JP2010043949A - Stepping motor control circuit and analog electronic timepiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve appropriate rotational drive in accordance with temperature changes in a stepping motor control circuit. <P>SOLUTION: A predetermined current is supplied to a drive coil of a stepping motor 105 from a constant current drive circuit 108. The voltage generated in the drive coil is detected by a comparison circuit 106. A temperature determination section 110 of a control circuit 103 determines the ambient temperature of the stepping motor 105 on the basis of the comparison result of the comparison circuit 106. The control circuit 103 selects a principal drive pulse P1 having a pulse width corresponding to the determined temperature. A motor drive circuit 104 rotationally drives the stepping motor 105 by the selected principal drive pulse P1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stepping motor control circuit and an analog electronic timepiece using the stepping motor control circuit.

  Conventionally, it has a rotor housing hole and a stator having a positioning portion for determining the stop position of the rotor, a rotor disposed in the rotor housing hole, and a drive coil, and supplies an alternating signal to the drive coil. A stepping motor that rotates the rotor by generating magnetic flux in the stator and stops the rotor at a position corresponding to the positioning portion is used in an analog electronic timepiece or the like.

FIG. 10 is a configuration diagram of a general stepping motor used in an analog electronic timepiece.
In FIG. 10, a stepping motor 102 is wound around a stator 201 having a rotor accommodating through hole 203, a rotor 202 rotatably disposed in the rotor accommodating through hole 203, a magnetic core 210 joined to the stator 201, and a magnetic core 210. A rotated drive coil 211 is provided. When the stepping motor 102 is used in an analog electronic timepiece, the stator 201 and the magnetic core 210 are fixed to a base plate (not shown) with screws (not shown) and joined to each other. The drive coil 211 has a first terminal O1 and a second terminal O2.

The rotor 202 is magnetized to two poles (S pole and N pole). Two notches (outer notches) 206 and 207 are provided on the outer end portion of the stator 201 formed of a magnetic material at positions facing each other with the rotor accommodating through hole 203 interposed therebetween. Saturable portions 208 and 209 are provided between the outer notches 206 and 207 and the rotor accommodating through hole 203.
The saturable portions 208 and 209 are configured so as not to be magnetically saturated by the magnetic flux of the rotor 202 but to be magnetically saturated and increase in magnetic resistance when the drive coil 211 is excited. The rotor accommodating through hole 203 is formed in a circular hole shape in which two half-moon-shaped notches (inner notches) 204 and 205 are integrally formed at a portion opposite to a through hole having a circular outline.

The notches 204 and 205 constitute a positioning part for determining the stop position of the rotor 202. In a state where the drive coil 211 is not excited, the rotor 202 is at a position corresponding to the positioning portion, in other words, at a position where the magnetic pole axis A of the rotor 202 is orthogonal to the line segment connecting the notches 204 and 205. Stops stably.
Now, the main drive pulse P1 is supplied between the terminals O1 and O2 of the drive coil 211 (for example, the first terminal O1 side is positive and the second terminal O2 side is negative), and the current i flows in the direction of the arrow in FIG. Then, a magnetic flux is generated in the stator 201 in the direction of the broken arrow. As a result, the saturable portions 206 and 207 are saturated to increase the magnetic resistance, and then the rotor 202 rotates 180 degrees in the direction of the arrow in FIG. 10 due to the interaction between the magnetic pole generated in the stator 201 and the magnetic pole of the rotor 202. And stop stably at that position.

Next, the main drive pulse P1 having the reverse polarity is supplied to the terminals O1 and O2 of the drive coil 211 (the first terminal O1 side is the negative electrode and the second terminal O2 side is the positive electrode so that the polarity is opposite to that of the drive). ), When a current is passed in the opposite direction, a magnetic flux is generated in the stator 201 in the opposite direction. As a result, the saturable portions 208 and 209 are first saturated, and then the rotor 202 rotates 180 degrees in the same direction as described above due to the interaction between the magnetic pole generated in the stator 201 and the magnetic pole of the rotor 202, as shown in FIG. Stops stably in position.
Thereafter, by supplying signals having different polarities (alternating signals) to the drive coil 211 in this way, the above operation is repeated, and the rotor 202 can be continuously rotated 180 degrees in the direction of the arrow. It is configured to be able to.

  In the stepping motor described above, when the ambient temperature is equal to or lower than a certain temperature, the viscosity of the oil used is increased, and therefore friction and load are increased. Further, when the ambient temperature is equal to or higher than a certain temperature, the resistance value of the drive coil for driving the stepping motor increases. Therefore, when the pulse width of the drive pulse is a constant value, the minimum drive voltage of the drive pulse for rotationally driving the stepping motor increases as the temperature drops below a certain temperature as shown by the characteristic B in FIG. It has a characteristic that it becomes higher as the temperature rises above a certain temperature. Therefore, when the stepping motor is rotationally driven by a main drive pulse having a constant pulse width regardless of the temperature, if the temperature falls below a certain value or exceeds a certain value, the drive energy becomes insufficient and rotational driving becomes difficult. There is a problem of becoming.

As the rotation driving method of the stepping motor, the stepping motor is driven to rotate by the main driving pulse P1, and the rotation is forcibly rotated by the correction driving pulse P2 when the rotation of the stepping motor is detected and determined to be non-rotating. A method is known (see, for example, Patent Document 1).
Patent Document 2 discloses a motor drive device that detects a rotation of a stepping motor by changing a reference voltage according to temperature in order to prevent the influence of a change in the viscosity of the lubricating oil. ing. For example, when the temperature is lower than −10 ° C., Vcomp2 lower than the normal reference voltage Vcomp1 is selected, and rotation detection is performed in comparison with the induced voltage Vrs. Although the reference voltage is changed according to the temperature, the main drive pulse P1 is not directly changed according to the temperature, so that it is difficult to quickly rotate the motor smoothly. Further, since a temperature sensor, a sensor driving circuit, and an analog / digital (A / D) conversion circuit are separately required, there is a problem in that there is a limit to reduction in consumption and size.

  On the other hand, Patent Document 3 discloses an electric actuator device that detects the coil temperature based on a correlation function between a coil resistance value and a coil temperature. While measuring the coil temperature of a motor correctly and monitoring coil temperature, when it becomes more than the preset temperature, it is comprised so that a drive of an actuator may be restrict | limited or stopped. Thereby, the motor drive can be changed according to the temperature, but the drive of the actuator is simply limited or stopped, and it is not an invention for appropriately rotating the motor according to the temperature change.

Patent Document 4 discloses a method for monitoring and controlling the temperature of a heating device to which a current is supplied. In the invention described in Patent Document 4, the temperature is detected from the resistance value using a measurement current pulse having a constant known value, and the drive current pulse length of the heat generating device is controlled. Although it is configured to change the drive pulse length, the field is different from the invention related to motor control and is not related to motor control.
Patent Document 5 discloses an invention relating to a resistance measurement circuit, a resistance measurement method, and the like. In the invention described in Patent Document 5, the resistance is measured using a constant current power supply. However, as in Patent Document 4, the field is different from motor control and is not related to motor control.

Japanese Patent Publication No. 61-15385 JP 2004-177172 A Japanese Patent Laid-Open No. 2004-328554 Japanese Patent Laid-Open No. 10-512989 Japanese Patent Laid-Open No. 2005-30828

The present invention has been made in view of the above problems, and an object of the present invention is to enable a stepping motor control circuit to appropriately perform rotational driving in accordance with a temperature change.
Another object of the present invention is to reduce the size and power consumption of a stepping motor control circuit.
Another object of the present invention is to provide an analog electronic timepiece using the stepping motor control circuit.

According to the present invention, the driving means for rotationally driving the stepping motor by the main driving pulse or the correction driving pulse corresponding to the control signal, and the stepping motor when the driving means rotationally drives the stepping motor by the main driving pulse. A rotation detecting means for detecting whether or not the stepping motor has rotated by comparing an induced voltage generated at a predetermined reference voltage for rotation detection and the driving means according to a detection result of the rotation detecting means. A stepping motor control circuit comprising a control means for selecting a main driving pulse or a correction driving pulse for rotating the motor and outputting the control signal corresponding to the selected driving pulse, and detecting an ambient temperature of the stepping motor Temperature detecting means for performing the control, and the control means detects the temperature detecting means. It was selected main drive pulse of energy according to the ambient temperature of the stepping motor, the stepping motor control circuit and outputs the control signal corresponding to the main drive pulse is provided.
The control means selects a main drive pulse of energy corresponding to the ambient temperature of the stepping motor detected by the temperature detection means, and outputs a control signal corresponding to the main drive pulse.

Here, the temperature detecting means may be configured to indirectly measure the ambient temperature of the stepping motor by measuring the resistance of the driving coil of the stepping motor.
The temperature detection means compares a current source that supplies a predetermined DC current to the drive coil, a coil voltage that is a voltage generated in the drive coil by the DC current, and a temperature detection reference voltage corresponding to the temperature. Determination means for determining the coil voltage, and the control means selects a main drive pulse of energy corresponding to the coil voltage determined by the determination means, and outputs the control signal corresponding to the main drive pulse. You may comprise so that it may output.

A plurality of temperature detection reference voltages are prepared, and the determination means determines the value of the coil voltage by determining a magnitude relationship between the coil voltage and the plurality of temperature detection reference voltages. The control means may be configured to select a main drive pulse of energy corresponding to the value of the coil voltage determined by the determination means, and to output the control signal corresponding to the main drive pulse.
Further, two types of temperature detection reference voltages are prepared, and the control means applies main drive pulses of the same energy to coil voltages in each region divided by the two types of temperature detection reference voltages. May be selected.

In addition, as the temperature detection reference voltage, a first reference voltage and a second reference voltage higher than the first reference voltage by a predetermined value are prepared, and the control means is configured such that the coil voltage is equal to the first reference voltage and the first reference voltage. The main drive pulse may be selected so that the energy increases in the order of two reference voltages, the second reference voltage or more, and the first reference voltage or less.
The temperature detection means detects the ambient temperature of the stepping motor before the drive means rotates the stepping motor, and the control means responds to the ambient temperature of the stepping motor detected by the temperature detection means. It is also possible to select a main drive pulse of the selected energy and output the control signal corresponding to the main drive pulse.

  According to the present invention, in the analog electronic timepiece having a stepping motor that rotationally drives the time hand and a stepping motor control circuit that controls the stepping motor, the stepping motor control circuit according to any one of the above An analog electronic timepiece using a stepping motor control circuit is provided.

According to the stepping motor control circuit of the present invention, it is possible to appropriately perform rotational driving in accordance with a temperature change. In addition, it is possible to reduce the size and power consumption.
In addition, according to the analog electronic timepiece according to the invention, it is possible to appropriately perform the rotational drive in accordance with the temperature change, and thus it is possible to perform an accurate time-measurement driving operation. In addition, it is possible to reduce the size and power consumption.

Hereinafter, a stepping motor control circuit and an analog electronic timepiece according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same parts are denoted by the same reference numerals.
FIG. 1 is a block diagram of an analog electronic timepiece using a stepping motor control circuit according to an embodiment of the present invention, and shows an example of an analog electronic wristwatch.
In FIG. 1, an analog electronic timepiece includes an oscillation circuit 101 that generates a signal of a predetermined frequency, a frequency dividing circuit 102 that divides the signal generated by the oscillation circuit 101 and generates a clock signal that serves as a time reference, and an electronic timepiece. A control circuit 103 that performs control of each electronic circuit element that is configured, control of change of drive pulse, and the like; a motor drive circuit 104 that outputs a drive pulse for driving motor rotation based on a control signal from the control circuit 103; and motor drive A stepping motor 105 that is driven by a driving pulse from the circuit 104 to rotationally drive a time hand or the like (not shown), and a comparison circuit that compares an induced voltage generated according to the rotation state of the stepping motor 105 with a predetermined reference voltage Vcomp. 106, a reference voltage circuit 107 for generating the predetermined reference voltage, and a resistance of a driving coil of the stepping motor 105 And a constant current driving circuit 108 for outputting a predetermined constant current when measuring the.

The control circuit 103 determines whether or not the stepping motor 105 has rotated based on the comparison result of the comparison circuit 106, and determines the ambient temperature of the stepping motor 105 based on the resistance value of the drive coil of the stepping motor 105. A temperature determining unit 110 for determining is provided.
The stepping motor 105 is a stepping motor having a general configuration shown in FIG. As shown in FIG. 8, the drive coil 211 of the stepping motor 105 has a characteristic that the resistance value increases as the temperature rises. Therefore, by detecting the resistance value of the drive coil 211, It is possible to indirectly detect the ambient temperature.

The reference voltage circuit 107 is a reference voltage used for detecting the rotation detection reference voltage Vcompk, which is a reference voltage used when detecting whether or not the stepping motor 105 has rotated, and the ambient temperature of the stepping motor 105. The temperature detection reference voltage Vcompt is output to the reference input unit of the comparison circuit 106.
When detecting the rotation, the comparison circuit 106 detects a detection signal corresponding to an induced voltage exceeding a predetermined rotation detection reference voltage Vcompk when the stepping motor 105 rotates, and when the stepping motor 105 does not rotate. The rotation detection reference voltage Vcompk is set so that the detection signal corresponding to the induced voltage does not exceed the rotation detection reference voltage Vcompk.

The temperature detection reference voltage Vcompt is set with a plurality of reference voltages (in this embodiment, reference voltages Vcompt1 and Vcompt2 corresponding to two temperatures T1 and T2 (T1 <T2)).
The reference voltage Vcompk for rotation detection and the reference voltage Vcompt for temperature detection may be different reference voltages or different reference voltages.
The oscillation circuit 101 and the frequency dividing circuit 102 constitute signal generating means. The motor drive circuit 104 constitutes drive means. The comparison circuit 106, the reference voltage circuit 107, and the rotation determination unit 109 constitute rotation detection means. The comparison circuit 106 and the reference voltage circuit 107 constitute determination means. The comparison circuit 106, the reference voltage circuit 107, the constant current drive circuit 108, and the temperature determination unit 110 constitute a temperature detection unit. The control circuit 103 constitutes a control means.

FIG. 2 is a circuit diagram showing a part of the motor drive circuit 104, the comparison circuit 106, the reference voltage circuit 107, and the constant current drive circuit 108 in detail.
In FIG. 2, N-channel MOS transistors Q1 and Q2, and P-channel MOS transistors Q3 to Q6 are components of the motor drive circuit 104. The source connection points of the transistors Q1 and Q3, the source connection points of the transistors Q2 and Q4, and Between them, the drive coil 211 of the stepping motor 105 is connected.
The detection resistor 301 connected in series to the transistor Q5, the detection resistor 302 connected in series to the transistor Q6, and the comparator 303 are components of the comparison circuit 106. The N-channel transistors Q7 and Q8 and the current source 304 that outputs a predetermined current are components of the constant current driving circuit 108.

The gates of the transistors Q1 to Q8 are on / off controlled by the control circuit 103. A connection point O2 between the detection resistor 301 and the drive coil 211 and a connection point O1 between the detection resistor 302 and the drive coil 211 are connected to an input unit of the comparator 303 in the comparison circuit 106.
When detecting rotation, the comparator 303 compares a detection signal corresponding to the induced voltage generated by the stepping motor 105 with a rotation detection reference voltage Vcompk input to the reference input unit, and outputs a rotation determination signal representing a comparison result. Output. The rotation determination unit 109 of the control circuit 103 determines whether or not the stepping motor 105 has rotated based on the rotation determination signal from the comparator 303.

  Further, the comparator 303 compares the coil voltage generated in the drive coil 211 of the stepping motor 105 with the temperature detection reference voltages Vcompt1 and Ccompt2 input to the reference input unit at the time of temperature detection, and represents a comparison result. Outputs a judgment signal. The temperature determination unit 110 of the control circuit 103 determines the ambient temperature of the stepping motor 105 based on the temperature determination signal from the comparator 303. In the present embodiment, two types of temperature detection reference voltages Vcompt are prepared. As will be described later with reference to FIG. 9, coil voltages in each region divided by the two types of temperature detection reference voltages Vcompt1 and Vcompt2. For this, the main drive pulses P11 to P13 having the same energy are selected.

  The transistor Q3 is a first switch element, the transistor Q1 is a second switch element, the transistor Q4 is a third switch element, the transistor Q2 is a fourth switch element, the transistor Q5 is a fifth switch element, the transistor Q6 is a sixth switch element, The transistor Q7 constitutes a seventh switch element, the transistor Q8 constitutes an eighth switch element, the detection resistor 301 constitutes a first detection element, and the detection resistor 302 constitutes a second detection element. The transistor Q5 and the detection resistor 301 constitute a first series circuit, and the transistor Q6 and the detection resistor 302 constitute a second series circuit.

3 to 6 are partial detailed circuits shown in FIG. 2, respectively, when the stepping motor 105 is stopped, when the temperature of the ambient temperature of the stepping motor 105 is detected, when the stepping motor 105 is normally rotated, and the stepping is performed. FIG. 7 is a timing diagram showing the timing of each operation. FIG. 7 is an operation explanatory diagram showing an operation at the time of detecting rotation for detecting whether or not the motor 105 has rotated.
FIG. 9 is a characteristic diagram showing the relationship between the pulse width of the main drive pulse P1 used in the present embodiment and the ambient temperature. Main drive pulses P11 and P12 having the same energy are applied to the coil voltages in the respective regions divided by the temperature T1 corresponding to the first temperature detection reference voltage Vcompt1 and the temperature T2 corresponding to the first temperature detection reference voltage Vcompt2. , P13 is selected. The energy (pulse width in this embodiment) is P11 <P12 <P13. Since the load at the low temperature becomes larger than that at the high temperature due to the viscosity or the like, the driving energy at the low temperature is maximized.

Hereinafter, the stepping motor control circuit and the analog electronic timepiece according to the present embodiment will be described with reference to FIGS.
First, when the stepping motor 105 is braked and stopped, the control circuit 103 drives the gates a and b of the transistors Q3 and Q4 to a low level to turn on the transistors Q3 and Q4 as shown in FIG. As a result, the drive coil 211 of the stepping motor 105 and the transistors Q3 and Q4 constitute a closed loop, and the drive coil 211 is short-circuited.

  Next, when detecting the ambient temperature of the stepping motor 105 (that is, the resistance value of the drive coil 211), the control circuit 103 sets the gates of the transistors Q3 and Q8 to low level and high level, respectively, as shown in FIGS. By driving to the level, the transistors Q3 and Q8 are driven to be turned on, and the other transistors Q1, Q2, and Q4 to Q7 are driven to be turned off. In this case, the control circuit 103 may be configured to drive and control only the transistors Q4 and Q7.

  As a result, a predetermined current is supplied from the current source 304 to the drive coil 211, and a drop voltage (coil voltage) corresponding to the ambient temperature is generated in the drive coil 211. The comparator 303 compares the coil voltage with the first and second temperature detection reference voltages Vcompt1 and Vcompt2 from the reference voltage circuit 107 under the control of the control circuit 103, and outputs a temperature determination signal representing the comparison result. The temperature determination signal is less than the first temperature detection reference voltage Vcompt1 (corresponding to less than the first temperature T1), greater than or equal to the first temperature detection reference voltage Vcompt1 and less than the second temperature detection reference voltage Vcompt (greater than or equal to the first temperature T1). Or a second temperature detection reference voltage Vcomp2 or higher (corresponding to a second temperature T2 or higher).

In the present embodiment, as shown in FIG. 9, when the ambient temperature of the stepping motor 105 is equal to or higher than the first temperature T1 and lower than the second temperature T2, the main driving pulse P11 of the first energy is equal to or higher than the second temperature T2. Is driven by the main drive pulse P12 of the second energy, and when it is lower than the first temperature T1, it is driven by the main drive pulse P13 of the third energy.
Based on the temperature determination signal from the comparator 303, the control circuit 103 determines the energy (pulse width in this embodiment) of the main drive pulse P1 as one of the main drive pulses P11 to P13, and rotates the stepping motor 105. At the time of driving, the motor driving circuit 104 is controlled so as to rotationally drive the stepping motor 105 by the main driving pulses P11 to P13 having the determined energy.

  That is, at the time of hand movement (rotational driving), the control circuit 104 rotationally drives the stepping motor 105 by the main drive pulse P1 selected by driving the transistors Q3 and Q2 on as shown in FIGS. In the next cycle, the transistors Q4 and Q1 are driven to turn on and driven by the selected main drive pulse P1 so that a reverse polarity current flows through the drive coil 211. Thereafter, before each stepping motor 105 is driven, the ambient temperature is measured to determine the corresponding main drive pulse P1, and the drive is rotated while alternately switching the drive polarity by the determined main drive pulse P1. The determination operation of the main drive pulse P1 corresponding to the ambient temperature is not necessarily performed every time for each drive, and can be changed such as performed every predetermined number of times.

Next, when detecting whether or not the stepping motor 105 has rotated, the control circuit 103 drives and controls the transistors Q3 and Q6 to be on and switches the transistor Q4 at a predetermined cycle as shown in FIGS. To drive. When the driving is reverse polarity, the transistors Q4 and Q5 are controlled to be turned on and the transistor Q3 is switched.
As a result, a detection signal corresponding to the induced voltage generated by the rotation of the stepping motor 105 is generated in the detection resistor 302. The comparator 303 compares the detection signal with the rotation detection reference voltage Vcompk from the reference voltage circuit 107 under the control of the control circuit 103, and outputs a rotation determination signal representing the comparison result. The rotation determination signal is a signal representing a magnitude relationship with the rotation detection reference voltage Vcompk.

The rotation determination unit 109 of the control circuit 103 determines whether or not the stepping motor 105 has rotated based on the rotation determination signal. When it is determined that the stepping motor 105 has rotated, it detects the temperature of the next cycle as described above. When it is determined that the motor has not been rotated, the motor driving circuit 104 is controlled to be driven to rotate by the correction driving pulse P2 having a pulse width larger than that of the main driving pulse P1, and the motor driving circuit 104 is driven to rotate.
In this way, by driving by changing the energy of the main drive pulse P1 according to the ambient temperature, the minimum drive voltage at the low temperature and at the high temperature can be lowered as shown by the characteristic A in FIG. Even if the ambient temperature changes, the main drive pulse can be driven to rotate more reliably, and the drive by the correction drive pulse is reduced, so that the power consumption can be reduced.

As described above, according to the stepping motor control circuit according to the present embodiment, a predetermined current is supplied from the constant current driving circuit 108 to the driving coil 211 of the stepping motor 105, and the direct current generated by the comparison circuit 106 in the driving coil 211. The DC voltage level is detected by comparing the voltage with a predetermined reference voltage, the temperature determination unit 110 of the control circuit 103 determines the ambient temperature of the stepping motor 105 based on the comparison result of the comparison circuit 106, and the control circuit 103 Determines a main drive pulse having a pulse width corresponding to the determined temperature, and the motor drive circuit 104 is configured to rotationally drive the stepping motor 105 by the determined main drive pulse.
Therefore, the main drive pulse of energy corresponding to the ambient temperature of the stepping motor is selected and rotationally driven, so that the rotational drive can be appropriately performed according to the temperature change.

In addition, when the temperature sensor is used, the number of parts and the circuit are complicated, so there is a limit to downsizing and low consumption. However, in this embodiment, a current is supplied from the constant current drive circuit 108 to the drive coil 211. Since the temperature is detected based on the coil voltage supplied and generated in the drive coil 211, a temperature sensor and its control circuit are not required, and an integrated circuit (IC) can be realized, thereby reducing the size and the consumption. Electricity can be achieved.
In addition, an analog electronic timepiece using the stepping motor control circuit can be provided.

In the above-described embodiment, the pulse width is changed in order to change the energy of each main drive pulse P1, but the drive energy can also be changed by changing the pulse voltage. When the main drive pulse P1 is a comb-like drive pulse composed of a plurality of pulses, the drive energy may be changed by changing the duty ratio of the pulse or by changing the number of pulses.
In addition to the time hand, the present invention can be applied to a stepping motor for driving a chronograph hand, a calendar and the like.
Moreover, although the example of the electronic timepiece has been described as an application example of the stepping motor, it can be applied to an electronic device using the motor.

The stepping motor control circuit according to the present invention is applicable to various electronic devices that use the stepping motor.
The electronic timepiece according to the present invention can be applied to various analog electronic timepieces, including analog electronic timepieces with various calendar functions such as an analog electronic wristwatch with a calendar function and an analog electronic table clock with a calendar function.

1 is a block diagram of an analog electronic timepiece according to an embodiment of the present invention. It is a partial circuit block diagram of the stepping motor control circuit which concerns on embodiment of this invention. It is operation | movement explanatory drawing of the stepping motor control circuit which concerns on embodiment of this invention. It is operation | movement explanatory drawing of the stepping motor control circuit which concerns on embodiment of this invention. It is operation | movement explanatory drawing of the stepping motor control circuit which concerns on embodiment of this invention. It is operation | movement explanatory drawing of the stepping motor control circuit which concerns on embodiment of this invention. It is a timing diagram of the stepping motor control circuit which concerns on embodiment of this invention. It is explanatory drawing of the stepping motor control circuit which concerns on embodiment of this invention. It is a characteristic view of the stepping motor control circuit which concerns on embodiment of this invention. It is a block diagram of the stepping motor used for embodiment of this invention. It is a characteristic view of the stepping motor control circuit which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Oscillator 102 ... Frequency divider 103 ... Control circuit 104 ... Motor drive circuit 105 ... Stepping motor 106 ... Comparison circuit 107 ... Reference voltage circuit 108 ... Constant Current drive circuit 109 ... rotation determination unit 110 ... temperature determination unit 201 ... stator 202 ... rotor 203 ... rotor accommodating through holes 204, 205 ... notches (inner notches)
206, 207 ... Notch (outer notch)
208, 209, saturable portion 210, magnetic core 211, drive coil O1, first terminal O2, second terminals Q1-Q8, transistors 301, 302, detection resistors. 303: Comparator 304 ... Current source

Claims (8)

Drive means for rotationally driving the stepping motor by a main drive pulse or correction drive pulse corresponding to the control signal; and an induced voltage generated by the stepping motor when the drive means rotationally drives the stepping motor by the main drive pulse; Rotation detection means for detecting whether or not the stepping motor has rotated by comparing a predetermined reference voltage for rotation detection, and main means for driving the rotation of the stepping motor by the drive means according to the detection result of the rotation detection means. In a stepping motor control circuit comprising a control means for selecting a drive pulse or a correction drive pulse and outputting the control signal corresponding to the selected drive pulse,
Temperature detecting means for detecting the ambient temperature of the stepping motor;
The control means selects a main drive pulse of energy corresponding to the ambient temperature of the stepping motor detected by the temperature detection means, and outputs the control signal corresponding to the main drive pulse. circuit.   2. The stepping motor control circuit according to claim 1, wherein the temperature detecting means indirectly measures an ambient temperature of the stepping motor by measuring a resistance of a driving coil of the stepping motor. The temperature detection means compares a current source that supplies a predetermined DC current to the drive coil, a coil voltage that is a voltage generated in the drive coil by the DC current, and a temperature detection reference voltage corresponding to the temperature. Determining means for determining the coil voltage;
3. The stepping motor according to claim 2, wherein the control means selects a main drive pulse of energy corresponding to the coil voltage determined by the determination means, and outputs the control signal corresponding to the main drive pulse. Control circuit. A plurality of the temperature detection reference voltages are prepared, and the determination means determines a value of the coil voltage by determining a magnitude relationship between the coil voltage and the plurality of temperature detection reference voltages,
The said control means selects the main drive pulse of the energy according to the value of the coil voltage determined by the said determination means, The said control signal corresponding to the said main drive pulse is output. Stepping motor control circuit.   Two types of temperature detection reference voltages are prepared, and the control means selects main drive pulses of the same energy for the coil voltages in each region divided by the two types of temperature detection reference voltages. The stepping motor control circuit according to claim 4 or 5, wherein As the temperature detection reference voltage, a first reference voltage and a second reference voltage that is higher than the first reference voltage by a predetermined value are prepared,
The controller drives the main drive so that the energy increases in the order of the coil voltage within the first reference voltage and the second reference voltage, when the coil voltage is greater than or equal to the second reference voltage, and less than or equal to the first reference voltage. 6. The stepping motor control circuit according to claim 5, wherein a pulse is selected. The temperature detecting means detects the ambient temperature of the stepping motor before the driving means rotationally drives the stepping motor,
The control means selects a main drive pulse of energy corresponding to the ambient temperature of the stepping motor detected by the temperature detection means, and outputs the control signal corresponding to the main drive pulse. The stepping motor control circuit according to any one of 1 to 6. In an analog electronic timepiece having a stepping motor that rotationally drives a time hand and a stepping motor control circuit that controls the stepping motor,
8. An analog electronic timepiece using the stepping motor control circuit according to claim 1 as the stepping motor control circuit.

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