. Note that these are polarized so their plus side must be connected to the plus side of the clutch coil.
     
  3. WBahn

    Moderator

    Mar 31, 2012
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    You might take a pause and consider that if something on the machine that used to work isn't working any more, then perhaps there is something wrong that should be fixed, and not just bandaged.

    Think about the safety implications of not getting it fixed properly. If you decide that the risk is acceptable and choose to proceed with the bandage approach, then that's your choice (and it might well be a perfectly reasonable one -- I'm not saying one way or the other or what I would do in your situation, because I frankly don't know).
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I agree, if this is a recent phenomenon and it has worked OK up till now, it is either due to a mechanical reason or electrical.
    It may be an idea to check the voltage across both coils when they are energized, it should presumably be equal, 24v across each, unless characteristic has changed?
    For mechanical, obvious reasons for the brake to be slow picking up would be sticking or binding.
    IMO, it is not of good design, I would have used 24vdc and fed the clutch through a relay that is in parallel with the brake, affording a slight delay to the clutch.
    Max.
     
    Last edited: Sep 1, 2013
  5. bertus

    Administrator

    Apr 5, 2008
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