JP2002058273A - Rotation control apparatus of dc motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure an effective rotation control by detecting the rotational speed and the revolutions of a DC brush motor through a simple arrangement which does not occupy a significant space. SOLUTION: A motor control circuit 15 generates a comparison reference voltage selection signal and a motor control signal being fed, respectively, to a comparison reference voltage selecting means and a motor drive circuit 12. A pulse interval measuring means 151 in the motor control circuit 15 measures the pulse interval of output pulses from a comparator 14 and delivers it to a rotational speed calculating means 152. The rotational speed calculating means 152 calculates the rotational speed of a rotor, and thereby a motor, based on the pulse interval received from the pulse interval measuring means 151. Based on a target rotational speed of the rotational speed calculating means 152, a speed-voltage converting means 153 determines a drive voltage for attaining the target rotational speed and delivers it to a variable output power supply circuit 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus which uses a direct current motor (DC motor) as a drive source for mechanical operation, and which is required to stabilize the rotational speed of the direct current motor and control the cumulative rotational speed. In particular, a pair of electrode brushes provided integrally with the stator is slidably contacted with a commutator connected to the rotor coil and provided on the rotor together with the rotor coil. Switching the DC drive voltage to supply to the rotor coil to detect at least one of the rotation direction, the rotation speed and the rotation position of the rotor in the DC motor to control the rotation operation of the rotor. The present invention relates to a preferred DC motor rotation detection device and rotation control device.

[0002]

2. Description of the Related Art For example, at least one of a photographing lens and an image forming surface is driven along an optical axis based on subject distance information such as a zoom operation for zooming a photographing lens including a zoom lens in a camera. A brush-type DC motor is often used as a driving source for mechanical operation such as focus driving for performing focusing and film feeding driving for winding and rewinding a photographic film. A brush type DC motor has a plurality of fixed magnetic poles using a permanent magnet or the like on a stator, and a plurality of rotor coils forming a plurality of rotor magnetic poles; a commutator that rotates integrally with the rotor; The DC driving voltage is switched and supplied according to the rotation angle from the stator side via a brush that comes into sliding contact with the commutator to rotate the rotor.

[0003] Such a DC motor, for example, in the case of a three-pole motor, is configured as shown in FIG. 16 and is supplied from a DC drive power source E0 via a pair of electrode brushes B01 and B02. And the commutator CM0 sliding on B02. A pair of electrode brushes B
01 and B02 are in contact with the commutator CM0 at positions different by 180 °. The commutator CM0 is provided by forming a cylindrical surface that operates integrally with the rotor. In this case, the commutator CM0 is configured by a contact piece obtained by dividing the cylindrical surface into three equal portions at approximately equal intervals of 120 °. Three rotor coils are respectively connected between adjacent contact pieces of the commutator CM0, and these rotor coils form three rotor magnetic poles. The rotor magnetic poles are made of permanent magnets on the stator side, with the polarity being changed by changing the contact state between the electrode brushes B01 and B02 and the contact pieces of the commutator CM0 according to the rotation angle. For example, a rotational driving force is generated between a pair of stator magnetic poles (not shown). With the rotation of the rotor, each rotor magnetic pole sequentially faces each stator magnetic pole and the electrode brush B0
The contact state between the contact pieces 1 and B02 and each contact piece of the commutator CM0 changes, and the polarity of each rotor magnetic pole sequentially changes, so that the rotor continuously rotates.

That is, when a voltage is applied from the power supply E0 to the pair of electrode brushes B01 and B02, a current flows from one of the electrode brushes B01 and B02 to the other through the rotor coil, and the rotor coil Generates a magnetic field to form a rotor magnetic pole. The action of the magnetic field generated by the rotor coil and the magnetic field by the stator magnetic pole causes the rotor to rotate. As a method for detecting the rotation of such a motor, a rotary encoder method is generally used. That is, the rotation is detected by providing a rotating slit disk having a slit formed on the peripheral surface thereof in the rotation output shaft of the motor or a transmission mechanism responsive thereto, and detecting the slit on the peripheral surface of the rotating slit disk with a photo interrupter. . This method can perform accurate rotation detection, but requires a rotating slit disk and a photo interrupter, which constitute a rotary encoder, and requires space and cost.

There is also a method of detecting rotation from a ripple of a current flowing through a motor as shown in FIGS. That is, as shown in FIG. 17, the driving voltage of the motor is changed from the driving power source E0 to one of the electrode brushes B0.
2, a resistor R0 is inserted in series in a power supply path for feeding power to the power supply line 2, and a terminal voltage of the resistor R0 is detected.
Obtain a periodic ripple waveform. Since this ripple waveform corresponds to the rotation angle position of the rotor, a pulse signal corresponding to the rotation angle position can be obtained by appropriately shaping the waveform. Although this method is advantageous in terms of cost and space, there is a concern in terms of detection accuracy, such as erroneous detection due to noise or the like. On the other hand, Japanese Patent Application Laid-Open No. 4-127864 discloses a method of detecting rotation by providing a rotation detection brush separately from a pair of electrode brushes. The rotation detecting brush slides on the commutator like the pair of electrode brushes, and extracts the voltage at the commutator. The rotation is detected based on the signal detected by the rotation detecting brush.

Japanese Unexamined Patent Publication No. 4-127864 discloses a configuration as shown in FIG. 19, for example. A rotation detection brush BD0 is provided separately from the pair of electrode brushes B01 and B02 of the motor M0. The rotation detecting brush BD0 includes a differentiating circuit 101,
The time constant reset circuit 102 and the time constant circuit 103 are sequentially connected. The output of the time constant circuit 103 is connected to the non-inverting input terminal of the comparator 105 in which the output of the comparison reference voltage generator 104 is connected to the inverting input terminal. The output of the comparator 105 is supplied to a relay 1 via a diode 106 having the polarity shown.
07 (the excitation coil thereof). Relay 10
7 (the excitation coil thereof) is connected to one end of the drive power source E0. The drive power source E0 has a contact 10
A pair of electrode brushes B01 and B02 are connected via 7a. The one end of the relay 107 (the excitation coil thereof) is connected to the collector of the transistor 109a of the motor starting circuit 109 via the diode 108 of the illustrated polarity. A motor start signal is supplied to the base of the transistor 109a via a resistor 109b, and a resistor 109c is connected between the base and the emitter of the transistor 109a.
Is connected. The emitter of the transistor 109a is connected to the other end of the drive power supply E0.

FIG. 20 shows a signal waveform of each part in such a configuration, that is, a motor start signal input to the motor start circuit 109 and a detection signal S of the rotation detection brush BD0.
A0, output signal SB0 of differentiating circuit 101, time constant circuit 1
03 output signal SC0 and comparator 105 output signal SD
0, the operation signal of the relay 107 and the waveforms of the drive power supply from the drive power supply E0 to the motor M0 are shown. When the transistor 109a of the motor starting circuit 109 is turned on by the motor starting signal, the relay 107 is turned on, the contact 107a is closed, and the electrode brushes B01 and B0 are turned on.
Electric power is supplied to the motor M0 via the motor 2 and the rotation of the motor M0 is started. With the rotation of the motor M0, a pulse train SA0 is output from the rotation detection brush BD0, differentiated by the differentiating circuit 101, and a signal S synchronized with the leading edge of each pulse.
B0 is supplied to the time constant reset circuit 102. The time constant reset circuit 102 resets the time constant circuit 103 in synchronization with the signal SB0.
As 0, a signal as shown in FIG. 20 is output.

In a steady state where the motor M0 is rotating at a normal rotation speed, the output signal S
C0 does not exceed the comparison reference voltage supplied from the comparison reference voltage generation unit 104. In this state, the comparator 10
5, the output signal SD0 is "L (low level)", the relay 107 is energized and keeps on, and the power supply to the motor M0 is maintained. However, when the rotation speed of the motor M0 decreases due to overload or the like, the output signal SC0 of the time constant circuit 103 exceeds the comparison reference voltage, the output signal SD0 of the comparator 105 becomes "H (high level)", and the relay 10
7 is turned off because the excitation voltage stops flowing through the contact 107.
a is opened and the power supply to the motor M0 is stopped. In this way, a decrease in the rotation speed of the motor M0 is detected, and the motor M0 is stopped to prevent an excessive current from continuously flowing through the motor M0.

[0009]

SUMMARY OF THE INVENTION The above-mentioned JP-A-4-14-1
The method disclosed in Japanese Patent No. 27864 and the like merely shows that the relay is operated only when the rotation speed of the motor is lower than a certain level. There is no clear description of a technique for detecting the rotation speed with high accuracy and using it for rotation direction control, rotation speed control, rotation speed control, and the like. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and has a simple and space-saving configuration to accurately detect the rotation speed and the number of rotations of a brush DC motor, thereby enabling effective rotation control. It is an object of the present invention to provide a rotation control device that controls a rotation speed by changing a voltage of a DC motor.

In particular, an object of claims 1 and 3 of the present invention is to provide a rotation control device for a DC motor capable of performing appropriate rotation control based on effective rotation detection with a simple configuration that does not take up space. To provide. An object of claims 2 and 4 of the present invention is to provide an appropriate rotation control that can quickly reach a target cumulative rotation speed based on effective rotation detection with a simple configuration that does not take up space. An object of the present invention is to provide a DC motor rotation control device that enables the rotation control.

[0011]

According to a first aspect of the present invention, there is provided a rotation control device for a DC motor according to the present invention, wherein the rotation control device is connected to a rotor coil together with the rotor coil. A pair of electrode brushes that are in sliding contact with a commutator provided in the motor and are supplied to the rotor coil by switching a DC drive voltage by the commutator; In the rotation control device that controls the operation, a single rotation detection brush provided on the stator side separately from the pair of electrode brushes to detect rotation of the rotor, A motor drive circuit that supplies the DC drive voltage to the brush to drive the DC motor, a DC power supply whose voltage can be changed, reference voltage generation means that generates a comparison reference voltage, and detection by the rotation detection brush. And a motor control circuit that controls the motor drive circuit in response to the output of the comparator, and wherein the motor control circuit includes the comparator A pulse interval measuring unit for measuring a pulse interval of the output pulse, a rotation speed detecting unit for determining a rotation speed of the rotor based on the pulse interval measured by the pulse interval measuring unit, and a rotation speed detection unit. Speed-voltage conversion means for calculating a voltage value of a DC drive voltage to be supplied to the pair of electrode brushes based on the rotation speed and the target rotation speed,
A drive voltage control unit that supplies the DC drive voltage corresponding to the voltage value based on the calculation result of the speed-voltage conversion unit to the motor drive circuit, controls a drive output, and sets the target rotation speed. It is characterized by:

According to a second aspect of the present invention, there is provided a rotation control device for a DC motor according to the present invention.
A pair of electrode brushes connected to the rotor coil and slidably contacting a commutator provided on the rotor together with the rotor coil, and switching the DC drive voltage by the commutator and supplying the brush to the rotor coil. A rotation control device for controlling the rotation operation of the rotor of the DC motor provided integrally with
The pair of electrode brushes are separately provided on the stator side, a single rotation detection brush for detecting rotation of the rotor, and the DC drive voltage is supplied to the pair of electrode brushes. A motor drive circuit that drives the DC motor, a DC power supply whose voltage can be changed, reference voltage generating means that generates a comparison reference voltage, and a voltage detected by the rotation detection brush and the comparison reference voltage. A comparator for comparing, and a motor control circuit for controlling the motor drive circuit in response to the output of the comparator, wherein the motor control circuit counts the number of output pulses of the comparator. Counting means; cumulative rotation number calculating means for calculating the cumulative rotation number of the rotor based on the number of pulses counted by the pulse counting means; output of the cumulative rotation number calculating means and a target cumulative rotation number; A remaining rotation speed calculating means for obtaining a remaining rotation speed from the above; a pulse interval measuring means for measuring a pulse interval of the output pulse of the comparator; and A rotation speed detection means for obtaining a rotation speed, and a voltage value of a DC drive voltage to be supplied to the pair of electrode brushes is calculated based on the rotation speed detected by the rotation speed detection means and a target rotation speed. It is determined whether the remaining rotation speed obtained by the speed-voltage conversion means and the remaining rotation speed calculation means has reached at least one preset remaining rotation speed, and according to the remaining rotation speed. A motor speed switching determining means for switching a target rotation speed and supplying it to the speed-voltage converting means, and a motor speed switching determining means corresponding to the voltage value based on a calculation result of the speed-voltage converting means. It is characterized in that the driving voltage by controlling the driving output is supplied to the motor driving circuit and a driving voltage control means for the rotation speed to the target.

According to a third aspect of the present invention, there is provided a rotation control device for a DC motor according to the present invention.
A pair of electrode brushes connected to the rotor coil and slidably contacting a commutator provided on the rotor together with the rotor coil, and switching the DC drive voltage by the commutator and supplying the brush to the rotor coil. A rotation control device for controlling the rotation operation of the rotor of the DC motor provided integrally with
The pair of electrode brushes are separately provided on the stator side, a single rotation detection brush for detecting rotation of the rotor, and the DC drive voltage is supplied to the pair of electrode brushes. A motor drive circuit that drives the DC motor, a DC power supply whose voltage can be changed, reference voltage generating means that generates a comparison reference voltage, and a voltage detected by the rotation detection brush and the comparison reference voltage. A comparator for comparing, and a motor control circuit for controlling the motor drive circuit in response to an output of the comparator, wherein the motor control circuit measures a pulse interval of an output pulse of the comparator. An interval measuring unit, a rotational speed detecting unit that determines a rotational speed of the rotor based on the pulse interval measured by the pulse interval measuring unit, and a rotational speed detected by the rotational speed detecting unit A rotation speed comparison unit that compares the rotation speed with a target rotation speed, and a speed-voltage conversion unit that calculates a voltage value of a DC drive voltage to be supplied to the pair of electrode brushes based on a comparison result by the rotation speed comparison unit. When,
A drive voltage control unit that supplies the DC drive voltage corresponding to the voltage value based on the calculation result of the speed-voltage conversion unit to the motor drive circuit, controls a drive output, and sets the target rotation speed. It is characterized by:

According to a fourth aspect of the present invention, there is provided a rotation control device for a DC motor according to the present invention, which achieves the above object.
A pair of electrode brushes connected to the rotor coil and slidably contacting a commutator provided on the rotor together with the rotor coil, and switching the DC drive voltage by the commutator and supplying the brush to the rotor coil. A rotation control device for controlling the rotation operation of the rotor of the DC motor provided integrally with
The pair of electrode brushes are separately provided on the stator side, a single rotation detection brush for detecting rotation of the rotor, and the DC drive voltage is supplied to the pair of electrode brushes. A motor drive circuit that drives the DC motor, a DC power supply whose voltage can be changed, reference voltage generating means that generates a comparison reference voltage, and a voltage detected by the rotation detection brush and the comparison reference voltage. A comparator for comparing, and a motor control circuit for controlling the motor drive circuit in response to the output of the comparator, wherein the motor control circuit counts the number of output pulses of the comparator. Counting means; cumulative rotation number calculating means for calculating the cumulative rotation number of the rotor based on the number of pulses counted by the pulse counting means; output of the cumulative rotation number calculating means and a target cumulative rotation number; A remaining rotation speed calculating means for obtaining a remaining rotation speed from the above; a pulse interval measuring means for measuring a pulse interval of the output pulse of the comparator; and Rotation speed detection means for obtaining a rotation speed; rotation speed comparison means for comparing the rotation speed detected by the rotation speed detection means with a target rotation speed; and the pair of rotation speed comparison means based on a comparison result by the rotation speed comparison means. A speed-voltage conversion means for calculating the voltage value of the DC drive voltage to be supplied to the electrode brushes, and the remaining rotation speed obtained by the remaining rotation speed calculation means being at least one predetermined remaining rotation speed. Motor speed switching determining means for determining whether or not the rotation speed has reached, switching a target rotation speed in accordance with the remaining rotation speed and supplying the rotation speed to the rotation speed comparison means, A drive voltage control unit that supplies the DC drive voltage corresponding to the voltage value based on the calculation result of the degree-voltage conversion unit to the motor drive circuit to control a drive output to set the target rotation speed. It is characterized by.

[0015]

That is, the DC motor rotation control device according to the present invention is connected to the rotor coil and slidably contacts a commutator provided on the rotor together with the rotor coil, and switches the DC drive voltage by the commutator. In a rotation control device that controls the rotation operation of the rotor of a DC motor provided integrally with a stator, a pair of electrode brushes supplied to the rotor coil is fixed separately from the pair of electrode brushes. A single rotation detecting brush for detecting rotation of the rotor is provided on the child side, and a reference voltage corresponding to the DC drive voltage supplied to the pair of electrode brushes from a motor drive circuit is used as a reference. The voltage generated by the voltage generating means and detected by the rotation detecting brush is compared with a comparison reference voltage by a comparator, and the motor control circuit responds to the output of the comparator. Controlling the motor driving circuit Te.

The motor control circuit calculates a pulse interval of the output pulse of the comparator, and determines a rotation speed of the rotor based on the pulse interval measured by the pulse interval measuring unit. A speed-voltage conversion unit that calculates a voltage value of a DC drive voltage to be supplied to the pair of electrode brushes based on the rotation speed calculated by the rotation speed calculation unit and a target rotation speed. And a drive voltage control unit that supplies the DC drive voltage corresponding to the voltage value based on the calculation result of the speed-voltage conversion unit to the motor drive circuit to control a drive output to set the target rotation speed. Including. With such a configuration, it is possible to perform appropriate rotation control based on effective rotation detection of the brush DC motor, particularly, by using a configuration that is simple and does not occupy space.

Further, the DC motor rotation control device according to the present invention is connected to the rotor coil and slidably contacts a commutator provided on the rotor together with the rotor coil to switch the DC drive voltage by the commutator. In a rotation control device that controls the rotation operation of the rotor of a DC motor provided integrally with a stator, a pair of electrode brushes supplied to the rotor coil is fixed separately from the pair of electrode brushes. A single rotation detection brush for detecting the rotation of the rotor is provided on the child side, and a comparison reference voltage corresponding to a DC drive voltage supplied from the motor drive circuit to the pair of electrode brushes is a reference voltage. A motor control circuit for comparing a voltage generated by the generation means and detected by the rotation detection brush with a comparison reference voltage generated by the reference voltage generation means by a comparator; Thus, controlling the motor drive circuit in response to the output of the comparator.

The motor control circuit includes pulse counting means for counting the number of output pulses of the comparator.
Cumulative rotation speed calculating means for calculating the cumulative rotation speed of the rotor based on the number of pulses counted by the pulse counting means, and calculating a remaining rotation speed from an output of the cumulative rotation speed calculation device and a target cumulative rotation speed. Remaining rotation speed calculation means, pulse interval measurement means for measuring the pulse interval of the output pulse of the comparator, rotation speed calculation means for determining the rotation speed of the rotor based on the pulse interval measured by the pulse interval measurement means, A speed-voltage conversion unit for calculating a voltage value of a DC drive voltage to be supplied to the pair of electrode brushes based on the rotation speed calculated by the rotation speed calculation unit and a target rotation speed; It is determined whether the remaining rotation speed obtained by the calculation means has reached at least one preset remaining rotation speed, and a target rotation speed is determined in accordance with the remaining rotation speed. And a motor speed switching determining unit that supplies the DC drive voltage corresponding to the voltage value based on the calculation result of the speed-voltage conversion unit to the motor drive circuit and drives the motor drive circuit. Drive voltage control means for controlling the output to achieve the target rotational speed is included.

With such a configuration, in particular, by using a simple and occupying space-saving configuration, it is possible to quickly reach the target cumulative rotational speed based on the effective rotation detection of the brush DC motor. Rotation control can be performed. Further, the rotation control device for a DC motor according to the present invention is configured such that the rotor is connected to a rotor coil and slidably contacts a commutator provided on the rotor together with the rotor coil, and switches the DC drive voltage by the commutator. A pair of electrode brushes to be supplied to the coil, in a rotation control device for controlling the rotation operation of the rotor of a DC motor provided integrally with the stator, the pair of electrode brushes separately on the stator side A single rotation detecting brush for detecting the rotation of the rotor, and a reference voltage generating means for generating a comparison reference voltage corresponding to the DC drive voltage supplied to the pair of electrode brushes from a motor drive circuit. And a comparison between the voltage detected by the rotation detection brush and a comparison reference voltage by a comparator. To control the motor drive circuit.

The motor control circuit determines a rotation speed of the rotor based on the pulse interval measured by the pulse interval measurement unit that measures a pulse interval of the output pulse of the comparator. A rotation speed calculation unit, a rotation speed comparison unit that compares the rotation speed calculated by the rotation speed calculation unit with a target rotation speed, and a rotation speed comparison unit that supplies the pair of electrode brushes based on a comparison result by the rotation speed comparison unit. Speed-voltage conversion means for calculating the voltage value of the DC drive voltage to be supplied, and the DC drive voltage corresponding to the voltage value based on the calculation result of the speed-voltage conversion means, being supplied to the motor drive circuit for drive output And a driving voltage control means for controlling the target rotation speed. Even with such a configuration, it is possible to perform appropriate rotation control based on effective rotation detection of the brush DC motor using a configuration that is simple and does not occupy space.

Further, the rotation control device for a DC motor according to the present invention is connected to a rotor coil and slidably contacts a commutator provided on the rotor together with the rotor coil to switch a DC drive voltage by the commutator. A pair of electrode brushes to be supplied to the rotor coil, in a rotation control device for controlling the rotation operation of the rotor of a DC motor provided integrally with a stator, separately from the pair of electrode brushes On the stator side, a single rotation detection brush for detecting rotation of the rotor is provided, and a reference voltage corresponding to a DC drive voltage supplied to the pair of electrode brushes from a motor drive circuit is used as a reference. The voltage generated by the voltage generation means and detected by the rotation detection brush is compared with a comparison reference voltage generated by the reference voltage generation means by a comparator. By the circuit, in response to the output of the comparator controls the motor drive circuit.

The motor control circuit includes pulse counting means for counting the number of output pulses of the comparator;
Cumulative rotation speed calculating means for calculating the cumulative rotation speed of the rotor based on the number of pulses counted by the pulse counting means, and calculating a remaining rotation speed from an output of the cumulative rotation speed calculation means and a target cumulative rotation speed. Remaining rotation speed calculation means, pulse interval measurement means for measuring the pulse interval of the output pulse of the comparator, rotation speed calculation means for determining the rotation speed of the rotor based on the pulse interval measured by the pulse interval measurement means, A rotation speed comparison unit that compares the rotation speed calculated by the rotation speed calculation unit with a target rotation speed, and a DC drive voltage to be supplied to the pair of electrode brushes based on a comparison result by the rotation speed comparison unit. And a speed-voltage conversion means for calculating the voltage value of the remaining rotation speed, wherein the remaining rotation speed obtained by the remaining rotation speed calculation means is at least one preset remaining rotation speed. It is determined whether or not the motor speed has been reached, the target rotation speed is switched according to the remaining rotation speed, and the motor speed switching determination unit that supplies the target rotation speed to the rotation speed comparison unit, and the calculation result of the speed-voltage conversion unit. Drive voltage control means for supplying the DC drive voltage corresponding to the voltage value based on the drive value to the motor drive circuit to control the drive output and set the target rotation speed. Even with such a configuration, based on the effective rotation detection of the brush DC motor, the configuration is simple and does not occupy space.
It is possible to perform appropriate rotation control that can quickly reach the target cumulative rotation speed.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a rotation control device for a DC motor according to the present invention will be described in detail based on an embodiment of the present invention with reference to the drawings. 1 and 2 show a configuration of a rotation control device for a DC motor according to a first embodiment of the present invention. FIG. 1 shows the configuration of the entire DC motor rotation control device, and FIG. 2 shows the configuration of mainly the variable output power supply circuit in the DC motor rotation control device of FIG. 1 in detail. FIG. 3 is a flowchart for explaining the operation of the DC motor rotation control device shown in FIGS. 1 and 2. The first embodiment of the present invention shown in FIGS.
Prior to the description of the DC motor rotation control device according to the embodiment, first, a DC motor rotation detection device used in the present invention will be described.

The DC motor rotation detecting device shown in FIG.
The drive power is supplied from a drive power source E1 via a switch SW1 to detect the rotation of a DC motor M1 driven. The DC motor M1 includes a pair of electrode brushes B.
11 and B12 and a rotation detection brush BD1. The DC motor rotation detection device shown in FIG. 4 includes a noise elimination circuit 1, a comparison reference voltage generation unit 2, and a comparator 3. The noise removing circuit 1 removes a noise component such as a steep surge waveform of a detection signal of the rotation detection brush BD1 and supplies the signal to the comparator 3. The comparison reference voltage generation unit 2 generates a comparison reference voltage for converting the detection signal of the rotation detection brush BD1 into a pulse train having a pulse period and a pulse width according to the rotation speed, and supplies the comparison reference voltage to the comparator 3. Comparator 3
Compares a signal obtained by removing noise from the detection signal of the rotation detection brush BD1 by the noise removal circuit 1 with a comparison reference voltage generated by the comparison reference voltage generation means 2 to determine a pulse period corresponding to the rotation speed. And a pulse train having a pulse width.

A more specific configuration of the DC motor rotation detector shown in FIG. 4 is the DC motor rotation detector shown in FIG. The rotation detecting device for a DC motor shown in FIG. 5 is similar to the device shown in FIG.
This is to detect the rotation of the DC motor M1 driven by supplying the drive voltage Eo via W1, and the motor M1 is provided with a rotation detection brush BD1 separately from the pair of electrode brushes B11 and B12. ing. 5 includes a noise removal circuit 1A, a comparison reference voltage generation unit 2
A and a comparator 3. The noise removal circuit 1A
This circuit removes a noise component such as a steep surge waveform of a detection signal of the rotation detection brush BD1 and supplies it to the comparator 3, and includes a constant voltage diode ZD1, a resistor R1, and a capacitor C1. The constant voltage diode ZD1 is
For example, it is composed of a Zener diode or the like, and is connected between the rotation detection brush BD1 and the common low potential side of the drive power supply E1.

The resistor R1 and the capacitor C1 are sequentially connected in series. The series circuit includes a resistor R1 on the side of the rotation detecting brush BD1 and a capacitor C1 on the common low potential side of the driving power source E1. In parallel with the rotation detection brush BD1 and the common low potential of the drive power supply E1. A voltage between both ends of the capacitor C1, that is, a connection point between the capacitor C1 and the resistor R1 and a common low potential of the drive power supply E1 is supplied to the non-inverting input terminal (+ side) of the comparator 3. The comparison reference voltage generation means 2A is a part that generates a comparison reference voltage for converting the detection signal of the rotation detection brush BD1 into a pulse train having a pulse period and a pulse width according to the rotation speed, and supplies the comparison reference voltage to the comparator 3. , And a potentiometer VR1.
Both ends of the potentiometer VR1 on the fixed side are the power supply voltage Vcc.
And a common low potential, respectively, and a voltage between the movable end of the potentiometer VR1 and the common low potential, for example, E
A voltage substantially equivalent to o / 4 is supplied to the inverting input terminal (− side) of the comparator 3.

The comparator 3 has substantially the same configuration as that shown in FIG. 4. A signal obtained by removing noise from the detection signal of the rotation detection brush BD1 by the noise removal circuit 1A is supplied to the non-inverting input side, The comparison reference voltage (Eo / 4) generated by the voltage generation means 2A is supplied to the inverting input side to compare the two. The comparator 3 includes a noise removal circuit 1A
Is higher than the comparison reference voltage (Eo / 4), the power supply voltage Vcc, ie, “H (high level)”. L (low level) "to output a pulse train having a pulse period and a pulse width corresponding to the rotation speed.

Next, the operation of the rotation detection device for a DC motor shown in FIG. 5 will be described with reference to the waveform diagrams of the respective parts shown in FIG. FIG. 6 shows an output signal SA1 of the rotation detection brush BD1, an output signal SB1 of the noise elimination circuit 1A, and an output signal S of the comparator 3 during high-speed rotation and low-speed rotation.
The waveform of each signal voltage of C1 is shown. The DC motor M1 having the rotation detecting brush BD1 is connected to a DC driving power source E1 of an output voltage Eo via a switch SW1 in series, and the rotation detecting brush BD1 of the DC motor M1 is connected to the noise removing circuit 1A. are doing. Noise removal circuit 1
In A, as described above, a constant voltage diode ZD1 such as a Zener diode is connected in parallel with the series circuit of the resistor R1 and the capacitor C1. Constant voltage diode Z
D1 clamps the voltage due to the back electromotive force due to the self-induction action of the rotor winding of the motor M1, that is, the rotor coil.

The resistor R1 and the capacitor C1 make up a low-pass filter for extracting an output from a connection point between the two and removing high-frequency components. An output taken from a connection point between the resistor R1 and the capacitor C1 constituting the low-pass filter is supplied to a non-inverting input terminal (+ side) of the comparator 3. When the switch SW1 is closed, a DC voltage is supplied from the drive power supply E1 to the DC motor M1 and the electrode brush B
The rotor coil is excited via 11 and B12,
The rotor rotates with respect to the stator having the magnetic poles formed by permanent magnets or the like. Due to the rotation of the DC motor M1, a substantially pulse-shaped voltage signal SA1 is applied to the rotation detecting brush BD1.
Occurs. The steep surge waveform of the leading edge of each pulse of the pulse train of the voltage signal SA1 output from the rotation detection brush BD1, that is, the rising portion shown in FIG.
When the contact pieces of the commutator contacting the brush switch, the magnitude of the current flowing through the rotor coil connected to each contact piece changes instantaneously. The magnitude of the current varies depending on the magnitude of the current flowing through the coil according to the rotation speed.

The slope portion of each pulse waveform is a composite of the voltage generated by the current flowing through the rotor coil and the DC resistance component of the coil, and the induced voltage generated by the coil rotating in the magnetic field. . At the time of high-speed rotation, the latter induced voltage becomes dominant, and at the time of low-speed rotation, the voltage by the former resistance component becomes dominant. Therefore, as shown in FIG. 6, the inclination angle of the inclined portion becomes gentler as the rotation speed is lower, and becomes closer to flat. The waveform of the output signal SB1 of the noise elimination circuit 1A excludes the above-described surge waveform and high-frequency noise such as mechanical noise generated by the contact between the rotation detection brush BD1 and the commutator. The comparator 3 includes the noise elimination circuit 1
The voltage of the output signal SB1 of A is compared with a comparison reference voltage of, for example, about Eo / 4 extracted from the potentiometer VR1. Therefore, the output signal SC1 of the comparator 3 is “H” which is the voltage Vcc in this case.
Only one of two levels of “L” which is a common low potential, that is, a ground level (GND) appears.
A stable rectangular wave is obtained.

The noise elimination circuit 1A may be appropriately configured in accordance with the characteristics of the DC motor to be used, the power to be used, the voltage of the signal processing circuit system, and the like. Alternatively, it may be omitted depending on the characteristics of the DC motor used, the power used, the voltage of the signal processing circuit system, and the like. FIG. 7 shows another configuration in which the rotation detection device for the DC motor shown in FIG. 4 is configured more specifically. The DC motor rotation detecting device shown in FIG. 7 detects the rotation of the DC motor M1 driven by supplying a driving voltage Eo from a driving power source E1 via a switch SW1 as in the case of FIGS. The motor M1 has a rotation detecting brush B separately from the pair of electrode brushes B11 and B12.
D1 is provided. 7 includes a noise removing circuit 1B, a comparison reference voltage generation unit 2B, and a comparator 3.

The noise elimination circuit 1B has a constant voltage diode ZD1,
It is configured to include a resistor R1 and a capacitor C1, and removes noise components such as a steep surge-like waveform of a detection signal of the rotation detection brush BD1 and supplies the signal to the comparator 3. The constant voltage diode ZD1 is composed of, for example, a Zener diode, and is connected between the rotation detection brush BD1 and the common low potential side of the drive power supply E1. The resistor R1 and the capacitor C1 are sequentially connected in series, and these series circuits are
The resistor R1 is on the side of the rotation detection brush BD1 and the capacitor C1 is on the side of the common low potential of the drive power supply E1. Connected between. The voltage between both ends of the capacitor C1, that is, the connection point between the capacitor C1 and the resistor R1 and the common low potential of the driving power source E1 is the non-inverting input terminal (+ side) of the comparator 3.
Supplied to

The comparison reference voltage generation means 2B generates a comparison reference voltage for converting the detection signal of the rotation detection brush BD1 into a pulse train having a pulse period and a pulse width corresponding to the rotation speed, and supplies the comparison reference voltage to the comparator 3. 2 and is constituted by a potentiometer VR2 almost in the same manner as the comparison reference voltage generating means 2A of FIG. Both ends of the fixed side of the potentiometer VR2 are connected between the electrode brush B11 and the electrode brush B12 of the DC motor M1, and the voltage between the movable end of the potentiometer VR2 and the common low potential, for example, E
o / 4 is supplied to the inverting input terminal (− side) of the comparator 3. The comparator 3 has substantially the same configuration as those of FIGS. 4 and 5, and a signal from which a noise is removed by the noise removal circuit 1B from the detection signal of the rotation detection brush BD1 is supplied to the non-inverting input side. The comparison reference voltage Eo / 4 generated by the voltage generation means 2B is supplied to the inverting input side to compare the two. The comparator 3 includes a noise removal circuit 1B
Is higher than the comparison reference voltage Eo / 4, the power supply voltage Vc
c, ie, “H”, and when the output of the noise elimination circuit 1B is equal to or lower than the comparison reference voltage Eo / 4, the output becomes a common low potential, that is, “L”, and outputs a pulse train having a pulse cycle and a pulse width according to the rotation speed.

Next, the operation of the rotation detection device for a DC motor shown in FIG. 7 will be described with reference to the waveform diagrams of respective parts shown in FIG. FIG. 8 shows signal voltage waveforms of the output signal SA2 of the rotation detecting brush BD1, the output signal SB2 of the noise removing circuit 1B, and the output signal SC2 of the comparator 3 when the drive voltage Eo of the DC motor M1 gradually decreases. Is shown. The difference between the configuration of FIG. 7 and FIG. 5 is that the power supply of the reference voltage generator 2B is the same as the drive power supply of the DC motor M1. Drive voltage Eo of DC motor M1
Gradually decreases, as shown in FIG. 8, the voltage of the output signal SA2 of the rotation detection brush BD1 and the voltage of the output signal SB2 of the noise elimination circuit 1B gradually decrease as Eo changes. At this time, if the load torque of the DC motor M1 is constant, the rotation speed gradually decreases.

However, since the output voltage of the potentiometer VR2, which is the comparison reference voltage, also decreases in proportion to Eo, the magnitude relationship between the inverting input and the non-inverting input of the comparator 3, that is, the ratio, is kept substantially constant. Will be.
Therefore, a stable rectangular wave can be obtained as the output signal SC2 of the comparator 3 irrespective of the fluctuation of the terminal voltage Eo of the DC motor M1. In an apparatus using a DC motor, it is often performed to control a rotation speed by changing a voltage applied to the DC motor, in other words, to control a generated torque of the DC motor.
On the other hand, in an apparatus using a battery as a power supply, the terminal voltage of the DC motor fluctuates frequently. The above-described rotation detection device for a DC motor in FIG. 7 is configured to obtain a stable rotation detection signal even when the terminal voltage of the DC motor changes in this way. By using the above-described DC motor rotation detection device, a DC motor rotation control device as shown in FIG. 9 can be configured, for example.

The DC motor rotation control device shown in FIG.
In addition to the DC motor M2 and the drive power supply circuit E2, a motor drive circuit 5, a noise removal circuit 6, a comparison reference voltage generation means 7, a comparison reference voltage selection means 8, a comparator 9, and a motor control circuit 10 are provided. 9 controls the rotation of a DC motor M2 driven by driving power supplied from a driving power supply circuit E2 via a motor driving circuit 5. The DC motor M2 includes: A pair of electrode brushes B21 and B22 and a rotation detection brush B
D2 is provided. Transistors Q1, Q2 are connected between the positive and negative output terminals of a drive power supply circuit E2 composed of a DC power supply of voltage Eo.
2, a motor drive circuit 5 including a switching unit that forms a bridge circuit by Q3 and Q4 is connected. One electrode brush B of the DC motor M2 is connected to one of the output terminals of the motor drive circuit 5, that is, the connection point between the collector of the transistor Q1 and the collector of the transistor Q3.
The other electrode brush B22 of the DC motor M2 is connected to the other output terminal 21 of the motor drive circuit 5, that is, a connection point between the collector of the transistor Q2 and the collector of the transistor Q4.

The control input terminal of the motor drive circuit 5 is connected to the motor control circuit 10, and the transistors Q1 to Q4
Of the DC motor M2 are controlled, such as forward rotation, reverse rotation, and stop. The output of the rotation detection brush BD2 of the DC motor M2 is input to the noise elimination circuit 6, and the output of the noise elimination circuit 6 is connected to the non-inverting input terminal (+ side) of the comparator 9. On the other hand, the comparison reference voltage generating means 7 includes two potentiometers VR21 and VR21.
R22 consisting of a series circuit and these potentiometers V
A series circuit on the fixed end side of each of R21 and VR22 is connected to the drive power supply circuit E2 in parallel with the motor drive circuit 5. That is, the potentiometers VR21 and VR2
2 generates a voltage proportional to the power supply voltage Eo. For example, the potentiometer VR21 takes out a voltage of approximately 3Eo / 4 from the movable end with respect to the common low potential, and the potentiometer VR22 outputs the voltage from the movable end to the common low potential. On the other hand, it is set so that a voltage of approximately Eo / 4 is taken out.

The comparison reference voltage selection means 8 is composed of two analog switches ASW1 and ASW2 and one inverter INV. Outputs taken out from the movable ends are connected to the inputs of the analog switches ASW2, respectively, and the outputs of the analog switches ASW1 and ASW2 are connected to the inverting input terminal (− side) of the comparator 9. Analog switches ASW1 and AS
A comparison reference voltage selection signal, which is a control signal from the motor control circuit 10, is supplied to the control terminal of W2 by inverting one analog switch ASW1 via an inverter INV, and supplied to the other analog switch ASW2. Supplied directly. That is, the analog switch AS
W1 and ASW2 are controlled by a comparison reference voltage selection signal from the motor control circuit 10 so that one of them is turned on and the other is turned off, and one of the potentiometers VR21 and VR22 of the comparison reference voltage generation means 7 is turned on. Is supplied to the inverting input terminal of the comparator 9.
The output of the comparator 9 is supplied to a motor control circuit 10.

The motor control circuit 10 is constructed using a microcomputer or the like, and receives a motor control signal and a comparison reference voltage selection means for the motor drive circuit 5 in response to the output of the comparator 9 and an external control instruction if necessary. A comparison reference voltage selection signal for each of the reference numbers 8 is generated and supplied to the motor drive circuit 5 and the comparison reference voltage selection means 8.
The analog switches ASW1 and ASW2 perform on / off operations depending on whether the state of the signal at the control terminal is “H” or “L”. In the on state, the voltage input to the input terminal is output as it is. The voltage is output to the terminal, and in the off state, the voltage input to the input terminal is not output to the output terminal. Specifically, for example, when the control terminal is “H”, it is turned on to allow the input signal to pass, and
At this time, it is turned off and enters a high impedance state.

Next, the operation of the DC motor rotation control device shown in FIG. 9 will be described with reference to the waveform diagrams of the respective parts shown in FIG. FIG. 10 shows that the DC motor M2 is clockwise (C
FIG. 9 shows the comparison reference voltage selection signal, the input signal at the non-inverting input terminal of the comparator 9 and the signal voltage waveform of the output signal of the comparator 9 when rotating in the W) direction and when rotating in the counterclockwise direction (CCW). ing. When a motor control signal is output from the motor control circuit 10 and the transistors Q1 and Q4 of the motor drive circuit 5 are turned on, the motor rotates clockwise. At the same time, “H” is output from the motor control circuit 10 as a comparison reference voltage selection signal. The voltage of the rotation detection brush BD2 of the DC motor M2 is input to the non-inverting input terminal of the comparator 9 via the noise removing circuit 6. On the other hand, a comparison reference voltage is input to the inverting input terminal of the comparator 9. In this case, since the comparison reference voltage selection signal is "H", the analog switch ASW1
Is off and the analog switch ASW2 is on, so that the potentiometer VR22 is used as the comparison reference voltage.
Is set to the voltage Eo / 4. Therefore, a rectangular wave as shown in FIG. 10A is obtained at the output of the comparator 9.

Next, the motor control circuit 10 outputs a motor control signal for turning on the transistors Q2 and Q3 of the motor drive circuit 5, and an "L" signal as a comparison reference selection signal. Then, the DC motor M
2 rotates counterclockwise, and the voltage based on the detection voltage of the rotation detection brush BD2 has a waveform at the non-inverting input terminal of the comparator 9 as shown in FIG. Since the analog switch ASW1 is turned on and the analog switch ASW2 is turned off by the comparison reference voltage selection signal, the voltage 3Eo / 4 set by the potentiometer VR21 is selected as the comparison reference voltage. Therefore, a rectangular wave as shown in FIG. 10B is obtained at the output of the comparator 9.

As described above, a pulse train is obtained from the output of the comparator 9 as the rotation signal of the DC motor M2. For example, the rotation detection brush BD2
When the angle between the electrode and the electrode brush B22 is 40 °, the pulse train has a duty of 1/3 when rotated clockwise and a duty of 2/3 when rotated counterclockwise. With the above configuration,
By obtaining a stable rotation signal with respect to the rotation of the DC motor M2 in both directions, the rotation of the DC motor M2 can be appropriately controlled. The DC motor rotation control device shown in FIG. 9 controls the rotation of the DC motor M2 by the switching control of the motor drive circuit 5 while keeping the output voltage of the drive power supply circuit E2 constant. The output voltage of the drive power supply circuit corresponding to the power supply circuit E2 is controlled to be variable by the DC motor rotation control device according to the first embodiment of the present invention shown in FIGS. 1 and 2.

FIG. 1 shows the configuration of a DC motor rotation control device according to the first embodiment of the present invention. The rotation control device for a DC motor shown in FIG.
1, motor drive circuit 12, DC motor 13, comparator 14
And a motor control circuit 15. The motor drive circuit 12, the DC motor 13, and the comparator 14 are configured in the same manner as the motor drive circuit 5, the DC motor M2, and the comparator 9 in the DC motor rotation control device of FIG. Although not shown in FIG.
The same configuration as the noise removing circuit 6, the comparison reference voltage generation means 7, the comparison reference voltage selection means 8, and the like is provided. The motor control circuit 15 provides a control signal to the motor drive circuit 12 based on the output of the comparator 14,
A voltage setting signal corresponding to a required rotation speed is supplied to the output variable power supply circuit 11. The variable output power supply circuit 11 controls the voltage supplied to the motor drive circuit 12 according to the voltage setting signal, and rotates the motor 13 at a required rotation speed.
The motor drive circuit 12 has a bridge circuit composed of the same transistors Q1 to Q4 as the motor drive circuit 5 of FIG. 9, and the DC motor 13 has a Brushes B21 and B22 and a rotation detection brush BD2 are provided.

The motor control circuit 15 is formed using a microcomputer or the like, generates a comparison reference voltage selection signal and a motor control signal, and respectively generates the comparison reference voltage selection means 8 (not shown in FIG. 1 to FIG. 9). ) And the motor drive circuit 12. Further, the motor control circuit 15
It has a pulse interval measuring unit 151, a rotation speed calculating unit 152, and a speed-voltage converting unit 153. The pulse interval measuring unit 151 measures the pulse interval of the output pulse of the comparator 14 and supplies the pulse interval to the rotation speed calculating unit 152. The rotation speed calculation unit 152 calculates the rotation speed of the rotor, that is, the motor, based on the pulse interval provided from the pulse interval measurement unit 151. The speed-voltage conversion means 153
Based on the rotation speed calculation means 152 and the target rotation speed, a drive voltage for obtaining the target rotation speed is obtained,
The power is supplied to the output variable power supply circuit 11.

As shown in detail in FIG. 2, the output variable power supply circuit 11 includes an operational amplifier (hereinafter, referred to as an "operational amplifier") OPA, a pnp transistor Q5, a D / A (digital-analog) converter DAC, a resistor R11, R12 has a so-called series regulator. The D / A converter DAC generates a reference voltage for the operational amplifier OPA based on the voltage instruction information supplied from the motor control circuit 15, and outputs the reference voltage to the operational amplifier OPA.
To the inverting input terminal of The transistor Q5 has an emitter supplied with a DC voltage from the DC power supply E, a base supplied with the output of the operational amplifier OPA, and a collector output supplied to the motor drive circuit 12. The collector output voltage is divided by series resistors R11 and R12 connected to a common potential, and the potential at the connection point between the resistors R11 and R12 is fed back to the non-inverting input terminal of the operational amplifier OPA.

Next, the operation of the rotation control device of the DC motor shown in FIG. 1 will be described with reference to the flowchart of the main part shown in FIG. In the initial state in which the DC motor 13 is stopped, the comparison reference voltage selection signal “H (high level)” is output from the motor control circuit 15 to the comparison reference voltage selection means (FIG. 9).
(See step S11).
The output voltage of the output variable power supply circuit 11 is
In response to the voltage setting signal supplied from the speed-voltage conversion means 153 of FIG. 5, the maximum value voltage E1 is obtained (step S12). Then, from the motor control circuit 15, the transistors Q1 and Q4 of the motor drive circuit 12 are output.
Is turned on, a voltage substantially equal to the power supply voltage E1 is applied between the electrode brushes B21 and B22 of the DC motor 13, and the DC motor 13 starts rotating clockwise (step S13). As described above, the comparison reference voltage selection signal “H” is output from the motor control circuit 15 at step S11 at substantially the same timing as the control of the motor, and is supplied to the comparison reference voltage selection means. Therefore, a reference voltage of, for example, Eo / 4 is input to the inverting input terminal of the comparator 14, and the DC motor 1
According to the rotation of the motor 3, the output of the comparator 14 is
A rotation signal pulse from the rotation detection brush BD2 appears.

The pulse interval T _M of the rotation signal pulse is measured by the pulse interval measurement means 151 of the motor control circuit 15 (step S14), and the rotation speed at that time is calculated by the rotation speed calculation means 152 (step S1).
5). The rotation speed N (current) based on the actually measured value is compared with the target rotation speed N (target) (step S1).
6). The rotation speed of the DC motor 13 is slow at first, but if a voltage is continuously applied, the rotation speed of the DC motor 13 will be a time constant until the generated torque and the load torque of the DC motor 13 finally reach a steady state with the load torque balanced. To increase. In the DC motor rotation control device of FIG. 1, when the rotation speed N (current) exceeds a preset target rotation speed N (target), the motor control circuit 15 controls the speed-voltage conversion means 153 and outputs A voltage change instruction is given to the variable power supply circuit 11 to set the drive power supply voltage from E1 to a lower set voltage E2 (step S17).

Further, after a predetermined wait time (step S18), the motor control circuit 15 measures the pulse interval T _M of the rotation signal pulse by the pulse interval measuring means 151 of the motor control circuit 15 (step S19), and performs rotation. The rotation speed at that time is calculated by the speed calculation means 152 (step S20). The rotation speed N based on this actually measured value
It is determined whether (current) is within the allowable range of the target rotation speed N (target) (step S21). Similar control is continued so that the rotation speed of the DC motor 13 falls within the allowable range of the target rotation speed N (target). In the rotation control device of the DC motor of FIG. 1 according to the first embodiment, the DC motor 13 is controlled by the drive voltage, and the rotation speed N (current)
Is lower than the target speed N (target), the drive power supply voltage is reduced to lower the rotation speed in order to reduce the rotation speed to the target speed N (target). Further, the rotation speed decreases, and the measured rotation speed N (current) becomes the target speed N (target).
Is out of the allowable range, the drive power supply voltage is increased to increase the rotation speed.

FIG. 11 shows a configuration of a DC motor rotation control device according to a second embodiment of the present invention. FIG.
1 is substantially the same as the DC motor rotation control device of FIG. 1 except that the motor control circuit 16 is used instead of the motor control circuit 15. The motor control circuit 16 is configured using a microcomputer or the like, and includes a pulse interval measuring unit 161,
Rotation speed calculation means 162, speed-voltage conversion means 163,
Pulse number counting means 164, cumulative rotation number calculating means 165,
Remaining rotational speed calculating means 166 and speed switching determining section 16
7 are provided. The pulse interval measuring means 151 and the rotational speed calculating means 162 in FIG.
It is almost the same as 2. The speed-voltage conversion means 163 not only responds to the rotation speed calculation means 162 like the speed-voltage conversion means 153 of FIG.
Responds to 7.

That is, the pulse interval measuring means 161
The pulse interval of the output pulse of the comparator 14 is measured and given to the rotation speed calculating means 162. Rotation speed calculation means 162
Calculates the rotation speed of the rotor, that is, the motor, based on the pulse interval given from the pulse interval measuring means 161. The pulse number counting means 164 counts the number of pulses of the output pulse of the comparator 14 and supplies the counted number to the cumulative rotation number calculating means 165. The cumulative number of revolutions calculating means 165 calculates the cumulative number of revolutions from the initial reference state based on the number of pulses given from the pulse number counting means 164, and calculates the remaining number of revolutions calculating means 166.
Give to. The remaining rotation speed calculating means 166 obtains the remaining rotation speed up to a target value of the cumulative rotation speed corresponding to the target position or the like based on the cumulative rotation speed given from the cumulative rotation speed calculating means 165 and supplies the obtained rotation speed to the speed switching determination unit 167. I do. The speed switching determination unit 167 determines whether the remaining rotation speed is a predetermined value set in advance and switches the rotation speed to the speed / voltage conversion unit 1.
63 is given a control signal.

The speed-voltage conversion means 163 obtains a drive voltage for achieving the target rotation speed based on the rotation speed calculation means 162 and the target rotation speed, and supplies the drive voltage to the output variable power supply circuit 11. Speed switching judgment unit 16
The target rotation speed is switched according to the control of step S7. In the DC motor rotation control device of FIG. 11 according to the second embodiment, the DC motor 13 is controlled by the drive voltage, and when the rotation speed N (current) exceeds the target speed N (target),
In order to reduce the rotation speed to the target speed N (target), the drive power supply voltage is reduced to reduce the rotation speed, the rotation speed is reduced, and the measured rotation speed N (current) is equal to the target speed N (target). If the rotation speed is out of the range (below), the drive power supply voltage is increased to increase the rotation speed. At the same time, the cumulative speed is counted, and when the cumulative speed reaches a predetermined value, the target speed is switched. Therefore,
Control such as promptly reaching the required cumulative rotation speed and smoothly stopping at the required cumulative rotation speed is possible.

FIG. 21 shows a configuration of a DC motor rotation control device according to a third embodiment of the present invention.
In the DC motor rotation control device shown in FIG.
Parts common to the drawings are denoted by the same reference numerals, and detailed description thereof is omitted. In this case, instead of the comparator 14 and the motor control circuit 15, the comparator 17 and the motor control circuit 18
Is provided. The motor control circuit 18 supplies a motor control signal to the motor drive circuit 12 based on the output of the comparator 17 and supplies a voltage setting signal corresponding to a required rotation speed to the variable output power supply circuit 11. The variable output power supply circuit 11 controls the voltage supplied to the motor drive circuit 12 according to the voltage setting signal, and rotates the motor 13 at a required rotation speed.

The motor control circuit 18 is configured using a microcomputer or the like, generates a comparison reference voltage selection signal and a motor control signal, and respectively generates the comparison reference voltage selection means 8 (not shown in FIG. 21; see FIG. 9). ) And the motor drive circuit 12. Further, the motor control circuit 18
Are pulse interval measuring means 181, rotation speed calculating means 18
2. It has a rotational speed comparing means 183 and a speed-voltage converting means 184. The pulse interval measuring unit 181 measures the pulse interval of the output pulse of the comparator 17 and supplies the pulse interval to the rotation speed calculating unit 182. The rotation speed calculation means 182
The rotation speed of the rotor, that is, the motor, is calculated based on the pulse interval provided from the pulse interval measurement unit 181.
The rotation speed comparison unit 183 compares the rotation speed obtained by the rotation speed calculation unit 182 with a target rotation speed. The speed-voltage conversion means 184 is provided for the rotation speed comparison means 1.
Based on the result of the comparison at 83, a drive voltage for achieving the target rotational speed is obtained and supplied to the output variable power supply circuit 11.

Next, the operation of the DC motor rotation control device of FIG. 21 will be described with reference to the flowchart of the main part shown in FIG. 22 and the waveform diagrams of each part shown in FIG. In the initial state where the DC motor 13 is stopped, the motor control circuit 18 determines whether or not a motor start signal has been given (step S111). Step S11
In step 1, when the motor start signal is not given, the determination in step S111 is repeated. If the motor start signal is given in step S111, the comparison reference voltage selection signal “H (high level)” is supplied to the comparison reference voltage selection means (see reference numeral 8 in FIG. 9) (step S112). Then, the initial voltage E1 is set in the power supply circuit 11 (step S113), and the DC motor 13
In order to start the rotation of the motor drive circuit 18, the transistors Q1 and Q
When a motor control signal for turning on the DC motor 4 is output, a voltage substantially equal to the power supply voltage E1 is applied between the electrode brushes B21 and B22 of the DC motor 13, and the DC motor 13 starts rotating clockwise (step S114). .

The motor control circuit 18 outputs the comparison reference voltage selection signal "H" at step S112 at substantially the same timing as the start of motor control, and is supplied to the comparison reference voltage selection means. Eo
/ 4 reference voltage is input to the inverting input terminal of the comparator 17,
According to the rotation of the DC motor 13, the output of the comparator 17 is
A rotation signal pulse from the rotation detection brush BD2 of the DC motor 13 appears. The pulse interval T _M of the rotation signal pulse is determined by the pulse interval measuring means 18 of the motor control circuit 18.
1 (step S115), and the rotational speed at that time is calculated by the rotational speed calculating means 182 (step S116). In the rotation speed comparison means 183,
The rotation speed N (current) based on the actually measured value is compared with the target rotation speed N (target) (step S117). The rotation speed of the DC motor 13 is slow at first,
If the voltage is continuously applied as it is, the time constant is increased until a steady rotation is finally reached with the generated torque of the DC motor 13 and the load torque balanced.

In step S117, if the rotation speed N (current) is not less than the preset target rotation speed N (target), the rotation control device 18 of the DC motor in FIG. It is determined whether (current) exceeds a preset target rotation speed N (target) (step S118). In step S118, the rotation speed N (current) is set to a preset target rotation speed N (target).
If the rotation speed N does not exceed the rotation speed N (current) and the target rotation speed N (target), the motor control circuit 18 outputs the rotation speed comparison means 183 and the speed-voltage conversion means 184.
, The DC motor 12 is driven with the same voltage (step S119). Then, it is determined whether there is a motor stop signal (step S120). If there is no motor stop signal, the process returns to step S115 to repeat the subsequent processing. If a motor stop signal is given in step S120, the motor control circuit 18 turns off the transistors Q1 and Q4 of the motor drive circuit 12 (step S121), and stops the DC motor 13 (step S122).

On the other hand, in step S117, the rotation speed N (current) is set to the preset target rotation speed N (target).
If it is less than the predetermined value, it is determined whether a predetermined time has elapsed after the voltage change (step S123). If the predetermined time has elapsed, the drive voltage is increased (step S124), and the process proceeds to step S120. In step S123, if the predetermined time has not elapsed, the drive voltage at that time remains unchanged.
Jump to step S120. Step S1
At 18, if the rotation speed N (current) exceeds a preset target rotation speed N (target), it is determined whether a predetermined time has elapsed after the voltage change (step S125).
If the predetermined time has elapsed, the drive voltage is reduced (step S126), and the process proceeds to step S120. Step S1
In 25, if the predetermined time has not elapsed, the process jumps to step S120 with the drive voltage at that time.

In the DC motor rotation control apparatus of FIG. 21 according to the third embodiment, the DC motor 13 is controlled by the drive voltage, and when the rotation speed N (current) exceeds the target speed N (target). In addition, the drive power supply voltage is reduced to lower the rotation speed. When the rotational speed decreases and the measured rotational speed N (current) falls outside the allowable range of the target speed N (target), the drive power supply voltage is increased to increase the rotational speed in order to increase the rotational speed. Further, when a predetermined time elapses in a state where the rotation speed N (current) is lower than the target speed N (target), the drive power supply voltage is increased to increase the rotation speed, and the rotation speed N (current) becomes equal to the target speed N (target). After a lapse of a predetermined time in a state in which the voltage exceeds the threshold, the drive power supply voltage is reduced to lower the rotation speed.

The rotation control device for a DC motor according to the fourth embodiment of the present invention has substantially the same configuration as that of FIG.
The operation of the fourth embodiment will be described with reference to the flowchart shown in FIG. 24 and the waveform diagrams of each part shown in FIG. In this case, the number of pulses C corresponding to the number of rotations of the motor will be used instead of the number of rotations of the motor, and the cumulative number of rotations will be described as the cumulative number of pulses, and the remaining number of rotations will be described as the number of remaining pulses. Here, a three-pole motor is described as an example of the DC motor M2. Therefore, as data handled in the motor control circuit 16, the output pulse of the comparator 14 is a pulse number C of three pulses per one rotation of the rotor. Suppose there is. In addition, a method of detecting a pulse will be described on the assumption that a rising edge is detected. In a state where the DC motor 13 is stopped (Step S201), the motor control circuit 16 checks whether or not a motor start signal is given (Step S202).

When the motor start signal is detected, the target first accumulated pulse number C1 is set to the pulse number C,
This is set as an initial value of the remaining pulse number R in a counter constituting the pulse number counting means 164 (step S2).
03), the comparison reference voltage selection signal is set to the H level output (step S204), and the initial voltage E is supplied to the output variable power supply circuit 11.
1 (step S205), the transistor Q1
And turn on Q4 to output a motor drive signal for DC drive (step S206). Then, a rotation signal pulse of the motor, which is an output pulse of the comparator 14, is detected (step S207), and the number of pulses is counted down as R = C1-1 (step 208). Step S2
At 07, when a rotation pulse is detected, step S
At 208, the count value R of the counter is reduced by "1", and as a result, it is determined whether or not the count value R becomes "0" (step S209). If the count value R is not "0" in step S209, step S20
7, the next rotation pulse is detected.

If no rotation pulse is detected in step S207, the flow shifts to step S222 to detect whether or not a motor stop signal is given. If the motor stop signal has not been given in step S222, the process returns to step S207 to continue detecting the rotation pulse. If a motor stop signal is given in step S222, the process proceeds to step S224, where the transistors Q1 and Q4 are turned off (step S224), and the motor M2 is stopped (step S225). In step S209, when the number of remaining pulses R = 0, that is, when the counting of C1 pulses from the start of rotation of the motor M2 is completed,
Second cumulative pulse number C2 which is the next target cumulative pulse number
Is set in the counter as the number R of remaining pulses (step S210), and the drive voltage is changed to a voltage lower than the initial voltage E1 (step S211).

After the drive voltage is changed in step S211 and a rotation pulse is detected (step S21)
2) The count value R of the counter is decreased by "1" (step S213), and it is determined whether or not the count value R has become "0" (step S214). Step S
At 214, if the count value R is not "0", it is determined whether or not the predetermined number of pulses have been counted after the voltage change (step S215). Then, the next rotation pulse is detected. If a rotation pulse is not detected in step S212, the process proceeds to step S223, and it is detected whether or not a motor stop signal is given. In step S223, if the motor stop signal has not been given, the process returns to step S212 to continue detecting the rotation pulse. If it is determined in step S223 that the motor stop signal has been given, the process proceeds to step S2.
24, the transistors Q1 and Q4 are turned off, and the motor M2 is stopped in step S225.

If it is determined in step S215 that the predetermined number of pulses have been counted, the rotation speed V is calculated based on the pulse interval T _M (step S216). The pulse interval T _M is a period from the rise of the previous pulse to the rise of the current pulse. Next, the current rotation speed V (current) is compared with the target rotation speed V (target) (step S217). If the rotation speed V (current) is lower than the rotation speed V (target), the rotation speed is determined. Then, the drive voltage is raised to increase (Step S220), and the process returns to Step S212 to detect the next pulse. In step S217, the rotation speed V (current) is
If it is not slower than the (target), the rotation speed V (current) is further compared with the rotation speed V (target) (step S21).
8) If the rotation speed V (current) is higher than the rotation speed V (target), the drive voltage is reduced to reduce the rotation speed (step S221), and the process returns to step S212 to detect the next pulse. If the rotation speed V (current) is not higher than the rotation speed V (target) in step S218, the motor drive is continued at the same drive voltage (step S219), and the process returns to step S212 to detect the next pulse. Do.

In step S215, it is determined whether or not the predetermined number of pulses have been counted after the drive voltage is changed. This is because there is a time lag before the rotation speed is reached. Finally step S21
4, the number of remaining pulses R = 0, and C
When the counting of two pulses is completed, step S2
At 24, the motor is turned off, and at step S225, the motor is stopped. In the rotation control device for a DC motor according to the fourth embodiment, the cumulative rotation speed is counted,
When the cumulative speed reaches a predetermined value, the target speed is switched.
Therefore, the required cumulative rotational speed is quickly reached,
In addition, it is possible to perform a control such as a smooth stop at a required cumulative rotational speed.

Next, in the above-described DC motor rotation control devices according to the first to fourth embodiments of the present invention, the rotation detection brush used for rotation detection will be described in detail. FIG. 12 shows a rotation detection brush BD according to the present invention.
This is an example in which No. 3 is arranged at an angle of 60 ° with respect to one of the pair of electrode brushes B31 and B32, that is, the electrode brush B32. In this case, regarding the contact position with respect to the commutator CM3, the electrode brush having the smaller angle difference with the contact position of the rotation detecting brush is B32, and the electrode brush having the larger angle difference between the contact positions is B31. FIGS. 12A to 12E show states in which the commutator CM3 is sequentially rotated clockwise by 30 ° with reference to FIG. 12A. FIG.
It is a predicted voltage waveform of the output V of the commutator CM3, that is, the rotation detection brush BD3 when the rotor rotates, as shown in FIGS. The output of the waveform of FIG. 13 greatly changes every 60 ° as can be seen from the comparison with the waveform of FIG. 18 in which the rotation speed is detected from the ripple of the drive voltage of the motor.

Similarly, FIG. 14 shows a rotation detecting brush BD3 'according to the present invention, which comprises a pair of electrode brushes B31 and B3.
32, that is, an example in which they are arranged at an angular position of 40 ° with respect to the electrode brush B32. (A) of FIG.
To (g) show the commutator CM3 based on FIG.
Indicates a state in which each is sequentially rotated clockwise by 20 °. FIG. 15 shows a rotation detection brush B when the commutator CM3 rotates as shown in FIGS.
It is a predicted voltage waveform of the output V of D3 '. With the waveforms shown in FIGS. 13 and 15, it is possible to detect information on the number of rotations based on a waveform obtained by removing a high-frequency component including a ripple from the output V by passing through a low-pass filter. Understand.

In addition, the present invention is not limited to the embodiment described above and shown in the drawings, and can be variously modified and implemented without changing the gist of the invention. For example, in the embodiments shown in FIGS. 1, 9, and 11, the reference voltage generation means is configured to generate two types of comparison reference voltages corresponding to different rotation directions of the rotor of the DC motor. However, a different reference voltage may be generated based on the voltage applied to the DC motor in addition to the rotation direction of the rotor. In the case of such a configuration, for example, the required number of potentiometers is increased in the comparison reference voltage generation means, the required number of analog switches is increased in the comparison reference voltage selection means, and the motor control circuit includes a plurality of analog switches. A plurality of comparison reference voltage selection signals for selecting only the analog switch to be output are output, and the comparison reference voltage according to the driving direction of the DC motor and / or the voltage applied to the DC motor is input to the input terminal of the comparator (for example, a non-inverting input). End), and controls the motor drive circuit in response to the output of the comparator. According to this structure, irrespective of fluctuations in the rotation direction of the DC motor and / or the voltage applied to the DC motor, there is no risk of erroneous detection of the rotation speed, and based on the effective rotation detection of the brush DC motor. Appropriate rotation control can be performed.

[0068]

As described above, according to the DC motor rotation control device of the first aspect of the present invention, the DC motor is connected to the rotor coil and slides on the commutator provided on the rotor together with the rotor coil. A rotation control device for controlling the rotation operation of the rotor of a DC motor provided integrally with a stator, wherein a pair of electrode brushes for supplying to the rotor coil by switching the DC drive voltage by the commutator are provided. A single rotation detection brush for detecting rotation of the rotor is provided on the stator side separately from the pair of electrode brushes, and supplied to the pair of electrode brushes from a motor drive circuit. A reference voltage generating unit that generates a comparative reference voltage that is the DC drive voltage and corresponds to one rotation direction of the rotor,
The voltage detected by the rotation detection brush and the comparison reference voltage generated by the reference voltage generation means are compared by a comparator, and the motor control circuit causes the motor to output the comparison reference voltage and one of the rotation directions. A comparison reference voltage corresponding to a DC drive voltage is supplied to the comparator, and the motor control circuit controls the motor drive circuit in response to an output of the comparator in the one rotation direction. Pulse interval measurement means for measuring the pulse interval of the output pulse of the comparator, rotation speed calculation means for obtaining the rotation speed of the rotor based on the pulse interval measured by the pulse interval measurement means, the rotation speed calculation means Calculating the voltage value of the DC drive voltage to be supplied to the pair of electrode brushes based on the rotation speed calculated in step (1) and the target rotation speed. Drive voltage control for supplying the DC drive voltage corresponding to the voltage value based on the calculation result of the conversion means and the speed-voltage conversion means to the motor drive circuit to control the drive output to set the target rotation speed With the configuration including the means, it is possible to perform appropriate rotation control based on effective rotation detection of the brush DC motor, particularly, using a simple and space-saving configuration.

According to the first and third aspects of the present invention, control is performed only in one rotational direction of the motor, and control of the speed and position is required in the other rotational direction. Instead, it is suitable for a control object that only needs to operate, and the number of components, the control circuit, and the like can be simplified, and cost reduction can be achieved. According to the second and fourth aspects of the present invention, based on the effective rotation detection of the brush type motor, the configuration is simple and does not occupy space.
It is possible to provide a DC motor rotation control device that can quickly reach a target cumulative rotational speed and can set a speed at the time when the target cumulative rotational speed has been reached as a target rotational speed.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically illustrating a configuration of a DC motor rotation control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram schematically showing a detailed configuration mainly of an output variable power supply circuit in the DC motor rotation control device of FIG. 1;

FIG. 3 is a flowchart of a main part for describing the operation of the DC motor rotation control device of FIG. 1;

FIG. 4 is a block diagram schematically showing a configuration of an example of a DC motor rotation detecting device used in the DC motor rotation control device according to the embodiment of the present invention;

FIG. 5 is a block diagram schematically showing the configuration of another example of the rotation detection device of the DC motor.

FIG. 6 is a waveform diagram of each part for explaining the operation of the rotation detection device for the DC motor in FIG. 5;

FIG. 7 is a block diagram schematically illustrating a configuration of another example of the rotation detection device of the DC motor.

8 is a waveform diagram of each part for describing the operation of the rotation detection device for the DC motor in FIG. 7;

9 is a block diagram schematically showing a configuration of an example of a DC motor rotation control device using the DC motor rotation detection device shown in FIG. 4, FIG. 5, or FIG.

10 is a waveform diagram of each part for describing the operation of the rotation control device for the DC motor in FIG. 9;

FIG. 11 is a block diagram schematically showing a configuration of a DC motor rotation control device according to a second embodiment of the present invention.

FIG. 12 is a schematic diagram for explaining a change in the positional relationship between the commutator and each brush when the rotation detection brush is set at a certain position for explaining the operation of the DC motor rotation detection device according to the present invention. FIG.

13 is a waveform diagram of an output signal of a rotation detection brush for explaining the operation of the rotation detection device for a DC motor in FIG. 12;

FIG. 14 is a view for explaining a change in the positional relationship between the commutator and each brush when the rotation detection brush is set at another position for explaining the operation of the rotation detection device of the DC motor according to the present invention. It is a schematic diagram.

15 is a waveform diagram of an output signal of a rotation detection brush for explaining the operation of the rotation detection device of the DC motor of FIG. 14;

FIG. 16 is a schematic diagram for explaining the principle configuration of a general three-pole DC motor.

FIG. 17 is a schematic diagram for explaining a rotation detection method in a conventional three-pole DC motor.

18 is a schematic diagram for explaining signal waveforms in the rotation detection method in the three-pole DC motor of FIG.

FIG. 19 is a schematic diagram for explaining a configuration of an example of a rotation control device in a DC motor using a conventional rotation detection brush.

20 is a schematic diagram for explaining signal waveforms at various parts in the rotation control device of FIG. 19;

FIG. 21 is a block diagram schematically showing a configuration of a DC motor rotation control device according to a third embodiment of the present invention.

22 is a flowchart of a main part for describing the operation of the rotation control device for the DC motor in FIG. 21.

23 is a waveform diagram of each part for describing the operation of the rotation detection device for the DC motor in FIG. 21.

FIG. 24 is a flowchart of a main part for describing the operation of the DC motor rotation control device according to the fourth embodiment of the present invention.

25 is a waveform diagram of each part for describing the operation of the rotation detection device for the DC motor in FIG. 24.

[Explanation of symbols]

 1, 1A, 1B, 6 Noise removal circuit 2, 2A, 2B, 7 Comparison reference voltage generation means 3, 9, 14, 17 Comparator 5, 12 Motor drive circuit 8 Comparison reference voltage selection means 10, 15, 16, 18 Motor control circuit 11 Variable output power supply circuit 13, M1, M2 DC motor 151, 161, 181 Pulse interval measurement means 152, 162, 182 Rotation speed calculation means 153, 163, 184 Speed-voltage conversion means 164 Pulse number counting means 165 Cumulative Rotation speed calculation means 166 Remaining rotation speed calculation means 167 Speed switching judgment unit 183 Rotation speed comparison means B11, B12, B21, B22 Electrode brushes BD1, BD2 Rotation detection brushes Q1, Q2, Q3, Q4, Q5 Transistor OPA Operational amplifier (Op Amp) DAC D / A (Digital-Analog) Converter R11, R12 resistor E, E1 power C1 capacitor ZD1 Zener diode VR1, VR21, VR22 potentiometer ANSW1, ANSW2 analog switch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Koyama 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. 5H571 BB06 BB07 BB09 EE02 GG02 HA08 HD01 JJ13 LL15 LL23 MM02 MM03

Claims (4)

[Claims] A pair of electrodes connected to a rotor coil and slidably contacting a commutator provided on the rotor together with the rotor coil, and switching a DC drive voltage by the commutator to supply the electrode to the rotor coil. In a rotation control device that controls a rotation operation of the rotor of a DC motor integrally provided with a stator, a brush is provided on a stator side separately from the pair of electrode brushes, and the rotation of the rotor is controlled. A single rotation detection brush for detecting the voltage, a motor drive circuit that supplies the DC drive voltage to the pair of electrode brushes to drive the DC motor, and a DC power supply whose voltage can be changed. Reference voltage generation means for generating a reference voltage; a comparator for comparing the voltage detected by the rotation detection brush with the comparison reference voltage; and a motor drive circuit controlled in response to an output of the comparator. And a motor control circuit that controls the motor control circuit, wherein the motor control circuit measures a pulse interval of the output pulse of the comparator, and a pulse interval measured by the pulse interval measurement unit. Rotation speed detection means for obtaining the rotation speed of the rotor; and a voltage value of a DC drive voltage to be supplied to the pair of electrode brushes based on the rotation speed detected by the rotation speed detection means and a target rotation speed. Speed-voltage conversion means for calculating the target rotation by supplying the DC drive voltage corresponding to the voltage value based on the calculation result of the speed-voltage conversion means to the motor drive circuit to control the drive output. And a drive voltage control means for controlling the speed. 2. A pair of electrodes connected to a rotor coil and slidably in contact with a commutator provided on the rotor together with the rotor coil, for switching a DC drive voltage by the commutator and supplying the electrode to the rotor coil. In a rotation control device that controls a rotation operation of the rotor of a DC motor integrally provided with a stator, a brush is provided on a stator side separately from the pair of electrode brushes, and the rotation of the rotor is controlled. A single rotation detection brush for detecting the voltage, a motor drive circuit that supplies the DC drive voltage to the pair of electrode brushes to drive the DC motor, and a DC power supply whose voltage can be changed. Reference voltage generation means for generating a reference voltage; a comparator for comparing the voltage detected by the rotation detection brush with the comparison reference voltage; and a motor drive circuit controlled in response to an output of the comparator. And a motor control circuit for controlling the number of pulses of the output pulse of the comparator, and the rotor based on the number of pulses counted by the pulse count means. Cumulative rotational speed calculating means for calculating the cumulative rotational speed of: a residual rotational speed calculating means for calculating a residual rotational speed from an output of the cumulative rotational speed calculating device and a target cumulative rotational speed; and a pulse of an output pulse of the comparator. A pulse interval measurement unit that measures an interval, a rotation speed detection unit that determines a rotation speed of the rotor based on the pulse interval measured by the pulse interval measurement unit, and a rotation speed that is detected by the rotation speed detection unit. Speed-voltage conversion means for calculating a voltage value of a DC drive voltage to be supplied to the pair of electrode brushes based on a target rotation speed; and the remaining rotation number calculation means. It is determined whether or not the remaining rotation speed obtained by the above has reached at least one predetermined remaining rotation speed, and the target rotation speed is switched according to the remaining rotation speed to perform the speed-voltage conversion. Means for judging motor speed switching to be supplied to the means; and supplying the DC drive voltage corresponding to the voltage value based on the calculation result of the speed-voltage conversion means to the motor drive circuit to control the drive output and set the target. And a drive voltage control means for setting a rotation speed. 3. A pair of electrodes connected to a rotor coil and in sliding contact with a commutator provided on the rotor together with the rotor coil, for switching a DC drive voltage by the commutator and supplying the electrode to the rotor coil. In a rotation control device that controls a rotation operation of the rotor of a DC motor integrally provided with a stator, a brush is provided on a stator side separately from the pair of electrode brushes, and the rotation of the rotor is controlled. A single rotation detection brush for detecting the voltage, a motor drive circuit that supplies the DC drive voltage to the pair of electrode brushes to drive the DC motor, and a DC power supply whose voltage can be changed. Reference voltage generation means for generating a reference voltage; a comparator for comparing the voltage detected by the rotation detection brush with the comparison reference voltage; and a motor drive circuit controlled in response to an output of the comparator. And a motor control circuit that controls the motor control circuit, wherein the motor control circuit measures a pulse interval of the output pulse of the comparator, and a pulse interval measured by the pulse interval measurement unit. Rotation speed detection means for obtaining the rotation speed of the rotor; rotation speed comparison means for comparing the rotation speed detected by the rotation speed detection means with a target rotation speed; and a comparison result by the rotation speed comparison means. Speed-voltage conversion means for calculating the voltage value of the DC drive voltage to be supplied to the pair of electrode brushes, and the DC drive voltage corresponding to the voltage value based on the calculation result of the speed-voltage conversion means. A drive voltage control means for controlling the drive output by supplying the drive output to the motor drive circuit to achieve the target rotational speed. 4. A pair of electrodes connected to a rotor coil and in sliding contact with a commutator provided on the rotor together with the rotor coil, for switching a DC drive voltage by the commutator and supplying the electrode to the rotor coil. In a rotation control device that controls a rotation operation of the rotor of a DC motor integrally provided with a stator, a brush is provided on a stator side separately from the pair of electrode brushes, and the rotation of the rotor is controlled. A single rotation detection brush for detecting the voltage, a motor drive circuit that supplies the DC drive voltage to the pair of electrode brushes to drive the DC motor, and a DC power supply whose voltage can be changed. Reference voltage generating means for generating a reference voltage; a comparator for comparing the voltage detected by the rotation detection brush with the comparison reference voltage; and controlling the motor drive circuit in response to an output of the comparator. And a motor control circuit for controlling the number of pulses of the output pulse of the comparator, and the rotor based on the number of pulses counted by the pulse count means. Cumulative rotational speed calculating means for calculating the cumulative rotational speed of: a residual rotational speed calculating means for calculating a residual rotational speed from an output of the cumulative rotational speed calculating device and a target cumulative rotational speed; and a pulse of an output pulse of the comparator A pulse interval measurement unit that measures an interval, a rotation speed detection unit that determines a rotation speed of the rotor based on the pulse interval measured by the pulse interval measurement unit, and a rotation speed that is detected by the rotation speed detection unit. A rotation speed comparison unit that compares the rotation speed with a target, and a DC drive power to be supplied to the pair of electrode brushes based on a comparison result by the rotation speed comparison unit. Speed-voltage conversion means for calculating the voltage value of the pressure, determining whether the remaining rotation speed determined by the remaining rotation speed calculation means has reached at least one preset remaining rotation speed, Motor speed switching determination means for switching a target rotation speed according to the remaining rotation speed and supplying the rotation speed to the rotation speed comparison means; and the DC drive corresponding to the voltage value based on the calculation result of the speed-voltage conversion means. And a drive voltage control means for supplying a voltage to the motor drive circuit to control a drive output to achieve the target rotation speed.