Importance

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Abstract

A feedback controlled elevator door control system 30 having motoring and generating modes, including a DC motor 35 connected to a DC power supply 36 via a power bridge circuit 68. Protective features include a dynamic current limit reference 200 having a magnitude which changes with motor speed; control 116 for providing an object detection safety-stop speed pattern having parameters which are selectable independent of the door stopping portions of normal opening and closing speed patterns; a bridge monitor 66 which prevents the changing of door commands when motor reversal could cause a bridge short; a power supply monitor 40 which blocks door commands when the control voltage is below standard; and an over-voltage protection monitor 38 which protects against excessive voltage build-up on DC power supply components when the bridge circuit 68 pumps power back to the DC power supply 36 during a generating mode.

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First Claim