| 摘要 |
PURPOSE:To obtain safety by detecting a disconnection based on a speed feedback signal, and switching a speed controller from a feedback control to an open loop control in response to its disconnection detection signal. CONSTITUTION:If a motor 2 is rotated based on a speed set single S6 from a speed setter 6, when a disconnection occurs in a speed detector 3, a speed feedback signals S5 is not output from the detector 3, and a disconnection detector 9 outputs a disconnection detection signal S9. The signal S9 is applied to an operation mode switching circuit 10 to switch a speed controller 7 from a feedback control to an open loop control and to control to decelerate to stop the motor 2 by regenerative braking. |
