Disk drive actuator velocity limiting circuit.

摘要

A control circuit for a disk drive actuator is shown wherein the power to the actuator is switched from the normal power source to the spindle drive motor windings (50) functioning as a generator, when the power is interrupted. The rectified output of the current from the stator windings has a polarity which drives the actuator to the home position. Back to back diode means (51, 52) are connected in parallel with the actuator coil (48) when the spindle motor windings are functioning to generate power. The number of series connected diodes in each of the diode means determines the upper limit of actuator velocity. The switching function can be actuated by either a power interruption or by an error condition.