JP2019140350A - Brake drive control circuit - Google Patents

Abstract

To provide a brake drive control circuit capable of stably controlling an electromagnetic brake against fluctuations in power supply voltage and suppressing heat generation in the electromagnetic brake.SOLUTION: A brake drive control circuit that controls an electromagnetic brake that releases the brake when energized includes monitoring means for monitoring a voltage or a current supplied to a circuit block constituted by the electromagnetic brake and a switch element provided in series with the electromagnetic brake, and calculating means for generating a brake control signal which is a PWM signal such that an operating voltage or an operating current of the electromagnetic brake becomes a value set in advance for releasing the electromagnetic brake on the basis of the monitoring result of the monitoring means. The conduction of the switch element is PWM-controlled by the brake control signal.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a brake drive control circuit that controls the drive of an electromagnetic brake attached to a motor or the like.

  For example, in a robot, an electromagnetic brake is attached to the motor shaft in order to prevent the robot arm from moving or dropping when the power of the motor that drives each shaft is cut off and to ensure safety. . The electromagnetic brake attached to the motor is generally of the non-excitation operation type, and when the electromagnetic brake is energized, the brake is released (released), and when the energization is interrupted, the brake operates. Is configured to lock. A state where the motor shaft is locked so as not to move is called a brake clamp state. Patent Document 1 discloses a device that includes a motor brake power supply unit for energizing an electromagnetic brake to release the brake, and can release the brake by operating a switch provided in the motor brake power supply unit. Yes.

  The electromagnetic brake is a mechanism related to safety and requires high reliability. When it is controlled by only one switch as shown in Patent Document 1, if the switch fails in a short-circuiting form, the brake is always released, and safety cannot be ensured. There is a fear. Therefore, Patent Document 2 discloses a brake drive control circuit in which switching control means is connected to both ends of the electromagnetic brake so as to be electrically in series with the electromagnetic brake in order to enhance safety. As the switching control means, a switching element such as a switching transistor is used. The brake drive control circuit described in Patent Document 2 also includes voltage detection means for detecting a failure by detecting the voltage across the electromagnetic brake. Similarly, in Patent Document 3, switch elements are provided at both ends of an electromagnetic brake in series with the electromagnetic brake, respectively, and further, a voltage detection unit that detects a voltage applied to the brake is provided and input to one switch element. It is disclosed that the voltage applied to the brake is detected by the voltage detector after delaying the switch command, and the failure of the switch element is determined. Patent Document 4 discloses detecting a voltage applied to an electromagnetic brake and observing the release and operating state of the electromagnetic brake based on a detected voltage fluctuation pattern.

  By the way, in the electromagnetic brake, in order to shift from the brake clamp state to the brake release state, it is necessary to apply a relatively large voltage to the solenoid of the electromagnetic brake to move the actuator in the electromagnetic brake to the position in the release state. The applied voltage for holding the actuator at the position as it is may be relatively small. In order to prevent heat generation of the solenoid, it is preferable to apply a relatively large voltage to the electromagnetic brake when shifting from the brake clamp state to the release state, and then continue to apply a relatively small voltage thereafter. Patent Document 5 discloses an electromagnetic brake drive configured to generate a first voltage when shifting to a release state, and to generate a second voltage during a period in which the release state is maintained after shifting to the release state. A control circuit is disclosed. Patent Document 5 also discloses that the voltage applied to the electromagnetic brake is substantially changed by pulse width (PWM) modulation. In Patent Document 6, the motor driving power source and the brake driving power source are shared, and the voltage applied to the electromagnetic brake is increased during a predetermined time immediately after the brake is released, and the brake is released after the predetermined time has elapsed. Therefore, it is disclosed that the period is kept low.

JP 2000-296492 A JP 2006-123118 A Japanese Patent No. 5653977 JP 2017-34856 A Japanese Patent No. 5911639 Japanese Patent No. 4202384

  Electromagnetic brakes consume less power than motors. On the other hand, providing a dedicated power supply circuit for the electromagnetic brake causes an increase in cost. Therefore, as described in Patent Document 6, it is considered to drive the electromagnetic brake with electric power from a power source for driving the motor. However, electromagnetic brakes are easily affected by fluctuations in power supply voltage, such as voltage drops due to the electrical resistance of the wiring from the power supply to the motor or electromagnetic brake, voltage rises due to regenerative power generated when the motor is controlled to stop, etc. Will be affected. If the voltage drop due to the wiring resistance cannot be ignored, the electromagnetic brake cannot be held during the period in which the electromagnetic brake should be kept in a released state, and an unintended break clamp may occur. In order to prevent such a malfunction due to a voltage drop, power is continuously supplied to the electromagnetic brake in consideration of a margin for the voltage drop, which causes unnecessary heat generation in the electromagnetic brake and the power supply device. On the other hand, an increase in power supply voltage due to motor regeneration causes unnecessary heat generation in the electromagnetic brake. A motor with an integrated brake is more affected by the heat generated by the electromagnetic brake than the motor, and the motor's rated output may have to be reduced. Even when a dedicated power supply for the electromagnetic brake is provided separately from the power supply for driving the motor, if the voltage from the power supply dedicated for the electromagnetic brake fluctuates, a problem occurs when the power is shared with the power supply for driving the motor Similar problems can occur.

  An object of the present invention is a brake drive control circuit for controlling an electromagnetic brake, which can stably control the electromagnetic brake against fluctuations in power supply voltage and can suppress heat generation in the electromagnetic brake. It is to provide a circuit.

  A brake drive control circuit according to the present invention is a brake drive control circuit that controls an electromagnetic brake that releases a brake when energized, and includes a circuit block including an electromagnetic brake and a switch element provided in series with the electromagnetic brake. The monitoring means for monitoring the supplied voltage or current, and the PWM signal so that the operating voltage or operating current of the electromagnetic brake becomes a preset value for releasing the electromagnetic brake based on the monitoring result of the monitoring means. And calculating means for generating a brake control signal, and conducting PWM control of conduction of the switch element by the brake control signal.

  In the present invention, the voltage or current supplied to the electromagnetic brake is monitored by the monitoring means, and the brake control signal that is a PWM signal is generated according to the monitoring result, so the circuit voltage or current supplied to the electromagnetic brake varies. Even when the electromagnetic brake is released, the current supplied to the electromagnetic brake can be made constant, and the electromagnetic brake can be released reliably. In order to make the circuit voltage constant, for example, it may be possible to provide a constant voltage circuit. However, in the present invention, a switch element provided in advance for driving the electromagnetic brake is operated by a PWM signal. There is no need to provide a voltage circuit. In addition, since the current flowing through the electromagnetic brake is prevented from fluctuating unintentionally, the electromagnetic brake can be used without taking an excessive current margin, power consumption can be reduced, and heat generation can be reduced.

  In the present invention, when the electromagnetic brake is supplied with power from a power supply that supplies power to the motor drive circuit, the monitoring means can be configured by a voltage monitor circuit that detects a voltage applied to the circuit block. In this case, since the voltage monitor circuit also monitors the circuit voltage supplied to the motor drive circuit, the detection result of the voltage monitor circuit is also supplied to the motor drive circuit. It is possible to predict the effect of the motor on the gain of the motor drive, etc., and the drive gain can be adjusted as necessary.

  In the present invention, the monitoring means can also be constituted by a current monitor circuit that detects the current supplied to the circuit block. By detecting the current, an appropriate current can be supplied to the electromagnetic brake without being affected by a change in resistance of the electromagnetic brake due to a temperature rise.

  In the present invention, as a preset value for releasing the electromagnetic brake, the first value for the initial release operation for setting the electromagnetic brake to the release state, and the second value for the holding operation for maintaining the release state, Is preferably used. Generally, in an electromagnetic brake, the current required for the initial release operation is larger than the current required for the holding operation. Therefore, after performing the initial release operation using the first value and releasing the electromagnetic brake, Further power savings can be achieved by using a second value that can be set smaller than a value of one.

  In the present invention, the initial release setting value that is the ratio of the first value to the reference value for PWM driving, the holding setting value that is the ratio of the second value to the reference value, and the duration of the initial release operation Storage means for storing the initial release time, and the calculation means determines the pulse width in the PWM signal by dividing each of the initial release setting value and the hold setting value by the monitoring result of the monitoring means. Can be. By storing each setting value in the storage means instead of setting by hardware, it is possible to set parameters necessary for calculation in the calculation means without increasing the circuit element scale. Also, by setting the set value as a ratio to the reference value for PWM driving, the calculation means can determine the pulse width of the PWM signal only by division, and the calculation load on the calculation means can be reduced. . The storage means may store an initial release set value, a hold set value, and an initial release time for each brake type corresponding to at least one type of electromagnetic brake. By storing each setting value and initial release time corresponding to multiple types of electromagnetic brakes in the storage means, even if multiple electromagnetic brakes are installed to be used properly, the voltage or The electromagnetic brake can be reliably released by the current.

  According to the present invention, the electromagnetic brake can be stably controlled against fluctuations in the power supply voltage, and heat generation in the electromagnetic brake can be suppressed.

It is a circuit diagram explaining the brake drive control circuit of one embodiment of the present invention. It is a figure explaining the voltage for driving an electromagnetic brake. It is a figure explaining the production | generation of the PWM signal which is a brake control signal. It is a figure explaining operation | movement of a brake drive control circuit. It is a circuit diagram explaining the brake drive control circuit of another embodiment.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining a brake drive control circuit according to an embodiment of the present invention. In addition to the brake drive control circuit, an electromagnetic brake 21 to be driven and controlled, and a motor to which the electromagnetic brake 21 is connected. 13 and so on.

  For example, a motor drive power supply 11 that receives AC 100V or 200V power from a commercial power supply and converts it into DC power of a predetermined voltage is provided. The DC power from the motor drive power supply 11 is a motor drive circuit that drives the motor 13. 12 is supplied. The motor drive circuit 12 includes an inverter circuit, for example, and receives a drive command for the motor 13 from a motor control device (not shown) so that the motor 13 rotates at a speed and torque specified by the drive command. 13 is driven by servo control. The motor 13 is, for example, a three-phase motor. As indicated by the double line in the figure, an electromagnetic brake 21 is mechanically connected to the rotating shaft of the motor 13. The solenoid (coil) of the electromagnetic brake 21 is provided with a surge absorber 22 in parallel for absorbing a large counter electromotive force generated when the current to the solenoid is interrupted. As the surge absorber 22, for example, a varistor, a diode or the like is used.

  The electromagnetic brake 21 is of a non-excitation operation type and is operated by electric power from the motor drive power supply 11. One end of the electromagnetic brake 21 is connected to the motor drive power supply 11, and the other end is grounded via a transistor Tr1 that is a switch element. In order to bring the electromagnetic brake 21 into the released state, the motor drive power supply 11 is in operation and the transistor Tr1 must be turned on. Generally, a safety circuit (not shown) is provided inside the motor drive power supply 11 or between the commercial power supply 11 and the motor drive power supply 11 so that the motor drive power supply 11 can output DC power only when it can be confirmed as safe. It has become. Therefore, it can be said that the configuration shown in FIG. 1 is a configuration in which switch elements are provided at both ends of the electromagnetic brake 21, and sufficient safety is ensured.

  The brake drive control circuit monitors the output voltage of the motor drive power source 11, that is, the voltage supplied to the electromagnetic brake 21, and drives the electromagnetic brake 21 based on the voltage monitor value. And a storage device 33 for storing a set value necessary for the calculation in the calculation device 32, and a calculation device 32 for outputting a brake control signal applied to the gate of the transistor Tr1 based on the calculation result. It is configured. As the voltage monitor circuit 31, for example, a ΔΣ A / D (analog / digital) converter is used. The voltage monitor value from the voltage monitor circuit 31 is used to monitor the circuit voltage of the motor 13 to predict the effect of fluctuations in the circuit voltage on the motor drive gain, and to perform appropriate control of the motor 13 drive. It is also supplied to the drive circuit 12. Therefore, when a circuit or device for monitoring the output voltage of the motor drive power supply 11 is already provided for control by the motor drive circuit 12, the circuit or device is connected to the voltage monitor circuit 31 of the brake drive control circuit. The voltage monitor circuit 31 need not be provided separately from these devices and circuits.

  In the brake drive control circuit of the present embodiment, the arithmetic device 32 drives the electromagnetic brake 21 from the brake clamp state to the released state in accordance with a brake command supplied from the outside of the arithmetic device 32. In particular, the arithmetic device 32 performs control such that the current supplied to the electromagnetic brake 21 is substantially constant even when the voltage supplied from the motor drive power supply 11 to the electromagnetic brake 21 fluctuates. Therefore, the arithmetic unit 32 reduces the pulse width in the brake control signal when the voltage applied to the electromagnetic brake 21 is high, and the PWM (pulse width modulation) signal so that the pulse width is widened when the applied voltage is low. Generate as Further, the arithmetic unit 32 has a pulse width in the brake control signal so that the current flowing through the electromagnetic brake 21 is large when shifting from the brake clamp state to the release state, and thereafter the current is reduced during the period of maintaining the release state. To change. Details of the calculation and generation of the brake control signal in the calculation device 32 will be described later.

  The storage device 33 is configured by, for example, a non-volatile memory, and stores data necessary for calculation in the calculation device 32. At least the initial release setting value, the holding setting value, and the initial release time for the electromagnetic brake 21 are stored. Store. In order to be able to apply the brake drive control circuit of the present embodiment to a plurality of types of electromagnetic brakes, the storage device 33 stores initial release setting values, holding setting values, and holding values for each of the plurality of types of electromagnetic brakes. It is preferable to store the initial release time. When the storage device stores these data for a plurality of types of electromagnetic brakes, the calculation device 32 reads the data for the electromagnetic brake that is the current drive target, and performs calculation for generating a brake control signal. Execute.

  Here, the initial release setting value, the hold setting value, and the initial release time stored in the storage device 33 will be described. FIG. 2 is a diagram for explaining a voltage necessary for driving the electromagnetic brake 21. In order to shift from the brake clamp state to the brake release state, it is necessary to flow a relatively large current to the solenoid in the electromagnetic brake 21 to move an actuator (not shown) in the electromagnetic brake 21. This is called an initial release operation, and a current predetermined as a current necessary for performing the initial release operation is called an initial release current, and a voltage that needs to be applied to the electromagnetic brake 21 to flow the initial release current is initialized. This is called the release voltage. The time required for the actuator to move and the magnetic circuit including the actuator and the solenoid to close is called the initial release time. During the initial release time, the initial release current needs to flow as an operating current to the electromagnetic brake 21, and therefore it is necessary to continue to apply the initial release voltage as the operating voltage.

  Once the actuator moves to the position in the brake released state and the magnetic circuit described above is closed, the current flowing through the solenoid may be small in order to maintain that state. The operation for maintaining the released state after the brake is released is referred to as a holding operation. A predetermined current as an operating current that must be passed through the solenoid in order to perform the holding operation is referred to as a holding current, and an operating voltage that must be applied to the electromagnetic brake 21 in order to pass the holding current is referred to as a holding voltage. Since the holding current is smaller than the initial release current, the holding voltage is lower than the initial release voltage. In the brake drive control circuit of this embodiment, even when the output voltage of the motor drive power supply 11 fluctuates, the current flowing through the electromagnetic brake 21 is the initial release current during the initial release operation and the hold current during the holding operation. In addition, the transistor Tr1 which is a switch element is controlled. In order to operate the electromagnetic brake 21 to be in the brake clamp state, it is only necessary to set the current flowing through the electromagnetic brake 21 to zero, so the applied voltage is set to zero.

  The storage device 33 may store the initial release voltage and the holding voltage as they are. However, in order to reduce the amount of calculation in the arithmetic device 32, in this embodiment, the initial release setting value and the holding voltage are replaced with the initial release voltage and the holding voltage. The retention setting value is stored in the storage device 33. In order to explain the use of the initial release set value and the hold set value, a method of generating a brake control signal that is a PWM signal will be described with reference to FIG. The arithmetic device 32 is provided with a PWM reference timer which is a counter that counts the PWM clock from 0 and returns to 0 when the predetermined upper limit value FullCount is reached and restarts counting. The arithmetic unit 32 constantly compares PWM_Set, which is a value given to determine the pulse width in PWM, with the value of the PWM reference timer, and sets the period in which PWM_Set is larger as the pulse period in the PWM signal. The duty ratio of the pulse in the PWM signal is expressed by PWM_Set / FullCount, and it can be seen from this that PWM_Set defines the pulse width in the PWM signal. Therefore, in the present embodiment, the initial release setting value and the holding setting value are determined and stored in the storage device 33 so that the calculation device 32 can immediately calculate the PWM_Set in each of the initial releasing operation and the holding operation.

When the voltage serving as the reference for the operation of the electromagnetic brake 21 is determined as the reference power supply voltage, the initial release setting value and the holding setting value are respectively
Initial release setting value = (initial release voltage / reference power supply voltage) x FullCount (1)
Holding setting value = (holding voltage / reference power supply voltage) × FullCount (2)
It is represented by A value obtained by dividing FullCount by the reference power supply voltage is a reference value for PWM driving. When each set value is determined in this way, PWM_Set for the initial release operation is
PWM_Set (initial release) = initial release set value / voltage monitor value (3)
PWM_Set for holding operation can be obtained by
PWM_Set (hold) = hold set value / voltage monitor value (4)
Can be obtained. Eventually, in order to calculate PWM_Set necessary for generating the PWM signal, the arithmetic unit 32 needs to perform division only once.

  Next, processing in the arithmetic device 32 will be described with reference to FIG. The arithmetic device 32 includes a division unit 41, a clamp unit 42, and a PWM signal generation unit 43. The division unit 41, the clamp unit 42, and the PWM signal generation unit 43 are realized by software executed in a microprocessor, for example. Alternatively, each of the division unit 41, the clamp unit 42, and the PWM signal generation unit 43 may be realized by hardware. The division unit 41 reads the initial release setting value, the hold setting value, and the initial release time from the storage device 33, and performs the division represented by the above formula (3) or formula (4). When the brake release is instructed by the brake command, the division unit 41 performs the calculation of Expression (3) until the initial release time elapses from the input of the command, and outputs PWM_Set for the initial release operation. After the initial release time has elapsed from the input, the calculation of Equation (4) is performed and PWM_Set for holding operation is output. The division unit 41 outputs 0 when the voltage monitor value is 0 due to a problem in the voltage monitor circuit 31 or the motor drive power supply 11 as a countermeasure against division by 0. When 0 is output, the pulse width in the PWM signal is also 0, the transistor Tr1 is not turned on, and the electromagnetic brake 21 is not released.

  Depending on the voltage monitor value and each set value, the calculation result in the division unit 41 may exceed the FullCount. Therefore, the calculation result PWM_Set of the division unit 41 is supplied to the clamp unit 42, and the maximum value clamp process is performed to obtain PWM_Set whose upper limit is FullCount. The PWM signal generation unit 43 includes the above-described PWM reference timer, receives the PWM clock and the PWM_Set subjected to the maximum value clamp from the clamp unit 42, and is a PWM signal according to the processing described with reference to FIG. Generate a brake control signal. As a result, even if the output voltage from the motor drive power supply 11 fluctuates, the voltage applied to the electromagnetic brake 21 during the release operation is on average the initial release voltage, and the electromagnetic brake 21 has a current during release. During the flow and holding operation, the applied voltage is an average holding voltage, and the flowing current is the holding current. This prevents the applied voltage to the electromagnetic brake 21 from being unintentionally lower than the holding voltage and causing the electromagnetic brake 21 to be in a clamped state or the electromagnetic brake 21 to generate heat unnecessarily.

[Effect of this embodiment]
According to the brake drive control circuit of the present embodiment, even when the voltage applied to the electromagnetic brake 21 fluctuates, the electromagnetic brake 21 can be prevented from being unintentionally clamped, and the electromagnetic brake 21 heat generation can be minimized. In addition, a voltage monitor circuit 31 is required for control, and a mechanism for monitoring the voltage of the motor drive power supply 11 has been conventionally provided for the purpose of improving the servo characteristics in the motor drive circuit 12. Since it can be used as the voltage monitor circuit 31, there is also an advantage that the voltage monitor circuit 31 need not be prepared only for driving control of the electromagnetic brake 21. By providing the storage device 33 and storing the initial release setting value and the holding setting value in advance, the calculation load on the calculation device 32 can be reduced.

[Another Embodiment of the Invention]
FIG. 5 shows a brake drive control circuit according to another embodiment of the present invention. Since the apparatus shown in FIG. 1 controls the supply current of the electromagnetic brake 21 based on the voltage applied to the electromagnetic brake 21, when the current-voltage characteristics of the electromagnetic brake 21 change due to a temperature rise of the solenoid, etc. You may not be able to follow the changes. Therefore, in the brake drive control circuit of another embodiment shown in FIG. 5, the current monitor circuit 34 is provided at a position where the current passing through the electromagnetic brake 21 flows, and the arithmetic device 32 is operated by the current monitor value output from the current monitor circuit 34. A brake control signal is generated. Since the transistor Tr1 is PWM-driven, the current flowing through the electromagnetic brake 21 also changes in the PWM waveform. However, the current monitor circuit 34 measures the averaged current with an appropriate time constant to obtain the current monitor value. Output. In FIG. 5, the current monitor circuit 34 is provided between the motor drive power supply 11 and the electromagnetic brake 21, but the position of the current monitor circuit 34 is not limited to this, and for example, the electromagnetic brake 21 and the grounding point It may be between. The position of the transistor Tr1 that is a switch element may also be between the motor drive power supply 11 and the electromagnetic brake 21.

In FIG. 5, the voltage monitor device 31 is left in order to use the voltage monitor value in the motor drive circuit 12. However, the voltage monitor value is not sent to the arithmetic device 32, and the voltage monitor device 31 does not constitute a brake drive control circuit. In the brake drive control circuit shown in FIG. 5, the supply current that is the reference for the operation of the electromagnetic brake 21 is used as the reference supply current, and instead of Expression (1) and Expression (2), Expression (5) and Expression (6) are used. The initial release setting value and the hold setting value that are represented are stored in the storage device 33.
Initial release setting value = (initial release current / reference supply current) x FullCount (5)
Holding setting value = (holding current / reference supply current) × FullCount (6)
Further, the arithmetic unit 32 calculates PWM_Set during the initial release operation and the holding operation based on the equations (7) and (8) instead of the equations (3) and (4).
PWM_Set (initial release) = initial release set value / current monitor value (7)
PWM_Set (hold) = hold set value / current monitor value (8)

[Effect of this embodiment]
Even in this embodiment, even when the voltage applied to the electromagnetic brake 21 fluctuates, the electromagnetic brake 21 can be prevented from being unintentionally clamped, and heat generation of the electromagnetic brake 21 can be minimized. can do. By providing the storage device 33 and storing the initial release setting value and the holding setting value in advance, the calculation load on the calculation device 32 can be reduced. Furthermore, since control is performed by detecting the supply current to the electromagnetic brake 12, appropriate control can be performed even when the resistance value of the electromagnetic brake 12 changes due to a temperature rise or the like.

  DESCRIPTION OF SYMBOLS 11 ... Motor drive power source, 12 ... Motor drive circuit, 13 ... Motor, 21 ... Electromagnetic brake, 22 ... Surge absorber, 31 ... Voltage monitor circuit, 32 ... Arithmetic unit, 33 ... Storage device, 34 ... Current monitor circuit, 41 ... Dividing unit, 42... Clamping unit, 43... PWM signal generating unit.

Claims (6)

A brake drive control circuit that controls an electromagnetic brake that releases a brake when energized,
Monitoring means for monitoring voltage or current supplied to a circuit block comprising the electromagnetic brake and a switch element provided in series with the electromagnetic brake;
Calculation means for generating a brake control signal, which is a PWM signal, so that the operating voltage or operating current of the electromagnetic brake becomes a preset value for releasing the electromagnetic brake based on the monitoring result of the monitoring means When,
With
A brake drive control circuit that performs PWM control of conduction of the switch element by the brake control signal. The electromagnetic brake is supplied with power from a power source that supplies power to the motor drive circuit,
The brake drive control circuit according to claim 1, wherein the monitoring unit is a voltage monitor circuit that detects a voltage applied to the circuit block.   The brake drive control circuit according to claim 1, wherein the monitoring unit is a current monitor circuit that detects a current supplied to the circuit block.   The preset value includes a first value for an initial release operation for bringing the electromagnetic brake into a release state, and a second value for a holding operation for maintaining the release state. The brake drive control circuit according to any one of the above. An initial release setting value that is a ratio of the first value to a reference value for PWM drive, a holding setting value that is a ratio of the second value to the reference value, and a duration of the initial release operation. A storage means for storing an initial release time;
5. The pulse width in the PWM signal is determined by dividing the initial release setting value and the hold setting value by the monitoring result of the monitoring unit in the calculation unit. The brake drive control circuit described in 1. 6. The brake drive control according to claim 5, wherein the storage unit stores the initial release setting value, the hold setting value, and the initial release time for each type corresponding to at least one type of electromagnetic brake. circuit.

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