Stop check May 1st 2004 A motion-monitoring device for use with trapped key access control systems has been developed by Castell Safety International.
The BEMF unit ensures that motor-driven equipment with a variable run-down time typically mixers, hammer mills and pellet mills has completely stopped before access is possible. This avoids reliance on a fixed time delay, which the company says can overcompensate run-down times for lighter loads.
When an electric motor is rotating, whether powered or not, it generates an electromotive force. This is monitored by the BEMF. When it detects zero EMF, it releases a trapped key that corresponds to a lock on the machines guard hatch. This can be used to access to the machine. More articles from Castell Safety International Ltd: |