JP3593899B2 - Electronic device and control method thereof - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electronic device equipped with a stepping motor such as a timing device and a control method thereof, and more particularly to an electronic device capable of fast-forwarding a stepping motor and a control method thereof.
[0002]
[Prior art]
The stepping motor is also called a pulse motor, a stepping motor, a stepping motor, a digital motor, or the like, and is a motor driven by a pulse signal that is frequently used as an actuator of a digital control device. In recent years, small electronic devices suitable for carrying have been developed, and small and lightweight stepping motors are often used as these actuators. A typical example of such an electronic device is a clock device such as an electronic timepiece, a time switch, or a chronograph.
[0003]
As shown in FIG. 7, a stepping motor 10 used in this timekeeping device and the like is an integrated stator in which the outside of a two-pole magnetized disk-shaped rotor 13 is connected via a notch-shaped magnetic saturation part 17. 12 to rotate inside. The rotor 13 is sequentially rotated by a driving pulse having an appropriate frequency such as 1 Hz, and the hands can be moved by the driving force. In order to eliminate hand movement errors, it is important to check whether or not the rotor 13 has been normally rotated by the drive pulse. For this purpose, the drive coil as shown in FIG. The detected current or voltage is detected.
[0004]
As shown in this figure, the current (back-induced current) counter-induced due to the rotation of the rotor 13 is substantially equal to the drive pulse DP and the first pole on the opposite pole side when passing through a position substantially 90 degrees from the stable position. Peak PM1 appears. Further, when the rotor 13 moves, the driving pulse DP and the driving pulse DP are passed when the rotor 13 passes a stable position B on the opposite pole side rotated by 180 degrees, which is the destination (reverse pole side), past the position A where the back induced current becomes zero. A large first peak PP1 on the same pole side appears. Thereafter, the second peaks PM2 and PP2 are generated with the swing (vibration) until the rotor 13 stops stably.
[0005]
Although the first peak PM1 or PP1 has a high intensity but is affected by the transient current TW of the drive pulse DP, it is difficult to temporally separate the drive pulse DP from the first peak PM1 or PP1. For this reason, the second peak PM2 or PP2, which is low in intensity at the time of the conventional normal hand operation but easy to separate, is used for rotation detection, and a method such as chopper amplification by a chopper pulse to increase the intensity is used. Has been adopted.
[0006]
[Problems to be solved by the invention]
In recent years, various functions have been incorporated into timekeeping devices such as wristwatch devices. One of them is to operate a stepping motor at a higher speed than during normal hand operation to automatically or manually set the time. There is a function. When performing fast-forwarding in which the stepping motor is moved at a high speed, it is necessary to supply a fast-forwarding drive pulse having a shorter interval (period) than a normal drive pulse. Further, in order to set the time, it is necessary to drive the hand so that there is no hand movement error even during fast-forwarding, that is, no rotation error of the rotor. For this purpose, it is necessary to detect the rotation of the rotor 13 at the earliest possible timing and to supply a drive pulse for fast-forwarding in accordance with the movement of the rotor at the detected timing. Therefore, it is considered that the detection timing is obtained by capturing the first peaks PM1 and PP1 or a phenomenon related thereto, for example, a phenomenon in which the polarity of the back induced current is reversed.
[0007]
However, as shown in FIG. 8, in order to catch the phenomenon in which the rotor 13 rotates at an early timing, if there is a transient current or a shift in sampling timing, the rotating phenomenon cannot be grasped. Timing may not be obtained. In such a case, in order to continue the fast-forward, it is necessary to continuously supply drive pulses for fast-forward having different polarities at appropriate timing. However, unlike the case where the drive pulse is output at a fixed timing such as 1 Hz as in normal hand operation, it is not possible to determine the timing that matches the rotation of the rotor 13 that is being fast-forwarded. Therefore, if the position of the rotor is not detected, it is not possible to supply a fast-forward drive pulse at an appropriate timing, which may cause a brake to the rotation of the rotor, and furthermore, the timing of the fast-forward drive pulse may be shifted one after another. There is. Further, once the timing of the drive pulse is shifted, the subsequent timing is also likely to be shifted, and it is difficult to perform fast forward stably.
[0008]
Therefore, in the present invention, even when the position of the rotor may not be obtained when the drive pulse is output based on the rotational position of the rotor and the drive is performed, the drive pulse for fast-forwarding is performed at a timing suitable for the rotation of the rotor. It is an object to provide an electronic device that can be supplied and a control method thereof. It is another object of the present invention to provide an electronic device capable of stably and quickly moving a stepping motor at a high speed and a control method thereof.
[0009]
[Means for Solving the Problems]
For this reason, in the electronic device including the stepping motor of the present invention, attention is paid to the influence of the power supply voltage of the drive pulse on the rotation speed and the acceleration of the rotor, and the level of the power supply voltage of the drive pulse is added to the control element. ing. That is, the electronic apparatus of the present invention includes a stepping motor capable of driving a multi-polarized rotor in a stator having a driving coil, and a driving pulse supplying a driving pulse capable of driving the rotor to the driving coil. Control means, and power supply means serving as a power source of the drive pulse, wherein the drive control means can change the timing of the drive pulse based on the power supply voltage of the drive pulse. Premise And Further, in the method of controlling an electronic device having a stepping motor capable of rotating and driving a multi-pole magnetized rotor in a stator having a driving coil according to the present invention, a driving method for driving the rotor with respect to the driving coil is provided. When supplying a pulse, a driving step for changing the timing of the driving pulse based on the power supply voltage of the driving pulse is provided. Assuming that are doing.
[0010]
When the power supply voltage of the drive pulse is high, the effective power becomes large even for a drive pulse having a narrow pulse width such as a drive pulse for fast forward. Therefore, the rotor rotates at a high speed and tends to increase in speed. On the other hand, when the power supply voltage is low, the effective power of the drive pulse decreases, so that the rotor rotates at a low speed and tends to decelerate. Therefore, by controlling the timing of the drive pulse by the power supply voltage, it becomes possible to output the drive pulse at a timing commensurate with the rotation of the rotor.
[0011]
When the rotor is rotated periodically, there is no need to adjust the timing of the drive pulse, so the power supply voltage may decrease or the power supply voltage may be changed to control the effective power for driving the rotor. However, the timing of the driving pulse was not controlled by the power supply voltage. However, an electronic device having a drive control unit including a fast-forward control unit that supplies a fast-forward drive pulse with a short interval to a normal drive pulse, or a fast-forward step of supplying such a fast-forward drive pulse is provided. This is very effective in a control method of an electronic device having a driving step.
[0012]
Therefore, when fast-forwarding is performed by using the position detecting means or the position detecting step capable of detecting the counter-induced power excited by the rotation of the rotor, the timing at which the drive pulse for fast-forwarding is output is determined based on the detection timing at which the position is detected. In the device or its control method, when the detection timing cannot be obtained, the driving pulse for the next fast-forward is output at an earlier timing when the power supply voltage is high, and the driving pulse for the fast-forward is output at a later timing when the power supply voltage is low. The drive pulse can be output at a timing that matches the rotation of the rotor even if the detection timing is not obtained.
[0014]
For this reason, a portable electronic device in which the voltage tends to fluctuate because a battery is used as a power supply, or a voltage control that can increase or decrease the power supply voltage in order to control the power of a driving pulse in a power supply unit. Even in an electronic device having the means, the rotor can be stably fast-forwarded.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 shows an example of a timing device such as a wristwatch device using a stepping motor. The timekeeping device 1 includes a stepping motor 10, a control device 20 for driving the stepping motor 10, a wheel train 50 for transmitting the movement of the stepping motor 10, and a second hand 61, a minute hand 62 and an hour hand driven by the wheel train 50. 63 is provided. The stepping motor 10 includes a driving coil 11 that generates a magnetic force by a driving pulse supplied from the control device 20, a stator 12 that is excited by the driving coil 11, and a magnetic field that is excited inside the stator 12. The rotating motor 13 is provided, and the rotor 13 is a stepping motor 10 of the PM type (permanent magnet rotating type) in which the rotor 13 is configured by a disk-shaped two-pole permanent magnet. The stator 12 is provided with a magnetic saturation portion 17 so that different magnetic poles are generated in the respective phases (poles) 15 and 16 around the rotor 13 by the magnetic force generated by the driving coil 11. In order to define the rotation direction of the rotor 13, an inner notch 18 is provided at an appropriate position on the inner periphery of the stator 12, so that cogging torque is generated so that the rotor 13 stops at an appropriate position. ing.
[0016]
The rotation of the rotor 13 of the stepping motor 10 is performed by the fifth wheel 51, the fourth wheel 52, the third wheel 53, the second wheel 54, the minute wheel 55, and the hour wheel 56 meshed with the rotor 13 through the pinion. Is transmitted to each needle by the train wheel 50. A second hand 61 is connected to the shaft of the fourth wheel & pinion 52, a minute hand 62 is connected to the second wheel & pinion 54, and an hour hand 63 is connected to the hour wheel & pinion 56. The hands indicate the time. It is of course possible to connect a transmission system (not shown) for displaying the date and the like to the wheel train 50.
[0017]
In the timing device 1, in order to display the time by the rotation of the stepping motor 10, a signal of a reference frequency is counted (timed) to the stepping motor 10 and a driving pulse for normal hand movement is supplied at a cycle of 1 Hz. . For this reason, the control device 20 of the present example that controls the stepping motor 10 includes a pulse synthesizing circuit 22 that generates a reference pulse having a reference frequency and a pulse signal having a different pulse width and timing using a reference oscillation source 21 such as a quartz oscillator. A drive control circuit 25 for controlling the stepping motor 10 based on various pulse signals supplied from the pulse synthesizing circuit 22, and a detection circuit 75 for detecting rotation.
[0018]
The drive control circuit 25 supplies a normal drive pulse having a frequency of 1 Hz to the drive coil 11 via the drive circuit 30, which will be described later, to drive the drive rotor 13 of the stepping motor 10 for normal hand movement. And an auxiliary function 27 for outputting an auxiliary pulse having an effective power larger than the driving pulse when the rotor 13 does not rotate. Further, the drive control circuit 25 of the present example has a fast-forward function 28 for supplying a drive pulse PW for fast-forwarding the rotor 13 at a shorter interval than the drive pulse for normal hand movement. Therefore, the drive control circuit 25 of the present example can drive the stepping motor at a high speed in the same direction as the normal hand movement or in the opposite direction by using the drive pulse PW.
[0019]
The drive circuit 30 that supplies various drive pulses to the stepping motor 10 based on the control signals φo1 and φo2 from the drive control circuit 25 includes a p-channel MOS 32a and an n-channel MOS 33a, and p-channel MOSs 32b and p connected in series. A bridge circuit constituted by a channel MOS 33b is provided, and the power supplied to the drive coil 11 of the stepping motor 10 from the power supply 41 can be controlled by these.
[0020]
In the coil section 19 of the stepping motor 10 of this example, a detection coil 71 is wound together with the drive coil 11, and the detection coil 71 is connected to a connection circuit 72. The connection circuit 72 is a circuit in which p-channel MOSs 72a and 72b are connected in parallel, and is controlled by control signals φt1 and φt2 supplied from the detection control circuit 75. By the connection circuit 72, the detection coil 71 is short-circuited after the drive pulse is supplied, is further chopped, amplifies the counter-induced power generated in the detection coil 71, and detects the amplified detection voltages φk1 and φk2. The information is fed back to the control circuit 75. Then, whether or not the rotor 13 has rotated is detected based on the detection signals φk1 and φk2.
[0021]
Further, the timekeeping device 1 of this example includes a power generation device 40 that can charge the power supply 41 and a step-up / down circuit 49 that steps up and down the power output from the power supply 41 and supplies the power to the drive circuit 30 of the control device 20. . The step-up / step-down circuit 49 of the present example is capable of performing multi-step step-up and step-down by using a plurality of capacitors 49a, 49b and 49c, and the drive circuit 30 according to the control signal φ11 from the drive control circuit 25 of the control device 20. Can be adjusted. The output voltage of the step-up / step-down circuit 49 is also supplied to the drive control circuit 25 by the monitor circuit φ12, so that the power supply voltage can be monitored. Therefore, the voltage of the drive pulse PW for fast-forwarding as well as the drive pulse during normal hand operation can be controlled, and the effective power of the drive pulse can be controlled by the pulse width and the voltage. For this reason, fine-grained control of the driving power is possible, and a driving pulse of electric power suitable for rotating the rotor 13 is supplied to save power, and high-speed fast-forwarding can be performed.
[0022]
FIG. 2 is a timing chart showing a state in which a drive pulse PW for fast-forward is supplied to the drive coil 11 to perform fast-forward. As shown in the figure, the rapid traverse in the present example detects the rotation of the rotor 13 by detecting the reverse induced voltage φk1 generated in the detection coil 71, instead of the periodic drive that supplies the driving pulse PW for rapid traverse at a predetermined cycle. Then, self-excited driving for supplying the next fast-forward driving pulse PW immediately after the timing (detection timing DT, for example, time t4) when the phenomenon that the rotor 13 rotates is detected or after a certain delay time d0 has elapsed is adopted. are doing. Therefore, fast-forwarding can be performed at a high speed corresponding to the actual condition of the stepping motor. In particular, since the position of the rotor 13 is detected, the next drive pulse can be supplied when the rotor 13 reaches an appropriate position. , The effective power of the drive pulse is not offset by the movement of the rotor, so that the effective power is not insufficient, and fast-forwarding can be reliably performed with a small amount of energy.
[0023]
The detection timing DT is to detect the first peak PP1 of the same polarity of the counter-induced power due to the rotation of the rotor 13, to determine the polarity of the counter-induced voltage, and to detect the point at which the counter-induced voltage becomes 0 (zero crossing). There is a method. In this example, the counter-induced voltage due to the first peak (peak PP1 shown in FIG. 8) is chopper-amplified, and the time when the level reaches a predetermined value L is adopted as the detection timing DT. Of course, the method is not limited, and the position of the rotor 13 can be detected even if the phenomenon of the back induced voltage other than the first peak PP1 is captured, and the drive pulse can be supplied at an appropriate timing based on the detected position. .
[0024]
FIG. 3 is a flowchart illustrating an outline of a control method in the fast-forward function 28 of the drive control unit 25 of the present example. First, at step ST1, a driving pulse PW for fast-forward is output. Next, in step ST2, a mask period τ0 is opened in order to avoid spikes S or the like generated in the detection coil due to the drive pulse, and in step ST3, the detection coil 71 is short-circuited by the connection circuit 72, and the generated reverse induced voltage. Is chopper-amplified. When the chopper-amplified voltage reaches a predetermined level L in step ST4, a predetermined delay time starts from the detection timing DT in step ST5. do Is opened, and the process returns to step ST1 to output a driving pulse PW of the opposite polarity. Thus, the rotor 13 can be fast-forwarded at a speed that matches the effective power of the drive pulse PW and the condition of the stepping motor 10.
[0025]
On the other hand, the rotation of the rotor may not be detected in the rotation detection in step ST3, and the detection timing DT may not be obtained. For this reason, in this example, when the fixed period I has elapsed in step ST6, the process forcibly shifts to step ST1, and the fast-forward is continuously performed by supplying the driving pulse PW of the opposite polarity. By changing the period I determined in step ST6 based on the power supply voltage V of the drive pulse PW, even when the detection timing DT is not obtained, the next drive pulse PW is generated at a timing that matches the movement of the rotor 13 as much as possible. We can supply them. Therefore, even if the detection timing DT cannot be obtained, fast forward can be performed stably.
[0026]
FIG. 4 is a graph showing a period I set by the power supply voltage V in the fast-forward function 28 of the present example. When the power supply voltage V is high, the effective power of the drive pulse PW is large. Therefore, the rotor 13 rotates at a high speed and tends to accelerate. When the power supply voltage V is low, the effective power of the drive pulse PW is small, so that the rotor 13 is rotating at a low speed and tends to decelerate in many cases. For this reason, in the fast-forward function 28 of this example, when the power supply voltage V is low, the period I is set long, and when the detection timing DT is not obtained, the timing of the next supplied drive pulse PW is delayed. . When the power supply voltage V is high, the period I is set short, and when the detection timing DT cannot be obtained, the timing of the next drive pulse PW to be supplied is advanced.
[0027]
An example in which the drive pulse PW is supplied under the control of the drive control unit 25 in the timing device 1 of the present example will be described in more detail based on the timing chart shown in FIG. In step ST1, a driving pulse PW for fast-forward is supplied at time t1, and when the driving pulse PW becomes low level at time t2, a mask period τ0 is opened from time t1 in step ST2, and then, detection is performed at time t3 in step ST3. The coil 71 is short-circuited to detect the back induced voltage. By providing the mask period τ0, noise such as spikes generated by the drive pulse PW is not chopper-amplified, so that highly reliable detection timing DT can be obtained. When the detection timing DT is obtained at time t4 in step ST4, the next drive pulse PW having a different polarity is supplied at time t5 after the delay time d0 has been opened in step ST5, and fast-forwarding is continuously performed.
[0028]
After the drive pulse is supplied, when the counter-induced voltage is detected from time t6 in the same manner as described above, the chopper-amplified counter-induced voltage may not reach level L due to some factors. In this case, in the fast-forward function 28 of this example, in step ST6, the elapsed time I from the time t5 at which the drive pulse PW was output is measured, and when the elapsed period I corresponding to the power supply voltage V of the drive pulse PW has elapsed. Stop the rotation detection. Then, the next forcibly driving pulse PW is forcibly output at time t7 when the elapsed period I has elapsed. In this step ST6, the drive control circuit 25 monitors the power supply voltage by the signal φ12, so that the period I corresponding to the power supply voltage V can be set by a table or a function I (V) based on the graph of FIG. For this reason, the timing at which the next drive pulse PW having a different polarity is forcibly output depends on the power supply voltage of the drive pulse, and is output earlier when the power supply voltage V is higher and later when the power supply voltage V is lower. You. As described above, since the power supply voltage V and the rotational speed of the rotor 13 are related to each other, such control may not be as appropriate as when the detection timing DT is obtained. The next drive pulse PW can be supplied at a timing that matches the rotational position of. Therefore, when the rotation of the next drive pulse PW is detected at time t8, the detection timing DT is obtained at time t9, and thereafter the detection timing DT is similarly obtained at time t12. It can be carried out.
[0029]
On the other hand, when the detection timing DT cannot be obtained, it is also possible to forcibly supply the next drive pulse having a different polarity at a fixed timing regardless of the power supply voltage. However, since control relating to the rotation speed of the rotor 13 cannot be performed, the timing of the next drive pulse may be too early or too late for the rotation position of the rotor 13. For this reason, the rotor 13 cannot be rotated, or even if the rotor 13 can be rotated, the timing for detecting the next counter-induced voltage becomes uncertain, and a series of control operations for driving the rotor causes rapid traverse such that the detection timing cannot be obtained again. It is likely to progress in a direction that makes it unstable. However, in this example, as described above, the timing of the drive pulse can be controlled based on a factor related to the rotation speed of the rotor 13 even when the detection timing is not obtained. Therefore, more stable fast-forward control can be performed.
[0030]
FIGS. 5 and 6 show the case where the driving pulse PW for fast-forward is supplied by a method different from the above. In the present example, the rotation of the rotor 13 is detected after the drive pulse PW for fast-forward is raised, and the drive pulse PW falls when the detection timing DT is obtained, and the pulse width of the drive pulse PW is detected at the detection timing DT. Is to be able to decide. Therefore, the effective power of the driving pulse PW can be controlled by the detection timing DT, that is, the position of the rotor 13 together with the timing of outputting the driving pulse PW.
[0031]
In this example, the stepping motor 10 is controlled by the fast-forward control function 28 as follows. First, when the drive pulse PW for fast-forwarding is raised at time t21 in step ST11, after the mask time τ1 elapses in step ST12, the detection circuit 71 is short-circuited by the connection circuit 72 at time t22 in step ST13 to detect rotation. Do. Then, when the detection timing DT is obtained at time t23 in step ST14, the drive pulse PW for fast forward falls at that timing in step ST16. Then, after opening the delay time d1 in step ST17, the process returns to step ST11, and at time t24, the next drive pulse PW of the opposite polarity is raised. Therefore, the drive pulse PW is continuously supplied until the rotation of the rotor 13 is detected, and when the rotation is detected, the drive pulse PW stops and the next drive pulse PW is supplied after the delay time d1. For this reason, the driving pulse PW of the timing and the effective power according to the rotation state of the rotor of the stepping motor 10 is supplied, and the stepping motor can be fast-forwarded stably.
[0032]
In the control method for supplying the driving pulse for fast-forwarding as described above, if the detection timing of the rotor 13 cannot be obtained for some reason, the driving pulse PW continues to be output, so that the rotor 13 is restrained and the rotor 13 stops. . If the timing of lowering the drive pulse PW is shifted, the effective power of the drive pulse PW does not match the rotation speed of the rotor, and the timing at which the next drive pulse is supplied is shifted.
[0033]
For this reason, in this example, when the detection timing is not obtained in step ST14, a predetermined period I is set in step ST15, and when the period I elapses, the drive pulse PW is forced to fall and the delay time is set. After the elapse, the next reverse-polarity drive pulse is started up. Then, the period I can be changed by the power supply voltage V of the drive pulse in the same manner as in the above-described control method, so that even when the detection timing is not obtained, a factor related to the rotation speed of the rotor can be taken into the control. . For example, in FIG. 5, after the drive pulse PW rises at the time t25, if the detection timing is not obtained despite the start of the position detection from the time t26, the drive is performed at the time t27 when the period I has elapsed from the time t25. The pulse width of the drive pulse PW is determined by forcibly falling the pulse PW. Then, at the time t28 after the delay time d1, the next reverse-polarity drive pulse PW is raised to enable the rapid traverse to be stably continued.
[0034]
Therefore, in the control of this example, when the power supply voltage V of the drive pulse is high, a drive pulse having a narrow pulse width is supplied at short intervals, and when the power supply voltage is low, a drive pulse having a wider pulse width is supplied at wide intervals. You. When the power supply voltage is high, the rotor is rotating at a high speed. By supplying the power at an early timing, it is possible to supply a drive pulse matching the speed of the rotor. On the other hand, when the power supply voltage is low, the rotor is rotating at a relatively low speed, so that the power can be supplied at a timing that matches the speed of the rotor by supplying the power at a late timing. Furthermore, the pulse width of the drive pulse is narrow when the power supply voltage is high and wide when the power supply voltage is low, so that substantially constant effective power is supplied, and the rapid traverse speed is reduced without abrupt speed change. It can be maintained stably.
[0035]
Such a difference in the power supply voltage V occurs when the voltage of the battery goes up and down. For example, in this example, the voltage of the power supply 41 of the supercapacitor fluctuates depending on the amount of charge by the power generator 40. Further, in the timekeeping device 1 of the present embodiment, the power supply voltage can be controlled by the step-up / down circuit 49 in accordance with conditions such as when the rotor is to be accelerated or decelerated, or when the rotor is to be fast forwarded reliably. As a result, the power supply voltage of the driving pulse also fluctuates. However, in any case, in this example, when the detection timing cannot be obtained, the drive pulse can be supplied at a timing considering the power supply voltage, so that the fast-forward can be continuously performed in a stable state. .
[0036]
Note that the waveforms of the drive pulse PW, the chopper pulse, and the like described above are merely examples, and it is needless to say that the waveforms can be set in accordance with the characteristics of the stepping motor 10 employed in the timing device. Further, in the above-described example, the present invention is described using a two-phase stepping motor suitable for a timing device as an example. However, it is needless to say that the present invention can be similarly applied to a three-phase or more stepping motor. . Also, instead of performing control common to each phase, it is also possible to supply a drive pulse with a pulse width and timing suitable for each phase. Also, the driving method of the stepping motor is not limited to one-phase excitation, but may be two-phase excitation or 1-2-phase excitation. Further, the present invention is not limited to a clock device such as a wristwatch device, but may be applied to a multifunction timepiece such as a chronograph and other electronic devices having a built-in stepping motor.
[0037]
【The invention's effect】
As described above, in the present invention, the power supply voltage of the drive pulse is added to one of the factors for controlling the timing of the drive pulse, and when the rotor is not rotating regularly, for example, the drive pulse Even if the position of the rotor cannot be determined during fast-forwarding by self-excited drive that supplies the next drive pulse based on the timing, the rotor speed is considered even after the rotor position is detected. Thus, the timing of the driving pulse can be determined. Therefore, it is possible to provide an electronic device suitable for a timekeeping device having a function of automatically performing time adjustment using the stepping motor and a method of controlling the same, in which fast-forwarding of the stepping motor can be performed stably at high speed. .
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a timing device provided with a stepping motor according to an embodiment of the present invention.
FIG. 2 is a timing chart showing an operation of a fast-forward function of the control drive circuit shown in FIG.
FIG. 3 is a flowchart showing a control operation of a fast-forward function shown in FIG. 2;
FIG. 4 is a graph showing a period set by a power supply voltage of a driving pulse.
FIG. 5 is a timing chart showing different operations of the fast-forward function.
FIG. 6 is a flowchart showing a control operation of the fast-forward function shown in FIG.
FIG. 7 is a diagram schematically showing how a rotor rotates in a stator.
8 is a diagram schematically showing a change in current of a driving coil when the rotor rotates as shown in FIG. 7, and a change in a counter-induced current generated with the change.
[Explanation of symbols]
1 .. Timing device
10. Stepping motor
11. Drive coil
12. Stator
13. Rotor
17. Magnetic saturation
19. Coil section
20 Control device
21 ・ ・ Crystal oscillator
22..Pulse synthesis circuit
25 ·· Drive control circuit
26 ... Normal hand movement function
28..Fast forward function
30..Drive circuit
40 ・ ・ Power generator
41 ... power supply
49 ・ ・ Step-up / step-down circuit
50 ... train wheel
51 ... Fifth car
52 ... 4th car
53 ... Third car
54 ... second car
55 ...
56 ...
61 second hand
62 minute hand
63 hour hand
71 ・ ・ Detection coil
72 ... Connection circuit
75 ・ ・ Detection circuit

Claims (4)

A stepping motor capable of rotationally driving a multipolar magnetized rotor in a stator having a driving coil,
Drive control means capable of supplying a drive pulse for driving the rotor to the drive coil;
Power supply means serving as a power source of the drive pulse,
Having position detection means capable of detecting the back-induced power excited by the rotation of the rotor,
The drive control means includes a fast-forward control unit that supplies a drive pulse for fast-forward with a short interval with respect to a normal drive pulse,
The fast-forward control unit determines the output timing of the drive pulse for fast-forward based on the detection timing detected by the position detection unit, and when the detection timing is not obtained, the high-speed And outputting the next drive pulse for fast-forwarding, and outputting the driving pulse for fast-forwarding at a late timing when the power supply voltage is low. 2. The electronic device according to claim 1, wherein the power supply unit includes a voltage control unit capable of increasing or decreasing the power supply voltage. A method for controlling an electronic device having a stepping motor capable of rotating and driving a multi-polar magnetized rotor in a stator having a driving coil,
  When supplying a drive pulse for driving the rotor to the drive coil, a driving step of changing the timing of the drive pulse based on the power supply voltage of the drive pulse,
  Having a position detection step capable of detecting the back induced power excited by the rotation of the rotor,
  The driving step includes a fast-forward step of supplying a drive pulse for fast-forward with a short interval with respect to a normal drive pulse,
  In the fast-forwarding step, the timing at which the drive pulse for fast-forwarding is output is determined based on the detection timing detected in the position detecting step. When the detection timing is not obtained, if the power supply voltage is high, the next And outputting the driving pulse for fast-forwarding at a later timing when the power supply voltage is low. 4. The control method for an electronic device according to claim 3, further comprising a voltage control step of increasing or decreasing a power supply voltage of the drive pulse.

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