Title:
DEMAGNETIZATION PREVENTING CIRCUIT FOR DC MOTOR
Document Type and Number:
Japanese Patent JPS59144380
Kind Code:
A
Abstract:
PURPOSE:To eliminate the demagnetization of a motor even if a regenerative brake is operated when reaching the abnormal rotating speed by adding a resistor further to the regenerative brake circuit when counterelectromotive voltage of the armature circuit of a motor exceeds the prescribed value. CONSTITUTION:When a regenerative brake is necessary, a switch 22 is closed to connect a resistor 23 to the armature circuit of a DC motor 11. The resistor 23 is selected so that, when the counterelectromotive voltage of the motor 11 is lower than the counterelectromotive voltage at the rated rotating time, the armature current by the regenerative brake does not demagnetize a field permanent magnet of the motor. When a motor counterelectromotive voltage detector 21 detects the counterelectromotive voltage equal to or higher than the prescribed value, a switch 24 is opened, and a resistor 25 is inserted. The resistor 25 is determined to prevent the demagnetization of the motor even if the counterelectromotive voltage equal in absolute value to the maximum drive power source voltage of the motor is generated in the armature circuit.
Inventors:
KOBARI KATSUO
KOBAYASHI TOSHIO
KOBAYASHI TOSHIO
Application Number:
JP1455983A
Publication Date:
August 18, 1984
Filing Date:
February 02, 1983
Export Citation:
Assignee:
FANUC LTD
International Classes:
H02P3/14; H02P3/08; (IPC1-7): H02P3/14
Attorney, Agent or Firm:
Aoki Akira