JPH05184174A - Motor controlling circuit - Google Patents

Abstract

PURPOSE:To stop a d.c. motor at a specified location accurately in a driving mechanism wherein the d.c. motor is used. CONSTITUTION:When an index sensor 34 sends a signal to stop a d.c. motor 12 to a flip-flop circuit 30, a transistor Q2 is turned on by an output -Q of the flip-flop circuit 30 and both terminals of the d.c. motor 12 are shorted and the d.c. motor 12 is stopped at an accurate position by electromagnetic braking.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control circuit, for example, a motor control circuit used in a page turning device for a telephone number list.

[0002]

2. Description of the Related Art In various devices driven by a motor, it is sometimes necessary to accurately control the stop position of a driven member by accurately controlling the amount of rotation of the motor. For example, there is known a device that turns a page and stops it at a predetermined page position so that a predetermined page of a telephone number list can be viewed. The motor rotation must be stopped exactly at the position.

[0003]

When a servo motor is used, the amount of rotation as described above can be accurately controlled. However, since the servo motor is expensive, it is not practical to use it in a simple drive device. On the other hand, when an inexpensive DC motor is used, it is difficult to accurately control its rotation. Therefore, for example, when the telephone number list is rotated by driving the DC motor, it is accurately stopped at a predetermined page position. There was a problem that I could not.

An object of the present invention is to provide a control circuit capable of controlling the rotation of a DC motor in a drive mechanism using the DC motor more accurately.

[0005]

According to the present invention, the motor control circuit for controlling the rotation of the DC motor in the drive mechanism driven by the DC motor has a power supply means for supplying a predetermined voltage to both terminals of the DC motor. A short-circuit means for short-circuiting both terminals of the DC motor, and a control means for controlling each means in response to an input instruction to start and stop rotation of the DC motor. When the instruction to start the DC motor is input, the power supply unit supplies voltage to the DC motor, and when the instruction to stop the rotation of the DC motor is input, the short-circuiting unit short-circuits both terminals of the DC motor to generate counter electromotive force. , It is to accelerate the stop of the DC motor.

Further, according to the present invention, a telephone number list composed of a plurality of pages and rotatably provided is rotated by driving a DC motor to stop the telephone number list at a predetermined page position. The page turning device of
When the instruction to stop the rotation of the DC motor including the above control circuit is input at a predetermined position, both terminals of the DC motor are short-circuited by the short-circuiting means to immediately stop the DC motor and the telephone number list is displayed. It is stopped at a predetermined page position.

[0007]

Embodiments of the motor control circuit according to the present invention will now be described in detail with reference to the accompanying drawings.

2 to 5 show an overview of a telephone number list page turning apparatus using a motor control circuit according to the present invention. As shown in FIG. 2, a telephone number list having a plurality of index pages 10 is installed in the device. This device has a driving DC motor 12 and a predetermined number of gears 14, 14 for transmitting the rotation of the DC motor 12,
The rotation of the DC motor 12 is transmitted to the index turning gear 16 via the gears 14, 14. DC motor 12
Since the rotation is accurately controlled by the control circuit described later, the index turning gear 16 is accurately stopped at a predetermined position, and the operator can see the predetermined index page 10.

On the front surface of the apparatus, a transparent window 18 for viewing the index page 10 and a touch switch 2 for the operator to input the designation of the page number of the index page 10 and the like.
0 is provided. In addition, a DC motor 1 is installed inside the device.
A battery 22 and other necessary components for driving the vehicle 2 are provided.

3 to 5, the left side surface of the page turning device,
A front view and a right side view are respectively shown. As shown by the dotted line in FIG. 3, an IC substrate 24 is mounted on the device,
A control circuit for the DC motor 12 described later is mounted on the C board 24 as an integrated circuit.

FIG. 1 shows an embodiment of a motor control circuit provided on the IC substrate 24 of the page turning device. As shown in the figure, this circuit includes the touch switch 20 shown in FIG. From the touch switch 20, the operator
Enter the page number you want to see and an instruction to start the page turning operation. The operation start instruction signal input from the touch switch 20 is input to the set input S of the flip-flop circuit 30. On the other hand, at the reset input R of the flip-flop circuit 30, the index page is touch switch 20.
The stop instruction signal output from the index sensor 34 is input when the position of the page input from is reached.

The output Q of the flip-flop circuit 30 is connected to the base of the transistor Q1 via the resistor R1. The DC motor 12 is connected to the collector of the transistor Q1.
One terminal of the DC motor 12 is connected, and the other terminal of the DC motor 12 is connected to the battery 22. The emitter of the transistor Q1 is grounded.

The output -Q of the flip-flop circuit 30 is
It is input to the monostable multivibrator 32. When a signal is input from the flip-flop circuit 30, the monostable multivibrator 32 outputs a signal that maintains the state. The output of monostable multivibrator 32 is sent to the base of transistor Q2. The emitter and collector of the transistor Q2 are connected to both terminals of the DC motor 12, respectively.

When the operator inputs the page number of the index to be viewed from the touch switch 20, the switch (not shown) of the corresponding portion of the index sensor 34 is closed. When the index page 10 is rotated by the drive of the DC motor 12, the index page 10
When reaches the position of that page, a current flows through the closed switch, and this current is sent to the reset input R of the flip-flop circuit 30 as a signal instructing to stop the DC motor 12.

When the operator inputs a page turning instruction from the touch switch 20, a start signal is output from the touch switch 20 and is input to the set input S of the flip-flop circuit 30. As a result, a signal is output from the output Q of the flip-flop circuit 30 and a predetermined voltage is applied to the base of the transistor Q1. Therefore, the transistor Q1 becomes conductive, the voltage is supplied from the battery 22 to the DC motor 12, and the DC motor 12 is driven. As a result, the rotation of the DC motor 12 causes the rotation of the gear 1
It is transmitted to the index-turning gear 16 via 4 and 14, the index page 10 is rotated, and the page is turned.

When the index page 10 reaches the position of the page that the operator wants to see input from the touch switch 20,
A signal is output from the index sensor 34 and sent to the reset input R of the flip-flop circuit 30. As a result, a signal is output from the output -Q of the flip-flop circuit 30 and sent to the monostable multivibrator 32.
When there is an input, the monostable multivibrator 32 maintains that state and outputs a signal until the next input. A signal from the monostable multivibrator 32 applies a predetermined voltage to the base of the transistor Q2. As a result, the transistor Q2 becomes conductive and the DC motor 1
Both terminals of 2 are short-circuited. Therefore, the electromagnetic braking force works due to the short circuit, the DC motor 12 stops at the predetermined position accurately, and the predetermined page of the index page 10 is opened.

At this time, since there is no output from the output Q of the flip-flop circuit 30, the transistor Q1 becomes non-conductive and the supply of the voltage from the battery 22 to the DC motor 12 is stopped.

As described above, according to this apparatus, the DC motor 12 is stopped immediately by short-circuiting both terminals of the DC motor 12 by the stop signal to exert an electromagnetic braking force, so that the index page 10 is a predetermined page. The DC motor 12 can be stopped exactly at a predetermined position so as to open. Therefore, it is possible to perform page turning accurately using the inexpensive DC motor 12. Moreover, since the control circuit is formed by an integrated circuit, it has a long life as compared with that using a mechanical switch.

Although the DC motor 12 is short-circuited by turning on / off the transistor in the above embodiment, the DC motor 12 may be short-circuited by using other means. The output of the signal instructing to stop the DC motor 12 is not limited to the flip-flop circuit 30 and the monostable multivibrator 32, and a circuit having the same function can be used.

[0020]

According to the present invention, when an instruction to stop the rotation of the DC motor is input, both terminals of the DC motor are short-circuited by the short-circuit means to generate an electromagnetic braking force to stop the rotation of the DC motor. .. Therefore, the rotation of the DC motor can be accurately controlled. Further, since the control circuit is formed by an integrated circuit, it has a long life as compared with one using a mechanical switch, and a highly reliable control function can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a motor control circuit according to the present invention.

FIG. 2 is a schematic perspective view showing a page turning device in which the motor control circuit according to the present invention is used.

FIG. 3 is a left side view showing a page turning device in which the motor control circuit according to the present invention is used.

FIG. 4 is a front view showing a page turning device in which the motor control circuit according to the present invention is used.

FIG. 5 is a right side view showing a page turning device in which the motor control circuit according to the present invention is used.

[Explanation of symbols]

 10 Index page 12 DC motor 20 Touch switch 22 Battery 30 Flip-flop circuit 32 Monostable multivibrator 34 Index sensor Q1 transistor Q2 transistor

Claims (2)

[Claims] 1. A motor control circuit for controlling rotation of the direct current motor in a drive mechanism driven by a direct current motor, wherein the control circuit comprises a power supply means for supplying a predetermined voltage to both terminals of the direct current motor, The DC motor includes short-circuiting means for short-circuiting both terminals of the DC motor, and control means for controlling the respective means according to an input instruction to start and stop rotation of the DC motor. When the instruction to start the rotation of the DC motor is input, the power supply unit supplies a voltage to the DC motor, and when the instruction to stop the rotation of the DC motor is input, both terminals of the DC motor are grounded by the short-circuiting unit. A motor control circuit characterized by short-circuiting so that a back electromotive force is generated in the motor. 2. A telephone number list including the control circuit according to claim 1, which is rotatably provided and has a plurality of pages, is rotated by driving the DC motor, and the telephone number list is displayed on a predetermined page. A page-turning device for a telephone number list to be stopped at a position, wherein when an instruction to stop the rotation of the DC motor is input at a predetermined position, both terminals of the DC motor are short-circuited by the short-circuiting means. A page turning device for a telephone number list, wherein the telephone number list is stopped at a predetermined page position.