×

Control system for an automatic door

  • US 4,673,848 A
  • Filed: 12/05/1985
  • Issued: 06/16/1987
  • Est. Priority Date: 12/29/1984
  • Status: Expired due to Term
First Claim
Patent Images

1. A control system for an automatic door comprising:

  • a brushless D.C. motor having a stator armature encircling a rotatably mounted magnetic field rotor defining magnetic poles and coupled to a door member;

    speed reduction means for transmitting driving power from said brushless D.C. motor to said door member;

    means for delivering magnetic pole position detection pulses from said brushless D.C. motor as said magnetic field rotor rotates;

    a position control circuit responsive to said magnetic pole position detection pulses delivered from said delivering means for determining the position of said door member and thereby generating a speed command signal indicating the direction and magnitude of the speed of said door member; and

    a speed control circuit responsive to said magnetic pole position detection pulses and said speed command signal connected to apply a drive control signal to said brushless D.C. motor so that said brushless D.C. motor is driven at such rotational speed that said door member is moved at the speed indicated by said speed command signal.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×