Granted Patent B1

US 6,876,508 · App. 10/209,734 · Granted Apr 5, 2005

Abstract

Claims (26)

1. A disk drive comprising:

(a) a disk comprising a plurality of tracks;

(b) a head;

(c) a voice coil motor for actuating the head radially over the disk;

(d) an interface for receiving a supply voltage from a host computer;

(e) a multi-phase spindle motor for rotating the disk, the multi-phase spindle motor comprising a plurality of windings, each winding comprising a first end and a second end, the second ends connected together at a center tap;

(f) a spindle driver, responsive to the supply voltage, for commutating the windings over commutation intervals during a normal operating mode of the disk drive; and

(g) control circuitry for controlling at least one operation of the disk drive, wherein:

a secondary voltage is supplied by the center tap of the windings; and

the control circuitry is powered by the secondary voltage during the normal operating mode.

2. The disk drive as recited in claim 1 , further comprising a voltage regulator for regulating the secondary voltage used to power the control circuitry during the normal operating mode.

3. The disk drive as recited in claim 1 , wherein the windings are wound to control the secondary voltage supplied by the center tap of the windings.

4. The disk drive as recited in claim 2 , wherein the center tap is connected directly to the voltage regulator.

5. The disk drive as recited in claim 2 , further comprising a switch for connecting the center tap to the voltage regulator, wherein the switch is modulated to control the secondary voltage supplied by the center tap of the windings.

6. The disk drive as recited in claim 1 , wherein the spindle driver connects the first end of a first one of the windings and the first end of a second one of the windings to ground for at least part of a commutation interval in order to control the secondary voltage supplied by the center tap of the windings.

7. The disk drive as recited in claim 6 , wherein the interval that the first end of the second one of the windings is connected to ground varies in order to control the secondary voltage supplied by the center tap of the windings.

8. The disk drive as recited in claim 6 , wherein the spindle driver is responsive to a modulation signal for modulating the connection of the first end of the second one of the windings to ground for at least part of the commutation interval in order to control the secondary voltage supplied by the center tap of the windings.

9. A method of operating a disk drive, the disk drive comprising a disk having a plurality of tracks, a head, a voice coil motor for actuating the head radially over the disk, an interface for receiving a supply voltage from a host computer, control circuitry for controlling at least one operation of the disk drive, and a multi-phase spindle motor for rotating the disk, the multi-phase spindle motor comprising a plurality of windings, each winding comprising a first end and a second end, the second ends connected together at a center tap, the method comprising the steps of:

(a) commutating the windings over commutation intervals in response to the supply voltage during a normal operating mode;

(b) generating a secondary voltage from the center tap of the windings; and

(c) using the secondary voltage to power the control circuitry during the normal operating mode.

10. The method as recited in claim 9 , further comprising the step of regulating the secondary voltage used to power the control circuitry during the normal operating mode.

11. The method as recited in claim 9 , wherein the windings are wound to control the secondary voltage generated from the center tap of the windings.

12. The method as recited in claim 9 , farther comprising the step of connecting the first end of a first one of the windings and the first end of a second one of the windings to ground for at least part of a commutation interval in order to control the secondary voltage generated from the center tap of the windings.

13. The method as recited in claim 12 , further comprising the step of varying the interval that the first end of the second one of the windings is connected to ground in order to control the secondary voltage generated from the center tap of the windings.

14. The method as recited in claim 12 , further comprising the step of modulating the connection of the first end of the second one of the windings to ground for at least part of the commutation interval in order to control the secondary voltage generated from the center tap of the windings.

Assignments (8)