KR19980059127A - Apparatus and method for determining rotation direction of V-Cal drum motor - Google Patents

Abstract

The present invention relates to an apparatus and method for determining the rotational direction of a BC head drum motor, and more particularly, to determine the rotational direction of a motor using pulses of back EMF generated from a coil wound on a stator during rotation of a rotor. The present invention relates to a rotation direction discrimination apparatus for a V-Cal head drum motor and a method thereof.

To this end, in a V-Cal head drum motor including a rotor in which the N pole and the S pole are alternately magnetized and a stator wound with a coil, a square wave outputting a counter electromotive force generated from the coil wound on the stator as a square wave. Rising edge detection circuit for detecting the rising time of the pulse of the counter electromotive force output from the square wave generator, and falling edge for detecting the falling time of the pulse of reverse electromotive force generated from the coil of the stator in parallel with the rising edge detection circuit A detection circuit, an output of the rising and falling edge detection circuits, and a determination circuit for determining a rotation direction as a reference signal for a microcomputer and outputting a predetermined determination signal.

Description

Apparatus and method for determining rotation direction of V-Cal drum motor

The present invention relates to an apparatus and method for determining the rotational direction of a BC head drum motor, and more particularly, to determine the rotational direction of a motor using pulses of back EMF generated from a coil wound on a stator during rotation of a rotor. The present invention relates to a rotation direction discrimination apparatus for a V-Cal head drum motor and a method thereof.

Typically, recording and playback heads are used to perform functions such as recording and playback in a V-Cal, and these recording and playback heads are mounted on drums, which are commonly referred to as head drums. Therefore, when the V-Cal is in the recording and reproducing mode, the drum on which the reproducing and recording head is mounted is rotated so that playback from the cassette tape proceeding at a constant speed or recording on the cassette tape is performed.

In addition, a drum motor is generally used as a device for driving the head drum, and the drum motor is generally divided into two parts, a stator and a rotor. Magnets are mounted on the inner and lower surfaces of the rotor. Consists of eight cores with multiple coils wound.

In such a drum motor, the determination of the rotation direction is very important. For this reason, the drum should always be made in a certain direction during regeneration. If the initial rotation direction of the drum motor is reversed, the regeneration operation cannot be performed. It was important.

Therefore, the present invention detects the rising edge and falling edge of the counter electromotive force generated from the coil wound on the stator during the initial driving of the rotor, and determines the rotation direction of the rotor based on the result. SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus and a method for determining the rotational direction of a VAL head drum motor, which enable precise control of the SAL drum motor.

In order to realize the above object, the present invention provides a square wave having a rising edge and a falling edge of the counter electromotive force generated from the coil of a drum head drum motor, and the rising edge and the rising edge of the square wave. The direction of rotation is determined according to the detection result of the falling edge.

In addition, the present invention is a V-Cal head drum motor comprising a rotor in which the N pole and the S pole are alternately magnetized with each other, and a stator wound with a coil, and outputs counter electromotive force generated from the coil wound on the stator as a square wave. A square wave generator, a rising edge detection circuit for detecting a rising point of a pulse which is a counter electromotive force output from the square wave generator, and a falling edge time of a pulse which is a counter electromotive force generated from a coil of a stator connected in parallel with the rising edge detection circuit. It consists of a falling edge detection circuit, an output of said rising and falling edge detection circuits, and a discriminating circuit which determines a rotation direction as a reference signal of a microcomputer and outputs a predetermined discriminating signal.

1 is a layout view of a stator and a rotor of a typical two-phase drum motor.

2 is a waveform diagram of the counter electromotive force according to the rotation direction of the rotor.

Figure 3 is a block diagram of the rotation direction determination device of the drum motor according to the present invention.

* Explanation of symbols for main parts of the drawings

1: rotor 2: stator

10: square wave generator 11: rising edge detection circuit

12: polling edge detection circuit 13: discrimination circuit

14: micom

Hereinafter, described in detail by the accompanying drawings as follows.

1 illustrates an example of a stator and a rotor of a general two-phase drum motor.

That is, in the rotor 1, the N poles and the S poles of the plurality of permanent magnets are alternately magnetized to each other, and the stator 2 includes the first stators 2a of L1 and L1 ', to which coils are wound, and L2, It consists of two phases of the 2nd stator 2b of L2 '.

For example, assuming that L1 of the first stator 2a coincides with the N pole of the rotor 1 as shown in FIG. 1 without knowing where the rotor 1 is located, the L1 is driven to the N pole. When a signal is applied to each other, the same poles prevent the rotation of the rotor 1 from occurring, so that the direction of rotation is unknown.

However, if it is desired that the rotor 1 rotate clockwise, when a driving signal is applied to L1, a signal is not applied to L2 of the second stator 2a, so that L2 and L2 'of the second stator 2b are not applied. The reverse electromotive force is generated in L2 due to the relationship between the N and S poles of the rotor 1.

If the rotor 1 rotates clockwise and the winding direction of the coil is wound so as to increase the counter electromotive force from the S pole to the N pole, the waveform is raised from low to high level as shown in FIG. .

However, if the rotor 1 rotates counterclockwise, the rotor 1 passing with respect to L2 of the second stator 2b is rotated from the north pole to the south pole, and the counter electromotive force induced in L2 is shown in FIG. The waveform falls from high to low level.

Therefore, when the waveform of the counter electromotive force is made into a square wave, as shown in (c) and (d) of FIG. 2, the rising edge and the falling edge can be made a clear square wave, and the square wave is clearly identified as the rotation direction discrimination apparatus shown in FIG. 3. Can be determined.

That is, Figure 3 is a block diagram of the rotation direction determination device of the drum motor according to the present invention, which is the counter electromotive force applied to the output side of the square wave generator 10 for outputting the counter electromotive force generated from the coil wound on the stator 2 as a square wave A rising edge detection circuit 11 for detecting the rising point of the pulse is connected, and a falling edge detection circuit 11 for detecting the falling time of the pulse which is the counter electromotive force generated from the coil of the stator 2 is connected in parallel thereto. The output terminal of the rising and falling edge detection circuits 11 and 12 is connected to a determination circuit 13 for determining a rotation direction together with a reference signal of the microcomputer 14 and outputting a predetermined determination signal.

The apparatus for determining the rotational direction of the drum motor configured as described above has a square wave having a counter electromotive force such as (a) or (b) of FIG. 2 generated from a coil wound around the first and second stators 2a and 2b of the stator 2. When input to the generator 10, as described above, a square wave pulse as shown in (c) or (d) of FIG. 2 is output.

Therefore, the square wave pulses output from the square wave generator 10 are detected by the rising edge detection circuit 11 and the falling edge detection circuit 12, respectively.

That is, when the pulse transitioning from the low level to the high level is output from the square wave generator 10, the rising edge detection circuit 11 outputs a high signal to the discriminating circuit 13 so that the rotor 1 in the discriminating circuit 13 is output. ) Rotates clockwise to output a predetermined rotation determination signal.

On the other hand, when a pulse transitioning from the high level to the low level is output from the square wave generator 10, the falling edge detection circuit 12 outputs a high signal to the discriminating circuit 13 so that the rotor 1 in the discriminating circuit 13 is output. ) Rotates in a counterclockwise direction and outputs a predetermined rotation discrimination signal.

As described above, the present invention generates a square wave having a rising edge and a falling edge by using back electromotive force generated from a coil wound on the stator during initial driving of the rotor, and rising edge and falling edge detecting circuit. The rotation direction of the rotor can be accurately determined by the rotation direction determination device including a falling edge detection circuit, a discrimination circuit, and a microcomputer.

Claims (2)

In the rotation direction determination method of V-Cal drum drum motor, a square wave having a rising edge and a falling edge is generated from the counter electromotive force generated from the coil of the drum motor, and the rotation direction is determined according to the detection result of the rising edge and the falling edge of the square wave. Rotational direction discrimination method of the BC head drum motor, characterized in that. A V-Cal head drum motor comprising a rotor (1) in which an N pole and an S pole are magnetized alternately with each other, and a stator (2) in which a coil is wound, and is generated from a coil wound in the stator (2). In parallel with the square wave generator 10 which outputs counter electromotive force as a square wave, the rising edge detection circuit 11 which detects the rising time of the pulse which is the counter electromotive force output from the square wave generator 10, and the rising edge detection circuit 11. The falling edge detection circuit 11 connected to detect the falling time of the pulse, the counter electromotive force generated from the coil of the stator 2, and the output of the rising and falling edge detection circuits 11 and 12 and the microcomputer 14 And a discrimination circuit (13) for discriminating the rotation direction as a reference signal and outputting a predetermined discrimination signal.