JP2001119992A - Motor driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor driving device, whose manufacturing time is reduced and whose usability is markedly improved. SOLUTION: A motor control device 21 is a device that controls the driven states of a plurality of motors M individually. The device is provided with changeover switches 29 provided for each motor M to supply or interrupt a drive current to each motor M, a remote controller 23 in which a plurality of operation switches SWa to SWf that control the switching states of each of the changeover switches 29 are provided, in such a way as to correspond to each changeover switch 29, an identifying signal generating part 36 connected to the remote controller 23 to generate different kinds of identifying signals, in compliance with the operation conditions of the operation switches SWa to SWf for selecting a motor to be driven, and a drive part that drives the selected motor at the rotational speed, corresponding to the identifying signal Vs from the identifying signal generating part 36.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device for controlling the rotation state of a motor such as a DC motor that performs forward rotation or reverse rotation.

[0002]

2. Description of the Related Art Electric linear actuators are used in nursing beds and the like. In order to expand and contract the linear actuator, a DC motor as a power source is rotated forward or backward by an operation of a remote controller (hereinafter, remote controller).

FIG. 9 is a circuit diagram showing the electrical configuration of a typical first prior art control device 1 for rotating such a plurality of DC motors forward or backward with a remote controller. The control device 1 of the prior art includes, for example, two motors M1,
The control device 1 controls the rotation state of M2 (indicated by the symbol M when collectively referred to) individually.
And the remote controller 3. The control device body 2 is provided with c-contact type relay switches 4a, 4b, 4c, and 4d (indicated by a reference numeral 4 in a generic name) for each of the motors M1 and M2. A pair of relay switches 4a, 4
A DC motor M1 is connected between the respective b contacts c, and a DC motor M2 is connected between the respective c contacts of the relay switches 4c and 4d.

Each of the relay switches 4 has exciting coils 5a, 5b, 5c, and 5d (indicated by a reference numeral 5 in general) and change-over switches 9a, 9b, 9c, and 9d (indicated by a reference numeral 9 in general). ). Each a contact of each changeover switch 9 is connected to the power supply line 7 connected to the positive pole of the DC power supply 6, and each b contact of each changeover switch 9 is connected to the power supply line 8 connected to the negative pole of the DC power supply 6. It is connected.

[0005] One end of each exciting coil 5 is connected to the reference potential Vcc, and the other end is an operation switch S of the remote controller 3.
Wa, SWb, SWc, and SWd (collectively indicated by the symbol SW) are respectively connected to one contact.
The other end of each operation switch SW is connected to the ground potential. Thereby, each changeover switch 9 is turned on / off by each operation switch SW. a contact or b
Each is switched to the contact side.

When such a control device 1 is used, as shown in the following Tables 1 (a) and 1 (b), the c contact of each changeover switch 9 is changed to the a contact on the power supply line 7 side or the power supply line 8 Depending on which of the b contacts on the side
The rotation direction of the motors M1 and M2 is switched. In the following tables, the symbols “↑” and “↓” indicate that the motors M1 and M2 rotate in the forward or reverse direction, respectively, and the symbol “−” indicates that the motors M1 and M2 are stopped. Table 1
(A) shows the control of the motor M1, and Table 2 (b) shows the control of the motor M2.

[0007]

[Table 1] On the other hand, in general, there are cases where individual rotational speeds V1, V2,..., Vn (n ≦ N) are set for N motors. When the control device 1 as described above is used, it is necessary to use, as each motor M, n types of motors having different rotation speeds. Alternatively, it is necessary to use n types of gear mechanisms having different gear ratios as a gear mechanism for transmitting rotation from each motor M to the above-described actuator.

In such a conventional technique, it is necessary to prepare various types of motors and gear mechanisms having different characteristics.
There is a problem that the number of types of parts such as a nursing bed, which is a product using the motor M, is increased, and manufacturing is troublesome. Further, there is a problem that it is difficult to adjust the rotation speed of each motor M and the usability is low.

FIG. 10 is a circuit diagram showing an electric configuration of a motor control device 1a according to a second prior art. This prior art is similar to the first prior art, and corresponding parts are denoted by the same reference numerals. The feature of the prior art is to individually control three motors M1, M2 and M3, for example, and to use a c-contact type relay switch 4a, 4b, 4c, 4d, 4c.
e, 4f (generally indicated by reference numeral 4) are provided in the control device main body 2, and the relay switches 4a, 4f
b, 4c, 4d, 4e, and 4f are excitation coils 5 respectively.
a, 5b, 5c, 5d, 5e, 5f (indicated by reference numeral 5 when collectively referred to) and changeover switches 9a, 9b, 9c, 9
d, 9e and 9f.

The relay switches 4a, 4a
b, 4c, 4d, 4e, 4f, corresponding to the operation switches SWa, SWb, SWc, SWd, SWe, SW
f (indicated by a symbol SW when collectively referred to) is provided on the remote controller 3. The manner of connection between them is the same as in the first prior art.

Further, in the case of the prior art, the DC power supply 6
Is connected in parallel with a series circuit of a diode D1 and a transistor T1. The diode D1 is connected such that the power supply line 7 side is a cathode. Further, each operation switch SWa, SWb, SWc, S
A resistor R1 is provided between Wd, SWe, SWf and the ground potential.
Are connected in series. Operation switch SW for resistor R1
Side potential is connected to the inverting input terminal of the comparison circuit 10,
The non-inverting input terminal of the comparison circuit 10 is connected to the reference potential V1. The output of the comparison circuit 10 is the transistor T1
Input to the gate.

In this prior art, each of the motors M1, M2, M3 is individually driven by operating the operation switches SWa, SWb, SWc, SWd, SWe, SWf of the remote controller 3 in an operation mode similar to that of Table 1 above. / Stop and rotation in the forward / reverse direction. Further, according to the prior art, the operation switches SWa, SWb, S
The more the Wc, SWd, SWe, and SWf are operated, the more the current flowing through the resistor R1 increases. By comparing this current with the reference potential V1 set in advance by the comparison circuit 10, the number of operation switches SWa equal to or more than a predetermined number is determined. , SW
When the switches b, SWc, SWd, SWe, and SWf are operated, the output of the comparison circuit 10 is inverted from a high level to a low level as an example, and the transistor T1 is switched from the conductive state to the cutoff state by this output. And the driving of the motors M1, M2, M3 is stopped.

As a result, an excessive current is output from the DC power supply 6 to prevent the DC power supply 6 from being deteriorated or damaged, or an excessive current flows through the power supply lines 7 and 8 so that the power supply Problems such as an excessive rise in the temperature of the lines 7 and 8 are prevented.

On the other hand, in the prior art, as an example, if the maximum number of motors to be driven among the motors M1, M2 and M3 is two,
Drivable motor combinations are motors M1, M2; M
2, M3; M3, M1. At this time, when the motors M1, M2, and M3 are used, for example, in a nursing bed or the like, when the user uses the electric function, the motors that are simultaneously driven so as not to give the user anxiety or pain. There is a case where it is desired to specify the motor M or the motor M which should not be driven simultaneously. In this prior art, it is difficult to meet such a demand, and there is a problem that usability is low.

FIG. 11 is a circuit diagram showing an electrical configuration of a motor control device 1b according to a third prior art. This prior art is
The present invention relates to a control device for a motor of a dual power supply system of a commercial AC power supply and a battery. An AC power supply 12 is connected to the control device 1b via a power transformer 11, and the transformed AC current from the power transformer 11 is supplied to the rectifier / smoothing circuit 1b.
The DC current is output after rectification and smoothing via 3.
The rectification / smoothing circuit 13 includes a full-wave rectification circuit 14 using a diode, and a capacitor C1 connected in parallel between a pair of power supply lines 7 and 8 connected to the full-wave rectification circuit 14. A diode D2 is connected in series to the power line 7 in the forward direction, and a motor M is connected between the power lines 7 and 8 via a power switch SW1.

A constant voltage circuit 14 for generating the predetermined reference voltage Vcc based on the power supply voltage from the power supply lines 7 and 8 is connected between the power supply lines 7 and 8. The power supply lines 7 and 8 are connected to a chargeable / dischargeable battery 15. Battery 1
A diode D between the positive pole of the power supply line 5 and the power supply line 7;
3 is connected with the battery 15 side as an anode.
Further, a charging circuit 16 is connected to the power supply line 7, and charges the battery 15 as necessary as described later. At this time, at the connection point 17 between the diodes D2 and D3 in the power supply line 7, the diodes D2 and D3 are wired-OR connected.

In the prior art, the power switch SW1
Is shut off, no power supply current is supplied to the motor M, and the battery 15 is charged by the charging circuit 16.
When the power switch SW1 is turned on, a DC current through the rectifying / smoothing circuit 13 and a DC current from the battery 15 are supplied to the motor M through the wired-OR connection.

In this prior art, if the current exceeding the capacity of the power transformer 12 continues to flow through the power lines 7 and 8 after the power switch SW1 is turned on and the motor M continues to be overloaded, for example, Battery 15
, The battery 15 is over-discharged and the life of the battery 15 is shortened.

In this case, after the battery 15 is discharged,
Since the voltage between the terminals of the battery 15 decreases, the current IB flowing through the diode D3 decreases, and the diode D3
2, the current IT from the power transformer 12 flowing through
The power transformer 12 is overloaded and the temperature rises excessively, causing a problem such that a fuse usually mounted on the power transformer 12 is blown. That is, there is a problem that the power transformer 12 cannot cope with an overload state and the usability is low at this point.

[0020]

As described above, these prior arts require time and effort for manufacturing. In addition, there is a problem that the usability is low.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a motor control device in which the labor required for manufacturing is reduced and the usability is significantly improved.

[0022]

A motor control device according to the first aspect of the present invention is a control device for individually controlling the driving states of a plurality of motors, and is provided for each motor. A changeover switch for supplying / cutting off current, a plurality of operation switches for controlling the switching state of each changeover switch, a remote operation device provided corresponding to each changeover switch, and a remote operation device are connected and driven. Identification signal generating means for generating different types of identification signals in accordance with the operation mode of the operation switch for selecting the motor,
A drive unit for driving the selected motor at a rotation speed corresponding to the identification signal from the identification signal generating means.

According to a second aspect of the present invention, in the motor control apparatus according to the first aspect, the identification signal generating means includes a plurality of resistors connected in series, and a predetermined connection point between the resistors. In this case, there is provided a voltage dividing circuit which is connected to each operation switch and generates a divided voltage obtained by dividing the reference voltage according to the operation mode of each operation switch as an identification signal.

A motor control device according to a third aspect of the present invention is a control device for individually controlling the driving states of a plurality of motors, and is provided for each motor and supplies / interrupts a driving current to each motor. A changeover switch, a current adjusting means connected to at least one changeover switch for adjusting a current flowing through the changeover switch when the changeover switch is turned on, and a plurality of current adjusting means connected to each changeover switch to respectively control a switching state of each changeover switch. A remote operation device provided with the operation switches, a current amount detection unit that is commonly connected to each operation switch and detects a total current amount flowing through each operation switch, and a total current amount detected by the current amount detection unit. Motor stopping means for stopping at least a part of the motor when the predetermined range is exceeded.

According to a fourth aspect of the present invention, there is provided a motor control device, comprising: a power supply for supplying a drive current to the motor; a power switch provided on a power supply line connecting the power supply and the motor; A secondary battery provided closer to the power supply unit than the switch, a charging unit for charging the secondary battery when the power switch is turned off, and detecting that the discharge of the secondary battery has become equal to or greater than a predetermined amount, and starting the motor. And a motor stop unit for stopping the motor.

According to a fifth aspect of the present invention, there is provided a motor control device according to the fourth aspect, further comprising a reference voltage generation section for generating a predetermined reference voltage, wherein the motor stop section divides the voltage between the power supply lines. Voltage dividing means for outputting a divided voltage by voltage dividing, and a switch driving means for shutting off a second power switch provided in series with the power supply line when the divided voltage from the voltage dividing means falls below the reference voltage. This is the case.

[0027]

In the motor control device according to the first aspect of the present invention, the switching mode of the changeover switch is controlled by appropriately operating a plurality of operation switches of the remote control device, so that the supply of the drive current to each motor is controlled. Shutdown is set.
That is, by appropriately operating the operation switch, a desired motor can be individually driven or stopped among a plurality of motors. At this time, the identification signal generating means generates different types of identification signals according to the operation mode of the operation switch of the remote operation device. The identification signal from the identification signal generating means is input to a driving unit, and the driving unit drives the selected motor at a rotation speed corresponding to the input identification signal.

Here, when all the motors are rotated at non-constant rotational speeds, an identification signal generated when operating an operation switch to select a predetermined motor corresponds to a desired rotational speed. Thus, the identification signal generating means is determined. Thereby, even when all of the plurality of motors have the same characteristic, when selecting a predetermined motor by the remote control device, an identification signal corresponding to a desired rotation speed is generated from the identification signal generating means, The selected motor is driven to rotate at the desired rotation speed.

Therefore, when all the motors are to be rotated at non-constant rotation speeds, a plurality of types of motors having different rotation speeds are used, or the rotation from each motor is reduced to a predetermined reduction ratio. The necessity of using n types of power transmission mechanisms having mutually different reduction ratios as power transmission mechanisms for transmitting power by the motor is eliminated, and the motors and the power transmission mechanisms and the like all have the same characteristics. Thus, the number of types of parts can be reduced, and the labor required for manufacturing can be significantly reduced.

The rotation speed of each motor can be adjusted by changing only the identification signal generating means in each motor, or making the element for determining the type of the identification signal generated from the identification signal generating means variable. It can be easily performed, and usability is significantly improved in this respect.

In the motor control device according to the second aspect of the present invention, in the first aspect of the present invention, the identification signal generating means includes a plurality of resistors connected in series, and a predetermined connection point between the resistors is set to In this case, there is provided a voltage dividing circuit that is connected to the operation switches and generates a divided voltage obtained by dividing the reference voltage according to the operation mode of each operation switch as an identification signal. Even in this case, by making each resistor a variable resistor or the like, it is possible to easily change the type of the identification signal, which is a divided voltage by a plurality of resistors, and to easily adjust the rotation speed of each motor. be able to. Therefore, it is possible to achieve the same curing effect as the above-described function and effect.

In the motor control device according to the third aspect of the present invention, the switching mode of the changeover switch is controlled by appropriately operating a plurality of operation switches of the remote control device, and supply / cutoff of the drive current to each motor. Is set.
That is, by appropriately operating the operation switch, a desired motor can be individually driven or stopped among a plurality of motors.

At this time, at least one of the plurality of changeover switches provided in the control device is provided with current adjusting means for adjusting the current flowing through the changeover switch when the changeover switch is turned on. An operation switch provided in the remote control device is connected to each of the changeover switches. When the operation switch is operated, a current flows to the operation switch via the controlled changeover switch. This current is detected by a current amount detecting means, the total amount of current flowing through each operation switch. The motor stopping means stops at least some of the motors when the total current amount detected by the current amount detecting means exceeds a predetermined range.

That is, when a changeover switch provided with the current adjusting means having appropriately set characteristics or a plurality of changeover switches including this changeover switch is controlled by operating an operation switch, the total current detected by the current detection means is obtained. The current has a different amount of current compared to a case where only the changeover switch provided with no current adjusting means is controlled by the operation switch.

Accordingly, by appropriately setting a predetermined range of the current amount relating to the current detected by the current detecting means, a motor corresponding to the changeover switch having the current adjusting means, or the changeover switch not having the current amphoteric means is provided. For certain motor combinations, including motors corresponding to
Controls such as simultaneous driving or simultaneous driving inhibition can be performed, and usability is significantly improved.

In the motor control device according to the fourth aspect of the invention, the power supply current from the power supply section is supplied to the motor via the power supply line. When the power switch provided on the power supply line is in a conductive state, the power supply current from the power supply unit and the power supply current from the secondary battery are supplied to the motor. When the power switch is turned off, the secondary battery is charged by the charging unit. Here, in a case where the power switch is kept conducting and the discharge of the secondary battery continues, when the discharge of the secondary battery becomes equal to or more than a predetermined degree, the motor stop unit detects this and stops the motor. As a result, the power supply current stops flowing through the power supply line. The rechargeable battery is charged.

Here, as described above, even if the power supply switch continues to be conductive, the motor drive is automatically stopped when the discharge of the secondary battery exceeds a predetermined level. The situation where the secondary battery is overdischarged is prevented, and the life of the secondary battery can be extended. In addition, since the secondary battery is prevented from being over-discharged, the power supply current supplied from the secondary battery to the motor decreases due to a decrease in the terminal voltage of the secondary battery after the over-discharge, and A situation in which the supplied power supply current increases is prevented.

As a result, the power supply becomes overloaded,
It is possible to prevent an undesirable change in the characteristics of the power supply unit or a failure that causes physical damage.

According to a fifth aspect of the present invention, there is provided the motor control device according to the fourth aspect of the present invention, further comprising a reference voltage generation section for generating a predetermined reference voltage, wherein the motor stop section divides the voltage between the power supply lines. Voltage dividing means for outputting a divided voltage by voltage dividing, and a switch driving means for shutting off a second power switch provided in series with the power supply line when the divided voltage from the voltage dividing means falls below the reference voltage. Have.
Even in such a case, the same operation and effect as the above operation and effect can be realized.

[0040]

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a circuit diagram of a control device 21 of a DC motor (hereinafter, motor) according to a first embodiment, which individually controls the rotation state of a plurality of motors such as forward rotation or reverse rotation or rotation speed for each motor. It is. Further, the motor of the present embodiment is implemented, for example, in a nursing bed or the like. In such a nursing bed or the like, an electric linear actuator is used. In order to extend and contract the linear actuator, a motor as a power source is rotated forward or backward by an operation using a remote controller (hereinafter, a remote controller) as a remote operation device.

The control device 21 of the present embodiment is, for example, 3
The control device 21 individually controls the rotation states of the two motors M1, M2, and M3 (indicated by the symbol M in the generic name), and the control device 21 includes a control device main body 22 and the remote controller 23. Each of the motors M1, M2, M
For each three, a c-contact type relay switch 24a, 24
b, 24c, 24d, 24e and 24f (generally referred to by reference numeral 24) are provided.

A DC motor M1 is connected between the respective c contacts of the pair of relay switches 24a and 24b, a DC motor M2 is connected between the respective c contacts of the relay switches 24c and 24d, and each of the relay switches 24e and 24f is connected. A DC motor M3 is connected between the c contacts.

Each of the relay switches 24a to 24f includes an exciting coil 25a, 25b, 25c, 25d, 25e, 25
f (collectively indicated by reference numeral 25) and change-over switches 29a, 29b, 29c, 29d, 29e, 29f (collectively indicated by reference numeral 29). Each a contact of each changeover switch 29 is connected to a power supply line 27 connected to the positive pole of the DC power supply 26, and each changeover switch 2
Each of the b contacts 9 is connected to a power supply line 28 connected to the negative pole of the DC power supply 26.

One end of each exciting coil 25 is connected to the reference potential Vcc, and the other end is operated by the operation switches SWa, SWb, SWc, SWd, SWe, SWf of the remote controller 23.
(Indicated by the symbol SW in a generic case). The other end of each operation switch SW
Each is connected to the ground potential. Thus, each changeover switch 29 is turned on / off by each operation switch SW. The contact is switched to the contact a side or the contact b side.

A series circuit of a diode D11 and a transistor T11 is connected between the power supply lines 27 and 28 in parallel with the DC power supply 26. The diode D11 is connected such that the positive pole side of the DC power supply 26 is a cathode.

On the other hand, in the present embodiment, as an example. A diode D is connected to the connection point of each operation switch SWa, SWb, SWd with the corresponding excitation coil 25a, 25b, 25d.
The cathodes of D12, D13 and D14 are respectively connected. The anode of the diode D12 is connected to the reference potential Vcc.
Of three connection points 30, 31 of three resistors R11, R12, R13 as an example connected in series between
The anodes of the diodes D13 and D14 are connected to each other and connected to the connection point 31.

As will be described later, the signal output from the connection point 30 is an identification signal Vs capable of identifying the operation mode such as the number and type of the operated operation switches SW, and the identification signals Vs of the motors M1, M2 and M3. It becomes a speed command signal for commanding the rotation speed. An identification signal generator 36, which is an identification signal generator, includes the resistors R11, R12, and R13 and the diodes D12, D13, and D14.

The identification signal Vs is input to the arithmetic unit 32, and the rotation speed detection signal FB corresponding to the rotation speed of the motors M1, M2, M3 detected by the hall elements provided in the motors M1, M2, M3. Is subtracted between. The output of the arithmetic unit 32 is amplified by a speed amplifier circuit 33, and the output of the arithmetic unit 32 is converted into a pulse corresponding to a deviation between the identification signal Vs, which is the speed command signal, and the rotation speed detection signal FB by a PWM (pulse width modulation) circuit 34. A width modulated signal is generated.

The output of the PWM circuit 34 is input to a gate driver circuit 35, and the output of the gate driver circuit 35 controls on / off of the transistor T11. As will be described later, the motor M is driven at a rotational speed corresponding to the identification signal Vs.
1, M2 and M3 are rotationally driven. Here, the speed amplifier circuit 33, the PWM circuit 34, and the gate driver circuit 3
The driving unit 39 is configured to include 5.

When such a control device 21 is used, as shown in the following Tables 2 (a), (b) and (c), the c contact of each changeover switch 29 is changed to the a contact on the power line 27 side. Alternatively, the rotation direction of the motors M1, M2, and M3 is switched depending on which of the b contacts on the power supply line 28 side is connected.

In Table 2, the symbols "↑" and "↓" indicate that the motors M1, M2 and M3 rotate in the forward or reverse direction, respectively, and the symbol "-" indicates the motors M1 and M3.
2, indicating the stop of M3. Table 2 (a) shows the control of the motor M1, Table 2 (b) shows the control of the motor M2, and Table 2 (c) shows the control of the motor M3.

[0052]

[Table 2] Further, as described in the section of the related art, generally, individual rotation speeds V1, V2,
.., Vn (n ≦ N) may be set, and the rotational speed may be changed between forward rotation and reverse rotation of each motor.

The present embodiment is an example for answering this problem as described below. In response to the ON operation of each operation switch SW, the circuit shown in FIG. Are obtained.

[0054]

[Table 3] The voltage value of the identification signal Vs shown in Table 3 is the resistance R
1, R2, R3 and diodes D12, D1
3 and D14 in combination with the forward voltage drop (0.6 V). In Table 3, when one operation switch SW is turned on, the c contact of the changeover switch 29 of the corresponding relay switch 24 is switched from the b contact on the power supply line 28 side to the a contact on the power supply line 27 side. I do. The rotation speed of the motor M corresponding to each identification signal Vs is referred to as rotation speeds V1, V2, and V3.

Here, for each motor M, whether the rotation speed is set to be different between the motors M or not, whether the rotation speed of each motor M at the time of forward rotation and the rotation speed at the time of reverse rotation is different from each other. How the rotation speed of each motor M is set is determined by the identification signal generator 36 connected to each operation switch SW as shown in FIG.
Is realized by appropriately determining the specific circuit configuration.

Therefore, in the present embodiment, the drive / stop control can be individually performed for each motor M, the forward / reverse control can be individually performed, and the motor M can be individually controlled without depending on the characteristics of each motor M. Shows an example of a biographical configuration that enables the rotation speed to be set, and allows the rotation speed to be set to the same or different for normal rotation and reverse rotation. Therefore, the present invention is not limited to such a configuration example.

As shown in the circuit diagram of the motor control device 21b in FIG. 2 which is a modification of the present embodiment, the opposite side of the operation switch SW of the remote controller 23 from the relay switch 24 is the ground potential of the present embodiment. On the contrary, the present invention can be easily implemented even in the case of the configuration example in which the reference potential Vcc is connected. This modification is compared with the first embodiment. Only the calculation formula shown in Table 3 indicating the voltage value as the identification signal Vs generated from the identification signal generator 36 is different, and it is apparent that the same operation and effect as described above is realized.

As described above, in the control device 21 of the first embodiment, each motor M can be individually driven / stopped by using the remote controller 23, and the motor M can be rotated in the forward / reverse direction. The direction can be switched. Furthermore,
Even when all the motors M have the same characteristics, the rotation speeds can be set to be different from each other between the motors M. In each motor M, the rotation speed at the time of normal rotation and the rotation speed at the time of reverse rotation The rotation speed can be different from the rotation speed.

Therefore, when different rotation speeds are set for the respective motors M, as described in the section of "Technique", a plurality of types of motors having mutually different characteristics are used, or the rotation from each motor is used. Need to use n types of power transmission mechanisms having different reduction ratios as a power transmission mechanism for transmitting
As the motor and the power transmission mechanism, all having the same characteristics can be used, the types of parts can be reduced, and as an example including such a motor M, for manufacturing a product such as a nursing bed. The time and effort required can be significantly reduced.

In each motor M, only the circuit configuration of the identification signal generator 36 is changed,
By making the resistors R11, R12, and R13 constituting the variable resistors 6 variable, the rotation speed of each motor M can be easily adjusted, and in this respect, usability is significantly improved.

(Embodiment 2) FIG. 3 is a circuit diagram showing an example of an electrical configuration of a motor control device 21c according to Embodiment 2 of the present invention. This embodiment is similar to the first embodiment and corresponding parts are denoted by the same reference numerals. The feature of the present embodiment is that, in the circuit of FIG. 1, for example, resistors R21 and R22 are connected in parallel to the exciting coils 25a and 25b of the relay switches 24a and 24b related to the motor M1, respectively, and a diode D11 and an identification signal generation unit are connected. 36, speed amplifier circuit 33, P
Except for the WM circuit 34 and the gate driver circuit 35, a resistor R
23 to the ground potential.

The potential on the operation switch SW side of the resistor R23 is connected to the inverting input terminal of the comparing circuit 37, and the non-inverting input terminal of the comparing circuit 37 is connected to the reference potential V1. The output of the comparison circuit 37 is input to the gate of the transistor T12.

In this embodiment, by operating the operation switch SW of the remote controller 23 in an operation mode similar to that of Table 2, the motors M1, M2, and M3 are individually driven / stopped.
Alternatively, control for rotating in the forward / reverse direction is realized.

In this embodiment, as an example, the exciting coil 25 of the relay switches 24a and 24b related to the motor M1 is used.
The resistors R21 and R22 are connected in parallel to a and 25b, respectively. Therefore, the operation switches SWa, SWb
Is operated, the current Ir flowing through the resistor R23 increases as compared with the case where the other operation switches SWc to SWf are operated.

The magnitude relationship of the current Ir can be set as follows, for example. That is, the current Ir when all the operation switches SW are all operated, the operation switches SWa, SWb, SWc, SWd or the operation switches SWa, SWb, SWe, SWf corresponding to the motors M1, M2 or the motors M1, M3 are changed. Current Ir = I2 when operated, current I3 when operated switches SWc, SWd, SWe, and SWf corresponding to motors M2 and M3, and operation switch SWa related to motor M1
Is operated, and the operation switch SWc corresponding to one of the other motors M2 and M3, Ir = I4,
Regarding the current Ir = I5 when SWd or the operation switches SWe and SWf are operated, it can be set so that I1>I2>I3>I4> I5 (1).

Thus, by appropriately setting the reference potential V1, the current Ir flowing through the resistor R23 is adjusted to the value I1
When the current value becomes equal to or more than I5, the output of the comparison circuit 37 is inverted from high level to low level as an example, and the transistor T11 is switched from the conductive state to the cutoff state by this output, and the power supply line 28 is cut off. Each motor M
Drive is stopped.

Specifically, in this embodiment, the remote controller 23
The more the respective operation switches SW are operated, the more resistance R23
The current flowing to the comparator circuit 37 increases.
By comparing with a reference potential V1 set in advance,
When a predetermined number or more of the operation switches SW are operated, the output of the comparison circuit 37 is inverted from a high level to a low level as an example, and the output of the transistor T1
2 is switched from the conduction state to the interruption state, and the power supply line 28
And the driving of each motor M is stopped.

Therefore, in the present embodiment, an excessive current is output from the DC power supply 26 due to an erroneous drive of the excessive number of motors M, so that the characteristics of the DC power supply 26 are deteriorated or damaged. Or an excessive current flows in the power supply lines 27 and 28,
The occurrence of problems such as an excessive rise in the temperature of 8 is prevented.

In this embodiment, when the rotation of each motor M is stopped when the remote controller 23 is operated so that three or more motors M are simultaneously driven, two motors M are simultaneously driven. Until. At this time, in this embodiment,
Regarding the current Ir = I2, when Ir ≧ I2 (2), the reference potential V1 is appropriately set so that the transistor T12 is shut off and the rotation of the motor M is stopped. But the motors M2, M3
, The motors M1 and M
In the case of 2 or a combination of the motors M1 and M3, the transistor T12 is shut off and the motor M is stopped as described above.

As described above, in this embodiment, when a plurality of motors M can be driven simultaneously, a combination of motors M that can be driven simultaneously or a combination of motors M that cannot be driven simultaneously can be specified. . To specify the combination of the motors M, the relay switch 24 corresponding to the motor M to be specified is specified.
Then, the resistors R21 and R22 having appropriately set resistance values may be connected, and the reference potential V1 may be set as appropriate. Thereby, the combination of the motors M that can be simultaneously driven or cannot be simultaneously driven can be appropriately specified, and the usability is significantly improved.

The present embodiment can be implemented, for example, in an electric nursing bed. In the nursing bed, the movable part of the bed body is driven to expand and contract by the linear actuator as described above. FIG. 4 shows a system diagram of a configuration related to the linear actuator of the nursing care pet. The control device 21 includes a control device main body 22 and a remote controller 23. A one-axis or plural-axis linear actuator (hereinafter, referred to as an actuator) 38 is connected to the control device main body 22, and the actuator 38 is moved in a predetermined direction. A remote controller 23 for running or stopping is connected to the control device main body 22.

Of the plurality of operation switches SW provided on the remote controller 23, the actuator 3 of each axis to be driven
By operating two operation switches S1 and S2 corresponding to No. 8, the actuator 38 can be expanded and contracted. For example, the operation switch S for the A-axis in FIG.
When the user presses 1, the A-axis actuator 38 operates in the extending direction. When the other operation switch S2 is pressed, the A-axis actuator 38 operates in the contracting direction. If neither of the operation switches S1 and S2 is operated, the actuator 38 stops.

As described above, the control device 21 can extend and retract the actuator 38 of one or more axes by the remote controller 23 provided with two operation switches SW for one axis.

In the nursing care bed, for example, when the motor M1 is for adjusting the height of the entire bed, the motor M2 is for adjusting the height of the head, and the motor M3 is for adjusting the height of the foot, for example, The height adjustment and the head height adjustment, and the bed height adjustment and the foot height adjustment can be simultaneously adjusted by the individual actuators, but the head height adjustment and the foot height adjustment cannot be simultaneously adjusted. Can be set as follows. Accordingly, it is possible to prevent a situation in which the care receiver is lifted up at the same time by lifting the head and the foot and becoming in a posture in which a trouble is felt, and the usability is significantly improved.

Further, in this embodiment, the driving of each motor M is stopped when the condition of the above-mentioned third equation is satisfied with respect to the current Ir. At this time, only the combination of the motors M2 and M3 can be simultaneously driven as described above. Therefore, in the present embodiment, a motor of a type in which the minimum torque is set as the maximum output torque among the torques required for each motor M is used as each motor M.
May be adopted.

At this time, the actuator which requires a relatively small torque is driven by one motor M. For actuators that require a relatively large torque,
It is driven by two motors M. This may be achieved by transmitting the rotation from each motor M to a common actuator by a power transmission mechanism. In this embodiment,
Since two motors M can be specified as an example that can be driven simultaneously, these two motors M are used for driving the actuator requiring a relatively large torque.

Thus, a plurality of actuators having various necessary torques can be driven only by a motor M of a relatively small output torque. For example, the type of the motor M constituting the nursing bed is 1 The number of types can be reduced, and the number of types of parts required for manufacturing can be significantly reduced.

FIG. 5 is a circuit diagram showing an electric configuration of a motor control device 21d according to a modification of the present embodiment. This embodiment is similar to the second embodiment shown in FIG. 3, and corresponding parts are denoted by the same reference numerals. It should be noted that this modified example is not
Instead of connecting the resistors R21, R22 in 2 to the relay switches 24a, 24b associated with the motor M1,
Each of the relay switches 24a, 24b, 24c, 2c is connected in parallel to the excitation coil 25c, 25d of the relay switch 24c, 24d associated with the motor M2.
4D, 24E, 24F
23 is arranged between the connection point of each excitation coil 25 on the opposite side of the remote controller 23 and the reference potential Vcc. The voltage between the terminals of the resistor R23 is the same as that of the second embodiment.
As in the case of (1), it is input to the inverting input terminal of the comparison circuit 37 as an identification signal.

Even with such a configuration, the total current Ir flowing through the resistor R23 increases as the number of operated switches SW increases. In particular, the resistors R21, R2
Motors M including the motor M2 to which the motor 2 is connected
, The total current Ir increases.

As described above, with respect to such a current amount Ir, the resistance values of the resistors R21 and R22 and the reference potential V1
By appropriately setting, the same operation and effect as those of the second embodiment can be realized.

(Embodiment 3) FIG. 6 is a circuit diagram showing an electric configuration of a motor control device 21e according to Embodiment 3 of the present invention. The present prior art relates to a control device for a motor of a dual power supply system of a commercial AC power supply and a battery. An AC power supply 42 is connected to the control device 21e via a power supply transformer 41. The transformed AC current from the power supply transformer 41 is rectified and smoothed via a rectification / smoothing circuit 43 to output a DC current. You. The rectification / smoothing circuit 43 includes a full-wave rectification circuit 43a using a diode, and a capacitor C21 connected in parallel between a pair of power supply lines 27 and 28 connected to the full-wave rectification circuit 43a. A diode D21 is serially connected to the power line 27 in the forward direction, and a motor M is connected between the power lines 27 and 28 via a power switch SW.

A constant voltage circuit 44 for generating the reference voltage Vcc, which is a predetermined constant voltage, based on the power supply voltage from the power supply lines 27 and 28 is connected between the power supply lines 27 and 28. The power supply lines 27, 2
A chargeable / dischargeable battery 45 is connected to 8.
A diode D22 is connected between the positive pole of the battery 45 and the power supply line 27 with the battery 45 side as the anode. Further, the charging circuit 4 is connected to the power supply line 27.
6 is connected to charge the battery 45 via a diode D23 as necessary, as described later. At this time, the diodes D21 and D22 are wired-OR connected at a connection point 47a between the diodes D21 and D22 in the power supply line 27.

On the motor M side of the power supply lines 27 and 28 from the diode D21, a series circuit of resistors R31 and R32 and a resistor R31,
A connection point 47b between R32 is connected to a transistor T31 whose gate is connected. Transistor T31
Are connected to the reference potential Vcc, and the output from the collector is input to the motor stop circuit 48. The motor stop circuit 48 switches a transistor T32 having a power switch function such as a power transistor provided on the power supply line 28 from a conductive state to a cutoff state in response to a predetermined level change of the output from the transistor T31.

In this embodiment, when the power switch SW is turned off, no power current is supplied to the motor M,
A charging current flows in the forward direction through the diode D23 by the charging circuit 46, and the battery 45 is charged. When the power switch SW is turned on, the DC current from the battery 45 and the DC current through the rectifying / smoothing circuit 43 are supplied to the motor M through the wired-OR connection.

Here, after the power switch SW is turned on, the power transformer 41 and the battery 45 supply the motor M within the rating of the power transformer 41 and the battery 45.
Are in the normal range where overdischarge does not occur, resistors R31 and R3
2, the reference potential Vcc, the reference potential Vcc
Is divided by the resistors R31 and R32, and the divided voltage VA extracted from the connection point 47b and the steady power supply voltage V0 from the power transformer 41 and the battery 45 are set so that Vcc <VA <V0 (3) I do.

At this time, as long as the relationship of the fourth equation holds, the transistor T31 is in the off state, a low-level signal is input to the motor stop circuit 48 as an example, and the motor stop circuit 48 Maintain the conduction state.

At this time, if a current exceeding the capacity of the power transformer 42 continues to flow through the power lines 27 and 28 due to, for example, the overload state of the motor M, the current from the battery 45 also continues to flow. Therefore, battery 4
5 will continue for too long, and the battery 4
5 gradually decreases. As the output voltage of the battery 45 decreases, the divided voltage VA at the connection point 47b decreases. When the relationship of Vcc> VA (4) holds, the transistor T31 switches from the off state to the on state, and the motor stop circuit 48 is supplied with a high level signal. The motor stop circuit 48 detects this switching of the signal level, and
Is switched from the on state to the off state. In this way,
The supply of the power supply current to the motor M is stopped, and the motor M is stopped.

As a result, the motor M is stopped before the battery 45 is over-discharged. Therefore, the problem that the life of the battery 45 is shortened due to the over-discharge of the battery 45 is prevented, and the life of the battery 45 is extended. Can be realized.

In this embodiment, since the overdischarge of the battery 45 is prevented, it is possible to prevent the voltage between the terminals of the battery 45 from being lowered due to the overdischarge. For this reason, the current IB flowing through the diode D22, which is assumed when the battery 45 is overdischarged, decreases, and the current IT from the power transformer 42 flowing through the diode D21 increases accordingly, and the power transformer 42 is overloaded. In this state, it is possible to prevent the temperature from excessively rising, and to prevent the occurrence of problems such as the blowing of a fuse normally provided in the power transformer 42. That is, it is possible to cope with an overload state of the power transformer 42, and in this respect, usability is remarkably improved.

FIG. 7 is a circuit diagram showing an electrical configuration of a modification of the third embodiment shown in FIG. In the control device 21e having the configuration shown in FIG. 6, a transistor T33 and a relay switch 49 shown in FIG. 7 may be used instead of the transistor T32 and the motor stop circuit 48. At this time, the exciting coil 50 of the relay switch 49
Is connected to the power supply line 28, and the other end is connected to the emitter of the transistor T33. Transistor T33
Is connected to the reference potential Vcc, and the gate is connected to the connection point 47. The changeover switch 51 turned on / off by the exciting coil 50 is connected in series to the power supply line 28.

In this modification, as described above, as long as the relationship of the fourth equation holds, the transistor T33 is on and the switch 5 of the relay switch 49 is turned on.
1 continues the conduction state. On the other hand, if a current exceeding the capacity of the power transformer 42 continues to flow through the power lines 27 and 28, the discharge of the battery 45 continues for an excessively long time, and the output voltage of the battery 45 gradually decreases. At this time, when the voltage division value VA at the connection point 47 satisfies the relationship of the fifth equation, the transistor T33 switches from the on-state to the off-state, and the exciting current to the exciting coil 50 stops. Thereby, the changeover switch 51 is switched from the conductive state to the cutoff state. In this way, the supply of the power supply current to the motor M is stopped, and the motor M is stopped.

Thus, also in this embodiment, the same operation and effect as those in the third embodiment can be realized.

FIG. 8 is a circuit diagram showing an electrical configuration of still another modification of the third embodiment. This modification is similar to the third embodiment, and corresponding portions are denoted by the same reference numerals. It should be noted that in this embodiment, in the configuration of the third embodiment, the transistor T32 is connected in series to the power supply line 27, the emitter of the transistor T34 is connected to the reference potential Vcc, and the collector is connected to the motor stop circuit 48. That is.

Also in this modified example, as long as the relationship of the fourth equation is satisfied, the transistor T34 is on, and a high-level signal is input to the motor stop circuit 48, for example. At this time, the motor stop circuit 48 outputs a low-level signal, for example, to make the transistor T32 conductive.

On the other hand, if a current exceeding the capacity of the power transformer 42 continues to flow through the power lines 27 and 28, the battery 4
The discharge of battery 5 will continue for too long,
5 gradually decreases. At this time, the connection point 47
When the divided voltage value VA of the above expression has the relationship of the fifth formula, the transistor T34 switches from the on-state to the off-state,
The output to the motor stop circuit 48 becomes low level. At this time, the motor stop circuit 48 outputs a high-level signal and switches the transistor T32 to the cutoff state. In this way, the supply of the power supply current to the motor M is stopped, and the motor M is stopped. Thereby, also in this embodiment,
The same operation and effect as those in the third embodiment are realized.

[0096]

As described above, according to the DC motor control device of the present invention, by appropriately operating the plurality of operation switches of the remote operation device, the identification signal generating means can operate the operation switch of the remote operation device. , Different types of identification signals are generated. The identification signal from the identification signal generating means is input to a driving unit, and the driving unit drives the selected motor at a rotation speed corresponding to the input identification signal.

When all the motors are rotated at a rotational speed other than the constant speed, the identification signal generated when the operation switch is operated to select a predetermined motor corresponds to the desired rotational speed. Thus, the identification signal generating means is determined.

Thus, even when a plurality of motors all have the same characteristics, when a predetermined motor is selected by the remote control device, an identification signal corresponding to a desired rotation speed is output from the identification signal generating means. The generated and selected motor is rotationally driven at the desired rotational speed.

Therefore, when all the motors are to be rotated at non-constant rotation speeds, a plurality of types of motors having different rotation speeds are used, or the rotation from each motor is reduced to a predetermined reduction ratio. The necessity of using n types of power transmission mechanisms having mutually different reduction ratios as power transmission mechanisms for transmitting power by the motor is eliminated, and the motors and the power transmission mechanisms and the like all have the same characteristics. Thus, the number of types of parts can be reduced, and the labor required for manufacturing can be significantly reduced. Further, the rotation speed of each motor can be easily adjusted by changing only the identification signal generating means in each motor, or making the element for determining the type of the identification signal generated from the identification signal generating means variable. In this respect, usability is greatly improved.

In the motor control device according to the second aspect of the present invention, in the first aspect of the present invention, the identification signal generating means includes a plurality of resistors connected in series, and a predetermined connection point between the resistors is connected to each other. In this case, there is provided a voltage dividing circuit that is connected to the operation switches and generates a divided voltage obtained by dividing the reference voltage according to the operation mode of each operation switch as an identification signal.

Also in this case, by making each resistor a variable resistor or the like, it is possible to easily change the type of the identification signal which is a divided voltage by a plurality of resistors, and to adjust the rotation speed of each motor. It can be done easily. Therefore,
It is possible to achieve the same curing effect as the above-described effects.

In the motor control device according to the third aspect of the present invention, the switching mode of the changeover switch is controlled by appropriately operating the plurality of operation switches of the remote control device, and supply / cutoff of the drive current to each motor. Is set.
That is, by appropriately operating the operation switch, a desired motor can be individually driven or stopped among a plurality of motors.

At this time, at least one of the plurality of changeover switches provided in the control device is provided with current adjusting means for adjusting the current flowing through the changeover switch when the changeover switch is turned on. An operation switch provided in the remote control device is connected to each of the changeover switches. When the operation switch is operated, a current flows to the operation switch via the controlled changeover switch. This current is detected by a current amount detecting means, the total amount of current flowing through each operation switch. The motor stopping means stops at least some of the motors when the total current amount detected by the current amount detecting means exceeds a predetermined range.

That is, when a changeover switch provided with the current adjusting means having appropriately set characteristics or a plurality of changeover switches including the changeover switch is controlled by operating an operation switch, the total current detected by the current detection means is controlled. The current has a different amount of current compared to a case where only the changeover switch provided with no current adjusting means is controlled by the operation switch. Therefore, by appropriately setting the range of the predetermined amount of current relating to the current detected by the current detecting means, the motor corresponding to the changeover switch having the current adjusting means or the changeover switch not having the current amphoteric means can be supported. Control such as simultaneous driving prohibition or simultaneous driving prohibition can be performed on a specific motor combination including a motor, and usability is significantly improved.

In the motor control device according to the fourth aspect of the invention, the power supply current from the power supply section is supplied to the motor via the power supply line. When the power switch provided on the power supply line is in a conductive state, the power supply current from the power supply unit and the power supply current from the secondary battery are supplied to the motor. When the power switch is turned off, the secondary battery is charged by the charging unit. Here, in a case where the power switch is kept conducting and the discharge of the secondary battery continues, when the discharge of the secondary battery becomes equal to or more than a predetermined degree, the motor stop unit detects this and stops the motor. As a result, the power supply current stops flowing through the power supply line. The rechargeable battery is charged.

Here, as described above, even if the power switch is kept conducting, the motor drive is automatically stopped when the discharge of the secondary battery becomes equal to or greater than a predetermined level. The situation where the secondary battery is overdischarged is prevented, and the life of the secondary battery can be extended. In addition, since the secondary battery is prevented from being over-discharged, the power supply current supplied from the secondary battery to the motor decreases due to a decrease in the terminal voltage of the secondary battery after the over-discharge, and A situation in which the supplied power supply current increases is prevented. Accordingly, it is possible to prevent the power supply unit from being overloaded, and to prevent a problem that an undesired change in characteristics of the power supply unit or physical damage occurs.

According to a fifth aspect of the present invention, there is provided the motor control device according to the fourth aspect, further comprising a reference voltage generating section for generating a predetermined reference voltage, wherein the motor stopping section divides the voltage between the power supply lines. Voltage dividing means for outputting a divided voltage by voltage dividing, and a switch driving means for shutting off a second power switch provided in series with the power supply line when the divided voltage from the voltage dividing means falls below the reference voltage. Have.
Even in such a case, the same operation and effect as the above operation and effect can be realized.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a motor control device 21 according to a first embodiment of the present invention.

FIG. 2 shows a motor control device 21 according to a modification of the present embodiment.
It is a circuit diagram of b.

FIG. 3 is a circuit diagram of a motor control device 21c according to a second embodiment of the present invention.

FIG. 4 is a system diagram of a configuration related to a linear actuator of a nursing care pet.

FIG. 5 is a circuit diagram of a motor control device 21d according to a modification of the embodiment.

FIG. 6 is a circuit diagram of a motor control device 21e according to a third embodiment of the present invention.

FIG. 7 is a circuit diagram showing an electrical configuration of a modification of the third embodiment.

FIG. 8 is a circuit diagram showing an electrical configuration of still another modification of the third embodiment.

FIG. 9 is a circuit diagram of a typical first prior art control device 1;

FIG. 10 is a circuit diagram of a motor control device 1a according to a second prior art.

FIG. 11 is a circuit diagram of a motor control device 1b according to a third prior art.

[Explanation of symbols]

21, 21a, 21b, 21c, 21d, 21e, 21
f Control device 22 Control device main body 23 Remote control 24a, 24b, 24c, 24d, 24e, 24f, 4
9 Relay switches 25a, 25b, 25c, 25d, 25e, 25f, 5
0 Excitation coil 26 DC power supply 27, 28 Power supply line 29a, 29b, 29c, 29d, 29e, 29f, 5
DESCRIPTION OF SYMBOLS 1 Changeover switch 30, 31, 47 Connection point 32 Operation unit 33 Speed amplifier circuit 34 PWM circuit 35 Gate driver circuit 36 Identification signal generation unit 37 Comparison circuit 38 Linear actuator 39 Drive unit 41 Power supply transformer 42 AC power supply 43 Rectification / smoothing circuit 44 Constant voltage circuit 45 Battery 46 Charging circuit 48 Motor stop circuit C21 Capacitors D11, D12, D13, D14, D21, D22, D
23 Diode FB Rotation speed detection signal M1, M2, M3 Motor R11, R12, R13, R21, R22, R23, R
31, R32 resistance SW power switch SWa, SWb, SWc, SWd, SWe, SWf, S
1, S2 Operation switch T11, T31, T32, T33, T34 Transistor V1, Vcc Reference potential Vs Identification signal

Claims (5)

[Claims] A control device for individually controlling the driving states of a plurality of motors, comprising: a changeover switch provided for each motor to supply / cut off a drive current to each motor; and a switching state of each changeover switch. A plurality of operation switches to be controlled are provided corresponding to the respective changeover switches, and a remote operation device is connected to the remote operation device and corresponds to an operation mode of each operation switch for selecting a motor to be driven. A motor control device, comprising: identification signal generating means for generating different types of identification signals; and a drive unit for driving the selected motor at a rotation speed corresponding to the identification signal from the identification signal generating means. 2. The identification signal generating means according to claim 1, wherein a plurality of resistors are connected in series, a predetermined connection point between each resistor is connected to each operation switch, and a reference voltage corresponding to an operation mode of each operation switch. The motor control device according to claim 1, further comprising a voltage dividing circuit that generates a divided voltage obtained by dividing the voltage as an identification signal. 3. A control device for individually controlling the driving states of a plurality of motors, wherein the control device is provided for each motor and supplies / disconnects a drive current to each motor, and is connected to at least one changeover switch. Current control means for adjusting a current flowing through the changeover switch when the changeover switch is turned on; and a remote control device provided with a plurality of operation switches respectively connected to the changeover switches and respectively controlling a switching state of each changeover switch. Current amount detecting means commonly connected to each operation switch and detecting the total amount of current flowing through each operation switch; at least when the total amount of current detected by the current amount detecting means exceeds a predetermined range, A motor control device comprising: a motor stopping means for stopping a part of the motor. A power supply for supplying a drive current to the motor; a power switch provided on a power supply line connecting the power supply and the motor; and a power supply provided on the power supply side of the power supply line with respect to the power supply switch. A charging unit that charges the secondary battery when the power switch is turned off, and a motor stop unit that stops the motor by detecting that the discharge of the secondary battery has exceeded a predetermined level. Motor control device provided. 5. A reference voltage generating section for generating a predetermined reference voltage, wherein said motor stop section divides a voltage between said power supply lines to output a divided voltage, and said voltage dividing means. A switch driving means for turning off a second power switch provided in series with the power supply line when the divided voltage from the power supply falls below the reference voltage.
3. The motor control device according to claim 1.