KR930010331B1 - Generating apparatus for index signal of motor - Google Patents

Abstract

This system concerns motors that will create index signals without other index signal generating parts for spindles of Floppy Disk Drivers. This system generates index signals using motor driving. The pole length of one of the motor drivers is changed, and the counter senses the amplified voltage signals. This invention is composed of magnetic poles (8), which are distributed in order with the exception of one different length around the rotor (1), a Hall sensor (10) for current, which is generated according to the poles (8) and chooses and generates from one of the current Hall sensor (9).

Description

Index signal generator of motor

1 is a vertical cross-sectional view showing a configuration of a conventional spindle motor.

2 is an enlarged view of an index sensing portion of a conventional spindle motor.

3 is a schematic diagram of conventional index signal generation.

4 is a plan view of a conventional spindle motor.

5 is a block diagram of a conventional IC for controlling a spindle motor.

6 is an explanatory diagram of index signal generation according to a driving stimulus of the present invention.

7 is an internal block diagram of an IC for controlling a spindle motor of the present invention.

* Explanation of symbols for main parts of the drawings

1: Rotor 2: Index stimulus

3: index sensor 4: index sensor holder

5: index signal 8: driving stimulus

9, 10: rectifier Hall element 15: clock frequency generating element

19: counter

The present invention relates to an electric motor, and more particularly, to an index signal generator capable of generating an index signal of a spindle motor for a floppy disk driver (FDD) without a separate index signal generating component.

The spindle motor for FDD should generate one index signal per revolution, and by using this index signal, the computer senses the address allocation in the disk, the criteria for recording and reading information, and the rotational state of the spindle motor.

Therefore, a means for generating one index signal per one revolution of the motor is provided. As shown in FIG. 1, an index magnetic pole 2 is provided at an outer circumference of the rotor 1, and the index magnetic pole ( The index sensor 3 capable of detecting the magnetic flux 6 of 2) and the index sensor holder 4 for preventing the flow thereof are provided on the circuit board 16.

In addition, such a motor generates an index signal 5 only when the index stimulus 2 comes to the same position of the index sensor 3 by the rotation of the rotor 1 as shown in detail in FIG. In this operation, as shown in FIG. 3, when the magnetic flux 6 generated from the index stimulus 2 is applied to the index sensor 3, the index signal 5 is generated and the driving IC 13 of FIG. Controlled by

That is, in Fig. 5, the output of the rectifying hall element 9 which operates in accordance with the driving magnetic pole 8 is amplified and provided to the index signal output terminal 14, by a clock frequency generating element 15 such as a crystal oscillator. Be able to stay motivated. However, the index signal generator of such a motor requires an index stimulus 2, an index sensor 3, and an index sensor holder 4 as shown in FIG. 2, resulting in an increase in the price of the motor. Deviation problem and the actual diameter (7) of the rotor (1) increases, causing interference problems with the FDD deck, and rotation of the rotor (1) due to mutual suction between the index stimulus (2) and the index sensor (3) Many problems, such as speed unevenness, are pointed out.

The present invention is to solve this problem, it characterized in that it uses a method of generating the index signal using the driving magnetic pole and the rectifying Hall element without installing a separate index stimulus and index sensor to generate the index signal . In other words, by changing the length of one pole of the driving magnetic pole, a specific portion of the amplified signal that amplifies the voltage signal output by the specific rectifying hall element is detected using a counter, and the driving IC detects the index signal in this portion. Will be generated. In addition, any one pair of N · S pole magnetization ratios among the drive stimulators magnetized at equal intervals is not used to use a drive stimulus of 1: 1.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In the conventional spindle motor as shown in FIG. 4, the rotor with the index magnetic pole 2 and the index sensor 3 omitted, and one of the rectifying Hall elements 9 set to the specific rectifying Hall element 10, The driving magnetic pole 8 is formed such that the length of one of the driving magnetic poles 8 fixed at equal intervals is formed differently on the outer peripheral portion of (1). In addition, the IC internal block diagram of the present invention is configured such that one of the three rectifying Hall elements 9 forms the rectifying Hall element 10 instead of the index sensor, and the output of the rectifying Hall element 10 is amplified. The counter 19 is configured to be synchronized with the clock frequency generating element 15 and provided to the index signal output terminal 14 at the same time.

Referring to the operation of the present invention configured as described above, when the rotor 1 of the spindle motor rotates, the driving magnetic pole 8 also rotates together with the rotor 1. As a result, the voltage 17 as shown in FIG. 6 is induced in the rectifying hall element 9. At this time, of course, the voltage 17 is induced in the specific rectifying hall element 10.

Therefore, the voltage induced in the specific rectifying hall element 10 is provided to the driving IC 13 and amplified and provided to the counter 19, and compared with the period of the clock frequency generating element 15 to determine the presence or absence of an index signal. Detect. At this time, since one of the driving magnetic poles 8 has a short length (11 in FIG. 6), the amplitude of the specific rectifying hall element 10 is shortened, so that the specific short signal 12 is output from the amplifier. The index signal 15 is generated through the index signal output terminal 14.

That is, one of the conventional index stimulation 2 and the index signal generation rectification Hall element 9 by the index sensor 3 is induced by the driving magnetic pole 8 using the specific rectification Hall element 10. The index signal 15 is generated by matching the output of the voltage amplified with the amplitude of the clock frequency generating element 15. Therefore, the diameter of the spindle motor as small as the index magnetic pole 2 is provided becomes small.

As described in detail above, the present invention eliminates the need for the index sensor, the index stimulus, and the index sensor holder, which are necessary to generate the index signal, thereby reducing the cost of the electric motor, and reducing the assembly cost and eliminating the problem of deviating the index stimulus. Due to the improved motor reliability and miniaturization by reducing the diameter of the rotor, it is possible to bring about the effect of improving the speed constant by the exclusion of mutual attraction between the index stimulus and the index sensor.

Claims (3)

1. An electric motor requiring an index signal, comprising: a driving magnetic pole 8 sequentially arranged at the periphery of a rotor 1 with only one length different; An index signal generator of an electric motor, characterized in that it consists of a specific rectifying hall element (10) for an index sensor which acts as an alternative among the rectifying hall elements (9) operated according to the driving magnetic pole (8). 2. An apparatus as claimed in claim 1, characterized in that the magnetic poles for driving (8) are magnetized at equal intervals and any pair of N-S pole magnetization ratios are not 1: 1. 2. The motor index of claim 1, wherein the voltage generated by the specific rectifying hall element 10 is compared with the amplitude of the clock frequency generating element 15 to detect the generation of the index signal at the counter 19. Signal generator.