| 摘要 |
An overspeed protection signal override system disables the tach signal from a centrifuge rotor tachometer, so that the inverter-drive control circuit is unable to send a multi-phase motor drive signal to an A.C. induction motor, and the centrifuge rotor and motor are shut down, in response to an alarm signal from the overspeed protection circuit. The override signal is provided to assure that once the overspeed protection circuit of the centrifuge detects an alarm condition characteristic of rotor overspeed, the tach signal which drives the inverter is disabled and withdrawn from motor control, so that an A.C. induction motor will coast to rest even if the current control of the induction motor is not functioning properly. |
