JP7249740B2 - MOTOR DRIVE DEVICE, MOTOR SYSTEM, FAN MOTOR AND MOTOR DRIVING METHOD - Google Patents

Description

The present invention relates to a motor drive device, a motor system, a fan motor, and a motor drive method.

A lock protection circuit that stops power supply to the motor when the motor is locked due to a foreign object, etc., and deactivates the lock protection circuit when a control signal from an external controller instructs the motor to stop continuously for a predetermined time or longer. A drive circuit with a lock control is known. According to such a drive circuit, even if the power supply to the motor is stopped by the lock protection circuit, the lock protection circuit becomes inactive when the control signal instructing to stop the motor is continuously input for a predetermined time or longer. becomes. Therefore, if the control signal instructs the motor to be driven after the lock protection circuit becomes inactive, the motor can be quickly started. Such a function is also called a quick start function.

2010-220462 publication

In a motor drive having a quick start function, after the lock protection circuit is deactivated as described above, quick start is activated when the magnitude of the control signal crosses a predetermined activation threshold voltage. On the other hand, a motor driving device having a quick start function may have a function of rotating the motor at a set speed set by a predetermined set voltage. However, in a conventional motor drive device, adjusting (changing) such a set voltage that sets the rotational speed of the motor may change the operating threshold voltage for quick start.

Accordingly, the present disclosure provides a motor drive device, a motor system, a fan motor, and a motor drive method that can independently adjust a set voltage that sets the rotation speed of the motor and an operation threshold voltage for quick start.

This disclosure is
a drive unit that drives the motor;
a drive control unit that controls the drive unit;
a lock protection unit that instructs the drive control unit to stop the energization of the motor from the drive unit when the lock of the motor is detected;
a speed control terminal;
When the speed command voltage input to the speed control terminal has a magnitude between a predetermined set voltage capable of setting the minimum set speed of the motor to an arbitrary value and a first threshold voltage, the set voltage a speed control unit that commands the drive control unit so that the drive unit rotates the motor at a set speed set by
Lock protection control for deactivating the lock protection section when the voltage state in which the speed command voltage is opposite to the set voltage with respect to the first threshold voltage continues for a predetermined duration or longer. and
When the quick start activation threshold voltage is a second threshold voltage that can be adjusted independently of the set voltage or that is invariant when the set voltage is adjusted,
When the speed command voltage crosses the second threshold voltage between the set voltage and the first threshold voltage after the voltage state continues for the duration time or longer, the speed control unit controls the set speed. and commands the drive control unit to rotate the motor by the drive unit.

This disclosure also provides
A motor system including the motor driving device and the motor is provided.

This disclosure also provides
A fan motor is provided that includes the motor drive device, the motor, and a fan rotated by the motor.

This disclosure also provides
commanding to stop energizing the motor if lock of the motor is detected;
If the input speed command voltage has a magnitude between a predetermined set voltage capable of setting the minimum set speed of the motor to an arbitrary value and a first threshold voltage, the setting is set by the set voltage. commanding the motor to rotate at a speed;
When a voltage state in which the speed command voltage is on the opposite side of the first threshold voltage from the set voltage continues for a predetermined duration or longer, energization to the motor is stopped due to lock detection of the motor. deactivate the directive,
When the quick start activation threshold voltage is a second threshold voltage that can be adjusted independently of the set voltage or that is invariant when the set voltage is adjusted,
If the speed command voltage crosses the second threshold voltage between the set voltage and the first threshold voltage after the voltage state continues for the duration time or longer, the motor is rotated at the set speed. To provide a method for driving a motor.

According to the technology of the present disclosure, in addition to the set voltage for setting the rotation speed of the motor, the second threshold voltage is provided as the operation threshold voltage for quick start. It can be adjusted independently of the quick start activation threshold voltage.

1 is a block diagram illustrating the configuration of a motor system according to an embodiment of the present disclosure; FIG. 4 is a timing chart for explaining a lock protection function; FIG. 4 is a diagram showing an example of a correspondence relationship between a speed command voltage and a duty ratio; FIG. 5 is a diagram illustrating the relationship between a speed command voltage, a duty ratio, and the rotational speed of a motor; 4 is a timing chart for explaining generation of a duty ratio; 4 is a timing chart for explaining a quick start function;

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings.

FIG. 1 is a block diagram illustrating the configuration of a motor system according to this embodiment. A motor system 1 shown in FIG. 1 is an example of a system that controls the rotational operation of a motor 80 . The motor system 1 includes at least a motor 80 and a motor driving device 100 .

The motor 80 has at least one armature coil (hereinafter also simply referred to as "coil"). Motor 80 is, for example, a single-phase full-wave motor having one coil 80a. Both ends of the coil 80 a are connected to the driving section 2 of the motor driving device 100 . In this embodiment, the first coil end of the coil 80 a is connected to the first drive terminal 11 of the motor drive device 100 , and the first connection node of the drive section 2 is connected via the first drive terminal 11 . n1. On the other hand, the second coil end of the coil 80a is connected to the second drive terminal 12 of the motor drive device 100, and is connected to the second connection node n2 of the drive section 2 via the second drive terminal 12. It is

A specific example of the motor 80 is a DC brushless motor that rotates the fan 70 for blowing air. In FIG. 1, when the motor 80 is a motor that rotates the fan 70 for blowing air, the motor system 1 is a fan motor that includes the fan 70 as a component. The wind force generated by the rotation of the fan 70 by the motor 80 can, for example, discharge heat generated inside the device to the outside of the device to cool the inside of the device. Specific examples of the equipment include household appliances such as refrigerators, OA equipment such as copiers, and personal computers, but the equipment is not limited to these.

Motor driving device 100 drives motor 80 . The motor drive device 100 is, for example, an IC (Integrated Circuit) having a plurality of external connection terminals. FIG. 1 shows a plurality of external connection terminals including a first drive terminal 11, a second drive terminal 12, an overcurrent setting terminal 13, a frequency output terminal 14, a reference voltage output terminal 15, a selection terminal 16, and a speed control terminal. 17, a speed setting terminal 18, a power supply terminal 19 and a ground terminal 20 are shown.

The motor drive device 100 includes a drive section 2, a drive control section 3, a speed control section 4, a phase detection section 5, a frequency generator 6, a lock protection section 71, a lock protection control section 72, an overcurrent detection section 8, an oscillator 9 and A reference voltage generator 10 is provided.

The drive unit 2 is an output stage that rotates the rotor of the motor 80 by causing a drive current _IO to flow through the coil 80a of the motor 80 according to a plurality of drive signals generated by the drive control unit 3 .

The drive unit 2 is, for example, a single-phase inverter having transistors 21-24. The transistors 21 and 23 are high-side switching elements connected to the power supply terminal 19 via an internal power supply line. A DC power supply voltage VDD is input to the power supply terminal 19 . The transistors 22 and 24 are low-side switching elements connected to GND (ground).

In this embodiment, the transistors 22 and 24 are connected to the overcurrent setting terminal 13 and grounded via a resistor 13a externally connected to the overcurrent setting terminal 13. FIG. When the overcurrent detection unit 8 detects that the current value of the current flowing through the resistor 13a exceeds the overcurrent detection threshold value, the overcurrent detection unit 8 outputs an overcurrent detection signal indicating that an overcurrent has been detected in the drive unit 2 or the coil 80a. Output to the drive control unit 3 . The overcurrent detection threshold can be adjusted by the resistance value of the resistor 13a. The drive control unit 3 controls the drive unit 2 so as to stop the energization of the motor 80 when the overcurrent detection signal is detected.

If the overcurrent detection section 8 and the overcurrent setting terminal 13 are not provided, the transistors 22 and 24 may be connected to the ground terminal 20 via an internal ground line. The ground terminal 20 is connected to GND (ground) outside the motor drive device 100 .

In this embodiment, the first connection node n1 to which the transistor 21 and the transistor 22 are connected is connected to the first drive terminal 11, and the coil 80a of the motor 80 is connected via the first drive terminal 11. connected at one end. On the other hand, the second connection node n2 to which the transistor 23 and the transistor 24 are connected is connected to the second drive terminal 12, and is connected to the other end of the coil 80a of the motor 80 via the second drive terminal 12. It is connected.

The transistors 21 to 24 are switching elements that are turned on or off according to corresponding drive signals from the drive control section 3 . Specific examples of switching elements such as the transistors 21 to 24 include, but are not limited to, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors).

The drive control section 3 detects the rotational position of the rotor of the motor 80 based on the pulse-like phase detection signal _Hin output from the phase detection section 5 . The drive control unit 3 causes the drive unit 2 to reverse the polarity of the voltage applied to the motor 80 according to the detected rotational position of the rotor so that the rotational speed of the motor 80 reaches the duty ratio D generated by the speed control unit 4. The drive unit 2 is controlled to achieve the corresponding target rotational speed (including zero).

The phase detection unit 5 detects the phase of the rotor of the motor 80 and outputs a pulse signal (phase detection signal H _in ) whose pulse edge is inverted according to the detected phase to the drive control unit 3 and the lock protection unit 71 . The frequency of the phase detection signal H _in changes according to the rotation speed of the rotor of the motor 80 . When the rotor of the motor 80 stops rotating, the phase detection signal _Hin has a constant signal level that is not pulse-like.

The phase detector 5 has, for example, a Hall sensor 51, an amplifier 52, and a hysteresis comparator 53. The Hall sensor 51 outputs a pair of phase signals having phases opposite to each other. The Hall sensor 51 has, for example, a Hall element arranged near the rotor of the motor 80 and detecting the phase of the rotor of the motor 80 . The Hall sensor 51 outputs a pair of phase signals corresponding to the rotational position (rotational phase) of the rotor with respect to the coil 80a by detecting the main magnetic field for driving the rotor with the Hall element. The amplifier 52 amplifies the pair of phase signals output from the hall sensor 51 and supplies the amplified signals to the hysteresis comparator 53 . The hysteresis comparator 53 converts the pair of phase signals supplied from the amplifier 52 into a pulse-like phase detection signal Hin _and outputs it.

The frequency generator 6 generates a signal (FG signal) whose frequency changes according to the actual number of revolutions of the motor 80 calculated by the drive control section 3 based on the phase detection signal _Hin . The frequency generator 6 outputs the FG signal from the frequency output terminal 14 to the outside of the motor driving device 100 by driving the transistor 6a, for example.

The lock protection unit 71 prevents current from continuing to flow through the coil 80a of the motor 80 when the rotation of the rotor of the motor 80 is stopped (locked) due to, for example, being caught by a foreign object adhering to the motor 80 or the load connected to the motor 80. It has lock protection function to prevent. The lock protection unit 71 detects locking of the rotor of the motor 80 (also referred to simply as “locking of the motor 80”) based on the phase detection signal H _in (or the FG signal may be used). When the lock protection unit 71 detects that the motor 80 is locked, the lock protection unit 71 instructs the drive control unit 3 so that the drive unit 2 stops energizing the coil 80 a of the motor 80 .

The lock protection control section 72 generates an enable signal EN for switching between enabling and disabling the lock protection function, and outputs the enable signal EN to the lock protection section 71 . When the enable signal EN is asserted by the lock protection control section 72, the lock protection function is enabled (effective), that is, the lock protection section 71 is active. On the other hand, when the enable signal EN is negated by the lock protection control section 72, the lock protection function is disabled, that is, the lock protection section 71 is inactive.

When the lock protection function is enabled (when the lock protection unit 71 is active), the lock protection unit 71 detects whether or not the motor 80 is locked based on the phase detection signal _Hin (or the FG signal). To detect.

FIG. 2 is a timing chart for explaining the lock protection function. When the lock protection unit 71 detects that the motor 80 is locked based on the phase detection signal _Hin , it asserts a shutdown signal SD, which is a command signal for stopping power supply to the motor 80 .

For example, when the edge of the phase detection signal _Hin is not detected for a predetermined lock detection time T1 or longer, the lock protection unit 71 determines that the motor 80 is locked and asserts the shutdown signal SD (in the case of FIG. 2, the shutdown signal set the level of SD to low level). When the shutdown signal SD is asserted, the drive control section 3 controls the drive section 2 to stop energizing the motor 80 regardless of the duty ratio D generated by the speed control section 4 .

If the edge of the phase detection signal _Hin is not detected within a predetermined shutdown time T2 after asserting the shutdown signal SD, the lock protection unit 71 once negates the shutdown signal SD in order to attempt to restart the motor 80. do. When the shutdown signal SD is negated, the drive control unit 3 turns on the transistors 21 and 24 and turns off the transistors 22 and 23 to set the voltage O1 of the first drive terminal 11 to a high level, and The voltage O2 of the drive terminal 12 is set to low level. As a result, a restart current temporarily flows through the coil 80 a of the motor 80 . If the edge of the phase detection signal _Hin is not detected for a predetermined lock detection time T3 or longer, the lock protection unit 71 determines that the lock of the motor 80 continues, and asserts the shutdown signal SD again.

When the edge of the phase detection signal _Hin is detected, the lock protection unit 71 determines that the motor 80 is not locked (is rotating), and negates the shutdown signal SD.

According to such a lock protection function, it is possible to intermittently apply current to the coil 80a from the time the lock is detected until the lock is no longer detected. Therefore, heat generation of the coil 80a can be suppressed, and failures such as disconnection of the coil 80a can be prevented.

Note that the shutdown time T2 is sufficiently longer than the lock detection times T1 and T3. For example, the lock detection times T1 and T3 are set to about 0.4 seconds, and the shutdown time T2 is set to about 4 seconds which is ten times that. The lock detection times T1 and T3 have the same time width, but may be different. The lock protection unit 71 measures the passage of time, for example, by counting clock signals generated by the oscillator 9 .

The speed control unit 4 generates and outputs a PWM (Pulse Width Modulation) signal whose ON/OFF time changes with a duty ratio D corresponding to the speed command voltage V _PWM input from the external circuit 200 to the speed control terminal 17 . A speed command voltage V _PWM corresponding to the target rotational speed of the motor 80 is input from the external circuit 200 to the speed control terminal 17 .

The set voltage VL is a voltage set by voltage input to the speed setting terminal 18, and is a DC voltage for setting the minimum rotational speed of the motor 80 (hereinafter also referred to as minimum set speed SL). In the case of FIG. 1, the set voltage VL is input to the speed setting terminal 18 from a voltage setting circuit outside the motor driving device 100 . The voltage setting circuit shown in FIG. 1 has resistors 18a and 18b and a capacitor 18c, and divides the reference voltage VREF output from the reference voltage output terminal 15 by the resistors 18a and 18b to generate a constant set voltage VL. .

The reference voltage VREF is generated by the reference voltage generator 10 . The reference voltage generation unit 10 generates a constant reference voltage VREF from the power supply voltage VDD using, for example, a bandgap reference voltage.

The speed control unit 4 determines a duty ratio D corresponding to the speed command voltage V _PWM based on a predetermined correspondence relationship between the speed command voltage V _PWM and the duty ratio D. FIG.

FIG. 3 is a diagram showing an example of the correspondence relationship between the speed command voltage V _PWM and the duty ratio D. As shown in FIG. The speed controller 4 generates a PWM signal with a duty ratio D by comparing the speed command voltage V _PWM with the sawtooth waveform signal V _SAW . FIG. 3 shows an example in which a sawtooth waveform signal V _SAW (see FIG. 5) is used that varies triangularly between 0.5V and 2.5V.

In FIG. 3, the threshold voltage VS is an example of the first threshold voltage. The threshold voltage VQ is an example of a second threshold voltage and is set between the set voltage VL and the threshold voltage VS. The threshold voltage VO is an example of a third threshold voltage, and is a voltage that matches the set voltage VL that sets the lowest set speed SL to zero.

When the speed command voltage V _PWM is less than the set voltage VL, the speed control unit 4 sets the duty ratio D to 100% when the speed command voltage V _PWM is equal to or greater than zero and equal to or less than the threshold voltage VH. Further, the speed control unit 4 sets the duty ratio D to 100% to 0% according to the speed command voltage V _PWM when the speed command voltage V _PWM is equal to or higher than the threshold voltage VH and equal to or lower than the threshold voltage VO. Duty ratio D gradually decreases as speed command voltage V _PWM gradually increases. Further, the speed control unit 4 sets the duty ratio D to 0% so that the driving unit 2 stops the motor 80 when the speed command voltage V _PWM is equal to or higher than the threshold voltage VS (stop mode).

On the other hand, when the speed command voltage V _PWM is equal to or higher than the set voltage VL, the speed controller 4 sets the duty ratio D to a fixed value set by the set voltage VL when the speed command voltage V _PWM is equal to or greater than zero and less than the threshold voltage VS. set to Further, the speed control unit 4 sets the duty ratio D to 0% so that the driving unit 2 stops the motor 80 when the speed command voltage V _PWM is equal to or higher than the threshold voltage VS (stop mode).

Therefore, when the speed command voltage V _PWM is between the set voltage VL and the threshold voltage VS, the speed control unit 4 causes the drive unit 2 to drive the motor 80 at the lowest set speed SL set by the set voltage VL. The drive control unit 3 is instructed to rotate. Further, the speed control unit 4 instructs the drive control unit 3 so that the drive unit 2 stops the motor 80 when the speed command voltage V _PWM is on the opposite side of the threshold voltage VS from the threshold voltage VQ. command against. Further, when the speed command voltage V _PWM is on the side opposite to the second threshold voltage VQ with respect to the set voltage VL, the speed control unit 4 controls the speed command voltage V PWM faster than the lowest set speed SL and at the speed command voltage V _PWM . The drive control unit 3 is commanded so that the drive unit 2 rotates the motor 80 at the commanded speed corresponding to .

Note that FIG. 3 illustrates a case where threshold voltages VH, VO, and VS are set to 0.5 volts, 2.5 volts, and 3 volts, respectively, and set voltage VL is set to 2 volts.

In this example, as shown in FIG. 4, the speed control unit 4 controls the speed control unit 4 to set the speed control unit 4 to 100 so that the drive unit 2 rotates the motor 80 at a high speed when the speed command voltage V _PWM is 0 or more and less than 0.5 volts. % duty ratio D is output to the drive control unit 3 . Further, when the speed command voltage V _PWM is 2.5 volts, the speed control unit 4 has a duty ratio of 25% so that the drive unit 2 rotates the motor 80 at the lowest set speed SL set by the set voltage VL. D PWM signal is output to the drive control unit 3 . Further, the speed control unit 4 outputs a PWM signal with a duty ratio D of 0% so that the driving unit 2 stops the motor 80 when the speed command voltage V _PWM is 3 volts or more.

If the set voltage VL is set near the threshold voltage VO, which is the zero point of the speed curve (near 2.5 volts in this example), the torque will be insufficient and it will be difficult to rotate the motor 80 . Motors have mechanical load torque such as bearing load (bearing rattling, grease viscosity, sleeve metal bearing friction, oil viscosity, etc.), and magnetic load torque such as cogging torque. . It is important that the set voltage VL for setting the lowest set speed SL is set to a voltage value that generates torque exceeding those load torques. Therefore, the set voltage VL is preferably set to a voltage value about 20% away from the threshold voltage VO (in this example, a voltage value about 2 volts lower than the threshold voltage VO).

In FIG. 1, lock protection section 71 negates shutdown signal SD when the lock protection function is disabled (when lock protection section 71 is inactive) regardless of the state of phase detection signal _Hin .

The lock protection control unit 72 detects that the voltage state (hereinafter also referred to as voltage state VC) in which the speed command voltage V _PWM is on the opposite side of the set voltage VL with respect to the threshold voltage VS continues for a predetermined duration or more. If so, the lock protector 71 is deactivated. For example, in the case of FIG. 3, the lock protection control unit 72 deactivates the lock protection unit 71 when the voltage state VC in which the speed command voltage V _PWM is equal to or higher than the threshold voltage VS continues for a predetermined duration or longer. .

FIG. 6 is a timing chart for explaining the quick start function. The lock protection control unit 72 deactivates the lock protection unit 71 when the voltage state VC in which the speed command voltage V _PWM is equal to or higher than the threshold voltage VS continues for a predetermined duration T4 or longer. When the speed command voltage V _PWM reaches or exceeds the threshold voltage VS, the duty ratio D is set to 0% by the speed controller 4 . The lock protection control unit 72 measures the elapsed time after the duty ratio D becomes 0% based on the clock signal from the oscillator 9, and negates the enable signal EN when the elapsed time reaches the duration T4 or longer. , deactivates the lock protection 71 . That is, the lock protection function is disabled. When the enable signal EN is negated and the lock protection unit 71 becomes inactive, the shutdown signal SD is also negated, so that the power supply stop command to the motor 80 due to lock detection of the motor 80 becomes inactive. Even if the shutdown signal SD is negated, the motor 80 remains stopped because the voltage state VC in which the speed command voltage V _PWM is greater than or equal to the threshold voltage VS continues.

After the voltage state VC continues for the duration T4 or longer (that is, after the time elapsed since the duty ratio D was set to 0% reaches the duration T4 or longer), the speed control unit 4 sets the speed command voltage V _PWM to the threshold value. It is determined whether or not the voltage VQ is crossed. The threshold voltage VQ is a voltage between the set voltage VL and the threshold voltage VS. When the speed command voltage V _PWM crosses the threshold voltage VQ after the voltage state VC continues for the duration T4 or more, the speed control unit 4 causes the driving unit 2 to drive the motor 80 at the minimum set speed SL set by the set voltage VL. The drive control unit 3 is instructed to rotate. As a result, the speed command voltage V _PWM crosses the threshold voltage VQ after the voltage state VC continues for the duration T4 or longer, so that the rotation of the motor 80 can be restarted without waiting for the shutdown time T2 to elapse. Then, the rotational speed at the time of quick start can be set to the set speed by the set voltage VL.

The speed control unit 4 sets the minimum setting so that the driving unit 2 rotates the motor 80 at the minimum set speed SL when the speed command voltage V _PWM crosses the threshold voltage VQ after the voltage state VC continues for the duration T4 or more. A PWM signal with a duty ratio D corresponding to the speed SL is output. The lock protection control unit 72 asserts the enable signal EN and activates the lock protection unit 71 (enables the lock protection function) by receiving the PWM signal with the duty ratio D corresponding to the lowest set speed SL. .

Thus, in the present embodiment, the set voltage VL for setting the lowest set speed SL and the threshold voltage VQ, which is the operation threshold voltage for quick start, are provided separately as shown in FIG. Voltage VL and threshold voltage VQ can be adjusted independently. That is, even if the set voltage VL is adjusted (changed), the threshold voltage VQ, which is the operation threshold voltage for quick start, does not change.

Since the set voltage VL can be easily set to an arbitrary value using a resistor or the like on the circuit board, the set speed (rotational speed) set by the set voltage VL can also be changed by changing the specifications of the coil 80a of the motor 80. can be easily set to any value. Therefore, after quick start from the stop mode, it becomes easy to rotate the motor 80 at the set speed set by the set voltage VL.

When the speed command voltage V _PWM shifts to the voltage range between the set voltage VL and the threshold voltage VQ after the voltage state VC continues for the duration T4 or longer, the speed control unit 4 controls the drive unit at the set speed based on the set voltage VL. 2 may instruct the drive control unit 3 to rotate the motor 80 .

The external circuit 200 (see FIG. 1) is configured to switch the speed command voltage V _PWM to at least two voltages including a voltage equal to or higher than the threshold voltage VS and a voltage between the set voltage VL and the threshold voltage VQ. It is preferable that the circuit is a The external circuit 200 sets the speed command voltage V _PWM to a voltage equal to or higher than the threshold voltage VS, a voltage between the set voltage VL and the threshold voltage VQ, and a magnitude on the opposite side of the set voltage VL from the threshold voltage VS. A circuit configured to be capable of switching output to at least three voltages including the voltage of .

Also, the threshold voltage VQ is preferably a voltage between the threshold voltage VO and the threshold voltage VS (including the same voltage as the threshold voltage VO). As a result, the threshold voltage VQ is set to a voltage value relatively distant from the set voltage VL, so that it is possible to reduce erroneous determinations when comparing the speed command voltage V _PWM with the set voltage VL or the threshold voltage VQ. .

Although the motor driving device, the motor system, the fan motor, and the motor driving method have been described above with reference to the embodiments, the present invention is not limited to the above embodiments. Various modifications and improvements such as combination or replacement with part or all of other embodiments are possible within the scope of the present invention.

For example, FIG. 3 shows a case where the rotation speed of the motor changes from high speed to low speed (stop side) as the speed command voltage V _PWM changes from low to high. However, the present invention can also be applied when the rotation speed of the motor changes from the low speed side (stop side) to the high speed side as the speed command voltage V _PWM changes from the small side to the large side. For example, the change characteristic of the duty ratio D with respect to the speed command voltage V _PWM may be a characteristic obtained by horizontally inverting the characteristic shown in FIG. 3 around the speed command voltage V _PWM of 1.5 volts.

Further, for example, the application of the motor is not limited to the fan motor described above. Also, the type and number of phases of the motor are not limited to those in the above embodiment.

Further, for example, the phase detector 5 may be externally attached to the motor drive device 100 . Further, the motor drive device 100 is not limited to being configured as an IC (integrated circuit), and may be configured as a discrete circuit.

For example, the motor 80 may be a three-phase brushless motor having U-phase coils, V-phase coils, and W-phase coils. In this case, for example, the plurality of phase detection units 5 externally attached to the motor drive device 100 are arranged at equal intervals around the rotor of the motor 80 and have three Hall elements for detecting the phase of the rotor of the motor 80. . A plurality of phase detectors 5 detect the main driving magnetic field of the rotor with three Hall elements, and output three pairs of phase signals corresponding to the rotational position (rotational phase) of the rotor with respect to each phase coil. The drive control section 3 generates three pairs of drive waveform signals used for controlling the drive of the drive section 2 based on the three pairs of phase signals. The drive control unit 3 controls the gates of the six transistors included in the drive unit 2 having a three-phase inverter configuration so that the rotor of the motor 80 rotates in a desired state according to the three pairs of drive waveform signals.

1 motor system 2 drive section 3 drive control section 4 speed control section 5 phase detection section 17 speed control terminal 18 speed setting terminal 70 fan 71 lock protection section 72 lock protection control section 80 motor 100 motor drive device

Claims (10)

a drive unit that drives the motor;
a drive control unit that controls the drive unit;
a lock protection unit that instructs the drive control unit to stop the energization of the motor from the drive unit when the lock of the motor is detected;
a speed control terminal;
When the speed command voltage input to the speed control terminal has a magnitude between a predetermined set voltage capable of setting the minimum set speed of the motor to an arbitrary value and a first threshold voltage, the set voltage a speed control unit that commands the drive control unit so that the drive unit rotates the motor at a set speed set by
Lock protection control for deactivating the lock protection section when the voltage state in which the speed command voltage is opposite to the set voltage with respect to the first threshold voltage continues for a predetermined duration or longer. and
When the quick start activation threshold voltage is a second threshold voltage that can be adjusted independently of the set voltage or that is invariant when the set voltage is adjusted,
When the speed command voltage crosses the second threshold voltage between the set voltage and the first threshold voltage after the voltage state continues for the duration time or longer, the speed control unit controls the set speed. and commanding the drive control unit so that the drive unit rotates the motor. When the speed command voltage shifts to a voltage range between the set voltage and the second threshold voltage after the voltage state continues for the duration time or longer, the speed control unit controls the drive unit at the set speed. 2. The motor drive device according to claim 1, wherein commands the drive control unit to rotate the motor. When the third threshold voltage is a voltage that matches the set voltage that sets the set speed to zero,
the second threshold voltage is a voltage between the third threshold voltage and the first threshold voltage;
3. The motor driving device according to claim 1, wherein said set voltage is set such that said third threshold voltage is between said set voltage and said second threshold voltage. 4. The motor driving device according to claim 3, wherein said set voltage is set to a voltage value about 20% away from said third threshold voltage. The speed control unit controls a command speed higher than the set speed and in accordance with the speed command voltage when the speed command voltage is opposite to the second threshold voltage with respect to the set voltage. 5. The motor drive device according to any one of claims 1 to 4 , wherein the drive unit commands the drive control unit to rotate the motor at . The speed control unit controls the driving unit so that the driving unit stops the motor when the speed command voltage is opposite to the second threshold voltage with respect to the first threshold voltage. 6. The motor driving device according to any one of claims 1 to 5 , which commands a control unit. Equipped with a speed setting terminal,
7. The motor driving device according to claim 1, wherein said set voltage is set by voltage input to said speed setting terminal. A motor system comprising the motor driving device according to any one of claims 1 to 7 and the motor. A fan motor comprising: the motor driving device according to any one of claims 1 to 7 ; the motor; and a fan rotated by the motor. commanding to stop energizing the motor if lock of the motor is detected;
If the input speed command voltage has a magnitude between a predetermined set voltage capable of setting the minimum set speed of the motor to an arbitrary value and a first threshold voltage, the setting is set by the set voltage. commanding the motor to rotate at a speed;
When a voltage state in which the speed command voltage is on the opposite side of the first threshold voltage from the set voltage continues for a predetermined duration or longer, energization to the motor is stopped due to lock detection of the motor. deactivate the directive,
When the quick start activation threshold voltage is a second threshold voltage that can be adjusted independently of the set voltage or that is invariant when the set voltage is adjusted,
If the speed command voltage crosses the second threshold voltage between the set voltage and the first threshold voltage after the voltage state continues for the duration time or longer, the motor is rotated at the set speed. How to drive the motor to command.

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