Results 1 to 2 of 2

Thread: Electromagnets: Use of other forces to intentionally overpower the hold force of EM

  1. #1
    Join Date
    Jan 2010
    Posts
    0

    Default Electromagnets: Use of other forces to intentionally overpower the hold force of EM

    We have a design that we would like to use that uses an electromagnet.
    A retract stroke moves the leg back and touches steel to a powered off electromagnet.
    This is the normal position of the kicker.

    For the fire command, the electromagnet is powered on to temporarily hold the leg in its current position.
    The solenoid for the retract stroke is then released and the leg holds in place due to the electromagnet.
    The solenoid for the extension stroke is then powered: Due to cambered leverage, the magnet does not need to hold much holding force- maybe 10 pounds-
    and within 1 second the software control automatically removes power from the electromagnet and the leg moves forward for the kick.

    The electromagnet is only used to hold the leg in place and is only used temporarily as part of the sequence of a "fire" command.

    It is a low power 12V magnet using less than 350 milliamps.

    This is our basic planned use of the electromagnet.
    Is a basic design such as this, generally consistent with the GDC intent for allowed use of an EM as a holding force?

    In addition to the basic method, we believe we have found a quite novel way to adjust the power of the kick by adjusting the voltage to the electromagnet.
    Under some conditions, we would like to lower the voltage to the EM to reduce its holding force. When the built up force related to pressure in the extend stroke of the pneumatic cylinder exceeds the holding force of the magnet, the leg would move forward. The software control would then turn off the EM before the leg is retracted again. At no time does the EM force cause any movement of objects toward the EM- it is only used to resist objects trying to move away from it.

    From our current point of view, this is using an EM as a holding force- just not a holding force that always exceeds the other forces in the mechanism.

    Would use of an EM as a holding force that is sometimes exceeded by other forces in a mechanism considered an allowed use of an EM as a holding force?

  2. #2
    Join Date
    Jan 2006
    Posts
    2,777

    Default Re: Electromagnets: Use of other forces to intentionally overpower the hold force of

    We cannot approve/disapprove specific designs. It is noted however that electromagnets that are used to increase the effective inertia of an object are generally acceptable, while electromagnets that are used to increase the momentum of an object are not.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •