JPH03243194A - Number of rotation controller for motor - Google Patents

Abstract

PURPOSE:To reduce the scale of a circuit and miniaturize a device by a method wherein a signal, showing the detected number of rotation of a motor selected from a plurality of motors, is outputted to a servo circuit while the selected signal is inputted into a driver switching circuit to drive the motor. CONSTITUTION:A mode switching signal A, selecting a play mode from a CPU, is outputted to a FG switching circuit 17 and a driver switching circuit 18. Then, the FG switching circuit 17 provides a servo circuit 15 with only the output of a FG amplifier 14a, which shows the detected number of rotation of a capstan motor 11. At the same time, the driver switching circuit 15 is operated so as to give an output from the servo circuit 15 to only a driver 16a which drives the capstan motor 11. Accordingly, the servo circuit 15 is used only for effecting the servo of the capstan motor 11 and forms a servo system for the capstan motor 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to the rotation speed of motors such as capstan motors and reel motors used in DAT (digital audio tape recorder), VTR (video tape recorder), etc. This relates to a motor rotation speed control device for constant control, and in particular, a motor rotation speed control device that reduces the circuit scale by sharing one servo circuit with multiple motors, making it possible to downsize the device. Regarding.

[Prior Art] Tape players such as DATs and VTRs have a drum motor for driving a rotating drum, a capstan motor for driving a capstan, a reel motor on the take-up side for driving the reel table, and a reel motor on the supply side. Various motors are used, such as a supply-side reel motor for driving the reel stand. These various motors are subjected to rotation servo corresponding to various modes such as play (recording/reproduction), FF direction high speed search, and REW direction high speed search.

For example, in the play mode, drum servo and capstan servo are performed. Further, in the FF direction high speed search mode, drum servo and take-up side reel servo are performed, and in the REW direction high speed search mode, drum servo and supply side reel servo are performed.

Each of these various motors is provided with a servo system as shown in FIG. In other words, the reference numeral 1 in Fig. 2 is a motor, and this motor 1 has F G (Fr
Equency Generator) is built-in. Further, reference numeral 2 is an FG amplifier, 3 is a servo circuit, and 4 is a driver.

[Problems to be Solved by the Invention] However, in conventional servo systems, each of a plurality of motors is provided with a servo circuit, as shown in Figure 2. There is a problem in that servo circuits are required for the number of motors, resulting in an increase in circuit scale and an increase in the size of the device.

The present invention is intended to solve the above-mentioned problems, and provides a motor rotation speed control device that reduces the circuit scale and enables downsizing of the device by sharing one servo circuit with multiple motors. The purpose is to provide

[Means for Solving the Problems 1] A motor rotation speed control device according to the invention of the present application includes a plurality of motors each driven by a plurality of drivers, and a motor rotation speed control device that is provided to each of these motors and controls the rotation speed of each motor. a plurality of rotation speed detection means for detecting the respective rotation speeds, and a servo circuit that compares the detected rotation speed of the motor with a reference rotation speed and controls the power supplied to the motor. a motor selection means for outputting a selection signal instructing whether to perform the rotation; and a motor selection means to which the outputs of the motor selection means and each of the rotation speed detection means are input; A rotational speed input switching circuit outputs to the support circuit, and outputs from the servo circuit and motor selection means are input, and output from the servo circuit is inputted to a driver that drives the motor designated by the selection signal among the plurality of drivers. and a driver switching circuit that provides an output.

[Operation] According to the above means, the selection signal output from the motor selection means is input to the rotation speed input switching circuit, thereby indicating the detected rotation speed of one motor selected from each of the plurality of motors. A signal is output to the servo circuit. Also, by inputting the selection signal output from the motor selection means to the driver switching circuit, the servo signal from the servo circuit is
It is output to a driver that drives one motor selected from a plurality of drivers. Therefore, one support circuit can be shared by a plurality of motors, and the servo of the plurality of motors can be performed by one servo circuit.

[Example] The present invention will be described in detail below based on the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

This embodiment shows an example in which the present invention is applied to a DAT. In FIG. 1, reference numeral 11 is a capstan motor, 12 is a take-up side reel motor, and 13 is a supply side reel motor, each of which is not shown.
ncy Generator) is provided. Among these motors 11 to 13, the capstan motor 11 is servoed together with a drum motor (not shown) in a play (recording/reproduction) mode. The take-up reel motor 12 is servoed together with the drum motor in the FF high-speed search mode, and the supply reel motor 13 is servoed together with the drum motor in the REW high-speed search mode. In this way, each motor 11-1
3, one servo is performed in each mode of play, FF high-speed search, and REW high-speed search.

Further, reference numerals 14a, 14b, and 14c in the figure are FG amplifiers for amplifying signals from FGs provided in each of the motors 11, 12, and 13, respectively. Reference numeral 15 receives a rotation speed signal indicating the detected rotation speed of any one of the motors 11 to 13, and controls the rotation speed so that the detected rotation speed of that motor matches a reference rotation speed preset for each mode. Servo circuit for controlling power supplied to the motor, reference numeral 16a
, 16b, and 16c are drivers that drive each motor 11 to 13 in response to a servo signal from the servo circuit 15, respectively.

Further, in this embodiment, the servo circuit 15 and each FG
An FG switching circuit 17 is connected between the amplifiers 14a to 14C. This FG switching circuit 17 receives signals from the CPU (not shown) such as play mode, FF high speed search mode, R
A mode switching signal instructing one of the EW high speed search modes is input. When this mode switching signal is input, the FG switching circuit 17 detects the rotation of the motor (any one of the motors 11 to 13) that requires servo in the mode instructed by the mode switching signal. A rotation speed signal indicating the number of rotations is output to the servo circuit 15. Further, in this embodiment, the servo circuit 15 and each of the drivers 16a to 16c are
A driver switching circuit 18 is connected between them. This driver switching time! A mode switching signal is input to 818 from the CPU. When this mode switching signal is input, the driver switching circuit 18 selects a driver (each driver 16a to
A servo signal from the servo circuit 15 is applied to one of the servo circuits 16c).

Next, the operation will be explained.

First, when a mode switching signal A for selecting a play mode is output from the CPU (not shown) to the FG switching circuit 17 and the driver switching circuit 18, the FG switching circuit 17 sends an FG amplifier that indicates the detected rotation speed of the capstan motor 11. 14a
The driver switching circuit 18 operates to provide only the output from the servo circuit 15 to the support circuit 15, and the driver switching circuit 18 provides the output from the servo circuit 15 only to the driver 16a that drives the capstan motor 11. Therefore, in this play mode,
The servo circuit 15 is used to servo the capstan motor 11, forming a servo system for the capstan motor 11. In this play mode, a constant voltage is applied to each reel motor 12, 13 so that it rotates under appropriate tension. Further, a servo is separately applied to the drum motor (not shown) so that the relative speed to the rotational speed of the capstan is constant.

Next, when the CPU outputs a mode switching signal B for selecting the FF high-speed search mode, the FG switching circuit 17 switches to the FF high-speed search mode.
The driver switching circuit 18 operates to apply only the output from the G amplifier 14b to the servo circuit 15, and to apply the output from the servo circuit 15 only to the driver 16b. Therefore, in this FF high-speed search mode, the servo circuit 15 is used to servo the take-up reel motor 12, and a servo system for the take-up reel motor 12 is formed. In this FF high-speed search mode, a constant voltage is applied to the supply side reel motor 13 so that it rotates with an appropriate tension applied thereto.

Further, six separate servos are applied to drum motors (not shown).

Further, when the CPU outputs a mode switching signal C for selecting the REW high-speed search mode, the FG switching circuit 17
provides only the output from the FG amplifier 14c to the servo circuit 15, and the driver switching circuit 18 operates so as to provide the output from the servo circuit 15 only to the driver 16c. Therefore, in this REW high-speed search mode, the servo circuit 15 is used to servo the supply reel motor 13, and a servo system for the supply reel motor 13 is formed. In this REW high-speed search mode, a constant voltage is applied to the take-up reel motor 12 so that it rotates under appropriate tension. A servo is also applied to a drum motor (not shown) separately.

As described above, according to this embodiment, one servo circuit 15 can be connected to the capstan motor 11, the winding The motor is switched to be used for the servo of either one of the take-side reel motor 12 and the supply-side reel motor 13. Therefore, one servo circuit 15 can be shared by the three motors 11-13, and there is no need to provide a servo circuit for each motor 11-13 as in the conventional case. Therefore, the circuit scale can be made smaller than before, and the board can also be made smaller, so devices such as DATs can be made smaller.

[Effect 1 As described above, according to the present invention, a driver switching circuit is connected between a driver that drives a plurality of motors and a servo circuit, and a rotation speed detection circuit provided in each of the servo circuit and a plurality of motors is connected. A rotation speed input switching circuit is connected between the motor selection means and the input side and output side of the servo circuit are switched by a selection signal from the motor selection means, so that one servo circuit can control which of the plurality of motors. It will also be possible to form a servo system. Therefore, it is no longer necessary to use as many servo circuits as there are motors as in the conventional case. Therefore, the circuit scale of the motor rotation speed control device can be made smaller than before, and the board can also be made smaller, so devices such as DATs and VTRs can be made smaller.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a conventional motor servo system. 11... Capstan motor, 12... Winding side reel motor, 13... Supply side reel motor, 15.
... Servo circuit, 16a, 16b, 16cm... Driver, 17... FG switching circuit, 18... Driver switching circuit.

Claims (1)

[Scope of Claims] 1. A plurality of motors each driven by a plurality of drivers; a plurality of rotation speed detection means provided for each of these motors and configured to respectively detect the rotation speed of each motor; A servo circuit that compares the motor rotation speed and a reference rotation speed to control power supplied to the motor, and a motor selection circuit that outputs a selection signal that instructs which motor among the plurality of motors should be servoed. a rotational speed input switching circuit which receives the outputs of the motor selection means and each of the rotational speed detection means and outputs a signal indicating the detected rotational speed of the motor designated by the selection signal to the servo circuit; It is characterized by comprising a servo circuit and a driver switching circuit into which the output of the motor selection means is input and which gives the output from the servo circuit to the driver that drives the motor designated by the selection signal among the plurality of drivers. Motor rotation speed control device