JP2001157483A - Dc brushless motor drive and tape winder using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize regenerative brake of a DC brushless motor effectively through a simple arrangement at the time of interrupting power supply. SOLUTION: When power interruption is detected at a power interruption detecting section 60 under a state where a DC brushless motor M1 is supplied with a symmetrical AC three-phase current by supplying a switching pattern from a switching pattern generating section SP1 to the transistors Tr11-Tr16 of an inverter bridge circuit IB1, a specified switching pattern is supplied from the switching pattern generating section SP1. A regenerative current is generated by turning all transistors Tr12, Tr14, Tr16 on the lower side (or the upper side) of the inverter bridge circuit IB1 forcibly on and turning the remaining transistors off thus braking DC brushless motor M1 regeneratively. The DC brushless motor M1 can be subjected to regenerative brake by simply contriving the switching pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless DC motor driving device configured to drive a motor by an inverter bridge circuit of a plurality of switching elements. The present invention also relates to a tape winding device configured to drive each of the first and second reels with the aforementioned brushless DC motor driving device. The tape winding device according to the present invention mainly includes
The present invention is effective as a magnetic tape recording / reproducing apparatus such as a video tape recorder and an audio tape recorder.

[0002]

2. Description of the Related Art For example, in a tape winding device mounted on a video tape recorder, there has been known a technique of mechanical braking as a measure against tape loosening and tape tension at the time of power interruption due to a power failure or the like. I have. In this prior art, when a power supply interruption is detected, a brake pad is brought into contact with a rotating reel to apply braking to the reel.

However, in recent video tape recorders, the tape thickness tends to become thinner as the recording time becomes longer, while the demand for improved operability calls for a higher winding speed. Have been. When the reel, which is the other side of the brake pad that is in contact with the brake pad, is rotating at high speed, the wear of the brake pad increases, and it becomes difficult to stably stop the reel. This is even more so in the case of tape high-speed running, which is a recent trend (technical trend).

When the brake torque exceeds the allowable limit due to the wear of the brake pad, a difference in rotation speed between the take-up reel (first reel) and the supply reel (second reel) increases. For this reason, when the reel is stopped when the power is shut off, there is a possibility that the tape may unnecessarily be loosened or a tension exceeding an allowable value may be applied. Either will damage the tape.

It is desirable that a motor rotating at a high speed decelerate as fast as possible for safety when the power is turned off. However, the mechanical braking method using the brake pad as described above has a problem of wear, and thus it is difficult to cope with high-speed rotation.

Therefore, instead of a mechanical braking system,
An electromagnetic braking system has been proposed in a tape winding device described in JP-A-4-366451 (Japanese Patent No. 2544318). This utilizes regenerative braking when the power is turned off.

The tape winding device utilizing regenerative braking at the time of power shutoff described in this publication is generally configured as follows. The motor is a DC motor. A power-off detection responsive short circuit is connected between both terminals of the DC motor. Note that this power-supply-detection responsive short circuit is simply referred to as a “power failure detection circuit” in the gazette. The substance is that the motor coils are short-circuited in response to the power cut-off detection. The power-off detection responsive short circuit is
A normally-on contact in which the movable iron piece is urged to the ON side by a tension spring; and a relay coil that is turned off by attracting the movable iron piece against the tension spring by excitation (electromagnetic attraction) by energization. It has.
When the power is cut off due to a power failure or the like, the relay coil is demagnetized, and the movable iron piece that has been attracted until then is returned by the tension spring, and the contact is turned on. As a result, both terminals of the DC motor are short-circuited via the contact that has been turned ON. The DC motor whose power is cut off by the power cutoff still tries to continue to rotate due to inertia,
Back electromotive force is generated between both terminals of the DC motor in a state where the DC motor is used as an induction generator. As a result, the current flows back to the coil of the DC motor to provide electromagnetic braking, that is, regenerative braking.

[0008]

In response to recent demands for higher speeds and maintenance-free requirements, the use of brushless DC motors has increased more than DC motors having brush wear.

It is well known that brushless DC motors use a U, V, W three-phase coil as an armature and allow a symmetric three-phase AC current to flow in most cases.

If the technique of the above-mentioned Japanese Patent Application Laid-Open No. 4-366451 is applied to such a brushless DC motor in order to provide a function of regenerative braking when power is cut off, the following inconvenience occurs.

Since there is a three-phase coil, it is necessary to short-circuit the three terminals when the power is turned off. Assuming that the three terminals are N ₁ , N ₂ and N ₃ , if the terminals N ₁ and N ₂ and the terminals N ₂ and N ₃ are short-circuited, respectively, the terminal N
_3, N ₁ also will be short-circuited. Accordingly, two sets of power-supply-detection responsive short circuits are required.

The tape winding device has two brushless DC motors on a winding side and a supply side.
If a power supply cutoff detection responsive short circuit is added to each brushless DC motor, a total of four power supply cutoff detection responsive short circuits are required. However, this leads to disadvantages such as an increase in the number of parts and space, an increase in power consumption, an increase in cost, and the like.

Further, in the braking technique disclosed in JP-A-4-366451, the DC motor is stopped only by regenerative braking. However, when the winding diameter is large, in addition to the large inertial force, Since the regenerative voltage is low because the rotation speed is low, there is a problem that it takes a long time from the start to the stop of the braking.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and has as its object to effectively realize regenerative braking of a brushless DC motor at the time of power-off with a simple configuration. Also, in the tape winding device, the tape running can be stopped smoothly without generating unnecessary unnecessarily large slack and excessive tension in the tape, especially when the power is cut off during high-speed tape running such as fast-forward or rewind. It is an object.

[0015]

SUMMARY OF THE INVENTION The present invention relates to a brushless DC motor driving device which aims to solve the above-mentioned problems, and has a circuit configuration for supplying a regenerative current to a motor coil. By using the original inverter bridge circuit and devising only the switching pattern, regenerative braking is realized.

According to the present invention having this configuration, the brushless D
In the case where the prior art is applied to the C motor, the necessity of adding two power supply cutoff detection responsive short circuits outside the drive circuit is eliminated, and the inverter bridge circuit originally required for driving the motor is eliminated. The regenerative braking can be applied to the motor coil when the power is cut off only by adjusting the switching pattern for the motor. Therefore,
It is possible to effectively realize the regenerative braking of the brushless DC motor when the power is turned off with a simple configuration.

The present invention with respect to the tape winding device is such that the first brushless DC motor driving device causes the tape to run in the forward direction and the second brushless DC motor driving device causes the tape to run in the reverse direction. When a cutoff is detected, a regenerative braking is performed by controlling a switching element group of an inverter bridge circuit in a brushless DC motor driving device on the side corresponding to the upper side in the running direction of unwinding the tape with a specific switching pattern. .

According to the present invention having this configuration, the brushless DC motor can be stopped smoothly when the power is turned off, and the tape is unnecessarily large especially when the power is cut off during high-speed tape running such as fast-forward or rewind. Tape running can be stopped smoothly without generating slack or excessive tension.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be generally described.

A brushless DC motor driving device according to a first aspect of the present invention is a brushless DC motor driving device for driving a brushless DC motor by controlling a plurality of switching elements in an inverter bridge circuit in a predetermined switching pattern, When the interruption is detected, a regenerative current is supplied to the motor coil by controlling the switching element group in a specific switching pattern.

According to the first aspect of the invention, the regenerative braking at the time of power shutdown can be performed only by adjusting the switching pattern in the inverter bridge circuit itself. The detection-responsive short circuit is unnecessary, and the configuration is simplified.

According to a second aspect of the present invention, in the brushless DC motor driving apparatus according to the first aspect, the inverter bridge circuit includes a symmetric three-phase AC current formed by bridge-connecting three sets of a pair of push-pull switching elements. And when the power cutoff is detected, three of the three sets of push-pull switching elements on the low potential side are simultaneously turned on, or the switching on the high potential side is performed. The structure is such that three of the elements are conducted simultaneously. This second invention describes the first invention in more detail.

According to the second aspect, the following operation is provided. The reason why the three switching element groups on the low potential side or the three switching element groups on the high potential side among the pair of push-pull switching elements are brought into conduction collectively is as follows. In this case, it is equivalent that the switching element group only on the low potential side and the switching element group only on the high potential side are to be brought into conduction collectively. Since a symmetric three-phase AC is supplied, the phases of current and voltage change in chronological order, but no matter what timing the power supply shuts down, the regenerative current must always flow through the motor coil. Thus, regenerative braking can be applied to the brushless DC motor.

In the brushless DC motor driving apparatus according to the third aspect of the present invention, in the first and second aspects of the present invention, the specific switching pattern is used for supplying a regenerative current to the motor coil when a power cutoff is detected. The mechanical braking is started immediately after controlling the switching element group.

According to the third aspect, the following operation is provided. That is, the regenerative current generated when the power is turned off is relatively short. Therefore, when the inertia force of the motor rotation when the power is shut off is relatively large, there is a possibility that the motor cannot be stopped immediately by regenerative braking alone. Even in such a case, the mechanical braking is applied subsequent to the regenerative braking, so that the time from the start to the stop of the braking can be shortened.

The fourth and subsequent inventions of the present application relate to a tape winding device.

A tape winding device according to a fourth aspect of the present invention winds a tape around a first reel by operation of a first brushless DC motor driving device in a forward running direction, and a second brushless DC motor in a reverse running direction. A tape winding device that winds the tape around a second reel by an operation of a driving device, and a brushless DC on a side corresponding to an upper side in a traveling direction in which the tape is unwound when power cutoff is detected.
The regenerative current is supplied to the motor coil by controlling the switching element group of the inverter bridge circuit in the motor drive device with a specific switching pattern.

According to the fourth aspect, as apparent from the operation of the first aspect, the two brushless D
2 external sets for each C motor (4 sets in total)
The power-off detection-responsive short circuit is unnecessary and the regenerative braking of the brushless DC motor can be realized with a simple configuration. In the brushless DC motor on the side corresponding to the lower side in the running direction of winding the tape, a load of winding the tape is applied. On the other hand, the brushless DC motor on the side corresponding to the upper side in the running direction in which the tape is unwound assists feeding, and has a strong element of inertia. Therefore, if both brushless DC motors are handled in the same manner when the power is turned off, the slackness of the tape is particularly likely to increase.
This tendency becomes stronger as the motor rotation speed increases. Therefore, by applying regenerative braking to the brushless DC motor on the side corresponding to the upper side of the running direction in which the tape is unwound, it is possible to reliably prevent the tape from being unnecessarily large slack when the power is turned off. Damage can be prevented.

A tape winding device according to a fifth aspect of the present invention includes a first brushless DC motor that winds a tape around a first reel during forward running, and a first inverter that drives the first brushless DC motor. A bridge circuit; first switching pattern generating means for supplying a predetermined switching pattern to a plurality of switching elements in the first inverter bridge circuit;
A second brushless DC motor for winding the tape on a reel, and a second brushless DC motor for driving the second brushless DC motor.
An inverter bridge circuit, a second switching pattern generating means for supplying a predetermined switching pattern to a plurality of switching elements in the second inverter bridge circuit, A tape running direction detecting means for providing detected running direction information to the second switching pattern generating means; and a power cutoff detecting means, wherein the first and second switching pattern generating means are superior in the running direction in which the tape is unwound. The switching pattern generating means on the side corresponding to the side includes a specific switching pattern for controlling the switching element group so as to allow a regenerative current to flow to a motor coil when power cutoff detection is received from the power cutoff detecting means. Is generated. The fifth invention describes the above fourth invention in more detail.

The operation of the fifth invention is as follows. When the power is cut off, the switching element group is controlled in a specific switching pattern such that a regenerative current is supplied to the motor coil by controlling a switching pattern generating means corresponding to the brushless DC motor on the side corresponding to the upper side of the running direction in which the tape is unwound. , It is possible to reliably prevent the tape from being unnecessarily large slack when the power is turned off, and to prevent tape damage, even if the motor rotation speed is relatively high. In addition, for each of the two brushless DC motors, two external (two in total) power cutoff detection responsive short circuits are unnecessary, and regenerative braking of the brushless DC motor can be realized with a simple configuration.

The tape winding device according to a sixth aspect of the present invention is the tape winding device according to the fourth aspect, wherein the first mechanical braking means acting on the first reel and the second mechanical braking means acting on the second reel. A mechanical braking unit configured to start a timing operation when a power cutoff is detected and to start the mechanical braking units in the brushless DC motor driving devices after a predetermined timer time has elapsed. It has become.

According to the sixth aspect, the following operation is provided. In general, when the tape winding diameter is large when the power is shut off, the regenerative voltage is low because the inertia force is large and the rotational speed is low, and a long time is required from the start to the stop of the regenerative braking. On the other hand, the regenerative current generated when the power is turned off is relatively short. Therefore, in the sixth invention, although the regenerative braking is not performed at the initial stage when the power is cut off, the braking is performed at a high reaction speed, and at the same time, the impact due to friction is relatively large. The mechanical braking is not operated, and the mechanical braking is operated only when the effect of the deceleration by the regenerative braking is exerted to some extent, that is, when a predetermined timer time has elapsed. In this case, since the mechanical braking has a strong effect, if the mechanical braking is applied to only one of the first and second reels, an unnecessarily large slack or excessive tension is induced. Therefore, mechanical braking is applied to both reels simultaneously. As a result, it is possible to perform reasonably smooth braking, and even if the motor rotation speed is relatively high, it is ensured that excessive tension is applied to the tape and unnecessarily large slack occurs when the power is turned off. And tape damage can be prevented. In addition, since the mechanical braking is applied subsequent to the regenerative braking, the time from the start to the stop of the braking can be shortened.

According to a seventh aspect of the present invention, in the tape winding device according to the fifth aspect, a first mechanical braking means acting on the first reel and a second mechanical braking means acting on the second reel are provided. A mechanical braking means for starting a timing operation when a power cutoff is detected from the power cutoff detecting means and outputting a start signal after a predetermined timer time has elapsed; It is configured to include timer means for operating the braking means. The seventh aspect of the present invention describes the above-described sixth aspect of the present invention in more detail, and the above-described operation can be effectively exerted by adding a timer.

Hereinafter, specific embodiments of a tape winding device according to the present invention will be described in detail with reference to the drawings. Here, a video tape recorder is taken as an example.

(Embodiment 1) FIG. 1 is a block circuit diagram showing an electric circuit portion in a tape winding device according to Embodiment 1 of the present invention, and FIG. 2 is a schematic configuration diagram showing a mechanical portion.

First, the circuit configuration will be described with reference to FIG.
I will tell. In FIG. 1, the symbol M₁Is the first brushless
DC motor, MD₁Is the first brushless DC motor M₁
Is a first motor drive circuit for driving the motor. First
Motor drive circuit MD₁To explain the components of IB,₁
Is the first brushless DC motor M₁The first for driving
1 inverter bridge circuit, E₁Is the first inverter
Bridge circuit IB₁A first DC power supply for supplying power to the
SP₁Is the first inverter bridge circuit IB₁In
NPN-type transistors as multiple switching elements
Data Tr₁₁~ Tr ₁₆Predetermined switching pattern
Is a first switching pattern generation unit that supplies the first switching pattern.

M ₂ is a second brushless DC motor, and MD ₂ is a second motor drive circuit for driving the _second brushless DC motor M ₂ . To explain the second component of the motor driving circuit MD _2, IB ₂ second inverter bridge circuit for driving the second brushless DC motor M _2, E ₂ is the second inverter bridge circuit IB ₂ second DC power supply for supplying power, SP ₂ is the transistor Tr ₂₁ NPN type as a plurality of switching elements in the second inverter bridge circuit IB ₂
A second switching pattern generating unit for supplying a predetermined switching patterns for to Tr _26.

The first brushless DC motor M ₁ is a motor coil in which a first coil L ₁₁ , a second coil L ₁₂ and a third coil L ₁₃ are star-connected.
The first inverter bridge circuit IB ₁ includes a first transistor Tr ₁₁ emitter-collector-connected circuit of the second transistor Tr _12, and the third transistor Tr ₁₃ 4
Are those with the transistor Tr ₁₄ and the emitter-collector-connected circuit and the fifth transistor Tr ₁₅ and the respective emitter-collector connection circuit of the transistor Tr ₁₆ of the sixth is connected to the first DC power source E _1, each the transistor Tr ₁₁ to Tr ₁₆ are freewheeling diode D ₁₁ to D ₁₆ of the first through sixth are connected in antiparallel.
The connection point between the first and second transistors Tr ₁₁ and Tr ₁₂ is the first coil L ₁₁ of the first brushless DC motor M ₁ .
Is connected to the terminal N _11, terminal N ₁₂ of the third and the connection point of the fourth transistor Tr _13, Tr ₁₄ and the second coil L ₁₂
And the fifth and sixth transistors Tr ₁₅ , T ₁₅
connection point of the r ₁₆ is connected to the terminal N ₁₃ of the third coil L _13.

First switching pattern generator SP₁
Of the first drive pulse P₁₁Output terminal is the first transistor
Data Tr₁₁Connected to the base of the
Inverter I₁₁Through the second transistor Tr₁₂Bee
Connected to Similarly, the second drive pulse P₁₂
Output terminal of the third transistor Tr₁₃Connect to the base of
And the second inverter I₁₂Through the
Fourth transistor Tr ₁₄Connected to the base of the
The third drive pulse P₁₃Output terminal is the fifth transistor
Star Tr_FifteenConnected to the base of the third
Inverter I₁₃Through the sixth transistor Tr₁₆No
Source is also connected.

The second brushless DC motor M ₂
Coil L ₂₁ and the second coil L ₂₂ and the third coil L ₂₃ and is obtained by star connection. The second inverter bridge circuit IB ₂ includes a first transistor Tr ₂₁ second
Emitter-collector connection circuit with the third transistor Tr ₂₂ , the third transistor Tr ₂₃ and the fourth transistor T
r ₂₄ and the emitter-collector connection circuit between the fifth transistor Tr ₂₅ and the sixth transistor Tr ₂₆ are connected to the second DC power supply E ₂
Are connected to the respective transistors Tr _{21 to} T _21.
freewheeling diode D ₂₁ to D ₂₆ of the first through sixth are connected in inverse parallel to r _26. The connection point of the first and second transistors Tr ₂₁ and Tr ₂₂ is connected to the terminal N ₂₁ of the first coil L ₂₁ of the second brushless DC motor M ₂ , and the third and fourth transistors Tr ₂₃ and Tr ₂₂ connection point ₂₄ is connected to the terminal N ₂₂ of the second coil L _22, fifth
The connection point between the sixth transistor Tr ₂₅ and the sixth transistor Tr ₂₆ is connected to the terminal N ₂₃ of the third coil L ₂₃ .

The connection of the motor coil is not limited to the star connection described above, but may be a delta connection.

Second switching pattern generator SP_Two
Of the first drive pulse P_{twenty one}Output terminal is the first transistor
Data Tr_{twenty one}Connected to the base of the
Inverter I_{twenty one}Through the second transistor Tr_{twenty two}Bee
Connected to Similarly, the second drive pulse P_{twenty two}
Output terminal of the third transistor Tr_{twenty three}Connect to the base of
And the second inverter I_{twenty two}Through the
Fourth transistor Tr _{twenty four}Connected to the base of the
The third drive pulse P_{twenty three}Output terminal is the fifth transistor
Star Tr_{twenty five}Connected to the base of the third
Inverter I_{twenty three}Through the sixth transistor Tr₂₆No
Source is also connected.

Reference numeral 40 is a main DC power supply, 50 is a tape running direction detecting section, and 60 is a power cutoff detecting section. The main DC power supply 40, the tape running direction detecting section 50, power-off detection unit 60, so as to supply the main DC power source to the first and second switching pattern generation unit SP _1, SP ₂ other circuit portions I have. The tape running direction detecting section 50 detects forward and reverse running directions of the magnetic tape 103 (see FIG. 2), and outputs the detected running direction information to the first and second running directions.
To the switching pattern generators SP ₁ and SP ₂ . The power cutoff detecting section 60 outputs the power cutoff detection signal S _OFF when detecting a power cutoff such as a power failure, to the first and second switching pattern generating sections SP ₁ , S
And outputs it to the P _2. When the first and second switching pattern generators SP ₁ and SP ₂ receive the power cutoff detection signal, they check the detected traveling direction information and check the traveling direction of the magnetic tape on the upper side (the tape unwinding side). switching pattern generation unit towards corresponding to a brushless DC motor corresponding to the switching element group to flow regenerative current to the motor coil of the brushless DC motor corresponding thereto _{(Tr 11 ~Tr 16, Tr 21} ~T
r ₂₆ ) is configured to generate a specific switching pattern for controlling r ₂₆ ).

Next, the mechanical part will be described with reference to FIG. The first brushless DC motor M ₁ is the take-up reel mount is intended for rotationally driving the (first reel stand) 11, a second brushless DC motor M ₂ is the supply side reel table (second reel base) 12 is driven to rotate.

In FIG. 2, reference numeral 13 is a rotary head cylinder, 14 and 15 are guide posts, 16 is a movable post, 17 is a tension spring, 18 is a magnet, 19 is a magnetic sensor, and 21 is a first brushless DC motor M. first frequency signal generator for generating a frequency of the sine wave signal corresponding to the _first rotational speed, a second frequency signal generator similar to the second brushless DC motor M ₂ is 22, 23, 24 waveform shaping Circuit.

A video cassette tape (not shown) is loaded into the video tape recorder. A take-up reel (first reel) 101 of the cassette tape is set on a take-up reel base 11 and a supply reel (second reel) is set. The reel 102 is set on the supply reel base 12, and the magnetic tape 103 is loaded on the rotary head cylinder 13 via the guide posts 14 and 15.

The microcomputer μC operates the fast forward (F
Back mode command signal and turns of F) based on the mode command signal (REW), and controls the first motor drive circuit MD ₁ and the second motor driving circuit MD _2, the first brushless DC motor M the _first and second brushless DC motor M ₂ is driven to rotate. In this case, the first frequency signal generator 21 detects a first rotational speed of the motor M _1, a second
Of the frequency signal generator 22 detects a second rotational speed of the motor M _2, gives the frequency signal to the microcomputer μC via a respective waveform shaping circuits 23 and 24. The microcomputer μC operates the first and second motor drive circuits MD ₁ and MD ₂ on the lower side in the running direction of the magnetic tape so that the running speed of the magnetic tape 103 is maintained constant based on the frequency signal. The motor drive circuit corresponding to (tape winding side) is controlled.

The displacement of the magnet 18 connected to the movable post 16 is detected by the magnetic sensor 19, and the detection signal is taken in from the A / D input port of the microcomputer μC, so that the tension of the magnetic tape 103 becomes constant. controls the second torque of the motor M ₂ via the second motor drive circuit MD ₂ so.

When the magnetic tape 103 runs in the forward direction, the first
Brushless DC motor M ₁ of, which operates as a take-up reel table 11 and rotated to wind the magnetic tape 103 on the take-up side reel 101, the brushless DC motor M ₂ of the second this time The magnetic tape 10 from the supply-side reel 102 is rotated by following the supply-side reel base 12.
Assist the feeding of 3.

When the magnetic tape 103 runs in the reverse direction
The second brushless DC motor M_TwoIs the supply reel
The table 12 is driven and rotated, and a magnetic tape
It operates to wind up 103.
First brushless DC motor M ₁Is the take-up reel base 11
The magnetic tape from the take-up reel 101 is rotated
It assists in feeding the loop 103.

Next, a brushless DC motor will be described with reference to FIG.
A specific operation of the driving device will be described. Here, bra
First motor drive circuit as a DC motor drive device
MD ₁Will be described representatively.

Period T₁In the first switching
Pattern generator SP₁To the “H” level first drive path.
Luth P₁₁And the second drive pulse P at “H” level₁₂When
"L" level third drive pulse P₁₃Is output.
As a result, the first transistor Tr₁₁Is ON
And the first inverter I₁₁Through the second transistor
Tr₁₂Is turned off, and the third transistor Tr₁₃Is O
N and the second inverter I₁₂Through the fourth tran
Jista Tr₁₄Is turned off, and the fifth transistor Tr
_FifteenIs turned off and the third inverter I₁₃Through the sixth
Transistor Tr ₁₆Turns ON. Therefore, the first
DC power supply E₁From the positive electrode of the first transistor T
r₁₁, The first coil L₁₁, The third coil L₁₃, Sixth
Transistor Tr₁₆Through the first DC power supply E₁Negative electrode
Electric current flows. At the same time, the first DC power supply E₁Positive
From the pole, the third transistor Tr₁₃The second coil
L₁₂, The third coil L₁₃, The sixth transistor Tr₁₆To
Via a first DC power supply E₁A current flows through the negative electrode of. Soshi
And the potential difference between the terminals is V (U-V) = 0, V (V-W) = +
E₁, V (W-U) =-E₁Becomes

The period T_TwoIn the first switch
Ching pattern generator SP₁"H" level
Bell first drive pulse P₁₁"L" level after inversion
Second drive pulse P₁₂"L" level following
Of the third drive pulse P₁₃Is output. As a result
And the first transistor Tr₁₁Continues ON, and the second
Transistor Tr₁₂Continues OFF, and the third transition
Star Tr₁₃Is inverted and turned off, and the second inverter
I₁₂Through the fourth transistor Tr₁₄Turns ON
And the fifth transistor Tr_FifteenContinues OFF,
Sixth transistor Tr₁₆Continue ON. Accordingly
And the first DC power source E₁From the positive electrode of the
Transistor Tr₁₁, The first coil L₁₁, The third carp
Le L₁₃, The sixth transistor Tr₁₆Through the first direct current
Power supply E₁A current flows through the negative electrode of. At the same time, the first
DC power supply E₁From the positive electrode of the first transistor Tr₁₁,
First coil L₁₁, The second coil L₁₂, The second transi
Star Tr₁₂Through the first DC power supply E₁Current is applied to the negative electrode of
Flows. The potential difference between the terminals is V (U-V) = + E ₁,
V (V-W) = 0, V (W-U) =-E₁Becomes

The above period T₁To T_TwoSwitch to
At the moment, the third transistor Tr₁₃Is from ON
Switches to OFF, causing high voltage at its collector
However, since the flyback current flows, the third transistor
Data Tr₁₃Is protected. The flyback current is
Transistor Tr₁₃From the collector of the first DC power supply E
₁Positive electrode, negative electrode, fourth freewheeling diode
D₁₄, The second coil L₁₂, The third coil L₁₃, The fifth
Rea diode D_FifteenIs discharged through the path of
You.

The period T_ThreeIn the first switch
Ching pattern generator SP₁"H" level
Bell first drive pulse P₁₁"L" level
Second drive pulse P₁₂"H" level after inversion
Of the third drive pulse P₁₃Is output. As a result
And the first transistor Tr₁₁Continues ON, and the second
Transistor Tr₁₂Continues OFF, and the third transition
Star Tr₁₃Continues to be OFF, and the fourth transistor Tr
₁₄Continues ON, and the fifth transistor Tr_FifteenIs inverted
And the third inverter I₁₃Through the sixth
Transistor Tr ₁₆Is turned off. Accordingly
And the first DC power source E₁From the positive electrode of the
Transistor Tr₁₁, The first coil L₁₁, The second carp
Le L₁₂, The fourth transistor Tr₁₄Through the first direct current
Power supply E₁A current flows through the negative electrode of. At the same time, the first
DC power supply E₁From the positive electrode of the fifth transistor Tr_Fifteen,
Third coil L₁₃, The second coil L₁₂, The fourth transi
Star Tr₁₄Through the first DC power supply E₁Current is applied to the negative electrode of
Flows. The potential difference between the terminals is V (U-V) = + E₁,
V (V-W) =-E₁, V (W-U) = 0.

In the period T ₄ , an “L” level first drive pulse P ₁₁ after inversion from the first switching pattern generation unit SP ₁ and a subsequent “L” level second drive pulse. the subsequent pulse P ₁₂ "H" and the third driving pulse P ₁₃ level is output. As a result, OFF becomes inverted first transistor Tr ₁₁ is, the second transistor Tr ₁₂ via the first inverter I ₁₁ is ON, the third transistor Tr ₁₃ is OF
Continued F, the fourth transistor Tr ₁₄ continues the ON, the fifth transistor Tr ₁₅ continues the ON, transistor Tr ₁₆ of the sixth continues means OFF. Therefore,
From the first positive electrode of the DC power source E _1, the fifth transistor T
r _15, the third coil L _13, a second coil L _12, current flows through the fourth first through the transistor Tr ₁₄ of the negative electrode of the DC power source E _1. At the same time, the first positive electrode of the DC power source E _1, the fifth transistor Tr _15, the third coil L _13, the first coil L _11, a first DC power source through the second transistor Tr ₁₂ current flows to the negative electrode of the E _1. The potential difference between the terminals is V (UV) = 0, V (VW) =-
E ₁ , V (WU) = + E ₁ .

The above period T_ThreeTo T_FourSwitch to
At the moment, the first transistor Tr₁₁Is from ON
Switches to OFF, causing high voltage at its collector
However, since the flyback current flows, the first transistor
Data Tr₁₁Is protected. The flyback current is
Transistor Tr₁₁From the collector of the first DC power supply E
₁Positive and negative electrodes, second freewheeling diode
D₁₂, The first coil L₁₁, The second coil L₁₂, The third
Rea diode D₁₃Is discharged through the path of
You.

Period T_Five~ T₁₂The operation of each individual period of
Although the description is omitted, the timing chart of FIG.
It is as shown in. One cycle of the switching pattern is the period
Interval T ₁~ T₆And one cycle of the three-phase terminal potential difference is a period.
Interval T₁~ T₁₂It is. End shown in this timing chart
Change in waveform of potential difference V (U-V), V (V-W), V (W-U) between children
As is clear from FIG. 5, the potential difference between terminals V (U-V) and the
There is a phase difference of 120 degrees with the potential difference V (V-W), and the potential between terminals is
Both the difference V (V-W) and the potential difference between terminals V (W-U) are in phase of 120 degrees
There is a difference between the terminal potential difference V (W-U) and the terminal potential difference V (U-U
V) both have a phase difference of 120 degrees. Therefore, the first
Motor M₁, A symmetric three-phase alternating current flows.

Next, the operation when a power failure occurs will be described. Power-off detection unit 60 detects the power-off of the power failure, and outputs a first power-off detection signal S _OFF to the switching pattern generating unit SP ₁ and the second switching pattern generation unit SP _2. Among the first and second switching pattern generators SP ₁ and SP ₂ , the switching pattern generator corresponding to the brushless DC motor corresponding to the upper side (the tape unwinding side) in the running direction of the magnetic tape is provided therein. The regenerative current flows through the motor coil of the corresponding brushless DC motor.

Now, as an example, the tape running direction detecting section 50 is provided with the first and second switching pattern generating sections S.
It is assumed that the detected traveling direction information given to P ₁ and SP ₂ indicates that the traveling direction of the magnetic tape is the reverse direction. At this time, a brushless DC motor corresponding to the upstream side in the running direction of the magnetic tape (tape unwinding side), it comes to the first brushless DC motor M _1. In the brushless DC motor M ₁ corresponding to the upstream side of the traveling direction (the tape unwinding side), the first switching pattern generation unit SP ₁ is to flow a regenerative current corresponding thereto.

[0061] In the first switching pattern generation unit SP ₁ which corresponds to the upper side of the running direction (the tape unwinding side), as the timing is the period T ₁₀₃ of FIG. 3, the power-off detection unit 60 at the timing It is assumed that the power cutoff detection signal S _OFF has been input. This period T
₁₀₃ is equivalent to the period T _3. This will be described with reference to FIG. 6 (FIG. 6 is shown first for convenience of description).

At this time, the first switching pattern is generated.
Ikube SP₁Is the first drive pulse P ₁₁, The second driving pal
SU₁₂And the third drive pulse P₁₃To force everything
Switch to “L” level. Note that the period T₁₀₃Then,
1 drive pulse P₁₁And the third drive pulse P₁₃But
Forcibly switched from “H” level to “L” level,
Also, the second drive pulse P₁₂Is originally at “L” level
Therefore, that state will be maintained.

All the driving pulses P ₁₁ , P ₁₂ , P
_With all ₁₃ “L”, the first transistor Tr ₁₁ , the third transistor Tr ₁₃ and the fifth transistor Tr ₁₅ located on the upper side are all turned off, and the second transistor Tr ₁₅ located on the lower side is turned off. The transistor Tr ₁₂ , the fourth transistor Tr ₁₄ and the sixth transistor Tr ₁₆ are all turned on.

At the timing immediately before the power-off detection signal S _OFF is input, the first motor M ₁
Drive current flows toward the terminal N ₁₂ from the terminal N _11, terminal N
Drive current is flowing toward the terminal N ₁₂ from _13. Therefore, regarding the potential difference, the potential difference E _12-11 from the terminal N ₁₂ to the terminal N ₁₁ (corresponding to the potential difference V (UV) = + E ₁ between the terminals) and the potential difference E from the terminal N ₁₂ to the terminal N _13
12-13 has a (inter-terminal voltage difference V (VW) = -E ₁ equivalent).

When the power cutoff detection signal S _OFF is input and all the upper transistors Tr ₁₁ , Tr ₁₃ , Tr ₁₅ are switched off, the three coils L ₁₁ , L
_12, the flow of the driving current is interrupted in any of the L _13. As a result, back electromotive forces Einv ₁ and Einv ₂ are generated.

The back electromotive force Einv ₁ causes the terminal N ₁₁ to
Second transistor Tr of N state _12, a fourth free-wheeling diode D _14, terminal N _12, the second coil L _12, a regenerative current Irb ₁ flows through a path of the first coil L _11. At the same time, by the counter electromotive force EINV _2, from the terminal N ₁₃ O
Sixth transistor Tr ₁₆ of the N states, the fourth free-wheeling diode D _14, terminal N _12, the second coil L _12, a regenerative current Irb ₂ flows through a path of the third coil L _13. Thus, the regenerative braking with respect to the first motor M ₁ that is rotating at a current high speed; will be (Regenerative Braking electromagnetic brake) is applied. Regenerative braking is to apply an electromagnetic brake by returning a current generated by a motor as a generator to a power supply.

The second transistor Tr ₁₂ and the sixth transistor Tr ₁₆ through which the regenerative current Irb flows are forced OFF.
It is located below the first transistor Tr ₁₁ and the fifth transistor Tr ₁₅ thus formed. It is easy to understand if you think like this.

[0068] Figure 4, in the period T ₁ corresponding to the timing, showing the flow of regenerative current Irb when there is power-off detection. This is because the upper two first transistors Tr ₁₁ ,
A third transistor Tr ₁₃ and a lower one of the sixth transistor Tr ₁₆ is forced under the three transistors Tr ₁₂ from the ON state of, Tr _14, Tr ₁₆ are all ON, all the remaining transistors are turned OFF This is the case. Regenerative current Irb, the first transistor Tr from ₁₁ and the second transistor Tr ₁₂ and the fourth transistor Tr ₁₄ which is positioned on the lower side of the third transistor Tr ₁₃ of the sixth freewheeling diode D ₁₆ which is forced OFF Reflux through Thus, the regenerative braking is applied to the first motor M ₁ which rotates at high speed.

[0069] Figure 5, in the period T ₂ corresponding to the timing, showing the flow of regenerative current Irb when there is power-off detection. This upper one of the first transistor Tr ₁₁ and the lower two of the fourth transistor Tr ₁₄ and the sixth force the lower three transistors Tr ₁₂ transistor Tr ₁₆ is from the state of ON of, Tr _14, Tr ₁₆ are all turned on and all the remaining transistors are turned off. The regenerative current Irb is supplied to the first transistor Tr forcibly turned off.
₁₁ to the fourth transistor Tr ₁₂ located below
Refluxed through the freewheeling diode D ₁₄ and the free wheel diode D ₁₆ of the sixth. This allows
Regenerative braking is applied to the first motor M ₁ which rotates at high speed.

FIG. 6 shows a case corresponding to the period T ₃ .

[0071] Figure 7, in the period T ₄ corresponding timing, showing the flow of regenerative current Irb when there is power-off detection. This upper one fifth transistor Tr ₁₅ and the lower two of the second transistor Tr ₁₂ and the fourth transistor Tr ₁₄ forcibly lower three transistors Tr ₁₂ are in the state of ON, Tr _14, Tr ₁₆ are all turned on and all the remaining transistors are turned off. The regenerative current Irb is supplied to the forcibly turned-off fifth transistor Tr.
₁₅ from the sixth transistor Tr ₁₆ located below
Refluxed through the freewheeling diode D ₁₂ and the fourth free-wheeling diode D _14. This allows
Regenerative braking is applied to the first motor M ₁ which rotates at high speed.

[0072] Figure 8 is, in the period T ₅ corresponding timing, showing the flow of regenerative current Irb when there is power-off detection. This is because the upper two third transistors Tr ₁₃ ,
A fifth transistor Tr ₁₅ and a lower one of the second transistor Tr ₁₂ forcibly lower three transistors Tr ₁₂ are in the state of ON, Tr _14, Tr ₁₆ are all ON, all the remaining transistors are turned OFF This is the case. Regenerative current Irb, the third transistor Tr ₁₃ and the fourth transistor Tr ₁₄ and the sixth transistors Tr ₁₆ of the second located on the lower side of the fifth transistor Tr ₁₅ of the free wheel diode D ₁₂ which is forced OFF Reflux through Thus, the regenerative braking is applied to the first motor M ₁ which rotates at high speed.

[0073] Figure 9 is the timing of the period T ₆ corresponds, showing the flow of regenerative current Irb when there is power-off detection. This upper one third transistor Tr ₁₃ and the lower forcibly lower three transistors Tr ₁₂ 2 one second transistor Tr ₁₂ and the sixth transistor Tr ₁₆ is from the state of ON, Tr _14, Tr ₁₆ are all turned on and all the remaining transistors are turned off. The regenerative current Irb is the third transistor Tr forcibly turned off.
₁₃ from the fourth transistor Tr ₁₄ located below
Refluxed through the freewheeling diode D ₁₂ and a sixth freewheeling diode D _16. This allows
Regenerative braking is applied to the first motor M ₁ which rotates at high speed.

FIG. 10 shows the transition of the back electromotive force in the period T _{1 to} T ₆ for one cycle. FIG. 11 shows a combination of elements through which a regenerative current flows. It is clear that the change is periodic.

In the above description of the operation, when regenerative braking is given
All drive pulses P₁₁, P ₁₂, P₁₃Oar
By "L", the first transistor located above
Tr₁₁, The third transistor Tr₁₃And the fifth tran
Jista Tr_FifteenAre all turned OFF and are located on the lower side
Second transistor Tr₁₂, The fourth transistor Tr₁₄
And the sixth transistor Tr₁₆Turned on all
However, it is not always necessary to be caught in that.
It is also possible to apply regenerative braking in a reverse pattern. You
That is, all drive pulses P₁₁, P₁₂, P₁₃Oar
By "H", the second transistor located on the lower side
Tr₁₂, The fourth transistor Tr₁₄And the sixth tran
Jista Tr₁₆Are all OFF and are located on the upper side
First transistor Tr₁₁, The third transistor Tr₁₃
And the fifth transistor Tr_FifteenEven if all are turned on
It is good.

[0076] The above description of the operation, in the direction of travel opposite the direction of the magnetic tape, but a brushless DC motor corresponding to the upstream side in the running direction (the tape unwinding side) has been a first brushless DC motor M ₁ on the contrary, in the traveling direction is a positive direction of the magnetic tape, of course, when the brushless DC motor corresponding to the upstream side in the running direction (the tape unwinding side) is in the second brushless DC motor M ₂ possible. In this case, the second brushless DC motor M ₂ corresponding to the upstream side of the running direction (the tape unwinding side), the second power-off detection unit 60 to the switching pattern generating section SP ₂ corresponding thereto Power cutoff detection signal S
The operation when _OFF is input is exactly the same as the above case.

(Embodiment 2) Embodiment 2 uses mechanical braking in addition to regenerative braking. FIG.
Is a block circuit diagram showing an electric circuit portion in the tape winding device according to the second embodiment of the present invention, and FIG. 13 is a schematic configuration diagram showing a mechanical portion.

As shown in FIG.
And the first mechanical braking means MB ₁ acting on the take-up reel base 11.
Is provided with a second mechanical braking means MB ₂ acting on the supply reel stand 12 and. Timer means 70 starts the time count operation at the timing when the power-off detection unit 60 enter the power-off detection signal S _OFF, MB first and second mechanical braking means after timeout of a predetermined timer time _1, MB ₂ Is configured to output a start signal.

A take-up reel base 11 is provided with a brake pad 31 for applying a braking force by contacting the take-up reel base 11, and the brake pad 31 is driven by a solenoid 32 to move in and out. 33 is a drive circuit of the solenoid 32. Further, a similar brake pad 34 is disposed on the supply-side reel base 12, and is configured to be driven in and out by a solenoid 35. 36 is a drive circuit for the solenoid 35. Each brake pad 3
1 and 34 are configured to be separated from the reel bases 11 and 12 while the magnetic tape 103 is running.

Next, the operation of the tape winding device according to the second embodiment configured as described above will be described.

The power cut-off detection unit 60 detects a power cut-off such as a power failure.
Is detected, the power cutoff detection signal S _OFFThe first and the second
2 switching pattern generator SP₁, SP_TwoSent to
At the same time, it is also sent to the timer means 70. timer
Means 70 starts the timing operation. First and second
Switching pattern generator SP₁, SP_TwoFire
Either of them is shifted toward the upper side (unwinding side) of the running direction.
The right side of the running direction (tape unwinding side)
The switching pattern generator corresponding to
The same operation as in the first embodiment is performed, and the brush
The regenerative braking is applied to the DC motor.

On the other hand, the timer means 70 continues to count up, and when the predetermined timer time expires, the first and second mechanical braking means MB ₁ , MB ₂
Simultaneously output a start signal. First and second
It operates the driving circuit 33, 36 of the mechanical braking means MB _1, MB _2, corresponding winding reel by the urging force of the spring (not shown) or the like brake pads 31 and 32 to demagnetize the solenoid 32, 35 base 11 and Mechanical braking is applied by pressing both of the supply-side reel bases 12.

The time during which the regenerative current generated when the power is cut off is relatively short. Therefore, the predetermined timer time is set to a time that elapses before the regenerative current falls below the predetermined level. As a result, mechanical braking can be applied immediately before the end of the regenerative braking, and a smooth stop can be achieved. In particular, when the power is cut off, the tape winding diameter is large and the inertia force is large, so that it is effective when regenerative braking alone requires a long time from braking start to stop. Smooth and smooth braking is possible, and even if the motor rotation speed is relatively high, it is possible to prevent the tape from being unnecessarily large slack or excessive tension being applied when the power is turned off. , Tape damage can be prevented. In addition, since the mechanical braking is applied subsequent to the regenerative braking, the time from the start to the stop of the braking can be shortened. Deterioration in the brake pad can be suppressed as compared with the case where only mechanical braking is performed by the brake pad without using regenerative braking.

In the above description, the braking means is configured so that the brake pad is pressed against the reel base to perform braking by the frictional force. However, the braking means does not have to be limited to the frictional force. It may be a configuration to make it.

In the above embodiment, the present invention is applied to a video tape recorder. However, the tape winding device according to the present invention is not limited to the video tape recorder, but may be used for other magnetic recording / reproducing such as an audio tape recorder. You may apply to an apparatus. Here, the expression “record / reproduce”
The meaning of “recording and reproduction” and the meaning of “recording or reproduction” are integrated. Further, the brushless DC motor driving device according to the present invention may be applied to any device.

[0086]

According to the present invention, the regenerative braking is applied to the motor when the power is turned off, and the motor is regeneratively braked only with a simple configuration that simply adjusts the switching pattern for the inverter bridge circuit that is originally required for driving the brushless DC motor. The cost and downsizing and power consumption can be reduced as compared with the related art in which a short circuit responsive to power-off detection must be added outside the drive circuit.

Further, when applied to a tape winding device, the tape can be moved without causing unnecessarily large slack or excessive tension especially when the power is cut off during high-speed tape running such as fast-forward or rewind. Can be stopped very smoothly, and tape damage can be eliminated.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing an electric circuit portion in a tape winding device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a mechanical part in the tape winding device according to the first embodiment;

FIG. 3 is a timing chart showing the operation of the brushless DC motor driving device in the tape winding device according to the first embodiment;

FIG. 4 is an explanatory diagram of an operation of regenerative braking when power is cut off in the brushless DC motor driving device according to the first embodiment.

FIG. 5 is an explanatory diagram of an operation of regenerative braking when the power of the brushless DC motor driving device according to the first embodiment is cut off;

FIG. 6 is an explanatory diagram of an operation of regenerative braking when power is cut off in the brushless DC motor driving device according to the first embodiment.

FIG. 7 is an explanatory diagram of an operation of regenerative braking when power is cut off in the brushless DC motor driving device according to the first embodiment.

FIG. 8 is an explanatory diagram of an operation of regenerative braking when power is cut off in the brushless DC motor driving device according to the first embodiment.

FIG. 9 is an explanatory diagram of an operation of regenerative braking when power is cut off in the brushless DC motor driving device according to the first embodiment.

FIG. 10 is an explanatory diagram of a change in back electromotive force when the power of the brushless DC motor driving device according to the first embodiment is cut off.

FIG. 11 is an explanatory diagram of a combination of elements through which a regenerative current flows when the power of the brushless DC motor driving device according to the first embodiment is cut off;

FIG. 12 is a block circuit diagram showing an electric circuit part in the tape winding device according to the second embodiment of the present invention;

FIG. 13 is a schematic configuration diagram showing a mechanical part in the tape winding device according to the second embodiment;

[Explanation of symbols]

M ₁ … first brushless DC motor M ₂ … first brushless DC motor MD ₁ … first motor drive circuit MD ₂ … second motor drive circuit IB ₁ … first inverter bridge circuit IB ₂ … second Inverter bridge circuit E ₁ ... first DC power supply E ₂ ... second DC power supply SP ₁ ... first switching pattern generator SP ₂ ... second switching pattern generator MB ₁ ... first mechanical braking means MB ₂ ... second mechanical braking means 11 ... take-up reel stand (first reel stand) 12 ... supply reel stand (second reel stand) 31 ... brake pad for first reel stand 34 ... second Brake pad for reel stand 40 ... Main DC power supply 50 ... Tape running direction detecting unit 60 ... Power cutoff detecting unit 70 ... Timer means 101 ... Winding-side reel (first reel) ) 102 ... supply reel (second reel) 103 ... magnetic tape

Claims (7)

[Claims] 1. A brushless DC motor driving device for driving a brushless DC motor by controlling a plurality of switching elements in an inverter bridge circuit with a predetermined switching pattern, wherein a specific switching is performed when a power cutoff is detected. A brushless DC motor driving device, wherein a regenerative current is supplied to a motor coil by controlling the switching element group in a pattern. 2. The inverter bridge circuit according to claim 1, wherein said inverter bridge circuit is configured to supply a symmetric three-phase alternating current by bridge-connecting three sets of a pair of push-pull switching elements. It is characterized in that three low-potential switching elements of a pair of push-pull type switching elements are simultaneously turned on, or three high-potential switching elements are turned on simultaneously. The brushless DC motor driving device according to claim 1. 3. A system in which mechanical braking is started immediately after controlling the switching element group in the specific switching pattern to supply a regenerative current to the motor coil when power cutoff is detected. The brushless D according to claim 1 or 2, wherein
C motor drive. 4. The tape is wound on a first reel by an operation of a first brushless DC motor driving device during forward running, and the tape is wound on a second reel by an operation of a second brushless DC motor driving device during reverse running. A tape winding device that winds a reel on a reel, and detects a power supply cutoff, and detects a switching element group of an inverter bridge circuit in a brushless DC motor driving device on a side corresponding to an upper side in a traveling direction in which the tape is unwound. A tape winding device characterized in that a regenerative current is supplied to a motor coil by controlling with a specific switching pattern. 5. A first brushless DC motor for winding a tape on a first reel during forward running, a first inverter bridge circuit for driving the first brushless DC motor, and a first inverter bridge. A first switching pattern generating means for supplying a predetermined switching pattern to a plurality of switching elements in the circuit; a second brushless DC motor for winding a tape on a second reel during reverse running; and the second brushless DC A second inverter bridge circuit for driving a motor; a second switching pattern generating means for supplying a predetermined switching pattern to a plurality of switching elements in the second inverter bridge circuit; and detecting the forward and reverse running directions of the tape. And the first and second
A tape running direction detecting means for providing the detected running direction information to the switching pattern generating means, and a power cutoff detecting means, wherein the first and second switching pattern generating means are located on the upper side in the running direction in which the tape is unwound. The switching pattern generating means on the corresponding side generates a specific switching pattern for controlling the switching element group so as to allow a regenerative current to flow to the motor coil when power cutoff detection is received from the power cutoff detecting means. A tape winding device, wherein 6. A first mechanical braking means acting on the first reel, a second mechanical braking means acting on the second reel, and a time counting operation is started when power cutoff is detected. 5. The tape winding device according to claim 4, wherein the two mechanical braking means in the two brushless DC motor driving devices are activated after a predetermined timer time has elapsed. 7. A first mechanical braking means acting on the first reel, a second mechanical braking means acting on the second reel, and a power cutoff detected by the power cutoff detecting means. A timer means for starting a timing operation and outputting a start signal after a predetermined timer time has elapsed to operate the first and second mechanical braking means. 6. The tape winding device according to 5.