JPH0365085A - Motor controller for magnetic disc device - Google Patents

Abstract

PURPOSE:To improve power consumption efficiency by judging whether it is the stoppage due to at least power interruption or not, when a motor driving means stops, and in case of the stoppage due to power interruption, by starting a brake means so as to stop a spindle motor quickly. CONSTITUTION:CPU 24 judges whether it is the one by power interruption or the one by the motor stop command from a host device 25 when stopping the driving of a spindle motor 21. The CPU 24, when it confirms that the power is interrupted, stops output of driving signal S1 and also outputs a brake control signal S2. Thereupon, a relay switch 27 is turned on. Hereby, a dynamic brake is started, and the currents which were left inside coils 22a-22c at the time of motor stoppage, flow to a resistance 26, and the rotation of a spindle motor 21 stops quickly.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a magnetic disk device suitable for being installed in equipment where power consumption is an issue, such as a battery-powered laptop personal computer. The present invention relates to a motor control device.

(Prior Art) In a magnetic disk device, a disk, which is a recording medium (not shown), is rotated by driving a spindle motor 11 as shown in FIG. The spindle motor 11 has coils 12a to 12c having a three-phase structure. The motor drive circuit 13 drives the coils 12a-12 under the control of the CPU 14.
c is sequentially energized to rotate the spindle motor 11. Note that drive methods in this case include a full-wave drive method in which the coil is energized in both directions, and a half-wave drive method in which the coil is energized in one direction. Here, it is assumed that the spindle motor 11 is driven by a full-wave drive method by sequentially passing current in the directions of arrows aSb and c through each coil 12a to 12c.

The CPU 14 stops outputting the motor drive signal SL when the power is cut off or when a motor stop command from the host device 15 is input manually. This motor drive signal S1 is a signal for driving the spindle motor 11. When the output of the motor drive signal S1 stops, the motor drive circuit 13 stops supplying power to the spindle motor 11. As a result, the spindle motor 11 will gradually stop.

Here, in the magnetic disk device, the spindle motor 11
It is equipped with a brake function called dynamic brake to quickly stop the rotation of the motor. This is an electric brake that quickly stops the motor rotation by consuming the current remaining in the coils 12a to 12c through the resistor (6) when the motor drive is stopped.This dynamic brake relay switch 17
is launched via.

Conventionally, when the power is cut off or when a motor stop command is manually issued, the CPU 14 outputs the motor drive signal S.
The configuration was such that when the output of l is stopped, the relay switch 17 is turned on to activate the dynamic brake. When the dynamic brake is activated, an electric brake is applied to the spindle motor 11, and the spindle motor 1
1 stops quickly without rotating due to inertia.

By the way, when restarting a motor that has been stopped for a while, a large current is required. Magnetic disk drives, especially magnetic disk drives installed in devices where power consumption is an issue, such as battery-powered laptop personal computers, are required to reduce power consumption as much as possible. For this reason, in accesses that require repeated motor starting operations, it is better to stop driving the spindle motor 11 without using the dynamic brake. That is, it is more efficient in terms of power consumption to allow the spindle motor 11 to rotate for a while by inertia force in preparation for restarting.

(Issue 8 to be solved by the invention) As mentioned above, in the past, the activation of the dynamic brake was controlled by the motor drive signal.
When the motor drive is stopped, the dynamic brake is always activated, regardless of whether the power is cut off or a motor stop command is issued.
There was a problem of poor power consumption efficiency.

The present invention has been made in view of the above points, and provides a motor control for a magnetic disk device that can improve power consumption efficiency by applying a brake function as necessary when stopping the drive of a spindle motor. The purpose is to provide equipment.

[Configuration of the Invention (Means for Solving the Problems) In other words, the motor control device for a magnetic disk drive according to the present invention, when the motor drive means for driving the spindle motor stops, at least controls whether the stop is due to power cutoff or not. If the spindle motor is stopped due to power cutoff, the brake means is activated to quickly stop the spindle motor.

(Function) According to the above configuration, when stopping the drive of the spindle motor, the brake function can be activated as needed, such as when the power is cut off, instead of always operating the brake function as in the conventional case. Therefore, power consumption efficiency is improved.

(Embodiment) Hereinafter, a motor control device for a magnetic disk device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing its configuration. The spindle motor 21 is, for example, a brushless DC motor that rotates a recording medium (not shown). This spindle motor 21
has coils 22a to 22c with a three-phase structure. Each of the coils 22a to 22c has one end commonly connected and the other end connected to the motor drive circuit 23. Motor drive circuit 23
Based on the motor drive signal S1 output from the CPU 24, the coils 22a to 22c are sequentially energized to rotate the spindle motor 21.

Note that drive methods in this case include a full-wave drive method in which the coil is energized in both directions, and a half-wave drive method in which the coil is energized in one direction. Here, it is assumed that the spindle motor 21 is driven by a full-wave drive method by sequentially passing current in the directions of arrows a1b and c through each of the coils 22a to 22c.

The CPU 24 stops outputting the motor drive signal SL and stops the motor drive by the motor drive circuit 23 when the power is cut off or when a motor stop command from the host device 25 is input manually. Also, CPU
24 is the brake control signal S2 when %M is cut off.
is output to activate a brake function called dynamic brake.

This dynamic brake is an electric brake that causes the current remaining in the coils 22a to 22c to be consumed by the resistor 2B when the motor drive is stopped, thereby quickly stopping the motor rotation.

This dynamic brake is activated via relay switch 27. The relay switch 27 is controlled on/off by a brake control signal S2.

Next, the operation of this embodiment will be explained.

When the CPU 24 stops driving the spindle motor 21, it first determines whether it is due to power cutoff or a motor stop command from the host device 25.

Here, in the case of a motor stop command, the CPU 24 stops the motor drive without using the dynamic brake (brake function). That is, when the CPU 24 receives a motor stop command from the host device 25, it simply stops outputting the drive signal SL and stops the motor drive circuit 23 from driving the motor. When the motor drive circuit 23 stops driving the motor, the power supply to the spindle motor 11 is interrupted, and the spindle motor 21 stops. In this case, the spindle motor 21 is
It continues to rotate due to inertia for a while, and then gradually comes to a stop.

On the other hand, in the case of power cutoff, the CPU 24 uses the dynamic brake to stop the motor drive.

That is, when the CPU 24 confirms that the power is cut off, it stops outputting the drive signal St and outputs the brake control signal S2. When the brake control signal S2 is output, the relay switch 27 is turned on. This results in
When the dynamic brake is activated, the current remaining in the coils 22a to 22c when the motor drive is stopped flows through the resistor 2B.
, and the rotation of the spindle motor 21 immediately stops.

In this way, when the motor drive is stopped, the dynamic brake is selectively used depending on whether the power is cut off or when a motor stop command is issued. Here, when the drive of the spindle motor 21 is stopped without using the dynamic brake, the spindle motor 21 is stopped for a while.
Since the spindle motor 21 can be kept rotating by inertia, low electric power is required when starting the spindle motor 21 again. This situation is shown in FIG.

In FIG. 2, the solid line indicates when the dynamic brake is used, and the dotted line indicates when the dynamic brake is not used. In accesses that require repeated motor starting operations, it is more efficient in terms of power consumption to stop the drive of the spindle motor 11 without using the dynamic brake in preparation for restarting.

In this embodiment, in order to improve the power consumption efficiency, the drive of the spindle motor 21 is stopped without using the dynamic brake except when the power is cut off, that is, when the motor stop command is manually operated. Note that even when a motor stop command is input, if necessary, for example, if the spindle motor 21 will not be restarted immediately, the dynamic brake may be used to stop the drive of the spindle motor 21. good.

[Effects of the Invention] As described above, according to the present invention, when stopping the drive of the spindle motor, the brake function can be activated as necessary, such as when the power is cut off, so that power consumption efficiency is improved. Therefore, it can be installed in equipment where power consumption is a problem, such as a laptop-type personal computer.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a configuration according to an embodiment of the present invention, FIG. 2 is a diagram for explaining motor starting efficiency in the same embodiment, and FIG. 3 is a block diagram showing a conventional configuration. 21... Spindle motor, 22a-22c... Coil, 23... Motor drive circuit, 24... CPU,
25...Host device, 2B...Resistor, 27...Relay switch, Sl...Motor drive signal, S2...
Brake control signal.

Claims (1)

[Scope of Claims] A spindle motor for rotating a recording medium, a motor drive means for driving the spindle motor, a brake means for promptly stopping the rotation of the spindle motor, and a motor driving means for stopping the motor drive by the motor drive means. Occasionally,
What is claimed is: 1. A motor control device for a magnetic disk drive, comprising at least brake control means for determining whether or not the stop is due to a power cutoff, and in the case of a stoppage due to a power cutoff, for activating the brake means.