JP2003037996A - Control method, control system and time keeping device for step motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method which can additionally reduce consumption power to drive a step motor installed in an electronic wrist watch and the like. SOLUTION: The invention is designed to possibly adjust effective power of driving pulse for each step motor's phase. In other words, driving pulse DP(i) with the effective power in each phase is supplied, the effective power of the driving pulse DP(i) is increased by certainly rotating the step motor by the driving pulse with fully large effective power when the step motor doesn't rotate and the effective power of the driving pulse DP(i) is decreased when it is confirmed that the step motor rotates by the driving pulse DP(i) of the same effective power for predetermined times. By repeating this for each phase, the step motor can be driven by the driving pulse which is suitable for each phase and small in effective power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step motor control device and control method, and more particularly to a power saving type control device and control method suitable for driving a step motor of an electronic timepiece.

[0002]

2. Description of the Related Art A step motor is also called a pulse motor, a stepping motor, a stepping motor or a digital motor, and is a motor driven by a pulse signal which is widely used as an actuator of a digital controller. In recent years, small electronic devices or information devices suitable for carrying have been developed, and small and lightweight step motors are often used as these actuators. Typical of such electronic devices are electronic clocks and time switches such as time switches. In this time measuring device, a reference pulse is supplied from an oscillation circuit using a crystal oscillator or the like, and the reference pulse is divided into a time signal having a frequency suitable for time measurement such as 1 MHz. Then, a drive pulse is supplied to the step motor in accordance with the time signal to move the second hand or the like of the timekeeping device.

[0003]

In such a small electronic device suitable for carrying, since the power source that can be mounted is limited, in order to perform a stable operation for a long time, it is consumed by a step motor or the like. It is important to reduce the power consumed as much as possible. For this reason, in the electronic timepiece using the step motor, the effective power of the drive pulse supplied to the step motor is gradually reduced to drive the step motor in a state where the power consumption is small. On the other hand, if the stepper motor does not rotate normally with the supplied drive pulse, it is rotated by the auxiliary pulse with sufficiently large effective power and the effective power of the drive pulse is increased to ensure that the stepper motor can be driven with the lowest possible power. I have to.

Electronic devices that are small in size and suitable for carrying have been integrated, and, for example, wrist-worn electronic timepieces have become multifunctional in response to various needs of users. Therefore, in addition to the clock function, various functions that consume power are installed, and the overall power consumption tends to increase. In addition, a solar cell and a power generation system that automatically generates power in synchronization with the movement of the user's arm have been introduced, and portable electronic devices have been devised that can be freely used anywhere for a long time without battery replacement. . Since it is difficult to obtain a large current density from the power generation system mounted on these devices, it is desired to further reduce the power consumed by the time measuring device and the like.

Therefore, in the present invention, it is an object of the present invention to provide a control device and a control method capable of further reducing the power consumed to drive a step motor, and to further reduce the power consumption of the clock device. There is.
Then, it is an object of the present invention to provide a power-saving type step motor control device and control method applicable to a portable device that adopts a power generation system such as a solar cell that does not require disposal or replacement of batteries, which is multifunctional. .

[0006]

In the present invention, in order to realize further power saving, the electric power required to rotate the rotor of the step motor from each phase to the next phase is different for each phase. In order to reduce the power consumed to drive the step motor by supplying the optimum drive pulse with the smallest effective power for each phase or each group of appropriate phases. I have to. That is, in the present invention, the first drive pulse supplied to the step motor for rotating from the first position to the next position, for example, from one phase to the next phase.
And the second effective power of the drive pulse supplied to the step motor for rotating from the second position to the next position can be individually optimized by the control method having the following flow. I am trying.

1. A drive pulse with a first effective power is provided to rotate the stepper motor from a first position.

2. The rotation / non-rotation of the step motor is detected.

3. When the step motor is not rotating, the step motor is rotated by supplying a drive pulse having an effective power sufficiently larger than the first effective power to the step motor.

4. The first effective power is decreased / increased by the rotation / non-rotation of the step motor when the drive pulse having the first effective power is supplied.

5. A drive pulse with a second effective power is provided to rotate the stepper motor from the second position.

6. The rotation / non-rotation of the step motor is detected.

7. When the step motor is not rotating, the step motor is supplied with a drive pulse having an effective power sufficiently larger than the second effective power to rotate the step motor.

8. The second effective power is decreased / increased by the rotation / non-rotation of the step motor when the drive pulse having the second effective power is supplied.

Further, in the step of reducing the first and second effective powers, after confirming that the step motor has rotated for each of the first and second effective powers a predetermined number of times, the respective effective powers are reduced. It is desirable to do.

In such a control method, the driving means for supplying the driving pulse to the step motor and the first pulse for generating the driving pulse having the first effective electric power for rotating the step motor from the first position. A first pulse output means for outputting a signal, and a second pulse for outputting a second pulse signal for generating a drive pulse having a second effective power when the step motor is rotated from the second position. Output means and auxiliary pulse output means for outputting an auxiliary pulse for generating a drive pulse having sufficiently large effective power when the step motor is not rotated by the drive pulse having the first or second effective power A detecting means for detecting the rotation / non-rotation of the step motor, and the first / second rotation by the rotation / non-rotation of the step motor when the drive pulse having the first effective power is supplied. And a control means for decreasing / increasing the effective power and decreasing / increasing the second effective power by rotating / non-rotating the step motor when a drive pulse having the second effective power is supplied. A step motor control device can be adopted. The control means includes the first and second
It is desirable to reduce the first and second effective powers after confirming that the step motor is rotated by the driving pulse of the effective power for each of the first and second effective powers a predetermined number of times.

Further, a pulse signal generating means capable of outputting a plurality of signals having different pulse widths is provided, and the first and second pulse outputting means change the first and second effective power from the pulse signal generating means. The first and second pulse signals having different pulse widths may be selected and output.

In the step motor, the rotor is rotated with respect to the stator by the drive pulse to obtain power or control force. Therefore, depending on the assembly error when assembling the stator and the rotor, individual differences such as eccentricity of the rotor with respect to the stator, and the effect of the mechanism driven via the train wheel, etc. Since various conditions such as detent torque are different, the energy required for each step angle rotating from one position to the next is often different. Therefore, in the present invention, not all rotations (step angles) from a certain position of the step motor to the next position are handled in common, but at predetermined step angles or by grouping a plurality of step angles, It is possible to set a drive pulse with an effective power that is optimal and has the lowest effective power.
If all the rotations of the step motor are handled in common, the effective power of the drive pulse will be set according to the step angle that requires the most energy. In contrast,
In the present invention, since the effective power of the drive pulse can be set according to each step angle, the step motor can be driven by using the drive pulse having a lower effective power. Since the rotor makes a rotary motion, various conditions such as torque periodically become substantially the same. Therefore, by handling step angles for each step angle or grouping step angles having similar conditions, it is possible to save power without complicating the configuration and control of the drive device.

The present invention naturally includes a control method and a control device capable of setting a third effective power or a plurality of effective powers in addition to the first and second effective powers.

In the electronic timepiece having the step motor for moving the clock hands, the step motor is supplied with the first effective power by the first time signal supplied from the reference signal generating means for outputting the time signal at a constant time interval. The driving pulse having the second effective power may be supplied to the step motor according to the second time signal. Then, the rotation of each step motor can be detected by the detection means, and the effective powers of the first and second drive pulses can be optimized.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below with reference to the drawings. FIG. 1 shows a schematic configuration of a timing device 1 according to the present invention. The timekeeping device 1 of this example includes a step motor 10, a control device 20 that controls the step motor 10, a train wheel 50 that transmits the movement of the step motor 10, and a second hand 6 that is moved by the train wheel 50.
1, a minute hand 62 and an hour hand 63 are provided. The step motor 10 of this example includes a drive coil 11 that generates a magnetic force by a drive pulse supplied from the control device 20, a stator 12 that is excited by the drive coil 11, and a rotor 13 that rotates inside the stator 12. Is equipped with. The rotor 13 is composed of a disc-shaped two-pole permanent magnet, and is of a PM type (permanent magnet rotating type).
It is a phase step motor 10. The stator 12 is provided with a magnetic saturation part 17 so that different magnetic poles are generated in the respective phases 15 and 16 around the rotor 13 by the magnetic force generated in the drive coil 11. Further, in order to define the rotation direction of the rotor 13, an inner notch 18 is provided at an appropriate position on the inner circumference of the stator 12, which causes a cogging torque to stop the rotor 13 at an appropriate position. I am trying.

The rotation of the rotor 13 of the step motor 10 is caused by rotation of the fifth wheel & pinion 51, which is meshed with the rotor 13 via a pinion.
It is transmitted to each hand by a train wheel 50 including a fourth wheel 52, a third wheel 53, a second wheel 54, a date wheel 55 and a hour wheel 56. The second hand 61 is connected to the shaft of the fourth wheel 52,
A minute hand 62 is connected to 4 and an hour hand 63 is connected to the hour wheel 56, and the time is displayed by these hands in conjunction with the rotation of the rotor 13. In the train wheel 50,
Furthermore, it is of course possible to connect a transmission system or the like (not shown) for displaying the date and the like.

The timekeeping device 1 of the present embodiment comprises a step motor 10
The time is displayed by rotating. Therefore, the step motor 10 is driven by the drive pulse output according to the predetermined time signal. The control device 20 of this example for controlling the step motor 10 includes a reference oscillation source 2 such as a crystal oscillator.
1, an oscillator circuit 22 that outputs a reference pulse of a reference frequency, a frequency divider circuit 23 that divides the reference pulse and outputs a pulse of several specific frequencies, and a step motor 10
The pulse signal generating circuit (waveform synthesizing circuit) 25 that outputs a pulse signal or the like for generating a drive pulse to be supplied to the frequency converter 23 based on the pulse 24 supplied from the frequency dividing circuit 23. A plurality of pulse signals are output from the waveform synthesizing circuit 25. In the present example, for example, a pulse signal (trigger) for starting a timing operation, that is, a cycle for supplying the drive pulse DP to the step motor 10 is started. Signal) P0, a pulse signal P1 for generating a drive pulse DP to be supplied to the step motor 10, and a pulse for supplying a sufficiently large drive pulse to rotate the step motor 10 when the step motor 10 does not rotate. A signal (auxiliary pulse) P2, a pulse signal P3 for generating a demagnetization pulse PE to be supplied to erase the magnetic force remaining in the drive coil 11 after a large drive pulse is supplied, and the like are output.

In the control device 20 of this example, the waveform synthesizing circuit 25 is connected with two setting circuits 26a and 26b in which data for defining the pulse width of the pulse signal P1 is set. One setting circuit 26a, for example, in the step motor 10, sets the S pole of the rotor to the stator 1
The pulse width of the P1 pulse for generating the drive pulse DP to be supplied to the step motor 10 when rotating from the first phase 15 to the second phase 16 of 2 (hereinafter, the first step angle) is defined. The data to be stored is stored. The opposite is supplied to the other setting circuit 26b, that is, when the S pole of the rotor is rotated from the second phase 16 of the stator 12 toward the first phase 15 (hereinafter, second step angle). Data that defines the pulse width of the P1 pulse for generating the drive pulse DP is stored. In the setting circuits 26a and 26b of this example, a digital counter 27 is adopted to store the above data, and the value of the counter 27 is raised or lowered by the control circuit 30 as described later, and the first and second
The pulse width of the P1 pulse for moving the step angle of is determined. The device for storing data in the setting circuit 26 is not limited to the counter, and other types of memories may be used as a matter of course.

As described above, in the control device 20 of this example, the waveform synthesizing circuit 25 generates the pulse signal P1 (1) for the first step angle and the pulse signal P1 (2) for the second step angle. Further, it also has a function of outputting a pulse signal (auxiliary pulse) P2 for assisting these and generating a drive pulse having a sufficiently large effective power. These pulse signals output from the waveform synthesis circuit 25 are supplied to the control circuit 30. Control circuit 30
Drives the CMOS forming the drive circuit 31, supplies a drive pulse to the drive coil 11 of the step motor 10, and drives the step motor 10. Further, the wiring for supplying the drive pulse from the drive circuit 31 to the drive coil 11 is connected with a detection circuit 39 for detecting the rotation / non-rotation of the rotor 13 from the induced voltage generated after the drive pulse is supplied, and the control is performed. The circuit 30 further controls by the detection signal from the detection circuit 39.

FIG. 2 shows a control flow for driving the step motor 10 by the control device 20 of this example, and the operation of the control device 20 of this example will be described based on this flow. First,
In step 71, it is detected whether or not a time signal indicating the passage of time is output. In the control device 20 described above, the reference pulse output from the oscillation circuit 22 is frequency-divided by the frequency dividing circuit 24, and a signal of, for example, 1 Hz is supplied to the waveform synthesizing circuit 25. Based on this, the waveform synthesizing circuit 2
5 outputs a pulse signal P0 (trigger signal) which becomes a time signal. With this trigger signal, the control device 20 of the present example
Supplies a drive pulse to the step motor 10 every 1 second to move the timekeeping device 1.

Next, at step 72, it is determined from which position of the step motor 10 the rotor 13 should be rotated. Since the step motor 10 of the present example is a two-pole motor having two phases, it drives the first step angle from the first phase to the second phase, or it drives the first phase from the second phase to the first phase. It is determined whether to drive the second step angle toward the phase. Then, if the first step angle is to be driven, in step 73 the parameter i
Is set to 1, and if the second step angle is to be driven, 2 is set to the parameter i in step 74. If it is a two-phase stepping motor as in this example, the value of the parameter i may be changed alternately. If the step motor has three or more phases, the step angle can be determined using a counter or the like. Further, if the step motor has a symmetrical property, it is possible to group a plurality of step angles and change the value of the parameter i depending on the value of each group.

Next, at step 75, the drive pulse DP (i) of the selected parameter i is supplied from the drive circuit 31 to the step motor 10 to drive the step motor. In the control device 20 of the present example shown in FIG. 1, the data for generating the drive pulse for driving the first and second step angles is set by the setting circuits 26a and 26b.
Is set to. Therefore, the waveform synthesizing circuit 25 sets the setting circuit 26a or 26b based on the value of the parameter i.
The pulse signal P1 (i) for generating the drive pulse DP (i) according to the data of 1 is output to the control circuit 30 after the trigger signal P0. The control circuit 30 uses the pulse signal P1
A generation signal is sent to the drive circuit 31 based on the pulse width of (i) and the polarity determined by the value of the parameter i. In the control device 20 of the present example, the effective power of the drive pulse supplied to the step motor is controlled by changing the pulse width of the drive pulse. Therefore, the setting circuits 26a and 26b store data for determining the pulse width of the pulse signal P1 and select a signal having a predetermined pulse width from the signals having the pulse width that can be output from the waveform synthesizing circuit 25. The data is stored. Of course, changing the voltage of the drive pulse, PWM (pulse width modulation), PFM
(Pulse frequency modulation), PAM (pulse amplitude modulation) or the like may be used to control the power of the drive pulse.

The drive circuit 31 of this example comprises two columns of n-channel MOS 33 and p-channel MOS 3 connected in series.
It is configured by a bridge circuit configured by 2. By inverting the polarities of the generated signals applied to the gates of the MOSs 32 and 33 in accordance with the first and second step angles, the step motor 1
Driving pulses having different polarities are supplied to the driving coil 11 of 0, and magnetic fields having different polarities are alternately generated in the stator 12 to rotate the rotor 13 in one direction. In the control device 20 of this example, the pulse width of the drive pulse DP (1) supplied for moving the first step angle is determined by the pulse signal P1 (1) generated by the data of the setting circuit 26a, and The pulse width of the drive pulse DP (2) supplied to move the step angle of 2 is determined by the pulse signal P1 (2) generated by the data of the setting circuit 26b. The drive circuit 31 is
It is needless to say that the present invention is not limited to this example as it can be configured by using a bipolar transistor or the like, or may be a unipolar type drive circuit.

When the drive pulse for the first or second step angle is supplied, it is detected in step 76 whether or not the rotor 13 is rotated by the drive pulse. In this example, the induced voltage generated by the rotation of the rotor 13 is detected to determine whether the rotor 13 is rotating or not. The means for detecting rotation is not limited to this.
Means such as detecting a difference in time constant for generating a magnetic flux in the stator 12 or detecting the rotation angle of the rotor 13 using a sensor or the like, which is disclosed in 1-15-1384, may be adopted. Rotation of the rotor by the induced voltage in this example
The method of detecting non-rotation is suitable for a very small step motor used in a time measuring device, etc. Furthermore, since it is possible to determine whether rotation or non-rotation is performed immediately after supplying a drive pulse, It is possible to smoothly supply a large drive pulse by the pulse signal P2 (correction pulse).

In step 76, when the rotor 13 is not rotating, subsequently, a drive pulse having a long pulse width generated by the auxiliary pulse P2, that is, a sufficiently large effective power is supplied to the step motor 10, and the step motor 10 is driven. Surely rotate. In this example, a pulse signal (auxiliary pulse) P2 having a constant pulse width sufficient to drive a step motor that is about 2 to 3 times the pulse signal P1 from the waveform synthesis circuit 25 follows the pulse signal P1. It is supplied to the control circuit 30. The pulse signal P2 is supplied to the control circuit 30 with an interval for detecting rotation / non-rotation after the pulse signal P1. Control circuit 30
On the basis of this pulse signal P2, supplies a generation signal whose polarity is inverted according to the step angle to the drive circuit 31, and a drive pulse having a wide pulse width and sufficiently large effective power is supplied from the drive circuit 31 to the step motor 10. To be done.

When the drive coil 11 is excited by the drive pulse having a large effective power, the magnetic field remains, which may be an obstacle when driving the next step angle.
Therefore, a pulse signal P3 having a short pulse width supplied from the waveform synthesis circuit 25 is output following the pulse signal P2,
As a result, the demagnetizing pulse PE having the opposite polarity to the drive pulse having the large effective power applied immediately before is supplied to the step motor 10.

When a drive pulse having a large effective power is supplied by the auxiliary pulse P2, in the next step 81,
The effective power of the drive pulse DP (i) when the step angle is rotated in the next cycle is increased. In the control device 20 of the present example, for example, the control circuit 30 does not rotate the step angle pulse signal P1 (i).
The data stored in the setting circuit 26a or the setting circuit 26b is changed so that a pulse signal having a pulse width one step larger is output from the waveform synthesizing circuit 25.

On the other hand, when it is detected in step 76 that the rotor 13 is rotated by the drive pulse DP (i), the counter C (i) is incremented in step 77. The counter C (i) is a counter that counts the number of times that the step angle can be continuously rotated by the drive pulse DP (i), and the number of the counter C (i) reaches a predetermined number C0 in step 78. Judge whether or not. If the predetermined number of times C0 has not been reached, the process returns to step 71 and waits until the time signal, that is, the next trigger signal P0 is output.

In step 78, the counter C (i)
If the value of has reached C0, the drive pulse DP (i)
Indicates that the drive pulse DP can be continuously driven C0 times, for example, the second step angle.
There is a possibility that the second step angle can be driven even if the effective power of (i) is further reduced. Therefore, step 7
In 9, the effective power of the drive pulse DP (i), that is, the pulse width is reduced. In the control device 20 of this example, the control circuit 30 controls the setting circuit 26a or 2
The data stored in 6b is modified so that the pulse signal P1 having a pulse width narrower by one step is output from the waveform synthesis circuit 25.

If the effective power of the drive pulse DP (i) for the first or second step angle is increased or decreased in step 78 or step 81, step 8
2, the counter C for the step angle increased or decreased
Clear (i) to zero. Then, the process returns to step 71 and waits until the next trigger signal is output. In the control device 20 of the timekeeping device 1 of the present example, the steps described above are repeated for each trigger signal to move the step motor 10 from phase 1 to phase 2 (first step angle) and from phase 2 to phase 1 ( It is repeatedly driven with the second step angle). Then, the drive pulses DP (1) and DP (2) set to the optimum effective power are supplied for each of the first and second step angles, and the step motor can be driven with low power consumption.

FIG. 3 shows the waveform synthesis circuit 25 to the control circuit 3
0 shows each pulse signal supplied to 0 and the corresponding drive pulse supplied from the drive circuit 31 to the step motor 10. At time t1, the trigger signal P0 for driving the first step angle is output. This starts the cycle for driving the first step angle. At time t2, the pulse width T from the waveform synthesis circuit 25
The pulse signal P1 (1) of 1 is output, and the drive pulse DP (1) having a pulse width corresponding to this is supplied to the step motor. Time t after the drive pulse DP (1) is supplied
Rotation / non-rotation of the rotor 13 is detected from around 3. If it is not rotating, a drive pulse having a large effective power corresponding to the pulse signal P2 having the pulse width T10 output from the waveform synthesizing circuit 25 at time t4 is supplied to the step motor to reliably rotate. Next, in order to erase the magnetic field remaining in the drive coil 11, the demagnetization pulse PE having the opposite polarity is output according to the pulse signal P3 output at the time t5.

By the trigger signal P0 at time t6, the second
The cycle to drive the step angle of starts. At time t7, the waveform synthesizing circuit 25 outputs the pulse signal P1 (2) having the pulse width T1, and the drive pulse DP (2) having the pulse width corresponding to the pulse signal and having the opposite polarity is supplied to the step motor. In this case, first, the same pulse width T is used for the first step angle and the second step angle.
A drive pulse of 1 is supplied. At the second step angle, the rotation of the rotor was detected after the time t8 when the drive pulse DP (2) was supplied, and the step motor could be normally rotated by the drive pulse having the pulse width T1. Therefore, the pulse signal P2 output at time t9 and the time t
The drive pulse and the degaussing pulse corresponding to the pulse signal P3 output to 10 are not supplied to the step motor.

The trigger signal at time t11 starts the next cycle for driving the first step angle. In the cycle that drives the first step angle,
Rotation of the rotor is not detected in the previous cycle, and a drive pulse with a large effective power is supplied according to the pulse signal P2. Therefore, at time t12, the pulse width changes from T1 to T2.
The pulse signal P1 (1) spread to the step motor is output from the waveform synthesizing circuit 25, and the drive pulse having the expanded pulse width, that is, the increased effective power is supplied to the step motor. If the rotation of the rotor is not detected again at time t13 when the drive pulse ends, at time t14, a drive pulse having a large effective power according to the pulse signal P2 is supplied to surely rotate the rotor. After that, time t
A demagnetizing pulse of reverse polarity is supplied to 15.

The trigger signal at time t16 starts the next cycle for driving the second step angle. In the cycle that drives the second step angle,
Since it is rotating normally in the previous cycle, time t17
The pulse signal P1 having the same pulse width T1 as in the previous cycle
(2) is output from the waveform synthesis circuit 25, and the drive pulse is supplied to the step motor accordingly. Time t18
When it is detected that the rotor has rotated normally again,
The drive pulse and degaussing pulse corresponding to the pulse signals P2 and P3 are not supplied.

The trigger signal at time t19 starts the next cycle for driving the first step angle. In the cycle that drives the first step angle,
In the previous cycle, it cannot rotate with the drive pulse DP (1),
A drive pulse having a wide pulse width corresponding to the pulse signal P2 and a large effective power is supplied. Therefore, time t2
At 0, the pulse signal P1 (1) having a pulse width wider than T2 to T4 from the previous cycle is output from the waveform synthesizing circuit 25, and a drive pulse having a wider pulse width is supplied to the step motor accordingly. Since the rotation of the rotor is detected after the time t21 by the drive pulse having the wider width, the drive pulse and the degaussing pulse corresponding to the pulse signals P2 and P3 are not supplied to the step motor.

The trigger signal at time t22 starts the C0 + 1th cycle for driving the second step angle. Since it is confirmed that the rotor is normally rotating C0 times by the pulse signal P1 (2) having the pulse width T1, the pulse signal P1 (2) having the pulse width narrowed from T1 to T3 is waveform-synthesized at time t23. It is output from the circuit 25 and the pulse width is narrowed accordingly, that is,
The drive pulse with reduced effective power is supplied to the step motor. After that, when the rotation of the rotor is confirmed, the drive pulse and the degaussing pulse corresponding to the pulse signals P2 and P3 are not supplied.

As described above, when the control device and control method of this example are used, even if control is started with the pulse signal P1 having the same pulse width T1 for the first and second step angles, time elapses. , A pulse signal P1 having a wide pulse width, that is, a large effective power is output for the first step angle, while a pulse signal having a narrow pulse width, that is, a small effective power is output for the second step angle. The pulse signal P1 is output. Therefore, in the control device and the control method of this example, when the rotating step angle is different with respect to the same step motor, that is, depending on the position where the rotation is started,
Drive pulses of different effective power are supplied.

In the step motor, the rotor rotation position is influenced by an assembly error when the stator and the rotor are assembled, an individual difference such as an eccentricity of the rotor with respect to the stator, and an influence of a mechanism driven through a train wheel or the like. Since various conditions such as holding torque and detent torque are different depending on the situation, the energy required for each step angle rotating from one position to the next is often different. In contrast to such a stepping motor, in the control method and the control device of the present example, all the step angles are not commonly handled, but the individual step angles or a plurality of grouped step angles are optimized and the power is most optimized. It is possible to set a drive pulse having a lower effective power. On the other hand, if all the rotations of the step motors are handled in common, the effective power of the drive pulse will be set according to the step angle that requires the most energy. For example, in the case shown in FIG. 3, the pulse widths of all drive pulses are set to the maximum pulse width T4. On the other hand, in the present invention, since the effective power of the drive pulse can be set in accordance with each step, it is possible to use the drive pulse of low effective power for the step angle that can be driven with low energy and drive the step motor. It is possible to reduce the power consumed for doing so. According to the measurement results of the inventors, the driving pulse for the first step angle and the driving pulse for the second step angle are individually handled in the above-described timing device, so that the driving pulse for all the step angles can be controlled. It was found that power consumption could be reduced by about 5% compared with the case of handling in common.
This measurement result is an effect obtained when the present invention is applied to a step motor for a highly accurate timekeeping device, and by applying the present invention to a step motor used for an actuator or the like, further significant power saving is expected. it can.

In the above example, 2 which is suitable for the timing device.
The present invention has been described by taking a phase stepping motor as an example.
It goes without saying that the present invention can be similarly applied to step motors having more than one phase. For step motors with three or more phases, the drive pulse with the optimum effective power may be set for each step angle, or each phase may be grouped to drive the optimum effective power for each group. The pulse may be set as described above. In addition, the driving method of the step motor is
Power consumption for driving a motor by applying the present invention to a drive pulse that rotates from a predetermined position to the next position, not only for 1-phase excitation but also for 2-phase excitation or 1-2 phase excitation Can be reduced. Further, it goes without saying that the step motor controlled by the control method and the control device of the present invention is not limited to the PM type,
The present invention can be applied to step motors of the type or hybrid type.

[0046]

As described above, according to the present invention, the effective electric power of the drive pulse supplied to the step motor can be set for each rotational position of the step motor, and the minimum value suitable for each rotational position can be set. The step motor can be driven by a drive pulse with a limited effective power.
Therefore, according to the present invention, the power consumed for driving the step motor can be minimized.
It is possible to provide a step motor control method and a control device that are suitable for a portable device that is becoming smaller and more multifunctional. For example, in a portable device such as an electronic wristwatch, power consumption is increased due to the multi-functionalization, while at the same time, it is possible to eliminate battery replacement by miniaturization and by incorporating a power generation device such as a solar battery. . By applying the control method and control device of the present invention, it is possible to reliably measure time with low power consumption even with a device using a power source with a small amount of power generation. It is possible to effectively utilize the various functions that have been performed.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a timing device that stores a control device of the present invention.

FIG. 2 is a flowchart showing a control flow of the control device shown in FIG.

3 is a timing chart showing how a drive pulse supplied from the control device shown in FIG. 1 to a step motor changes.

[Explanation of symbols]

1 ... Timer 10 ... Step motor 11 ... Drive coil 12 ... stator 13 ... Rotor 20..Control device 21 .. Crystal unit 22 ... Oscillation circuit 23..Dividing circuit 25..Waveform synthesis circuit 26..Setting circuit 30 ... Control circuit 31 ... Drive circuit 39 ... Rotation / non-rotation detection circuit 50 ... 61 ... second hand 62 ... 63 ... hour hand

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Claims (7)

[Claims] 1. A first step of supplying a drive pulse having a first effective power for rotating a step motor from a first position, and a second step of detecting rotation / non-rotation of the step motor. And a third step of rotating the step motor by supplying the drive pulse having an effective power sufficiently larger than the first effective power to the step motor when the step motor is not rotating, A fourth step of decreasing / increasing the first effective power by rotating / non-rotating the step motor when the drive pulse having the first effective power is supplied; Fifth for supplying the drive pulse with a second effective power for rotating from the position
And a sixth step of detecting rotation / non-rotation of the step motor, and when the step motor is non-rotation, the step motor is provided with effective power sufficiently larger than the second effective power. The seventh step of supplying the drive pulse to rotate the step motor, and the second effective by rotation / non-rotation of the step motor when the drive pulse having the second effective power is supplied. An eighth step of reducing / increasing electric power, the method of controlling a step motor. 2. The method according to claim 1, wherein, in the fourth step, after confirming a predetermined number of times that the stepper motor is rotated by the drive pulse having the first effective power, the first effective value is determined. Reducing the electric power, and in the eighth step, decreasing the second effective power after confirming a predetermined number of times that the stepper motor is rotated by the drive pulse having the second effective power. A method of controlling a step motor, characterized by: 3. A drive means for supplying a drive pulse to the step motor, and when rotating the step motor from a first position,
First to generate the drive pulse with a first effective power
A first pulse output means for outputting a pulse signal of, and when the step motor is rotated from the second position,
A second for generating the drive pulse with a second effective power;
Second pulse output means for outputting a pulse signal of, and the drive having sufficiently large effective power when the step motor is not rotated by the drive pulse having the first or second effective power. Auxiliary pulse output means for outputting an auxiliary pulse for generating a pulse, detection means for detecting rotation / non-rotation of the step motor, and the step motor when the drive pulse having the first effective power is supplied. The first effective power is reduced / increased by rotation / non-rotation of the second effective power by rotation / non-rotation of the step motor when the drive pulse having the second effective power is supplied. And a control means for decreasing / increasing the value of the step motor. 4. The control unit according to claim 3, wherein the stepper motor is rotated by the drive pulse having the first and second effective powers for each of the first and second effective powers. A control device for a step motor, wherein the first and second effective powers are respectively reduced after confirmation is performed a predetermined number of times. 5. The pulse signal generating means according to claim 3, which is capable of outputting a plurality of signals having different pulse widths, wherein the first and second pulse outputting means have the first and second effective powers. The step motor control device is characterized in that the first and second pulse signals having different pulse widths are respectively selected and output from the pulse signal generating means by increasing or decreasing the number of pulses. 6. A drive means for supplying a drive pulse to a step motor to move a clock hand, a reference signal generating means for outputting a time signal at a constant time interval, and a step signal for the step motor according to a first time signal. A first pulse output means for outputting a first pulse signal for supplying the drive pulse having a first effective power; and a second effective power for the step motor provided by a second time signal. Second pulse output means for outputting a second pulse signal for supplying a drive pulse, and a sufficiently large value when the step motor is non-rotating due to the drive pulse having the first or second effective power. Auxiliary pulse output means for outputting an auxiliary pulse for generating the drive pulse having effective power; detection means for detecting rotation / non-rotation of the step motor; When the first effective power is reduced / increased by the rotation / non-rotation of the step motor when the drive pulse having the effective power is supplied, and the drive pulse having the second effective power is supplied. And a control means for decreasing / increasing the second effective power by rotating / non-rotating the step motor. 7. The control unit according to claim 6, wherein the stepper motor is rotated by the drive pulse having the first and second effective powers for each of the first and second effective powers. A timekeeping device, characterized in that the first and second effective powers are respectively reduced after confirmation of a predetermined number of times.