Supplying power from a spindle motor in a disc drive system

A disc drive system for unloading a transducer assembly from a disc having an inner diameter and an outer diameter, the system comprising:

• a spindle motor rotating the disc at a first rotational velocity being a normal operational velocity of the disc drive system;
• a spindlet motor control module removing power to the spindle motor;
• a positioning coil coupled to a power supply moving the transducer assembly relative to the disc;
• a back voltage switching module diverting back voltage generated from the spindle motor to supplement power provided to the positioning coil by the power supply, responsive to a retract signal;
• and
• a ramp positioned outside the outer diameter of the disc to which the positioning coil unloads the transducer assembly when powered by the power supply and the back voltage.

A method for unloading a transducer assembly to a ramp positioned outside an outer diameter of a disc in a disc drive system including a spindle motor for rotating the disc and a positioning coil coupled to a power supply for moving the transducer assembly relative to the disc, the method comprising:

• (A) rotating the disc at a first rotational velocity equaling a normal operational rotational velocity of the disc drive system;
• (B) receiving a retract signal;
• (C) accelerating rotation of the disc to a second rotational velocity that exceeds the normal operational rotational velocity of the disc drive system, responsive to the retract signal;
• (D) energizing the positioning coil with output from the power supply to retract the transducer assembly to the ramp, responsive to the retract signal;
• and
• (E) energizing the positioning coil with back voltage generated from the spindle motor to retract the transducer assembly to the ramp, concurrently with operation (D).

A disc drive system for unloading a transducer assembly from a disc having an inner diameter and an outer diameter, the system comprising:

• a spindle motor rotating the disc at a first rotational velocity being a normal operational velocity of the disc drive system;
• a positioning coil coupled to a power supply moving the transducer assembly relative to the disc;
• a back voltage switching module diverting back voltage generated from the spindle motor to supplement power provided to the positioning coil by the power supply, responsive to a retract signal;
• and
• a ramp positioned outside the outer diameter of the disc to which the positioning coil unloads the transducer assembly when powered by the power supply and the back voltage.