Patent ID: 7006799
Filing Date: 2006-02-28
Classification: G07C,H04W,Y02D

Abstract:
1. In an RF access control system, a method for reducing the power used to lock or unlock an access point, said access point including a locking shaft, a motor driving said locking shaft and a motor armature, and an electronic control processor controlling said motor; said method including the steps of: providing power to a motor during an initial drive time so that a locking shaft is set in motion; ceasing to supply power to said motor; periodically measuring the back EMF from said motor during a time interval when the motor armature has a substantially zero current value and summing the measurements of said back EMF to form a summed back EMF measurement; comparing said summed back EMF measurement to a predetermined threshold; again providing power to said motor if said summed back EMF measurement is less than said predetermined threshold.