JP4201886B2 - DC brushless motor speed control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a DC brushless motor speed control device for keeping the rotational speed of a DC brushless motor constant.
[0002]
[Prior art]
A conventional DC brushless motor speed control device will be described. FIG. 7 is a circuit diagram showing a first conventional example of a speed control device of a conventional DC brushless motor 1. The DC brushless motor 1 is provided with Hall elements 2, 3, and 4 that detect the position of the rotor magnet. The output signals of these Hall elements 2, 3, and 4 are originally used to rotate the rotor by switching the direction of the excitation current flowing in the coils of each phase. At the same time, this output signal is used to control the speed of the motor. Also use it.
[0003]
When speed control is performed using the rotor position detection signals obtained by the Hall elements 2, 3, and 4, there is an advantage that it is not necessary to provide a frequency generator for detecting the rotational speed of the motor 1. When the DC brushless motor 1 is a three-phase motor, the three Hall elements 2, 3, and 4 are arranged at positions shifted by 120 degrees in electrical angle.
[0004]
For the speed control, the analog signals obtained by the Hall elements 2, 3, 4 are shaped into a pulse waveform representing the magnetic pole, and then synthesized by an EXOR (exclusive OR) circuit 20. As a result, a speed control signal is output from the EXOR circuit 20. Since the cycle of the speed control signal becomes shorter as the rotational speed of the motor 1 becomes faster, the speed control device of the DC brushless motor 1 performs speed control so as to adapt to the target rotational speed state.
[0005]
Next, FIG. 8 is a circuit diagram of a second conventional example of the speed control device of the DC brushless motor 1. When the DC brushless motor 1 is a three-phase motor, the position of the rotor is detected by three Hall elements 2, 3, and 4 arranged at positions shifted by 120 degrees in electrical angle. The rotor position detection signal obtained by one Hall element 2 is divided by the frequency dividing circuit 21 so that one pulse is output every time the rotor makes one rotation. The speed of the motor 1 is controlled using the output of the frequency dividing circuit 21 as a speed control signal.
[0006]
[Problems to be solved by the invention]
In the conventional speed control device of the first DC brushless motor 1 (FIG. 7), timing deviation may occur in the speed control signal due to uneven magnetization of the rotor magnet and an error in the mounting position of the Hall element. Therefore, since the detection accuracy is not so high, there is a problem that high-precision speed control cannot be performed.
[0007]
On the other hand, in the speed control device of the conventional second DC brushless motor 1 (FIG. 8), the rotor position detection signal obtained by one Hall element 2 is divided to be a signal of one pulse per one rotation of the rotor. Therefore, it is not affected by uneven magnetization of the rotor magnet and an error in the mounting position of the Hall element. However, since one pulse is obtained by one rotation by the frequency dividing circuit 21, the frequency of the speed control signal is lowered, and the interval between pulses appearing in the speed control signal is increased. When the rotational speed control is performed by using this speed control signal, the pulse interval is widened, which may cause uneven rotation and may not result in smooth rotation. In particular, during low-speed operation, the pulse interval of the speed control signal is greatly widened, so that there is a problem that high-precision rotation control cannot be performed.
[0008]
SUMMARY OF THE INVENTION An object of the present invention is to provide a DC brushless motor that can perform highly accurate speed control even in low speed operation without being affected by uneven magnetization of a rotor magnet or an error in the mounting position of a Hall element.
[0015]
[Means for Solving the Problems]
  To achieve the above objective,First of the present invention1In the configuration of, ElectricFirst, second, and third Hall sensors arranged every 120 degrees, a frequency dividing circuit that divides the output of the first Hall sensor and outputs one pulse per one rotation of the rotor, and a reference clock An error signal generation circuit that outputs an error pulse corresponding to a rotation speed error signal of the rotor from a generation circuit, a reference clock, and an output of the frequency dividing circuit; and the error pulse is converted into a pulse having a width of 1/3. The speed control pulse is output at a timing related to the second Hall sensor from the pulse width adjusting circuit that outputs the speed control pulse, the output of the frequency dividing circuit, the output of the second Hall sensor, and the speed control pulse. The speed control pulse at a timing related to the third Hall sensor from the first timing adjustment circuit, the output of the frequency divider circuit, the output of the third Hall sensor, and the speed control pulse. A second timing adjusting circuit for outputting the pulse width adjustment circuit and the first, so that consisting of combining circuit outputs the output of the second timing adjusting circuit as the speed control signal.In this specification, the Hall sensor is a Hall element or Hall IC.
[0016]
According to such a configuration, when the DC brushless motor is a three-phase motor, the three Hall sensors provided for driving the motor are shared for speed control, and the rotor obtained by the three Hall sensors can be obtained. By dividing the signal representing the rotational position by a frequency dividing circuit, one pulse is output in one rotation. Then, an error pulse is generated by the error signal generation circuit from the reference signal obtained by the reference clock generation circuit and the output of the frequency dividing circuit. Then, the pulse width adjustment circuit converts the error pulse into a pulse having a width of 1/3. Then, the first timing adjustment circuit outputs a speed control pulse obtained by the pulse width adjustment circuit at a timing related to the second Hall sensor. The second timing adjustment circuit outputs a speed control pulse obtained by the pulse width adjustment circuit at a timing related to the third hall sensor. Then, by synthesizing the outputs of the pulse width adjustment circuit and the first and second timing adjustment circuits in the synthesis circuit, an error control signal having a cycle including three speed control pulses can be output in one rotation.
[0019]
  In addition, the first of the present invention2In the configuration of, ElectricFirst, second, and third Hall sensors arranged every 120 degrees, a frequency dividing circuit that divides the output of the first Hall sensor and outputs one pulse per one rotation of the rotor, and a reference clock A generation circuit; an error signal generation circuit that outputs an error pulse corresponding to a rotational speed error of the rotor from an output of a reference clock and the frequency divider; an acceleration pulse generator that generates a predetermined acceleration pulse; and the frequency divider An output of the circuit, an output of the second Hall sensor, a first timing adjusting circuit for outputting the acceleration pulse at a timing related to the second Hall sensor from the acceleration pulse, an output of the frequency dividing circuit, and a third Hall A second timing adjusting circuit for outputting the acceleration pulse at a timing related to a third Hall sensor from the sensor output and the acceleration pulse; and an output of the error signal generating circuit; 1, so that consisting of combining circuit outputs the output of the second timing adjusting circuit as the speed control signal.
[0020]
According to such a configuration, when the DC brushless motor is a three-phase motor, the three Hall sensors provided for driving the motor are shared for speed control, and the rotor obtained by the three Hall sensors can be obtained. By dividing the signal indicating the rotational position by a frequency dividing circuit, one pulse is output per one rotation. Then, an error pulse for the reference clock signal obtained by the reference clock generation circuit from the output of the frequency dividing circuit is generated by the error signal generation circuit. The first timing adjustment circuit outputs an acceleration pulse determined according to a target rotational speed or the like at a timing related to the second Hall sensor, and the second timing adjustment circuit at a timing related to the third Hall sensor. A predetermined acceleration pulse is output. The synthesizing circuit synthesizes the output of the error signal generation circuit and the outputs of the first and second timing adjustment circuits and outputs it as a speed control signal. Accordingly, the first Hall sensor output is output as a speed error signal with respect to the reference signal, and the first and second timing adjustment circuits output predetermined acceleration pulses at timings related to the second and third Hall sensor outputs, The rotational speed of the rotor can be controlled by the error signal and the acceleration pulse.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
<FirstReference example> Hereafter, the present inventionReference exampleWill be described. FIG. 1 shows a first embodiment of the present invention.Reference exampleIt is a block diagram of the speed control apparatus of the DC brushless motor 1 of. The DC brushless motor 1 is a three-phase motor, and a rotor is rotated by applying a magnetic field to a rotor magnet by a drive circuit (not shown). Hall elements 2, 3, and 4 detect the position of the rotor by detecting the magnetic poles of the rotor magnet. An analog signal obtained from the Hall elements 2, 3, and 4 is shaped into a binary-state rotor position detection signal indicating N pole or S pole. For example, the rotor position detection signal is an N pole when it is at a high level and an S pole when it is at a low level. A drive circuit (not shown) rotates the rotor by switching and controlling the direction of the coil current provided in each phase according to the rotor position detection signal output from the Hall elements 2, 3, 4.
[0022]
On the other hand, the speed controller of the DC brushless motor 1 controls the rotation of the motor 1 by using the rotor position detection signals obtained by the three Hall elements 2, 3 and 4. The Hall elements 2, 3, and 4 are arranged at positions shifted by 120 degrees in electrical angle. FIG. 2A shows the rotor position detection signal A output from the hall element 2.
[0023]
The frequency dividing circuit 5 divides the rotor position detection signal A to output a rotation speed signal B that outputs one pulse every time the rotor makes one rotation (see FIG. 2B). At the same time, the frequency dividing circuit 6 divides the rotor position detection signal indicating the magnetic pole obtained by the Hall element 3 to output a rotation speed signal that outputs one pulse every time the rotor makes one rotation. Further, the frequency dividing circuit 7 divides the rotor position detection signal indicating the magnetic pole obtained by the Hall element 4 to output a rotation speed signal that outputs one pulse every time the rotor makes one rotation. A three-phase rotational speed signal is obtained by the frequency dividing circuits 5, 6, and 7.
[0024]
The reference clock generation circuit 12 outputs a reference clock (reference signal) (see FIG. 2C) that is set according to the target rotational speed of the rotor of the motor 1. The error signal generation circuit 8 compares the rotational speed signal B output from the frequency dividing circuit 5 with the reference clock C, and indicates an error signal D representing the difference between the rotational speed of the rotor and the target rotational speed (FIG. 2D). Output).
[0025]
The error signal generation circuit 9 inputs the rotation speed signal output from the frequency divider circuit 6 and the reference clock, and outputs an error signal. The error signal generation circuit 10 inputs the rotation speed signal output from the frequency divider circuit 7 and the reference clock, and outputs an error signal. The signal synthesis circuit 11 synthesizes the three error signals output from the error signal generation circuits 8, 9, and 10 and outputs a speed control signal E (see FIG. 2E). The three reference clocks output from the reference clock generation circuit 12 are 120 degrees out of phase.
[0026]
  Figure 2 shows a bookReference exampleIt is a wave form diagram which shows operation | movement of the speed control apparatus of DC brushless motor 1 of. The rotor position detection signal A is a pulse waveform obtained by shaping the analog signal obtained by the Hall element 2, and indicates the rotational position of the rotor as the N pole when it is at a high level and as the S pole when it is at a low level. ing.
[0027]
This signal A is frequency-divided by the frequency-dividing circuit 5 so that the frequency becomes 1/6, and is converted into a rotation speed signal B that outputs one pulse every time the rotor makes one revolution. In FIG. 2, the signal B rises at the rising timing t1 of the signal A, then the signal B falls at the third rising timing t3 of the signal A, and then the rising timing t4 of the third signal A thereafter. Signal B rises. Thereafter, the signal B is periodically repeated at this level switching timing.
[0028]
The error signal generation circuit 8 compares the rotation speed signal B with the reference clock C. For example, since the reference clock C remains at the high level at the timing t1 when the rotation speed signal B rises to the high level, the error signal generation circuit 8 performs the rotation indicating the actual rotation state of the rotor with respect to the target rotation speed. It is determined that the phase of the speed signal B is advanced. At this time, the error signal generation circuit 8 outputs an error signal D having a predetermined positive voltage from timing t1 to timing t2 of the next falling edge of the reference clock C.
[0029]
When the error signal D is a positive voltage, the speed control device controls the drive circuit (not shown) to decelerate the motor 1. Conversely, the motor 1 is controlled to accelerate when the error signal D is a negative voltage. Further, since a period T1 from timing t1 to t2 indicates a phase shift between the rotation speed signal B and the reference clock C, the deceleration amount is also indicated.
[0030]
Since the signal synthesis circuit 11 synthesizes the error signals output from the error signal generation circuits 8, 9, and 10, a pulse 30 representing the acceleration of the motor appears in the speed control signal E from timing t1 to t2. Since the Hall elements 2, 3, and 4 are provided at positions where the electrical angles are shifted by 120 degrees, the speed control signal E is generated by the Hall element 3, the frequency dividing circuit 6, and the error signal generating circuit 9 thereafter. A pulse 31 due to the error signal appears. Thereafter, a pulse 32 due to an error signal obtained by the Hall element 4, the frequency dividing circuit 7, and the error signal generating circuit 10 appears in the speed control signal E. Since the error signal 32 is a negative voltage, acceleration control is performed.
[0031]
After that, in the error signal generation circuit 8, a period T2 from the rising timing t4 of the signal B to the falling timing t5 of the next reference clock C is set as a positive voltage. In the operation example shown in FIG. 2, since the period T2 is narrower than the period T1, it indicates that the deceleration amount is small. As a result, a pulse 33 for deceleration control appears in the signal E.
[0032]
Thereafter, the signal B rises at a timing t7 after the falling timing t6 of the reference clock C. The error signal generation circuit 8 can determine that the phase of the rotation speed signal B is delayed with respect to the reference clock C. At this time, the error signal generation circuit 8 outputs an error signal with a predetermined negative voltage from timing t6 to t7. A negative voltage pulse 34 appears in the speed control signal E, and the motor 1 is accelerated. A period T3 from timing t6 to t7 indicates the amount to be decelerated. Then, a pulse 35 due to the error signal obtained by the error signal generation circuit 9 appears.
[0033]
  As explained above, the bookReference exampleThen, the rotor position detection signals obtained by the Hall elements 2, 3, and 4 are respectively divided by the frequency dividing circuits 5, 6, and 7, so that one pulse is obtained for each rotation of the rotor, thereby controlling the speed. Since it is used to generate the signal E, the speed control signal E does not deteriorate the accuracy of the speed control signal E due to uneven magnetization of the rotor magnet in the motor 1. Further, since the speed control signal E is generated using the signals from the three Hall elements 3, 4, and 5, the frequency of the signal E is not reduced. Therefore, even when the motor 1 is operated at a low speed, uneven rotation is less likely to occur.
[0034]
  Also bookReference exampleThe frequency dividers 5, 6, and 7 output one pulse every time the rotor makes one revolution, but the speed controller of the DC brushless motor outputs one pulse every time the rotor makes two or more revolutions. In this way, it is possible to control the speed. However, in such a case, since the cycle of the speed control signal becomes large, it becomes impossible to perform highly accurate control. Therefore, the highest control accuracy is to output one pulse at one rotation. As shown in FIG. 2E, the pulses 30 to 35 are generated at timings related to the Hall elements 2, 3, and 4, that is, timings corresponding to known electrical angles of the Hall elements.
[0035]
  <No.1Embodiment> Next, the present invention will be described.1The embodiment will be described. FIG. 3 shows the first aspect of the present invention.1It is a block diagram of the speed control apparatus of the DC brushless motor 1 of the embodiment. The DC brushless motor 1 is a three-phase motor, and the three Hall elements 2, 3, and 4 are arranged at positions shifted by 120 degrees in electrical angle. In FIG. 3, the same parts as those in FIG. 1 are denoted by the same reference numerals (note that alphabets do not necessarily indicate the same parts), and detailed description thereof will be omitted. A rotor position detection signal A (see FIG. 4A) indicating the rotational position of the rotor is output from the Hall element 2 by detecting the magnetic poles of the rotor magnet. The frequency dividing circuit 5 divides the signal A to output a rotation speed signal B that outputs a pulse once for each rotation of the rotor.
[0036]
The reference clock generation circuit 12 outputs a reference clock (reference signal) C (see FIG. 4C) according to the target rotation speed. The error signal generation circuit 8 inputs the signal B and the reference clock C and outputs an error signal D (see FIG. 4D). The pulse width adjustment circuit 15 outputs a signal F (see FIG. 4F) obtained by reducing the period during which the error signal D is a positive voltage or a negative voltage to 1/3. The output timing of the signal F is synchronized with the fall of the signal B as will be described later.
[0037]
The hall element 3 outputs a rotor position detection signal GP of the motor 1. The rotor position detection signal GP is a signal having the same period as that of the rotor position detection signal A shown in FIG. 4A, but the timing adjustment circuit 16 receives the signal B as shown by a dotted line in FIG. The timing corresponding to the rotation speed signal of one pulse is taken in one rotation. This can be realized, for example, by inputting the signal B to the data terminal of the D flip-flop and inputting a predetermined detection signal GP (a pulse delayed by two cycles from the signal A) to the clock terminal. A signal I (see FIG. 4 (C)) having a positive period T3 obtained by the signal F at the falling timing t5 of the signal G (see FIG. 4 (G)) formed at the fetched timing. Output.
[0038]
The hall element 4 outputs a rotor position detection signal HP of the motor 1. The rotor position detection signal GP is a signal whose cycle coincides with that of the rotor position detection signal A. The timing adjustment circuit 17 inputs the signals B, F, and HP. First, the signals B and HP are dotted lines in FIG. The timing corresponding to one pulse is captured by one rotation as shown in FIG. Then, the signal J is output with the period T3 obtained from the signal F as a positive voltage at the falling timing t8 of the signal H formed at that timing. The signal synthesis circuit 11 generates the speed control signal K by synthesizing the signals F, I, and J.
[0039]
  As shown in the signal waveform diagram of FIG. 4, in this embodiment, the error signal (a positive pulse having a width of T1) formed at the timings t1 to t2 is divided into three equal parts, and t4 related to the Hall elements 2, 3, and 4 is obtained. , T5, and t8 (timing related to the electrical angle of each Hall element) and output. Similarly, the error signal (a positive pulse with a width of T4) formed at timings t6 to t7 is divided into three equal parts and distributed to timings t9, t10, and t13 and output. Further, the error signal (a negative pulse having a width of T6) formed at timings t11 to t12 is divided into three equal parts and output at timings related to the position of the Hall element. The three signals thus distributed (distributed) are synthesized by the signal synthesis circuit 11 and a speed control signal K is output. In this case, the period of the speed control signal K is the above-described first time.Reference exampleSimilar to FIG. 1, the speed is shortened, and highly accurate speed control can be performed.
[0040]
  <No.2Embodiment> Next, the present invention will be described.2The embodiment will be described. FIG. 5 shows the first aspect of the present invention.2It is a block diagram of the speed control apparatus of the DC brushless motor 1 of the embodiment. In the present embodiment, the above-mentioned first1The same parts as those of the embodiment (FIG. 3) are denoted by the same reference numerals (however, the alphabets are not necessarily shown the same), and the description thereof is omitted. First1The difference between this embodiment (FIG. 3) and this embodiment (FIG. 5) is that1In the present embodiment (FIG. 3), the pulse width adjusting circuit 15 is provided to give the pulse width to the timing adjusting circuits 16 and 17, but in this embodiment, the acceleration pulse generating circuit 18 is provided instead to adjust the timing. A pulse width is given to the circuits 16 and 17. The acceleration pulse generation circuit 18 outputs an acceleration pulse (acceleration signal) having a certain width according to the target rotation speed.
[0041]
FIG. 6 is a waveform diagram showing the operation of the speed control device of the DC brushless motor 1 of this embodiment. Signal A is a rotor position detection signal A output from the Hall element 2. The rotation speed signal B is obtained by dividing the signal A by the frequency dividing circuit 5. The reference clock C is a reference signal provided with a certain width according to the target rotational speed output from the reference clock generation circuit 12. Since the rotational speed signal B rises at the timing t2 after the falling timing t1 of the reference clock C, it indicates that the rotor is behind the target rotation, and the error signal generation circuit 8 starts from the timing t1. An error signal D is output with a period T1 up to timing t2 as a predetermined positive voltage. Since the signal D is synthesized by the signal synthesis circuit 11, a positive voltage pulse 50 appears in the speed control signal I, and the speed control device performs acceleration control.
[0042]
The hall element 3 outputs a rotor position detection signal EP. This rotor position detection signal EP is a signal whose period coincides with the rotor position detection signal A. The timing adjustment circuit 16 takes in the timing corresponding to one pulse (signal E) by one rotation as indicated by the dotted line by the input of the detection signal GP and the signal B. Then, for example, at the rising timing t3 of the signal E (see FIG. 4E), the control signal G is output with the acceleration pulse width T2 obtained from the acceleration pulse generation circuit 18 as a positive voltage. As a result, a pulse 51 appears in the speed control signal I.
[0043]
The hall element 4 outputs a rotor position detection signal FP. The rotor position detection signal FP is a signal whose period coincides with the rotor position detection signal A. The timing adjustment circuit 17 takes in the timing corresponding to one pulse (signal F) by one rotation as indicated by a dotted line by the input of the detection signal FP and the signal B. Then, for example, at the rising timing t6 of the signal F (see FIG. 4F), the control signal H is output with the acceleration pulse width T2 obtained from the acceleration pulse generation circuit 18 as a positive voltage. As a result, a pulse 52 appears in the speed control signal I.
[0044]
Thereafter, at the timing t8 when the rotation speed signal B rises, the reference clock C is at a high level, which indicates that the rotor has advanced from the target rotation. The error signal generation circuit 8 outputs a negative voltage during a period T3 from timing t8 to timing t9 from the next falling of the reference clock C to decelerate the rotor. As a result, a negative voltage pulse 53 appears in the rotational speed signal I. Then, the timing adjustment circuit 16 outputs a positive voltage at the pulse width T2 given by the acceleration pulse generation circuit 18 at the timing t10 given by the signal E. The timing adjustment circuit 17 outputs a signal H having a positive voltage during the period T2 at the timing t13 given by the signal F. As a result, a pulse 55 appears in the rotation control signal I.
[0045]
The error signal generation circuit 8 outputs an error signal D having a negative voltage from the next rising timing t15 of the rotation speed signal B to the falling timing t16 of the reference clock C. As a result, a pulse 56 instructing that the speed control signal I should be decelerated appears. As shown in FIG. 6I, the pulses 50 to 56 are generated at timings related to the electrical angles of the Hall elements 2, 3, and 4.
[0046]
As described above, in the speed control device for the DC brushless motor 1 according to the present embodiment, when the motor 1 is started, a constant acceleration control signal is generated in the rotation control signal I by the acceleration pulse output from the acceleration pulse generation circuit 18. As a result, the motor 1 is accelerated until the target rotational speed is reached. When the target rotational speed is exceeded, the error signal generation circuit 8 outputs an error signal D instructing deceleration of the rotor, so that the rotor is decelerated and accelerated by acceleration signals G and H. By repeating this, the rotational speed of the rotor can be maintained at the rotational speed set as a target. That is, in this embodiment, while accelerating with the acceleration signals G and H, it is controlled so as to keep the rotation speed constant by accelerating with the error signal (especially at startup) or decelerating.
[0050]
【The invention's effect】
    As explained above, Claims1According to the speed control device for a DC brushless motor described in 1), when the DC brushless motor is a three-phase motor, the first hall sensor of the three hall sensors for driving the motor disposed at every electrical angle of 120 degrees. Is divided by a frequency divider circuit to obtain one pulse per rotation. An error pulse for the reference clock output from the reference clock generation circuit is generated from this pulse, and the error pulse is converted into a pulse having a width of 1/3 by the pulse width adjustment circuit. Then, the first and second timing adjustment circuits output speed control pulses at timings related to the second and third Hall sensors. Then, the synthesis circuit synthesizes the outputs of the pulse width adjustment circuit and the first and second timing adjustment circuits. As a result, an error obtained from the output of one hall sensor can be divided into three equal parts and distributed at a timing related to each hall sensor and output as a control signal.
[0052]
  Claims2According to the DC brushless motor speed control device described in 1), when the DC brushless motor is a three-phase motor, the three hall sensors for driving the motor arranged at every 120 electrical angles are used to control the speed of the rotor. Shared for use. By dividing the output of the first Hall sensor with a frequency dividing circuit, one pulse is obtained in one rotation. An error signal generation circuit generates an error pulse corresponding to the rotation speed error from this pulse and the reference clock output from the reference clock generation circuit. Further, an acceleration pulse given by a target rotational speed or the like is generated by an acceleration pulse generation circuit. The first timing adjustment circuit outputs an acceleration pulse at a timing related to the second Hall sensor, and the second timing adjustment circuit outputs an acceleration pulse at a timing related to the third Hall sensor. In the synthesis circuit, the output of the error signal generation circuit and the outputs of the first and second timing adjustment circuits are output as speed control signals to perform rotor speed control. Therefore, the magnetic pole of the rotor can be detected by the Hall sensor, and a speed error signal is output by the error signal generation circuit using one of the outputs. Then, an acceleration signal is output by the first timing adjustment circuit and the second timing adjustment circuit. Then, the rotational speed of the rotor is controlled by the speed control signal output from the synthesis circuit.
[Brief description of the drawings]
FIG. 1 shows the first of the present inventionReference exampleThe block diagram of the speed control apparatus of DC brushless motor.
FIG. 2 is a waveform diagram showing the operation of the speed control device for the DC brushless motor.
FIG. 3 shows the first aspect of the present invention.1The block diagram of the speed control apparatus of the DC brushless motor of embodiment.
FIG. 4 is a waveform diagram showing the operation of the speed control device for the DC brushless motor.
FIG. 5 shows the first aspect of the present invention.2The block diagram of the speed control apparatus of the DC brushless motor of embodiment.
FIG. 6 is a waveform diagram showing the operation of the speed control device for the DC brushless motor.
FIG. 7 is a block diagram of a conventional first DC brushless motor speed control device.
FIG. 8 is a block diagram of a conventional second DC brushless motor speed control device.
[Explanation of symbols]
1 DC brushless motor
2, 3, 4 Hall elements
5, 6, 7 Frequency divider
8, 9, 10 Error signal generation circuit
11 Signal synthesis circuit
12 Reference clock generation circuit (reference signal generation circuit)
15 Pulse width adjustment circuit
16, 17 Timing adjustment circuit
18 Acceleration pulse generator (Acceleration signal generator)

Claims (2)

In a DC brushless motor control device,
The first Hall sensor is arranged for each electrical angle of 120 degrees, and the second Hall sensor, and a third Hall sensor,
A frequency dividing circuit that divides the output of the first Hall sensor and outputs one pulse per rotation of the rotor;
A reference clock generation circuit for generating a reference clock; and
An error signal generation circuit outputs an error pulse corresponding to the rotational speed error signal of the rotor from an output of said divider and said reference clock,
A pulse width adjusting circuit for outputting a speed control pulse obtained by converting the error pulse into a width of 1/3;
An output of said divider circuit, an output of the second Hall sensor, a first timing adjusting circuit for outputting the speed control pulse associated timing to the second Hall sensor from said speed control pulses,
An output of said divider circuit, an output of the third Hall sensor, a second timing adjusting circuit for outputting the speed control pulse associated timing to the third Hall sensor from said speed control pulses,
A combining circuit for outputting an output of the pulse width adjustment circuit and said first timing adjusting circuit and the second timing adjusting circuit as the speed control signal,
Forming Ru D C brushless motor speed controller from. In the DC brushless motor speed control device,
The first Hall sensor is arranged for each electrical angle of 120 degrees, and the second Hall sensor, and a third Hall sensor,
A frequency dividing circuit that divides the output of the first Hall sensor and outputs one pulse per rotation of the rotor;
A reference clock generation circuit for generating a reference clock; and
An error signal generation circuit outputs an error pulse corresponding to the rotational speed error of the rotor from the output of said divider and said reference clock,
Acceleration pulse generating means for generating a predetermined acceleration pulse;
An output of said divider circuit, an output of the second Hall sensor, a first timing adjusting circuit for outputting the acceleration pulse at the relevant time to the second Hall sensor from said acceleration pulse,
An output of said divider circuit, an output of the third Hall sensor, a second timing adjusting circuit for outputting the acceleration pulse at the relevant time to the third Hall sensor from said acceleration pulse,
A combining circuit for outputting the outputs of said first timing adjusting circuit and the second timing adjusting circuit of the error signal generating circuit as the speed control signal,
Forming Ru D C brushless motor speed controller from.

Images