Patent ID: 7068460

Claim:
A disk drive emergency retract architecture for providing power to a voice coil motor (VCM) to retract a transducing head from a surface of a recordable medium during loss of power from an external power supply, the disk drive emergency retract architecture comprising: a spindle motor for spinning the recordable medium, wherein the spindle motor includes an internal inductance and wherein the spinning recordable medium creates a back electromotive force (BEMF) in the spindle motor; a capacitor for storing and supplying power to the VCM; a switching circuit connected to the spindle motor, wherein the switching circuit causes only the internal inductance of the spindle motor to store the BEMF when in a first state and causes energy stored in the internal inductance of the spindle motor to be transferred to the capacitor when in a second state; and a logic circuit connected to selectively place the switching circuit in the first state following loss of power from the external power supply and in the second state following the first state.