CN1140358A - Motor control equipment for controlling DC brushless motors with tapped ends - Google Patents

Abstract

A motor control device used to control a battery-operated DC motor having a tapped end in the middle of each of the three coils. When the motor starts to work, the speed is low, so the whole coil drive operation is selected to drive the motor with high torque. When the rotation speed increases, select the split coil drive operation to drive the motor with a small torque. When the voltage drops due to the exhaustion of the battery, the rotational speed is reduced, so that the full coil drive operation is performed again. Thereafter, the selection prohibiting means prohibits the sub-coil driving operation even if the battery voltage rises temporarily. Therefore, the motor can be operated stably without repeated operation switching.

Description

Motor control equipment for controlling DC brushless motors with tapped ends

The present invention relates generally to a motor control device for a DC type brushless motor for portable recording and playback equipment, and more particularly to a motor control device for controlling a DC type motor driven by a battery used as a power source and having multiple The tap ends are arranged at prescribed positions of the plurality of coils corresponding to the plurality of phases.

At present, three-phase brushless DC motors driven by low-voltage power sources have been used in portable magnetic recording and playback equipment represented by headphone stereos to reduce the size of the motor, improve portability and drive with higher reliability electric motor. In addition, it is desirable to further reduce the operating time of the device during tape fast-forward and rewind operations. It is also desirable to further reduce the power consumed by the device for normal playback.

For example, a conventional three-phase brushless DC type motor is disclosed in Published Unexamined Japanese Patent Application No. 283088 (H1-283088) of 1989. In this conventional motor, each of the three-phase coils is provided with a tap end at a prescribed position. By supplying electric power to each entire coil, the three-phase brushless DC type motor performs a starting operation, which is called an operation of supplying power to the entire coil. When the number of revolutions of the motor reaches the specified value after the starting operation, power is supplied to the motor through the tap end to drive each partial coil (partial coil) between the common end of the coil and the tap end, and this operation is called to Sub-coil powered operation. Therefore, power consumption can be reduced.

In this case, the characteristic relationship between the required torque and the consumed motor current shown in Fig. 1 can be obtained. That is to say, since the number of turns of each coil used in the operation of supplying power to the sub-coils is less than the number of turns used in the operation of supplying power to the whole coil, the current consumed in the operation of supplying power to the sub-coils is generally lower than that in the operation of supplying power to the whole coil. big. Therefore, if a battery is used as a power source to drive the motor, the motor current supplied to the motor is generally limited under the control of the motor control device to prevent the battery from consuming too much power. For example, when the motor current is limited to the current limit value IL (Fig. 9), in the operation of supplying power to the whole coil, the maximum torque value obtained by the motor is T1, while in the operation of supplying power to the sub-coils, the motor obtains The maximum torque value is T2, and T1>T2 is satisfied.

In addition, as shown in FIG. 2, a characteristic relationship between the required torque and the number of revolutions of the motor can be obtained. In the range where the motor load applied to the motor is smaller than the torque value T2 corresponding to the current limit value IL when supplying power to the sub-coil, the motor rotation speed when supplying power to the sub-coil is greater than the rotation number of the motor when supplying power to the whole coil . Conversely, in a range in which the motor load applied to the motor is greater than the torque value T2, the motor revolutions when powering the sub-coils are smaller than when powering the whole coils.

Therefore, since the motor requires a high motor load at the start operation, the start torque is supplied to the motor by performing an operation of supplying power to the entire coil under the control of a conventional motor control device. Conversely, when the motor load required by the motor is reduced below a specified value due to the number of revolutions of the motor becoming sufficiently large in supplying the full coil operation, the type of operation is changed from full coil to full coil under the control of conventional motor control equipment. The power supply operation is switched to the power supply operation to the sub-coils, so that the number of revolutions of the motor reaches a high value in a shorter time.

However, if factors such as ambient temperature change during power supply operation to the sub-coils to increase the motor load, the motor current increases, and the motor current is limited to an allowable upper limit of the motor current by the function of the motor current limiting circuit, thereby The number of revolutions of the motor is reduced. Therefore, if the conventional motor control apparatus cannot perform a switching operation from supplying power to the entire coil to supplying power to the sub-coils, there is a disadvantage that the number of revolutions of the motor cannot be maintained. In addition, since the motor current increases up to the allowable upper limit of the motor current in the conventional motor control apparatus, there is a disadvantage that the power supply battery is quickly exhausted.

In addition, if the motor load or torque changes when the motor current value approaches the allowable upper limit of the motor current, the number of revolutions of the motor may rise and fall undesirably. Therefore, when it is detected that the number of revolutions decreases to a certain operation type change value Nc due to a change in the motor load, the switching operation from power supply to the sub-coils to power supply to the whole coil is performed under the control of the conventional motor control device, and the number of revolutions is within Raised during full coil power operation. Then, when the number of revolutions rises above the operation type change value Nc, switching operation from power supply to the whole coil to power supply to the sub-coils is performed under the control of the conventional motor control device, and the motor is driven in the power supply operation to the sub-coils. Therefore, a switching operation is performed every time a change in the number of rotations is detected, but there is a disadvantage that a stable motor operation that keeps the number of rotations constant cannot be performed.

In addition, if a battery is used as the power source, when the battery is almost exhausted and the power supply voltage drops during the operation of supplying power to the sub-coils, the motor current is increased to the allowable upper limit of the motor current under the control of the conventional motor control device to provide power to the sub-coils. The number of revolutions is maintained at a specified value during operation powered by the sub-coil. In this case, since the motor current increases up to the allowable upper limit of the motor current to compensate for the drop in the supply voltage, there is a disadvantage that the supply voltage drops at an accelerated rate.

In addition, even if the power supply voltage drops, the switching operation from power supply to the entire coil to power supply to the sub-coils is performed under the control of the conventional motor control device, the motor current increases, and the power supply voltage drops rapidly. Therefore, even if the motor requires a high rotational speed, there is still a disadvantage that the number of revolutions when operating with power supplied to the sub-coils is smaller than that when operating with power supplied to the full coils.

In view of the disadvantages of conventional motor control devices, a first object of the present invention is to provide a motor control device with which a motor is controlled so that even if the ambient temperature or the like changes or the voltage supplied from a battery used as a power source drops While changing the load of the motor, the number of revolutions of the motor can also be maintained within a wide power supply voltage range for tape fast-forward operation or tape rewind operation.

A second object of the present invention is to provide a motor control apparatus in which a magnetic tape can be wound rapidly during fast forward or rewind operation.

The first object is achieved by providing a motor control apparatus for controlling a direct current motor powered by battery power, wherein a tap terminal is provided at a prescribed position in the middle of each of one or more coils of the motor, The equipment includes:

Operation type selection means for selecting full-coil drive operation or sub-coil drive operation, in which the motor current supplied by the battery flows through each full coil of the DC motor, and in sub-coil drive operation, the motor current supplied by the battery Current flows through each sub-coil between the tap end and one end of the coil;

A number-of-rotation detection device for detecting the number of rotations of the direct current motor, if the number of rotations is low, the device outputs a signal of low number of rotations, and if the number of rotations is high, the device outputs a signal of high number of rotations; and

selection prohibiting means for commanding the operation type selection means to select the whole coil drive operation if a low-revolution signal is received from the revolving-number detection means, under the condition that the low-revolution signal is not received after receiving the high-revolution signal, If a high revolution signal is received from the revolution detection device, the command operation type selection device selects the sub-coil driving operation, and under the condition that the DC motor performs the sub-coil driving operation and then performs the whole coil driving operation, if it is detected again from the revolution number When the device receives the high rotation speed signal, it commands the operation type selection device to select the whole coil driving operation.

In the above structure, when starting the DC motor, since the number of revolutions of the DC motor is low, it is necessary to drive the DC motor with a large torque. Therefore, the rotation number detection means outputs a low rotation number signal to the selection prohibition means, the operation type selection means selects the full coil drive operation due to the command of the selection prohibition means, and performs the full coil drive operation of the DC motor. Then, the number of revolutions of the DC motor gradually increases.

When the number of revolutions of the DC motor becomes high, it is necessary to drive the DC motor with a lower torque. Therefore, the number of rotations detection means outputs a high number of rotations signal to the selection prohibition means, and the operation type selection means selects the sub-coil drive operation due to the command of the selection prohibition means, and performs a switching operation from the full coil drive operation to the sub-coil drive operation, and Performs split-coil drive operation on DC motors.

Then, if the motor load increases or the voltage supplied from the battery decreases due to the battery being almost exhausted, the number of revolutions of the DC motor decreases because the torque required for the sub-coil driving operation is too large. Therefore, the rotation number detection means outputs a low rotation number signal to the selection prohibition means, and the operation type selection means selects the full coil driving operation again by the command of the selection prohibition means. Therefore, the switching operation from the sub-coil driving operation to the full-coil driving operation is performed, and the full-coil driving operation is performed on the DC motor again.

Then, even if the motor load is temporarily reduced or the voltage supplied by the battery is temporarily increased, so that the revolution detection means outputs a high revolution signal to the selection prohibition means, the operation type selection means still keeps selecting the whole coil drive due to the command of the selection prohibition means operate. That is, the selection prohibiting means prohibits the selective sub-coil driving operation.

Thereby, repeated switching operations can be prevented, and the DC motor can be stably operated even if the load on the motor temporarily decreases or the voltage supplied from the battery temporarily increases. Therefore, it is possible to control the motor even if the load of the motor changes due to a change in the ambient temperature or the like or a drop in the voltage supplied by the battery used as the power source, within a wide power supply voltage range for tape fast-forward or tape rewind operation Maintain the number of revolutions of the motor.

The second object is achieved by providing a motor control device for controlling a direct current motor powered by battery power, wherein a tapped end, the device consists of:

The rotation number detection device is used to detect the rotation number of the DC motor;

operation type selection means, if the number of revolutions detecting means detects that the number of revolutions is lower than the first number of revolutions, it selects a full coil drive operation in which the motor current supplied by the battery flows through each full coil of the DC motor, and if the number of revolutions detecting means detects If the number of revolutions reached is equal to or greater than the first number of revolutions, it selects the sub-coil driving operation, at which time the motor current supplied by the battery flows through each sub-coil between the tap end and one end of the coil; and

Motor voltage setting means which sets the differential voltage applied to each coil of the DC motor as the voltage of the battery if the number of rotations detected by the number of rotations detection means is lower than a second number of rotations, wherein the second number of rotations is equal to or is greater than the first number of revolutions, and if the number of revolutions detected by the number of revolution detection means is equal to or greater than the second number of revolutions, it sets the differential voltage applied to each coil of the DC motor to be higher than the voltage of the battery. differential voltage.

In the above structure, when starting the DC motor, since the number of rotations of the DC motor is lower than the first number of rotations, it is necessary to drive the DC motor with a larger torque. Therefore, the operation type selection means selects the full-coil driving operation, and performs the full-coil driving operation on the DC motor. In this case, the motor voltage setting means sets the differential voltage applied to each coil of the DC motor as the voltage of the battery. Then, the number of revolutions of the DC motor gradually increases.

When the number of rotations of the DC motor reaches the first number of rotations, it is necessary to drive the DC motor with a lower torque. Therefore, the operation type selection means selects the sub-coil driving operation, performs switching operation from the full-coil driving operation to the sub-coil driving operation, and performs sub-coil driving operation on the DC motor. In this case, the motor voltage setting means still sets the differential voltage applied to each coil of the DC motor as the voltage of the battery.

Then, when the number of rotations of the DC motor reaches the second number of rotations, the motor voltage setting means increases the differential voltage applied to each coil of the DC motor to the increased differential voltage. Therefore, the number of revolutions of the DC motor can be quickly raised, and the magnetic tape can be wound quickly.

In order to achieve the first purpose, the motor control equipment preferably also includes:

Select the prohibiting device, if the operation type selection device selects the whole coil driving operation after selecting the sub-coil driving operation, then use it to prohibit the operation type selection device from selecting the sub-coil driving operation.

In the above structure, if the motor load increases or the voltage supplied from the battery drops because the battery is almost exhausted, the number of revolutions of the DC motor decreases below the second number of revolutions. In this case, the motor voltage setting means sets the differential voltage applied to each coil of the DC motor as the voltage of the battery to avoid a rapid drop in battery voltage. Then, since the torque required for the driving operation of the sub-coils is too large, the number of rotations of the DC motor falls below the first number of rotations. Therefore, the operation type selection means selects the full-coil driving operation again, and performs the full-coil driving operation on the DC motor again.

Then, even if the number of revolutions of the DC motor rises to be equal to or greater than the first number of revolutions due to a temporary decrease in the motor load or a temporary increase in the voltage supplied from the battery, the selection prohibiting means prohibits the operation type selection means from selecting the sub-coil driving operation. .

Thereby, repeated switching operations can be prevented, and the DC motor can be stably operated even if the load on the motor temporarily decreases or the voltage supplied from the battery temporarily increases. Therefore, it is possible to control the motor even if the load of the motor changes due to a change in the ambient temperature or the like or a drop in the voltage supplied by the battery used as the power source, within a wide power supply voltage range for tape fast-forward or tape rewind operation Maintain the number of revolutions of the motor.

Objects, features and advantages of the present invention will be apparent from the following description read in conjunction with the accompanying drawings, in which:

Fig. 1 shows the characteristic relationship curve between the required torque and the consumed motor current in an electric motor;

Fig. 2 has shown the characteristic relationship curve between required torque and revolution number in this motor;

FIG. 3 is a block diagram of a motor control device according to a first embodiment of the present invention;

The circuit diagram of Fig. 4 motor revolution detection device 17, selection prohibition device 20 and operation type selection device 21;

FIG. 5 is a block diagram of a motor control apparatus according to a second embodiment of the present invention;

Fig. 6 is a block diagram of a motor control apparatus according to a third embodiment of the present invention;

FIG. 7 is a block diagram of a motor control apparatus according to a fourth embodiment of the present invention;

Fig. 8 is a block diagram of a motor control apparatus according to a fifth embodiment of the present invention;

Fig. 9 shows the characteristic relationship curve between the required torque and the consumed motor current in the motor of the fifth embodiment;

Fig. 10 shows the characteristic relationship curve between the required torque and the number of revolutions in the motor of the fifth embodiment;

Fig. 11 is a block diagram of a modified motor control device of the fifth embodiment;

Fig. 12 is a block diagram of a motor control apparatus according to a sixth embodiment of the present invention;

Fig. 13 is a block diagram of a motor control apparatus according to a seventh embodiment of the present invention;

Fig. 14 is a block diagram of a motor control apparatus according to an eighth embodiment of the present invention;

FIG. 15 is a block diagram of a motor control apparatus according to a ninth embodiment of the present invention; and

Fig. 16 is a flow chart showing the operation performed in the motor control apparatus shown in Fig. 15 .

Preferred embodiments of the motor control apparatus of the present invention will now be described with reference to the accompanying drawings.

Fig. 3 is a block diagram of a motor control apparatus according to a first embodiment of the present invention.

Fig. 3 shows a kind of motor control device 11, and it is used for controlling three-phase DC type tape winding motor 12, and each of three coils 14 is provided with a tap terminal Tt in this motor, and this motor control device 11 comprises:

The motor driving device 15 is used to generate a motor driving signal corresponding to each coil 14 of the motor 12;

The voltage generating device 16 is used to generate an induced voltage whose value corresponds to the number of revolutions of the motor 12;

Motor rotation number detecting device 17, it detects the number of revolutions in the motor 12 (or the rotating speed of motor 12 rotors) according to the induced voltage value produced in the voltage generating device 16, if the detected number of revolutions is equal to or lower than the prescribed number of revolutions, then It generates a low revolution signal, and if the detected revolution is higher than the specified revolution, it generates a high revolution signal;

A motor current detection device 18, used to detect the motor current provided to the motor 12;

The motor current limiting device 19, if the motor current detected by the motor current detecting device 18 rises to an allowable current upper limit value, then use it to generate a motor current limiting signal, order to reduce the motor current, and output the motor current limiting signal To the motor drive device 15 to control the strength of the motor drive signal;

Select prohibiting device 20, if when receiving low revolution signal from motor revolution detection device 17, then use it to generate the whole coil drive operation selection signal, represent the operation that selects the power supply to whole coil, after receiving high revolution signal, there is no Under the condition of receiving the low-speed signal, if the high-speed signal is received from the motor-speed detection device 17, it will be used to generate a sub-coil drive operation selection signal, indicating that the operation to supply power to the sub-coil is selected, and in the previous operation Under the condition that the low-speed signal is received after receiving the high-speed signal, if the high-speed signal is received again from the motor-speed detection device 17, it is used to generate a full-coil drive operation selection signal;

The operation type selection means 21, if it receives a full-coil drive operation selection signal from the selection prohibition means 20, it selects a full-coil drive operation in which current passes through each full coil 14 of the motor 12, and if a sub-coil drive operation is received from the selection prohibition means 20 drive operation selection signal, it selects the sub-coil drive operation in which the current passes through the entire path between the common terminal Tc of the coil M and each tap terminal Tt;

Battery 22, which acts as a power supply, provides electric power from the positive pole of battery 22 through a power switch 13 to the motor drive device 15, the motor revolution detection device 17, the motor current limiting device 19, the selection prohibition device 20 and the operation type selection device 21, and add a voltage Vcc to the common terminal Tc; and

Current path selection means 23, if the operation type selection means 21 selects the whole coil drive operation, then use it to provide the first current path, make the electric current provided by the battery 22 pass through each full coil 14, if the operation type selection means 21 select the sub-coil drive It is used to provide a second current path, so that the current provided by the battery 22 passes between the common terminal Tc of the motor 12 and each tap terminal Tt, and the intensity of the current is controlled according to the intensity of the motor drive signal output by the motor drive device 15.

The operation type selection means 21 includes three switch circuits respectively corresponding to one coil 14 of the motor 12 . Each switch circuit has an input terminal Tc1, a first output terminal Tc2 and a second output terminal Tc3, wherein the input terminal Tc1 is used to receive the motor drive signal output by the motor drive device 15, when the full coil drive operation is selected, the first output terminal The terminal Tc2 is connected to the input terminal Tc1, and when the sub-coil driving operation is selected, the second output terminal Tc3 is connected to the input terminal Tc1.

The current path selection device 23 includes three first current path circuits corresponding to the driving operation of the full coil and three second current path circuits corresponding to the driving operation of the sub-coil. Each first current path circuit has a base resistor 23a connected to a first output terminal Tc2 and an npn type full-coil driving transistor 23b, wherein the base of the transistor 23b is connected to the base resistor 23a, and the emitter is grounded. The collector is connected to one end of a coil 14 for providing a first current path for passing current through a whole coil 14 and controlling the current intensity according to the motor driving signal input to the base. Each second current path circuit has a base resistor 23c connected to a second output terminal Tc3 and an npn type sub-coil driving transistor 23d, wherein the base of the transistor 23d is connected to the base resistor 23c, and the emitter is grounded. And the collector is connected to a tap terminal Tt for providing a second current path for the current between the common terminal Tc and a tap terminal Tt, and controlling the current intensity according to the motor driving signal input to the base.

The motor speed control device is composed of a motor speed detection circuit 17 and a voltage generating device 16 . The motor control device is composed of a motor drive device 15 , a motor revolution detection device 17 , a motor current limiting device 19 and a selection prohibition device 20 . The negative terminal of the battery is grounded.

FIG. 4 is a circuit diagram of the motor rotation number detection means 17 , the selection prohibition means 20 and the operation type selection means 21 .

As shown in FIG. 4 , the motor revolution detection device 17 includes a sample-and-hold circuit 17a for holding the induced voltage value generated in the voltage generating device 16, a reference voltage source 17b grounded at one end, and a comparator 17c. When the sample-and-hold circuit 17a When the retained induced voltage value is equal to or lower than the reference voltage provided by the reference voltage source 17b, the comparator 17c outputs a low level signal, and when the induced voltage value retained in the sample and hold circuit 17a is higher than the reference voltage provided by the reference voltage source 17b , the comparator 17c outputs a high level signal.

The selection prohibition circuit 20 includes a trigger circuit 20a and an "AND" gate 20b, wherein the trigger circuit 20a has an inverting terminal R for receiving the voltage Vcc of the battery 22, and a terminal R for receiving the low level or high level signal output by the comparator 17c. terminal S, and when the voltage Vcc of the battery 22 is added to the inverting 0 terminal R, the output terminal Q that initially outputs a high-level signal, when the output terminal Q of the comparator 17c and the trigger circuit 20a receives a high revolution signal When combined with a high-level signal, the "AND" gate 20b outputs a high-level signal as a full-coil drive operation selection signal, while in other cases, the "AND" gate outputs a low-level signal as a full-coil drive operation selection signal. The trigger circuit 20a is composed of a JK type trigger circuit, and after the output terminal Q outputs a low-level signal, even if the high-level signal of the comparator 17c is input to the 1-setting terminal S, the trigger circuit 20a will not output a high-level signal again. Signal.

Each switch circuit of the operation type selection device 21 includes a first npn transistor Q1, a second pnp transistor Q2, a third pnp transistor Q3, a fourth pnp transistor Q4, a fifth npn transistor Q5, a sixth npn transistor Q6, a seventh npn transistor transistor Q7 and an eighth npn transistor Q8. Among them, in the first transistor Q1, the base is connected to the motor driving device 15, and the emitter is grounded; in the second transistor Q2, the emitter is connected to the battery 22 through the switch 13, and the base and the collector are connected to the transistor Q1. collector; in the third transistor Q3, the emitter is connected to the battery 22 through the switch 13, and the base is connected to the collector of the transistor Q1; in the fourth transistor Q4, the emitter is connected to the battery 22 through the switch 13, and the base Connected to the collector of the transistor Q1, and the collector is connected to the second output terminal Tc3, a pair of constant current sources I1 and I2 are respectively connected to the battery 22 through the switch 13; in the fifth transistor Q5, the base receives the "AND" gate For the output signal of 20b, the emitter is grounded, and the collector receives the constant current of the constant current source I1; in the sixth transistor Q6, the base is connected to the collector of the transistor Q5, the emitter is grounded, and the collector receives the constant current source I2 In the seventh transistor Q7, the base receives the constant current from the constant current source I2, the emitter is grounded, and the collector is connected to the collector of the transistor Q3 and the first output terminal Tc2; in the eighth transistor Q8, The base receives a constant current from the constant current source I2, the emitter is grounded, and the collector is connected to the collector of the transistor Q4.

With the above structure, the operation of the motor control apparatus 11 will be described with reference to FIGS. 1 and 2. FIG.

When the switch 13 is turned on to supply power to the devices 15, 17, 19, 20, and 21, since the induced voltage value generated in the voltage generating device 16 is zero, it is generated in the comparator 17c of the motor revolution detecting device 17. The low revolution signal, and then the low revolution signal is input to the flip-flop circuit 20a and the AND gate 20b. Since a high-level signal is initially output from the flip-flop circuit 20a, and this signal is input to the AND gate 20b, the AND gate 20b of the selection prohibition device 20 outputs a low-level full-coil drive operation selection signal to the operation type Transistor Q5 of means 21 is selected, placing transistor Q5 in an off state. In addition, a motor drive signal is generated in the motor drive means 15 and input to the transistor Q1 of the operation type selection means 21, placing the transistor Q1 in an on state.

In device 21, the constant current from constant current source I1 places transistors Q6 and Q8 on since transistor Q5 is off, and transistor Q7 is off since transistor Q6 is on. In addition, since the transistor Q1 is turned on, the transistors Q2 to Q4 are placed in an on state. Therefore, the motor driving command represented by the motor driving signal is transmitted to the transistor Q3 and the transistor Q4 through the transistor Q1 and the transistor Q2, and since the transistor Q7 is turned off and the transistor Q8 is turned on, the motor driving command is transmitted from the transistor Q3 to the first output terminal Tc2 . That is, the motor drive command is transmitted through a current mirror circuit (current mirror circuit) composed of transistors Q1 to Q3.

Then, the motor drive command is transmitted to the full coil drive transistor 23b through the base resistor 23a, the full coil drive transistor 23b is placed in an on state, and the drive current provided by the battery 22 passes through the common terminal Tc, each full coil 14 and the full coil drive transistor 23b. The coil drive transistor 23b is then grounded.

Therefore, at the time of starting, the motor 12 performs a full-coil driving operation under the control of the motor control device 11, and the number of revolutions in the motor 12 gradually increases. Therefore, the maximum torque required by the motor at the time of starting can be reliably obtained by performing the full-coil driving operation (FIG. 2 and FIG. 3). Continue to drive the entire coil until the value of the induced voltage generated in the voltage generating device 16 reaches the reference voltage provided by the reference voltage source 17b. For example, when the number of revolutions of the motor 12 reaches a certain number of revolutions corresponding to the torque T2 (FIG. 2), the value of the induced voltage generated in the voltage generating device 16 reaches the reference voltage.

Then, when the number of rotations of the motor 12 exceeds the specified number of rotations, a reference voltage whose induced voltage value exceeds the reference voltage source 17b is generated in the voltage generating device 16 . Therefore, the output of the comparator 17c of the motor speed detection device 17 changes from a low speed signal to a high speed signal, and the high speed signal is input to the flip-flop circuit 20a and the AND gate 20b. Since the high rotation speed signal is input to the 1-setting terminal S of the flip-flop circuit 20a, the output of the output terminal of the flip-flop circuit 20a remains at a high level signal. Therefore, the AND gate 20b outputs a high-level signal as a full-coil drive operation selection signal, and inputs the signal to the transistor Q5 of the operation type selection device 21 to turn on the transistor Q5.

In device 21, transistors Q6 and Q8 are placed off due to the constant current from constant current source I1 through transistor Q5, and transistor Q7 is placed on close by the constant current from constant current source I2 since transistor Q6 is off. pass status. Therefore, the motor drive command represented by the motor drive signal is transmitted to the transistors Q3 and Q4 through the transistors Q1 and Q2, and since the transistor Q7 is turned on and the transistor Q8 is turned off, the motor drive command is transmitted from the transistor Q4 to the second output terminal Tc3. That is to say, the motor drive command is transmitted through the current mirror circuit composed of transistors Q1, Q2 and Q4.

Then, the motor drive instruction is transmitted to the sub-coil driving transistor 23d through the base resistor 23c, the sub-coil driving transistor 23d is placed in the ON state, and the driving current provided by the battery 22 passes through the common terminal Tc, each sub-coil 14, each A tap terminal Tt and sub-coil driving transistor 23d, and then grounded.

Therefore, after the number of revolutions of the motor 12 exceeds a certain number of revolutions, the motor 12 performs a separate-coil driving operation under the control of the motor control device 11, and the number of revolutions of the motor 12 increases again (FIG. 2). Therefore, the electric motor 12 can reliably obtain a high number of revolutions in a short time.

Then, when the required motor load or motor torque of the motor 12 reaches an allowable upper limit, the motor current detected by the motor current detection device 18 increases to an allowable upper limit current value, and the motor current limiting device 19 generates a command A motor current limit signal that reduces motor current and outputs this signal to the motor drive 15 . Thereby, the level of the motor drive signal is lowered, the level of the motor drive command is lowered, and the intensity of the drive current supplied from the battery 22 is lowered. As a result, the number of revolutions of the motor 12 is reduced to a specific number of revolutions, the output of the comparator 17c of the motor revolution number detecting device 17 changes from a high revolution number signal to a low revolution number signal, and the low revolution number signal is input to the flip-flop circuit 20a and AND gate 20b. Since the low rotation speed signal is input to the 1-setting terminal S of the flip-flop circuit 20a, the output of the output terminal of the flip-flop circuit 20a becomes a low-level signal. Therefore, the full coil drive operation selection signal is output from the AND gate 20b of the selection inhibiting means 20 to the operation type selection means 21 to select the full coil drive operation, and then the full coil drive operation is performed in the same manner as at startup. The motor 12 is operated. Therefore, the motor torque required for the motor 12 can be reduced ( FIGS. 2 and 3 ).

Then, since the motor torque required by the motor 12 is lowered in the full-coil driving operation, the number of revolutions of the motor 12 gradually increases, and the number of revolutions of the motor 12 increases beyond a certain number of revolutions. In this case, the output of the comparator 17c of the motor revolution detection device 17 changes from the low revolution signal to the high revolution signal, and again inputs the high revolution signal to the flip-flop circuit 20a and the AND gate 20b. In the flip-flop circuit 20a, even if the high-revolution signal is input to the 1-setting terminal S again, since the low-revolution signal has been received after the high-revolution signal in the previous operation, the output terminal Q outputs The full coil drive operation selection signal is maintained to select the full coil drive operation in the operation type selection means 21 . In other words, even if the motor rotation number detection means 17 outputs a high rotation number signal, the selection prohibition means 20 prohibits selection of the divided coil drive operation in the operation type selection means 21 . Therefore, regardless of the number of revolutions of the motor 12, the motor continues the full-coil driving operation until the switch 13 is turned off, and the sub-coil driving operation is prohibited after the sub-coil driving operation by the motor 12 becomes the full-coil driving operation.

When the switch 13 is turned off, since a low-level signal is input to the 0-set terminal of the trigger circuit 20a, the trigger circuit is set to 0. Therefore, when the switch 13 is turned on again, the full-coil driving operation is performed first, and then the switching operation from the full-coil driving operation to the sub-coil driving operation is performed.

Consequently, the motor torque required by the electric motor 12 can no longer reach the permissible upper limit. In other words, it is impossible to repeat the switching operation between the sub-coil driving operation and the full-coil driving operation, and it is possible to stably operate the motor 12 . In addition, even if the motor current detected by the motor current detecting means 18 increases to an allowable upper limit current value due to a decrease in the voltage Vcc of the battery 22, it can be realized by performing the full-coil driving operation in the motor 12 and prohibiting the divided-coil driving operation. Operate the motor 12 stably.

In the first embodiment, the first switching operation from the full-coil driving operation to the sub-coil driving operation is permitted by the function of the selection prohibition device 20, but the switching operation after the sub-coil driving operation performed in the motor 12 is changed to the full-coil driving operation is prohibited. Secondary switching operation from full-coil driving operation to sub-coil driving operation. However, the above functions can be performed by using a microcomputer instead of the trigger circuit 20a.

Next, a second embodiment of the present invention will be described.

Fig. 5 is a block diagram of a motor control apparatus according to a second embodiment of the present invention.

As shown in FIG. 5, the motor control device 31 for controlling the motor 12 includes:

Motor driving device 15; voltage generating device 16; motor revolution detection device 17; motor current detection device 18; motor current limiting device 19;

A power supply voltage detection and judging device 32, configured to detect the power voltage provided by the battery 22 through the power switch 13, and judge whether the power voltage is lower than a specific voltage value;

The number of revolution signal output device 33 formed by an "AND" gate, when the power supply voltage detection and judgment device 32 judges that the power voltage is not lower than a specific voltage value, the number of revolution signal output device 33 will output with the motor revolution number detection device 17 The low or high revolution signal of the same revolution signal is output to the selection prohibition device 20, and when the power voltage detection and judgment device 32 judges that the power voltage is lower than a specific voltage value, no matter whether the motor revolution detection device 17 outputs low or high The number of revolutions signal, the number of revolutions signal output device 33 outputs a low revolutions signal to the selection prohibition device 20;

Selection prohibition means 20; operation type selection means 21; battery 22 and current path selection means 23.

In the above-mentioned structure, when the switch 13 is turned on, since the motor revolution number detecting means 17 outputs the low revolution number signal to the revolution number signal output means 33, the means 33 outputs the low revolution number signal to the selection prohibition means 20, and uses A full-coil driving operation is performed in the motor 12 in the same manner as in the first embodiment.

Then, when the number of revolutions of the motor 12 exceeds a certain number of revolutions under the condition that the power voltage is not lower than a certain voltage value, a switching operation is performed from the full-coil driving operation to the sub-coil driving operation, and the same method as that of the first embodiment is used. Mode In the electric motor 12, a coil driving operation is performed.

When the battery 22 is almost exhausted and the power supply voltage of the battery 22 drops below a certain voltage value, the drop of the power supply voltage is detected by the power supply voltage detecting and judging device 32, which judges that the power voltage is lower than a certain voltage value, and regardless of the motor rotation speed Whether the number detection device 17 outputs a low or high rotation number signal, the rotation number signal output device 33 outputs the low rotation number signal to the selection prohibition device 20 . When the full-coil driving operation is performed in the motor 12, even if the number of revolutions of the motor 12 exceeds a certain number of revolutions, the full-coil driving operation is continued.

In addition, when the sub-coil drive operation is performed in the motor 12, since the revolution signal output device 33 outputs a low revolution signal to the selection prohibition device 20, and the device 20 outputs a full-coil drive operation selection signal to the operation type selection device 21 , so the switching operation from the sub-coil driving operation to the full-coil driving operation is performed, and then the full-coil driving operation is performed in the motor 12 . Therefore, even if the power supply voltage of the battery 22 is temporarily restored and rises to be equal to or greater than a certain voltage value, the full-coil driving operation selection signal output by the device 20 is maintained. That is, the full-coil driving operation is continued, and the switching operation from the full-coil driving operation to the sub-coil driving operation is prohibited until the switch 13 is turned off.

In the second embodiment, when the starting current flows through the power supply voltage detecting and judging device 32, the power voltage drops instantaneously. However, if a power voltage detection delay device is installed in the device 32 to set a time delay for the response time of detecting the number of revolutions of the motor 12, even if a momentary voltage drop is detected in the device 32, the power voltage will not be lower than the specified voltage value. judgment.

Therefore, when the battery 22 is almost exhausted and the power supply voltage of the battery 22 drops below a certain voltage value, since the selection prohibiting means 20 outputs the full-coil driving operation selection signal even though the motor rotation number detection means 17 still outputs a high rotation number signal, Therefore, the switching operation from the sub-coil driving operation to the full-coil driving operation can be performed immediately. Thus, the power supply voltage drop of the battery 22 can be minimized.

In addition, even if the power supply voltage of the battery 22 is temporarily restored and rises to be equal to or greater than a certain voltage value, the full-coil driving operation selection signal output by the device 20 is maintained. Therefore, since the full-coil driving operation is continued and the switching operation from the full-coil driving operation to the sub-coil driving operation is prohibited, power consumption is reduced and battery drain is delayed.

Next, a third embodiment of the present invention will be described.

Fig. 6 is a block diagram of a motor control apparatus according to a third embodiment of the present invention.

As shown in FIG. 6, the motor control device 41 for controlling the motor 12 includes:

Battery 22; motor drive device 15; voltage generating device 16; motor revolution detection device 17; motor current detection device 18; motor current limiting device 19;

The power supply voltage detection and judging device 42, even if the switch 13 is turned off, the device can detect the power voltage provided by the battery 22, and judge whether the power voltage is lower than a specific voltage value, once it is detected that the power voltage is lower than a specific voltage value , the device outputs a judgment that the power voltage is lower than a specific voltage value;

The rotation number signal output device 33 ; the selection prohibition device 20 ; the operation type selection device 21 and the current path selection device 23 .

In the above structure, when the switch 13 is turned on, the full-coil driving operation is performed in the motor 12 in the same manner as in the first and second embodiments. Thereafter, under the condition that the power voltage is not lower than a specific voltage value, when the number of revolutions of the motor 12 exceeds a specific number of revolutions, the switching operation from the full-coil driving operation to the sub-coil driving operation is performed, and used with the first and second The sub-coil driving operation is performed in the motor 12 in the same manner as in the embodiment.

If the battery 22 is almost exhausted and the power supply voltage of the battery 22 drops below a certain voltage value, the power supply voltage detection and judging means 42 detects the drop in the power supply voltage, and regardless of whether the motor revolution detection means 17 outputs a low or high revolution signal, The revolution number signal output device 33 outputs a low revolution number signal to the selection inhibiting device 20 . In the same manner as in the second embodiment, if the full-coil driving operation is performed in the motor 12, the full-coil driving operation is continued even if the number of revolutions of the motor 12 exceeds a certain number of revolutions.

In addition, in the same manner as the second embodiment, if a divided coil driving operation is performed in the motor 12, since the number of revolutions signal output device 33 outputs a low revolutions signal to the selection inhibiting device 20, and the device 20 performs the full coil driving operation The selection signal is output to the operation type selection means 21, so the switching operation from the divided-coil driving operation to the full-coil driving operation is performed, and then the full-coil driving operation is performed in the motor 12. Therefore, even if the power supply voltage of the battery 22 is temporarily restored and rises to be equal to or greater than a certain voltage value, the full-coil driving operation selection signal output by the device 20 is maintained. That is, the full-coil driving operation is continued, and the switching operation from the full-coil driving operation to the sub-coil driving operation is prohibited.

Thereafter, when the switch 13 is turned off, power supply to the devices 15, 17, 19, 20, and 21 is stopped, so that the transistors 23b and 23d of the current path selection device 23 are disconnected, and the drive current through each full coil 14 is blocked. , and the motor 12 stops working. However, since the power supply voltage detection and judgment device 42 is directly connected to the battery 22, even if the switch 13 is turned off, power is still provided to the detection and judgment device 42, thereby continuing to judge that the output power voltage is lower than a specific voltage value. Therefore, when the switch 13 is turned on again, since the detecting and judging means 41 continues to detect a power voltage lower than a certain voltage value, it is impossible to perform a split-coil driving operation in the motor 12 . If the battery 22 is replaced with a new one, a split-coil driving operation is performed in the motor 12 .

In the third embodiment, when the initial current flows through the power supply voltage detecting and judging means 42, the power voltage drops instantaneously. However, if a power voltage detection delay device is installed in the device 42 to set a time delay for the response time of detecting the number of revolutions of the motor 12, then even if a momentary drop in voltage is detected in the device 42, the power voltage is not lowered below the specified voltage value. judgment.

Therefore, since even if the switch 13 is turned off, the power of the battery 22 is always provided to the detection and judgment device 42, so once the detection and judgment device 42 detects that the power voltage is lower than a certain voltage value, when the switch 13 is turned on again after the switch 13 is turned off When it passes, the judgment can still be maintained. Therefore, even if the switching operation of the switch 13 is repeated, the sub-coil driving operation can be prohibited after the power voltage falls below a certain voltage value. Therefore, the operation of the electric motor 12 can be performed stably, the power consumption can be reduced, the exhaustion of the battery 22 can be delayed, and the electric motor 12 can be operated for a longer period of time.

Next, a fourth embodiment of the present invention will be described.

Fig. 7 is a block diagram of a motor control apparatus according to a fourth embodiment of the present invention.

As shown in FIG. 7, the motor control device 51 for controlling the motor 12 includes:

Battery 22; motor drive device 15; voltage generating device 16; motor revolution detection device 17; motor current detection device 18; motor current limiting device 19;

Power supply voltage detection and judgment device 42; revolution signal output device 33;

The selection prohibiting device 52 that is directly connected with the battery 22, if receive the low revolution signal from the revolution signal output device 33, then the device 52 produces a whole coil drive operation selection signal that represents the selection of the power supply operation to the whole coil. Under the condition of not receiving the low number of revolutions signal after the number of revolutions signal, if the motor number of revolutions detection device 17 receives the high number of revolutions signal, then the device 52 produces a sub-coil drive operation selection signal representing selection of the sub-coil power supply operation, and Under the condition of receiving the low-speed signal in the previous operation after receiving the high-speed signal, if the motor-speed detection device 17 receives the high-speed signal again, the device 52 generates a full-coil drive operation selection signal;

Operation type selection means 21 and current path selection means 23 .

In the above structure, in the same manner as in the first to third embodiments, the full-coil driving operation is initially performed in the initial operation, and then the divided-coil driving operation is performed when the number of revolutions of the motor 12 exceeds a certain number of revolutions.

If the battery 22 is almost used up in the off state of the switch 13 and the power supply voltage of the battery 22 drops below a certain voltage value, the power supply voltage detection and judging device 42 detects the drop of the power supply voltage, and the number of revolution signal output device 33 will be low The revolution number signal is output to the selection inhibiting device 20 . Thereafter, when the switch 13 is turned on, the selection inhibiting means 20 outputs a full coil drive operation selection signal to the operation type selection means 21 .

Therefore, even if the power supply voltage of the battery 22 falls below a certain voltage value in the off state of the switch 13, the driving operation of the sub-coils is always prohibited, and only the whole-coil driving operation is performed. If the battery 22 is replaced with a new one, the split-coil driving operation is performed in the motor 12 .

Therefore, because the power supply voltage detection and judging device 42 and the selection prohibiting device 52 are directly connected to the battery 22, instead of the switch 13 being contained between a group of devices 42 and 52 and the battery 22, so even under the switch 13 disconnection state, When the power supply voltage of the battery 22 drops below a specific voltage value, the power supply voltage of the battery 22 can still be detected by the power supply voltage detection and judgment device 42, even if the number of revolutions of the motor 12 exceeds a specific number of revolutions, the selection can still be prohibited by the function of the selection prohibition device 52 Split coil drive operation. Accordingly, power consumption is reduced, depletion of the battery 22 is delayed, and the electric motor 12 is operated for a longer period of time.

In the first to fourth embodiments, the motor rotation number detecting means 17 detects the voltage induced in the voltage generating means 16 according to the rotation of the rotor of the motor 12 . However, a plurality of frequency pulses may be generated in a frequency pulse generating means in accordance with the rotation of the rotor of the motor 12, and the frequency pulses may be detected by the motor rotation number detecting means 17.

A speed detection delay device can also be installed to set a time delay for the response time of detecting the number of revolutions of the motor 12 . In this case, even if the number of revolutions of the motor 12 decreases momentarily due to a momentary increase in the required load of the motor 12 , detection of the momentary decrease may not be considered. The selection inhibiting means 20 can also be formed using a memory of a system control circuit such as a microcomputer. The switching operation of the switch 13 may also be controlled by a microcomputer based on information representing a motor operation start or stop command.

Next, a fifth embodiment of the present invention will be described.

Fig. 8 is a block diagram of a motor control apparatus according to a fifth embodiment of the present invention.

As shown in FIG. 8, the motor control device 61 for controlling the motor 12 includes:

Battery 22; motor driving device 15; voltage generating device 16; motor revolution detection device 17; motor current detection device 18; motor current limiting device 19; selection prohibition device 20;

A first tape reel sensor 24, which is located on the base of the magnetically driven tape reel, is used to detect the first rotational speed of the first tape reel, and the tape is pulled out from the first tape reel;

The second tape reel sensor 25, which is positioned on the magnetic drive tape reel base, is used to detect the second rotating speed of the second tape reel, and the tape is wound on the second tape reel;

npn type power selection transistor 26, its collector is connected with the emitter of each transistor 23d, and the emitter is grounded;

Process controller 27, it controls the whole process of motor control device 61 and motor 12 according to the magnetic tape rotation that first and second tape reel sensor 24 and 25 detects and the motor drive signal of motor drive device 15, when from selection prohibiting device 20 When receiving the sub-coil driving operation selection signal, the process controller 27 outputs a high-level signal to the base of the power supply selection transistor 26 to turn on the transistor 26. After receiving the sub-coil driving operation selection signal, a certain period of time passes , the process controller 27 outputs a low-level signal to the base of the power selection transistor 26 to turn off the transistor 26, and outputs a voltage increase signal synchronously with the output low-level signal; and

The differential voltage increasing device 28 formed by the DC-DC converter, if the voltage increasing signal is received from the process controller 27, the device 28 will add the negative voltage -Vdd to the emitter of each transistor 23d to increase the voltage supplied to each transistor. The differential voltage of the sub-coil 14.

Power is supplied directly to the differential voltage increasing means 28 to generate a negative voltage - Vdd, while one output terminal of the DC-DC converter is grounded.

In the above structure, when the switch 13 is turned on, the motor revolution detection device 17 outputs a low revolution signal, and the selection prohibition device 20 outputs the whole coil drive operation selection signal to the operation type selection device 21, and the motor drive instruction is transmitted to Transistor 23b. Therefore, the full-coil driving operation is performed in the motor 12 in the same manner as in the first embodiment.

Then, when the number of rotations of the motor 12 exceeds a certain number of rotations, the motor rotation number detection means 17 outputs a high number of rotations signal, and the selection prohibition means 20 outputs a sub-coil driving operation selection signal to the operation type selection means 21 and the process controller 27 . Then, a motor drive command is sent to the transistor 23d in the same manner as in the first embodiment. In addition, in the process controller 27, a high-level signal is generated according to the sub-coil driving operation selection signal, and the signal is sent to the base of the power selection transistor 26, the transistor 26 is turned on, and the emitters of each transistor 23d pass through Transistor 26 is grounded. The divided coil driving operation is thus performed in the motor 12 in the same manner as in the first embodiment.

Then, when the sub-coil driving operation has passed through a certain period of time, the process controller 27 detects this certain period of time passed, and sends a low-level signal to the base of the power supply selection transistor 26 to turn off the transistor 26, and the The voltage increase signal is sent to the differential voltage increase means 28 . In the device 28, a negative voltage -Vcc (Vdd>0) is generated from the voltage Vcc of the battery 22 and applied to the emitter of each transistor 23d. Therefore, the differential voltage applied to each sub-coil 14 increases from Vcc to Vcc+Vdd. Then, when the increased differential voltage Vcc+Vdd is applied to each of the sub-coils 14, the sub-coil driving operation is continued with the increased differential voltage.

Therefore, since the differential voltage applied to each sub-coil 14 is increased due to the functions of the process controller 27 and the differential voltage increasing device 28, the number of revolutions of the motor 12 can be rapidly increased, and the number of revolutions of the motor 12 can reach a higher revolution. number.

FIG. 9 shows a characteristic relationship between the required torque and the motor current consumed in the electric motor 12 in the fifth embodiment. FIG. 10 shows a characteristic relationship between the required torque and the number of revolutions of the motor 12 in the fifth embodiment.

As shown in FIGS. 9 and 10 , when the required torque drops to T2, the switching operation from the full-coil driving operation to the sub-coil driving operation is performed. Then, when the required torque falls to T3, a switching operation from the sub-coil driving operation to the sub-coil driving operation with the increased differential voltage is performed.

If the battery 22 is almost exhausted and the power supply voltage of the battery 22 drops below a certain voltage value, the motor current detected by the motor current detection device 18 increases to an allowable upper current limit value, and a voltage is generated in the motor current limiting device 19. A motor current limit signal commands a reduction in motor current and is output to the motor drive 15 . Then, the motor drive circuit 15 sends the low-level motor drive signal to the process controller 27, and the process controller 27 outputs a stop signal to the differential voltage increasing device 28 to stop generating the voltage Vdd, and transmits the high-level signal to the base of transistor 26. Therefore, a switching operation from the sub-coil driving operation with the increased differential voltage to the sub-coil driving operation is performed. Also, in the same manner as the first embodiment, the motor drive circuit 15 sends a motor drive signal to the operation type selection device 21, the intensity of the drive current supplied from the battery 22 is reduced, and the number of revolutions of the motor 12 is decreased. Then, when the number of revolutions of the motor 12 drops to a certain number of revolutions, the motor 12 is subjected to a full-coil driving operation in the same manner as in the first embodiment.

Then, in the same manner as the first embodiment, if the number of revolutions of the motor 12 is gradually increased due to the decrease in the motor torque required for the motor 12 in the full-coil driving operation, and the number of revolutions of the motor 12 is increased beyond the number of revolutions , then the selection inhibiting means 20 keeps outputting the full-coil driving operation selection signal to select the full-coil driving operation in the operation type selecting means 21 .

Therefore, since the operation transition from the full-coil driving operation to the sub-coil driving operation with the increased differential voltage and another operation transition from the sub-coil driving operation with the increased differential voltage to the full-coil driving operation are prohibited, it is possible to Motor control operation is stably performed over a wide operating range of the number of revolutions.

When the switch 13 is turned off, the trigger circuit 20a is set to 0. Then, when the switch 13 is turned on again, the full-coil driving operation is performed initially, and then the switching operation from the full-coil driving operation to the divided-coil driving operation is performed.

In the fifth embodiment, the progress controller 27 is used to detect the elapsed specific time. However, as shown in FIG. 11 , the motor control device 61 may further include a second motor rotation speed detection device 29 and an increase differential voltage operation command device 30, and the device 29 is used to detect a second specific rotation speed corresponding to the torque T3 in the motor 12. When the second motor rotation number detection device 29 detects a second specific rotation number corresponding to the torque T3 in the motor 12, the device 30 commands the process controller 27 to increase the differential voltage. In this case, three types of operations can be performed reliably in sequence. In addition, when the voltage of the battery 22 drops below a certain voltage value during the sub-coil driving operation with the increased differential voltage, the sub-coil drive with the increased differential voltage is performed at the required torque T3 The switching operation to the sub-coil driving operation is performed, and the switching operation from the sub-coil driving operation to the full coil driving operation is performed at the required torque T2.

When the required torque is lowered to T3, switching operation from the full-coil driving operation to the sub-coil driving operation with the increased differential voltage can also be performed. In this case, the divided coil driving operation is not performed. When the voltage of the battery 22 drops below a certain voltage value during the sub-coil driving operation with the increased differential voltage, the sub-coil driving operation with the increased differential voltage can also be performed at the required torque T3 Switch operation to full coil drive operation. In this case, the divided coil driving operation is not performed.

Next, a sixth embodiment of the present invention will be described.

Fig. 12 is a block diagram of a motor control apparatus according to a fifth embodiment of the present invention.

As shown in FIG. 12, the motor control device 71 for controlling the motor 12 includes:

Battery 22; Motor drive device 15; Voltage generating device 16; Motor revolution detection device 17; Motor current detection device 18; Motor current limiting device 19; A tape reel sensor 24; a second tape reel sensor 25; npn type power selection transistor 26; process controller 27; differential voltage increasing device 28;

In the above structure, when the battery 22 is almost used up, and the power supply voltage of the battery 22 drops below a certain voltage value, since the motor rotation speed detection device 17 still outputs a high rotation speed signal, the selection prohibition device 20 produces a full-coil drive. The selection signal is manipulated, so the switching operation from the sub-coil driving operation with the increased differential voltage to the sub-coil driving operation and the switching operation from the sub-coil driving operation to the full coil driving operation can be performed in sequence at once. Therefore, the power supply voltage drop of the battery 22 can be minimized in the same manner as the second embodiment.

In addition, even if the power supply voltage of the battery 22 is temporarily restored and rises to be equal to or greater than a certain voltage value, the device 20 keeps outputting the full-coil driving operation selection signal. Therefore, since the full-coil driving operation is continued and the switching operation from the full-coil driving operation to the sub-coil driving operation is prohibited, power consumption is reduced and exhaustion of the battery 22 is delayed in the same manner as in the second embodiment.

Next, a seventh embodiment of the present invention will be described.

Fig. 13 is a block diagram of a motor control apparatus according to a seventh embodiment of the present invention.

As shown in FIG. 13, the motor control device 81 for controlling the motor 12 includes:

Battery 22; motor driving device 15; voltage generating device 16; motor revolution detection device 17; motor current detection device 18; motor current limiting device 19; selection prohibition device 20; operation type selection device 21; current path selection device 23; The first tape reel sensor 24; the second tape reel sensor 25; npn type power selection transistor 26; process controller 27; differential voltage increasing device 28;

In the above structure, since even if the switch 13 is turned off, the power of the battery 22 is always supplied to the detection and judgment device 42, so once the detection and judgment device 42 judges that the power voltage is lower than a specific voltage value, after the switch 13 is turned off, When turning on again, this judgment can be maintained. Therefore, even if the switching operation of the switch 13 is repeated, the sub-coil driving operation with the increased differential voltage and the sub-coil driving operation can be prohibited after the power voltage is lower than a certain voltage value. Therefore, in the same manner as the third embodiment, the operation of the motor 12 can be stably performed, the power consumption can be reduced, the exhaustion of the battery 22 can be delayed, and the motor 12 can be operated for a longer period of time.

Next, an eighth embodiment of the present invention will be described.

Fig. 14 is a block diagram of a motor control apparatus according to an eighth embodiment of the present invention.

As shown in FIG. 14, the motor control device 91 for controlling the motor 12 includes:

Battery 22; motor driving device 15; voltage generating device 16; motor rotation number detecting device 17; motor current detecting device 18; motor current limiting device 19; operation type selecting device 21; current path selecting device 23; first reel sensor 24 The second tape reel sensor 25; npn type power selection transistor 26; process controller 27; differential voltage increasing means 28; power supply voltage detection and judgment means 42;

In the above structure, since the power supply voltage detection and judging device 42 and the selection prohibiting device 52 are directly connected to the battery 22, rather than the switch 13 being installed between a group of devices 42 and 52 and the battery 22, even if the switch 13 is disconnected state, the power supply voltage of the battery 22 drops below a specific voltage value, the power supply voltage of the battery 22 can still be detected by the power supply voltage detection and judgment device 42, even if the number of revolutions of the motor 12 exceeds a specific number of revolutions, the selection prohibition device 52 can still be used. The function of prohibits the sub-coil driving operation and the sub-coil driving operation with the increased differential voltage. Therefore, in the same manner as the fourth embodiment, the operation of the motor 12 can be stably performed, power consumption can be reduced, the exhaustion of the battery 22 can be delayed, and the motor 12 can be operated for a longer period of time.

In the fifth to eighth embodiments, the voltage induced in the voltage generating means 16 according to the rotation of the rotor of the motor 12 is detected by the motor rotation number detecting means 17 . However, a plurality of frequency pulses may be generated in a frequency pulse generating means in accordance with the rotation of the rotor of the motor 12, and the frequency pulses may be detected by the motor rotation number detecting means 17.

A speed detection delay device can also be installed to set a time delay for the response time of detecting the number of revolutions of the motor 12 . In this case, even if the number of revolutions of the motor 12 decreases momentarily due to a momentary increase in the required load of the motor 12 , the detection result of the momentary decrease may not be considered. The selection inhibiting means 20 can also be formed using a memory of a system control circuit such as a microcomputer. The switching operation of the switch 13 may also be controlled by a microcomputer based on information representing a motor operation start or stop command.

Next, a ninth embodiment of the present invention will be described.

Fig. 15 is a block diagram of a motor control apparatus according to an eighth embodiment of the present invention.

As shown in FIG. 15, the motor control device 91 for controlling the motor 12 includes:

Battery 22; motor driving device 15; voltage generating device 16; motor revolution detection device 17; motor current detection device 18; motor current limiting device 19; first tape reel sensor 24; second tape reel sensor 25; npn type power supply selection Transistor 26; Differential voltage increasing means 28; Operation type selecting means 21; Current path selecting means 23;

The process controller 92, which has a microcomputer 92a, can control the operation of the motor 12 based on the first rotational speed of the first reel and the second rotational speed of the second reel detected by the first and second reel sensors 24 and 25. , if the voltage generating device 16 detects the initial operation of the motor 12, and the tape position detected by the first and second reel sensors 24 and 25 indicates that a medium volume of tape is wound on the second reel, or the motor current The motor current detected by the detection device 18 increases to the allowable current upper limit value, and the process controller 92 outputs the full coil drive operation selection signal to the operation type selection device 21; if the first and second tape reel sensors 24 and 25 detect If the tape position reached indicates that there is no medium-volume tape wound on the second reel, or the sub-coil driving operation with the increased differential voltage is stopped, the process controller 92 outputs a high level signal to the base of the power selection transistor 26. Pole to turn on the transistor 26; and under the condition that the motor revolution detection device 17 detects that the revolution number of the motor 12 reaches a certain revolution number, if the tape position detected by the first and second tape reel sensors 24 and 25 indicates that there is no medium The volume of magnetic tape is wound on the second tape reel, and the process controller 92 outputs a low-level signal and a voltage increase signal to the power selection transistor 26 and the differential voltage increasing device 28, so as to divide the motor 12 with the increased differential voltage. Coil drive operation.

With the above structure, the operation of the motor control apparatus 91 will be described with reference to FIG. 16. FIG.

FIG. 16 is a flow chart showing the operation procedure performed in the motor control apparatus 91. As shown in FIG.

When the motor is on, the motor 12 rotates the second reel, and when the first reel is rotated, the tape wound on the first reel is pulled to the second reel and the tape is wound on the second reel. In this case, the ratio of the number of revolutions of the first reel to the number of revolutions of the second reel gradually increases, the volume of the tape wound on the first reel decreases, and the volume of the tape wound on the second reel increases. Since the first reel sensor 24 detects the number of revolutions of the first reel, and the second reel sensor 25 detects the number of revolutions of the second reel, by calculating the ratio in the microcomputer 92a of the process controller 92, it is possible to Get the tape volume wound on the second tape reel.

As shown in FIG. 16, when the switch 13 is turned on in step S101, the induced voltage zero value generated in the voltage generating device 16 is input to the process controller 92, and the whole coil driving operation selection signal generated in the process controller 92 is selected. It is input to the operation type selection device 21, and in step S102, the whole coil driving operation is performed on the motor 12. Then, the first reel rotation number and the second reel rotation number detected by the first and second reel sensors 24 and 25 are input to the process controller 92 . In the process controller 92, the ratio of the number of revolutions of the first tape reel to the number of revolutions of the second tape reel is calculated, and in step S103 it is judged whether there is a medium volume magnetic tape wound on the second tape reel.

If a medium volume magnetic tape is wound on the second reel, then a larger torque is required to rotate the second reel. Therefore, it is inappropriate to perform a sub-coil driving operation with an increased differential voltage, and the process controller 92 sends a sub-coil driving operation selection signal to the selection type selection device 21, and the process controller 92 sends a high-level signal to the transistor 26 base, so that the sub-coil driving operation is performed in step S104.

On the contrary, if the tape volume wound on the second tape reel does not reach the medium volume, then the second tape reel needs to be rotated with a smaller torque, so it is suitable for sub-coil driving operation and sub-coil operation with increased differential voltage drive operation. Therefore, the sub-coil driving operation selection signal generated in the process controller 92 is input to the operation type selection device 21, and the high-level signal is input to the power selection transistor 26 to turn on the transistor 26, and the motor 12 is divided in step S105. Coil drive operation. Then, a low-level signal is input to the power supply selection transistor 26 to turn off the transistor 26, and in step S106, a voltage increase signal is input to the differential voltage increasing device 28, so as to perform a sub-coil driving operation on the motor with the increased differential voltage . Therefore, the second reel rotates at a high speed corresponding to 6500 to 7000 revolutions per minute of the rotor of the motor 12 . In this case, when the motor rotation number detecting device 17 detects that the rotation number of the rotor of the motor 12 reaches, for example, 5,000 revolutions per minute, the step from the sub-coil driving operation to the sub-coil driving operation performed with the increased differential voltage can be carried out. Toggle action.

Then, in step S107, it is judged by the process controller 92 whether the rotation speed of the motor 12 is lower than a specific rotation number, for example, 4000 rotations per minute. If the number of revolutions of the electric motor 12 is equal to or higher than a given specific number of revolutions, then there is no trouble with the battery 22 or the electric motor 12 . Then, in step S108, it is judged whether there is a medium volume magnetic tape wound on the second tape reel. If the tape volume wound on the second tape reel does not reach the middle volume, the sub-coil driving operation with the increased differential voltage is maintained.

On the contrary, if it is judged in step S107 or step S108 that the number of revolutions of the motor 12 is lower than a certain number of revolutions or that a medium volume magnetic tape is wound on the second tape reel, then since the battery 22 is almost exhausted or a larger rotational speed is required Torque rotates the second reel, so it is not suitable for split-coil drive operation with increased differential voltage. Therefore, in step S109, the process controller 92 sends a voltage increasing operation stop command to the differential voltage increasing device 28, and the process controller 92 sends a high-level signal to the base of the transistor 26, thereby stopping using the increased differential voltage Sub-coil drive operation performed. Then, in step S104, a separate coil driving operation is performed.

Then, in step S110, the process controller 92 judges whether the motor current detected by the motor current limiting device 19 exceeds the allowable current upper limit value IL. If it is judged that the motor current does not exceed the allowable current upper limit value IL, the judgment result shows that the motor 12 has no problem with the battery 22 work, and because the volume of the magnetic tape wound on the second tape reel is not large, it is necessary to divide the coil drive operation. The torque is small enough. Therefore, the divided coil drive operation is maintained. On the contrary, if it is judged that the motor current exceeds the allowable current upper limit value IL, then the judgment result shows that the battery 22 is almost exhausted, or the tape volume wound on the second tape reel is large for the split-coil drive operation, so the split The torque required for coil drive operation is too high. Therefore, in step S111 , the process controller 27 stops sending a high-level signal to the transistor 26 , and the process controller 27 sends a full-coil driving operation selection signal to the operation type selection device 21 , and performs a full-coil driving operation.

Then, in step S112, the process controller 92 judges whether the user has input an operation stop command. If an operation stop command is input, the switch 13 is turned off to stop the operation of the motor 12 . On the contrary, if the operation stop command is not input, it is judged by the process controller 92 in step S113 whether all the tapes are wound on the second tape reels. If not all of the magnetic tape is wound on the second reel, the full-coil drive operation is maintained since the winding operation of the magnetic tape on the second reel is not completed. On the contrary, if all the magnetic tapes are wound on the second tape reel, the switch 13 is turned off, so that the motor 12 is stopped.

Therefore, if the sub-coil driving operation with the increased differential voltage is stopped in step S109, the sub-coil driving operation with the increased differential voltage is prohibited even if the rotation number of the motor 12 reaches a certain number of rotations. Therefore, it is impossible to repeatedly switch between the sub-coil driving operation with the increased differential voltage and the sub-coil driving operation, thereby enabling the motor 12 to operate stably. Even if the motor current detected by the motor current detecting device 18 increases to the allowable current upper limit due to a drop in the voltage Vcc of the battery 22, the motor 12 can be stably operated by performing full-coil driving operation in the motor 12.

While the principles of the invention have been illustrated and described in terms of preferred embodiments, it will be apparent to those skilled in the art that changes in scheme and detail can be made therein without departing from these principles. The applicant desires all changes commensurate with the spirit and scope of the appended claims.

Claims (23)

1. A motor control device for controlling a direct current motor driven by electric power from a battery, the motor being provided with a tap end at a prescribed location in the middle of each of one or more coils, characterized in that it comprises: An operation type selection device for selecting a full-coil drive operation or a sub-coil drive operation, wherein in the full-coil drive operation, the motor current supplied by the battery flows through each full coil of the DC motor, and in the sub-coil drive operation, the battery-supplied The motor current flows through each sub-coil between the tap end and one end of the coil; a rotation number detection device for detecting the rotation number of the DC motor, and outputting a low rotation number signal if the rotation number is low, and outputting a high rotation number signal if the rotation number is high; and selection prohibiting means for commanding the operation type selection means to select the whole coil drive operation if a low-revolution signal is received from the revolving-number detection means, under the condition that the low-revolution signal is not received after receiving the high-revolution signal, If a high revolution signal is received from the revolution detection device, the command operation type selection device selects the sub-coil driving operation, and under the condition that the DC motor performs the sub-coil driving operation and then performs the whole coil driving operation, if it is detected again from the revolution number When the device receives the high rotation speed signal, it commands the operation type selection device to select the whole coil driving operation. 2. The motor control apparatus of claim 1, further comprising: The motor current limiting device is used to limit the motor current flowing through each coil of the DC motor to an allowable upper current limit. 3. The motor control apparatus of claim 1, further comprising: a motor drive device, which drives a DC motor according to the full or partial coil drive operation selected by the operation type selection device; 4. The motor control apparatus of claim 1, further comprising: A switch device which resets the selection prohibition device by interrupting the supply of power from the battery to the selection prohibition device, and if a high revolution number signal is received from the rotation number detection device after the selection prohibition device is reset, the operation type selection device operates according to the instruction of the selection prohibition device Select split coil drive operation. 5. The motor control apparatus of claim 1, further comprising: A power supply voltage detection device for detecting the power supply voltage of the battery; and The number of revolutions signal output device, if the power supply voltage detected by the power supply voltage detection device is not lower than a certain voltage value, the number of revolutions signal output device outputs the low or high revolutions signal output by the number of revolutions detection device to the selection prohibition device The same number of revolutions signal, instead of the output of the number of revolutions detection means, if the power supply voltage detected by the power supply voltage detection means is lower than a certain voltage value, said number of revolutions signal output means outputs to the selection prohibition means to replace the number of revolutions detection The low-speed signal output by the device is used for full-coil drive operation. 6. The motor control apparatus of claim 5, further comprising: A switch device which resets the selection prohibition device by interrupting the supply of power from the battery to the selection prohibition device, and if a high revolution number signal is received from the rotation number detection device after the selection prohibition device is reset, the operation type selection device operates according to the instruction of the selection prohibition device Select split coil drive operation. 7. The motor control apparatus of claim 1, further comprising: a motor drive device, which drives a DC motor according to the full or partial coil drive operation selected by the operation type selection device; a switch through which power from the battery is supplied to the motor drive to enable the motor drive to operate, and opening the switch stops supplying power from the battery to the motor drive to disable the motor drive; supply voltage detecting means capable of detecting the supply voltage of the battery whether the battery power is supplied to the motor drive by means of the switch or the supply of battery power to the motor drive is stopped by the switch; and The number of revolutions signal output device, if the power supply voltage detected by the power supply voltage detection device is not lower than a certain voltage value, the number of revolutions signal output device outputs the low or high revolutions signal output by the number of revolutions detection device to the selection prohibition device The same number of revolutions signal, instead of the output of the number of revolutions detection means, if the power supply voltage detected by the power supply voltage detection means is lower than a certain voltage value, said number of revolutions signal output means outputs to the selection prohibition means to replace the number of revolutions detection low revolution signal at the output of the device for full coil drive operation, and After the open switch is turned on, the selection inhibiting means instructs the operation type selecting means to select the full coil drive operation. 8. The motor control apparatus of claim 1, further comprising: a motor drive device, which drives a DC motor according to the full or partial coil drive operation selected by the operation type selection device; a switch through which power from the battery is supplied to the motor drive to enable the motor drive to operate, and opening the switch stops supplying power from the battery to the motor drive to disable the motor drive; supply voltage detecting means capable of detecting the supply voltage of the battery whether the battery power is supplied to the motor drive by means of the switch or the supply of battery power to the motor drive is stopped by the switch; and The number of revolutions signal output device, if the power supply voltage detected by the power supply voltage detection device is not lower than a certain voltage value, the number of revolutions signal output device outputs the low or high revolutions signal output by the number of revolutions detection device to the selection prohibition device The same number of revolutions signal, instead of the output of the number of revolutions detection means, if the power supply voltage detected by the power supply voltage detection means is lower than a certain voltage value, said number of revolutions signal output means outputs to the selection prohibition means to replace the number of revolutions detection low revolution signal at the output of the device for full coil drive operation, and Even if the power supply voltage detection means detects a power supply voltage lower than a certain voltage value when the motor drive means is stopped by the switch, the selection prohibition means instructs the operation type selection means to select the full coil drive operation. 9. A motor control device for controlling a DC motor driven by electric power from a battery, the motor being provided with a tap end at a specified position in the middle of each coil of one or more coils, characterized in that it comprises: The motor state detection device is used to detect the motor state of the DC motor, and the motor state is detected as the first motor state, the second motor state or the third motor state; The operation type selection means, if the motor state detection means detects the first motor state, the operation type selection means selects the full coil drive operation, at this time the motor current supplied by the battery flows through each full coil of the DC motor, if the motor state detection means detects To the second motor state or the third motor state, the operation type selection device selects the sub-coil driving operation, at this moment, the motor current provided by the battery flows through each sub-coil between the tap end and the coil end; and Motor voltage setting means, if the motor state detection means detects the first motor state or the second motor state, it sets the differential voltage applied to each coil of the DC motor as the voltage of the battery, and if the motor state detection means When the third motor state is detected, it sets the differential voltage applied to each coil of the DC motor to an increased differential voltage higher than the voltage of the battery. 10. The motor control apparatus of claim 9, further comprising: Select the prohibition device, if the operation type selection device selects the full coil drive operation after selecting the sub-coil drive operation, then the selection prohibition device prohibits the operation type selection device from selecting the sub-coil drive operation. 11. The motor control apparatus of claim 9, further comprising: The motor current limiting device is used to limit the motor current flowing through each coil of the DC motor to an allowable upper current limit. 12. The motor control apparatus of claim 9, further comprising: Motor drive means, which drive a DC motor in whole or sub-coil drive operation selected by the operation type selection means; 13. The motor control device according to claim 9, wherein the motor state detection means comprises a rotation number detection means for detecting the number of rotations of the DC motor, the number of rotations corresponding to the first motor state is lower than the first number of rotations, The number of rotations corresponding to the second motor state is equal to or greater than the first number of rotations and lower than the second number of rotations, and the number of rotations corresponding to the third motor state is equal to or greater than the second number of rotations. 14. The motor control device according to claim 9, wherein the motor state detecting means comprises a motor current detecting means for detecting the motor current, the current value corresponding to the first motor state is lower than the first motor current value, the second The current value corresponding to the second motor state is equal to or greater than the first motor current value and lower than the second motor current value, and the current value corresponding to the third motor state is equal to or greater than the second motor current value. 15. The motor control device as claimed in claim 9, wherein the motor state detection means comprises a magnetic tape volume detection means for detecting the volume of the magnetic tape wound by the DC motor, and the volume corresponding to the first motor state is equal to or greater than the first magnetic tape volume. A volume, the volume corresponding to the second motor state is smaller than the first volume of the tape and equal to or larger than the second volume of the tape, and the volume corresponding to the third motor state is smaller than the second volume of the tape. 16. The motor control apparatus of claim 15, wherein the magnetic tape volume detection means comprises: The first tape reel detection device is used to detect the first rotational speed of the first tape reel sent out of the magnetic tape; The second tape reel detecting device is used to detect the second rotational speed of the magnetic tape sent out from the first tape reel to be wound on the second tape reel; and The tape volume calculating means calculates the tape volume wound on the second tape reel according to the first rotation speed detected by the first tape reel detection means and the second rotation speed detected by the second tape reel detection means. 17. The motor control apparatus of claim 10, further comprising: Switching means for resetting the selection prohibiting means by interrupting the supply of power from the battery to the selection prohibition means, and if the motor state detection means detects the second motor state after the selection prohibition means is reset, the operation type selection means selects the sub-coil drive operation. 18. The motor control apparatus of claim 13, further comprising: A power supply voltage detection device for detecting the power supply voltage of the battery; The number of revolution signal output device, if the power supply voltage detected by the power supply voltage detection device is equal to or greater than a certain voltage value and the number of revolutions detected by the number of revolution detection device is equal to or greater than the first number of revolutions, the number of revolution signal output device outputs a high number of revolutions signal, if the power supply voltage detected by the power supply voltage detection means is lower than a specific voltage or the number of revolutions detected by the number of revolutions detection means is lower than the first number of revolutions, the number of revolutions signal output means outputs a low number of revolutions signal; and selection prohibiting means for commanding the operation type selection means to select the whole coil drive operation if a low-revolution signal is received from the revolving-number detection means, under the condition that the low-revolution signal is not received after receiving the high-revolution signal, If a high number of revolutions signal is received from the number of revolutions detection device, the command operation type selection device selects the sub-coil driving operation, and under the condition that the DC motor performs the sub-coil driving operation and then performs the full-coil driving operation, if it is detected from the number of revolutions When the device receives the high rotation speed signal, it commands the operation type selection device to select the whole coil driving operation. 19. The motor control apparatus of claim 10, further comprising: Switching means for resetting the selection prohibiting means by interrupting the supply of power from the battery to the selection prohibition means, and if the motor state detection means detects the second motor state after the selection prohibition means is reset, the operation type selection means selects the sub-coil drive operation. 20. The motor control apparatus of claim 13, further comprising: a motor drive device, which drives a DC motor according to the full or partial coil drive operation selected by the operation type selection device; a switch through which power from the battery is supplied to the motor drive to enable the motor drive to operate, and opening the switch stops supplying power from the battery to the motor drive to disable the motor drive; A power supply voltage detection device capable of detecting the power supply voltage of the battery no matter whether the battery power is supplied to the motor drive device through the switch or the battery power supply to the motor drive device is stopped by the switch; The number of revolution signal output device, if the power supply voltage detected by the power supply voltage detection device is equal to or greater than a certain voltage value and the number of revolutions detected by the number of revolution detection device is equal to or greater than the first number of revolutions, the number of revolution signal output device outputs A high revolution signal, if the power supply voltage detected by the power supply voltage detection device is lower than a specific voltage value or the revolution detected by the revolution detection device is lower than the first revolution, the revolution signal output device outputs a low revolution digital signal; and selection prohibiting means for commanding the operation type selection means to select the whole coil drive operation if a low-revolution signal is received from the revolving-number detection means, under the condition that the low-revolution signal is not received after receiving the high-revolution signal, If a high number of revolutions signal is received from the number of revolutions detection device, the command operation type selection device selects the sub-coil driving operation, and under the condition that the DC motor performs the sub-coil driving operation and then performs the full-coil driving operation, if it is detected from the number of revolutions When the device receives the high rotation speed signal, it commands the operation type selection device to select the whole coil driving operation. 21. The motor control apparatus of claim 13, further comprising: a motor drive device, which drives a DC motor according to the full or partial coil drive operation selected by the operation type selection device; a switch through which power from the battery is supplied to the motor drive to enable the motor drive to operate, and opening the switch stops supplying power from the battery to the motor drive to disable the motor drive; A power supply voltage detection device capable of detecting the power supply voltage of the battery no matter whether the battery power is supplied to the motor drive device through the switch or the battery power supply to the motor drive device is stopped by the switch; The number of revolution signal output device, if the power supply voltage detected by the power supply voltage detection device is equal to or greater than a certain voltage value and the number of revolutions detected by the number of revolution detection device is equal to or greater than the first number of revolutions, the number of revolution signal output device outputs A high revolution signal, if the power supply voltage detected by the power supply voltage detection device is lower than a specific voltage value or the revolution detected by the revolution detection device is lower than the first revolution, the revolution signal output device outputs a low revolution digital signal; and selection prohibiting means for commanding the operation type selection means to select the whole coil drive operation if a low-revolution signal is received from the revolving-number detection means, under the condition that the low-revolution signal is not received after receiving the high-revolution signal, If a high number of revolutions signal is received from the number of revolutions detection device, the command operation type selection device selects the sub-coil driving operation, and under the condition that the DC motor performs the sub-coil driving operation and then performs the full-coil driving operation, if it is detected from the number of revolutions When the device receives the high rotation number signal, even if the switch is turned off and then turned on again, the operation type selection device is still commanded to select the full coil drive operation. 22. The motor control apparatus according to claim 13, wherein the rotation number detecting means includes a rotation speed detection delay circuit for setting a time delay for a response time of detecting the rotation number of the DC motor. 23. The motor control apparatus according to claim 18, 20 or 21, wherein the power supply voltage detecting means includes a power supply voltage detection delay circuit for setting a time delay for a response time of detecting the power supply voltage.

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