JPH0923571A - Small electrical equipment - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] In a small electric device using a motor as a load, when an abnormality such as the rotation of the motor is locked or the winding is short-circuited, the abnormality can be detected quickly and reliably. At the same time, enable danger avoidance operation that appropriately corresponds to the details of the motor abnormality. A transistor 89 for interposing a switching transistor 89 in series with a motor 15 and for detecting an abnormality of the motor 15 increases with an increase in load current.
The surface temperature and collector-emitter voltage are detected individually, and when the temperature rises, it is judged to be a problem in use and the driving of the motor 15 is temporarily stopped, while the voltage rises. Causes the drive of the motor 15 to be constantly stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small electric device such as an electric razor which uses a motor as a drive source, and more particularly to a small electric device provided with means for detecting an abnormality of the motor.

[0002]

2. Description of the Related Art Conventionally, in a small electric device of this type, whether or not the motor itself is rotationally driven is checked directly or indirectly, and the motor rotation is stopped in spite of being supplied with drive power. When it is detected that it has been performed, it is common to display it and inform the operator.

[0003]

By the way, in recent years, there has been an increasing demand for safety in circuit operation, and there is a demand for the development of a safety device that operates more reliably. The present inventor has also conducted research on motor abnormality detection. As a result, when a switching transistor is provided in series with the motor, in addition to the surface temperature of the transistor in accordance with the magnitude of the load current flowing through the motor, We have found that the terminal voltage also rises, and the operating state of the motor can be double detected by changes in temperature and voltage.

The present invention has been made on the basis of the above-mentioned findings. When an abnormality such as the rotation of the motor being locked or the internal short circuit occurring, the abnormality can be detected quickly and surely. An object of the present invention is to provide a small electric device capable of performing a risk avoidance operation that appropriately responds to the contents of a motor abnormality.

[0005]

In order to achieve the above-mentioned object, a small electric device according to the present invention has a motor 1 as shown in FIG.
5 and a switching element such as a switching transistor 89 which is connected in series with the motor 15 and regulates the energization timing.

The present invention is characterized in that the switching element is automatically turned off when at least one of the voltage and the amount of heat generated corresponding to the magnitude of the current flowing through the motor 15 exceeds a set value. .

When the switching element is a transistor, a terminal voltage detecting means is provided by utilizing the fact that the collector-emitter voltage changes depending on the magnitude of the current flowing through it. Further, a temperature detecting means is provided by utilizing that the surface temperature of the element changes in accordance with the amount of heat generated. The voltage detecting means may be a means for detecting a voltage drop through a resistor in series with the motor or a means for detecting a terminal voltage of the motor. As the means for detecting the amount of heat generated, it is also possible to detect the surface temperature of the resistor which can be provided for detecting the voltage, the surface temperature of the motor, or the ambient temperature thereof.

Therefore, the structure for turning off the transistor 89 described above corresponds to the temperature detecting means capable of outputting a signal corresponding to the change in the surface temperature of the transistor 89 and the change in the emitter-collector voltage of the transistor 89. An ON signal is output to the switching transistor 89 while the voltage detection means capable of outputting a signal and the temperature detected by the temperature detection means are lower than a set value or the voltage detected by the voltage detection means is lower than the set value. Then
It is possible to provide a comparison unit that outputs an OFF signal when the detected temperature exceeds the set value or the detected voltage exceeds the set value.

Further, while the above-mentioned motor 15 drives the inner blade 14 of the electric razor, the temperature detecting means is provided with a thermistor 91 and a fixed resistor 92 provided on the surface of the transistor 89 to generate a motor drive voltage. It is assumed that the voltage is divided and the detection voltage is output from both ends of the fixed resistor 92, and the voltage detection means forms the reference voltage by dividing the motor drive voltage by the two fixed resistors 94 and 95.
The resistor 95 for generating the reference voltage may be short-circuited by the switching element 96 that is turned on when the emitter-collector voltage of the transistor 89 exceeds the set value. Further, it is preferable that the comparison means is an OP amplifier 93, and the reference voltage output from the voltage detection means is input to the positive side terminal thereof, while the detection voltage output from the temperature detection means side is input to the negative side terminal thereof.

In the above structure, for example, when the main switch 42 is turned on, an on signal is applied to the transistor 89 via the resistor 90 at the same time, so that the transistor 89 is turned on.
Is turned on, the electric power output from the battery 16 is supplied to the motor 15, and the motor 15 starts rotational driving.

In the overload state where the rotation of the motor 15 is locked, the load current flowing through the transistor 89 increases above the rated value. As a result, the surface temperature of the transistor 89 rises, the temperature rise is detected by the thermistor 91 provided in the temperature detecting means, and the output of the comparing means is inverted to forcibly turn off the transistor 89. As a result, the motor 15 is energized. Will stop. This deenergized state is released when the surface temperature of the transistor 89 decreases, and the rotational driving of the motor 15 is restarted.

On the other hand, in an abnormal state where the motor 15 is short-circuited internally, the output voltage of the battery 16 is directly applied to the transistor 89, so that the collector-emitter voltage of the transistor 89 rapidly rises. This voltage increase turns on the switching element 96 in the voltage detection means, shorts both ends of the resistor 95, and lowers the reference voltage. At the same time, the surface temperature of the transistor 89 also rapidly rises, and the temperature detection means lowers the detection voltage,
The detection voltage input to the comparison means rapidly exceeds the reference voltage, the output of the comparison means is inverted, the transistor 89 is turned off, and the power supply to the motor 15 is stopped. The detection state of the voltage by the voltage detecting means is maintained by the voltage supplied through the motor 15, and the energized state of the motor 15 is maintained as it is.

[0013]

As described above, according to the present invention, the abnormality of the motor 15 is detected by individually detecting the temperature and the voltage which increase with the increase of the load current, and when the temperature rises, the motor is not used. While temporarily stopping the driving of the motor 15 due to the problem of
By constantly stopping the drive of the motor 5,
The difference between the abnormal states can be accurately determined, and the risk avoiding operation due to the difference in the motor abnormality can be performed more reliably and stably.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An example of carrying out the present invention on an electric shaver will be shown below, but the present invention is not limited to this, and can be carried out in a similar manner to various small electric devices using a motor as a drive source such as an electric toothbrush. Of course.

In the electric shaver embodying the present invention, as shown in FIGS. 2 and 3, an outer blade holder 11 having an outer blade 10 on the upper surface side is detachably attached to an upper portion of a main body case 12, and Inside the outer blade 10, a cylindrical inner blade 14 provided with a spiral blade surface 13 on its peripheral surface is slidably arranged. Further, inside the body case 12, the inner blade 14
A motor 15 for rotationally driving the motor 15, a secondary battery 16 for supplying electric power for rotational driving to the motor 15, and a secondary battery 1 for the secondary battery 16.
Electronic circuit 1 for performing various controls such as charge control for 6
Store 7.

Further, a switch knob 18 of a main switch 42 which is formed in a sliding manner to regulate the timing of energizing the motor 15 is provided in the center of the front surface of the main body case 12, and below the switch knob 18, the secondary battery 16 of the secondary battery 16 is provided. Six light emitting diodes 19a to 19a to perform display corresponding to charge / discharge states
A battery capacity indicator 20 in which 9f are arranged vertically is provided. Furthermore, a power cord (not shown) having a power plug at the tip is provided at the lower part of the main body case 12 so that it can be inserted and removed, and in addition to charging the secondary battery 16, the commercial AC power source 21 directly drives the motor 15. It enables various driving.

FIG. 3 is a block diagram schematically showing the entire electronic circuit 17 incorporated in the main body case 12 described above, which is 100 to 240 V supplied from the commercial AC power source 21.
Rectifying and stepping down the AC voltage of the
A power supply unit 23 for supplying a low-voltage DC voltage necessary for driving the electronic circuit 17, an output control unit 24 for regulating the output state of the inverter circuit 22, and a charging for the secondary battery 16 provided in the power supply unit 23. The charge control unit 25 for regulating the state, the display control unit 26 for displaying the state of charge of the secondary battery 16, the motor control unit 27 for regulating the operation state of the motor 15, and the operation of each of the above-described units are described. A central control unit 28 for comprehensive regulation is provided.

Here, the power supply unit 23 is provided with a secondary battery 16 such as a nickel-cadmium battery capable of charging and discharging a plurality of times, in addition to the inverter circuit 22 having a structure similar to the conventional one, and is charged from the inverter circuit 22. Main power source 29 and the secondary battery 1 in the main power source 29 when the inverter circuit 22 operates.
A first auxiliary power source 30 that is connected to 6 and is capable of supplying a predetermined low-voltage DC voltage, and a second auxiliary source that directly rectifies and steps down the supply voltage from the commercial AC power source 21 to form a predetermined low-voltage DC voltage. It consists of a power supply 31 and a motor 15 if necessary.
Alternatively, electric power is supplied to the electronic circuit 17.

The output control unit 24 includes the first to third control circuits 32.
The output control of the inverter circuit 22 is provided by including 33 and 34, and the first control circuit 32 enables a substantially constant charge output control regardless of a large voltage change of the commercial AC power supply 21. On the other hand, the second and third control circuits 33,
In 34, the operation timing of the inverter circuit 22 is regulated in response to the input of various detection signals, and the electric power supplied to the main power supply 29 is controlled to prevent troubles such as overcharging or overheating.

The charge control unit 25 includes an upper limit voltage detection circuit 35.
And an upper limit temperature detection circuit 36.
By being driven by the power supplied from the auxiliary power source 30,
The inverter circuit 22 operates according to the operation timing. Here, the upper limit voltage detection circuit 35 examines the change in the terminal voltage Vm of the secondary battery 16 during charging, determines that the charging of the secondary battery 16 has reached a predetermined value when it exceeds a preset voltage value, and determines The detection signal Sh is sent to the control unit 28, and the steady charging control operation is started.

On the other hand, when the terminal voltage Vm of the secondary battery 16 reaches the peak value without the upper limit voltage detecting circuit 35 detecting the voltage, the upper limit temperature detecting circuit 36 detects the internal resistance of the secondary battery 16. When it is detected that the surface temperature of the battery temperature rises above the set temperature due to the increase, the detection signal S1 is sent directly to the output control unit 24, and the inverter circuit 2
The operation of 2 is forcibly stopped to prevent overcharge.

The central control unit 28 has a RAM 37 or R
A so-called "one-chip type microprocessor" in which various peripheral circuits such as the OM38 are integrally formed is used.
It operates in synchronization with the input of the clock signal,
Various buses 41 are provided between the central processing unit 39 and the I / O device 40.
Through the input port on the I / O device 40 so that the detection signals output from the above-described units can be captured. Further, such input signal is used as control data, and RO
Various arithmetic operations are performed according to a program stored in M38, and output control of a predetermined inverter circuit 22 from the output port via the output control unit 24 or display corresponding to a change in battery capacity of the secondary battery 16 is performed. Display 2
It outputs various control signals for performing 0.

The motor controller 27 includes a main switch 42.
The drive timing is supplied from the main power supply 29 to the motor 15 in conjunction with the ON operation of the motor 15 to rotate the motor, and the motor 15 is energized, but the energized state is abnormal. If it detects it, the motor 15
A motor abnormality detection circuit 44 for forcibly stopping the motor to prevent circuit damage, and a blade temperature detection circuit 45 for lowering the rotation speed of the motor 15 when an increase in blade temperature is detected.

The display control unit 26 is for supplying data for calculating the capacity change of the secondary battery 16 in the central control unit 28 when the motor is driven by the main power supply 29, and the load amount detecting circuit 46. When the magnitude of the power consumption of the motor 15 is detected at, the detection signal Sc corresponding thereto is detected.
To the central control unit 28 to relatively correct the discharge rate of the secondary battery 16.

Further, when the lower limit voltage detection circuit 47 detects that the terminal voltage Vm of the secondary battery 16 is lower than the set value, the detection signal Sb is output to absolutely correct the battery capacity to the preset lower limit value. Furthermore, the reset circuit 4 indicates that the terminal voltage is lower than the voltage that can drive the electronic circuit 17.
8 is detected, the central control unit 28
Reset signal Sr is sent to reset the circuit operation to the initial state.

When the AC input detecting circuit 49 detects the time when the AC input 21 is connected to the commercial AC power source 21, the detection signal S is detected.
a is output to switch the capacity change of the secondary battery 16 from the discharging side to the charging side, while the signal Ss corresponding to the on / off state of the main switch 42 is generated, and the standby state of the secondary battery 16 is switched to the discharging state. The central control unit 28 is notified of the time. Similarly, the above-mentioned charge control unit 25 also generates the signals Sh and St corresponding to the detected state, which are used for absolute correction of the charge amount display.

The configuration of each part in FIG. 3 schematically showing the contents thereof will be described more specifically based on the electric circuit diagrams shown in FIGS. 4 to 6.

[0028]

[Power Supply Unit] The inverter circuit 22 provided in the power supply unit 23 is
As shown in FIG. 4, the diode bridge 50 and the filter 5
1 and a rectifier circuit 53 having a temperature fuse 52 are provided on the input side, and the commercial AC power source 21 input to the main body case 12 via a detachable power source plug 54 is rectified by the rectifier circuit 5.
After full-wave rectification in 3, the voltage is applied to the inverter circuit 22.

The inverter circuit 22 includes a primary coil 56 and the primary coil 5 on the collector side of the output transistor 55.
A shock absorbing portion 57 that is connected to both ends of 6 and absorbs a shock voltage generated when the output transistor 55 is turned off is interposed, and a feedback portion 58 is provided between the base and the emitter.
Further, a feedback coil 59 and an output coil 60 are wound on the same iron core as the primary coil 56.

The feedback section 58 connects one end of the feedback coil 59 to the base end of the output transistor 55 and
A capacitor 61 and an emitter resistor 62 are connected between the other end of the output transistor 55 and the emitter of the output transistor 55, and a diode 63 is connected in parallel with the capacitor 61.
Further, the output voltage Vh from the rectifier circuit 53 can be applied to the connection point between the feedback coil 59 and the capacitor 61 via the resistor 64.

With the above structure, the charging of the capacitor 61 is started via the resistor 64 at the same time when the voltage is applied to the inverter circuit 22. When the voltage across the capacitor 61 rises to near the turn-on voltage of the output transistor 55, a current begins to flow in the primary coil 56 connected to the collector end of the transistor 55, and the increase in the current causes a voltage to appear in the feedback coil 59. Occurs. This voltage flows between the base and emitter of the output transistor 55, turning on the output transistor 55 and simultaneously rapidly charging the capacitor 61 in the opposite direction.

When the current flowing through the primary coil 56 is stabilized and the voltage across the feedback coil 59 decreases, the charging voltage of the capacitor 61 becomes a blocking voltage and the output transistor 55 is rapidly turned off. After the output transistor 55 is turned off, the charging voltage of the capacitor 61 is rapidly discharged through the diode 63, and then the capacitor 61 is charged in the positive direction through the resistor 64, and the on / off operation is repeated.

The main power source 29 connects the secondary battery 16 in series through the rectifying diode 65 and the smoothing coil 66 to both ends of the output coil 60 described above, and the diode between the smoothing coil 66 and the secondary battery 16 is connected. 67 connected to the output transistor 55 of the inverter circuit 22.
When ON, the pulsed charging current is sent from the output coil 60 to the secondary battery 16 via the rectifying diode 65, while the energy stored in the smoothing coil 66 during the ON period of the output transistor 55 is the output transistor. 55
Is turned off, it is sent to the secondary battery 16 via the diode 67 to be charged. The voltage V extracted from this main power supply 29
Since m has a relatively large capacity and is output irrespective of the input of the commercial AC power source 21, it is a circuit that needs to be in an always operable state such as motor drive or battery capacity display. Power is supplied to the.

On the other hand, the first auxiliary power supply 30 has a relatively large-capacity smoothing capacitor 69 at the emitter end of the switching transistor 68, a positive pole of the secondary battery 16 at the collector end, and a diode 70 at the base end. One end of the output coil 60 is connected via each. With such a configuration,
The pulse voltage output from the output coil 60 during the ON period of the output transistor 55 causes the transistor 68 to operate.
Is intermittently turned on, the secondary battery 16 is connected in parallel to the capacitor 69, and the capacitor 69 is rapidly charged to supply electric power at the charging voltage V1, and an inverter like the charging control unit 25 is provided. It is used as a power source for circuits that need to be operated in a limited manner only while the circuit 22 is operating.

The second auxiliary power supply 31 is the rectifier circuit 5 described above.
The high voltage Vh output from the device 3 is stepped down using the high resistance 71 and the constant voltage diode 72, and the output voltage V2 is stabilized by the capacitor 73 connected in parallel with the constant voltage diode 72. AC power supply 21
It operates in response to the application of the voltage, and a stable voltage can be output regardless of the control state of the inverter circuit 22.

[0036]

[Output Control Unit] The first control circuit 32, as shown in FIG.
100 to the voltage supplied from the commercial AC power supply 21
The power supplied from the inverter circuit 22 to the secondary battery 16 can be maintained substantially constant regardless of a large change of 240V, and a control transistor 74 is provided on the base side of the output transistor 55. By turning on the transistor 74 with the voltage across the emitter resistor 62, the output transistor 55 is forcibly turned off when the current flowing through the primary coil 56 exceeds a set value, and the output coil 60 is turned on.
Limits the current supplied from the secondary battery 16 to the secondary battery 16. Furthermore,
A zener diode 75 and a diode 7 are provided between one end of the output coil 60 and the base end of the control transistor 74.
6 is interposed, and when the input voltage to the inverter circuit 22 rises and the output voltage from the output coil 60 rises above the set value, the Zener diode 75 turns on and the control transistor 74 turns on, and the output The transistor 55 is forcibly turned off to suppress the output power from the output coil 60.

The second control circuit 33 is the inverter circuit 22.
A switching transistor 77 connected between the base end of the output transistor 55 and the ground,
When a predetermined control signal S1 is input from the upper limit temperature detection circuit 36 to the base end of the transistor 77, the transistor 7
7 is turned on, the base end of the output transistor 55 is forcibly grounded, and the operation of the inverter circuit 22 is constantly stopped.

The third control circuit 34, like the second control circuit 33, is connected between the base terminal of the output transistor 55 and the ground.
Darlington-connected switching transistor 78
Connected to the central control unit 28 or the blade temperature detection circuit 45.
Is turned on by the control signals S2 and S3 output from
The operation of the inverter circuit 22 is intermittently stopped.

[0039]

[Charging Control Unit] As shown in the detailed configuration of FIG. 5, the charging control unit 25 includes an upper limit voltage detection circuit 35 driven by the first auxiliary power supply 30 and the first and second auxiliary power supplies 30 and 3.
And an upper limit temperature detection circuit 36 driven by 1. The upper limit voltage detection circuit 35 uses the forward voltage of the diode 80 temperature-corrected by the thermistor 79 as a reference voltage,
When the detection voltage exceeds the reference voltage by dividing the output voltage V1 of the first auxiliary power supply 30 by the resistors 81 and 82 to create a detection voltage and comparing the both with the comparator 83 including an OP amplifier. Predetermined detection signal Sh
To the central control unit 28 to notify that the charging voltage for the secondary battery 16 has exceeded a predetermined upper limit value.

On the other hand, in the upper limit temperature detection circuit 36, the first thermistor 84 is provided on the surface of the secondary battery 16, while the second thermistor 84 is provided.
The thermistor 85 is provided on the circuit board, and resistors 86 and 87 are connected in series with both thermistors 84 and 85. Further, during the period of being connected to the commercial AC power source 21, the voltage V2 is constantly supplied from the second auxiliary power source 31 regardless of the operating state of the inverter circuit 22, and the surface temperature of the secondary battery 16 is supported from both ends of the resistor 86. A reference voltage corrected by the temperature around the substrate is taken out from both ends of the detected voltage. The detected voltage is further compared in magnitude with a reference voltage by a comparator 88 composed of an OP amplifier,
When the surface temperature of the secondary battery 16 exceeds a preset upper limit value, it is determined that the fully charged state is sufficiently exceeded, and the second control circuit 3
3 to send a control signal S1 to forcibly stop the inverter circuit 22 to prevent overcharge.

[0041]

[Motor Control Unit] The motor control unit 27 has a rotation timing control circuit 43 for flowing a load current to the motor 15 in synchronism with the ON operation of the main switch 42, as shown in FIG.
The motor abnormality detection circuit 44 that forcibly stops energization to the motor 15 when the load current to the motor 15 exceeds the set value, and regulates the output voltage of the inverter circuit 22 when the blade temperature exceeds the set value. And a blade temperature detection circuit 45 that can reduce the rotation speed of the blade 15.

The rotation timing regulating circuit 43 is a transistor 89 connected in Darlington. When the main switch 42 is turned on, a predetermined voltage is applied from the main power source 29 to the base terminal of the transistor 89 via the resistor 90 to turn the transistor 89 on. When turned on, the motor 15 connected to the collector side is energized.

In the motor abnormality detection circuit 44, when the load current flowing in the motor 15 increases, the collector current flowing in the transistor 89 of the rotation timing regulating circuit 43 also increases, and as a result, the collector-emitter voltage of the transistor 89 and the transistor 89. The fact that the surface temperature rises together is used, and when at least one of the temperature and the voltage rises above the set value, this is detected and the power supply to the motor 15 is stopped. That is, by individually detecting changes in temperature and voltage by the temperature detecting means and the voltage detecting means, a motor abnormality such as rotation of the motor 15 being locked or a rare short circuit inside the motor 15 can be detected quickly and reliably. In addition to making it possible, it is possible to perform a risk avoidance operation that appropriately responds to the details of the motor abnormality.

Here, as a structure for detecting an abnormality due to temperature, the thermistor 91 is brought into close contact with the surface of the transistor 89 and the output voltage Vm from the main power source 29 is used.
Is divided by the thermistor 91 and the resistor 92 to extract a detection voltage corresponding to the surface temperature of the transistor 89. This detected voltage is input to the negative terminal of the comparator 93 composed of an OP amplifier, while the comparator 93
A reference voltage obtained by dividing the voltage Vm from the main power supply 29 by the resistors 94 and 95 is applied to the positive terminal of the.

Furthermore, by setting the values of the resistors 91, 92, 94, and 95 so that the reference voltage and the detected voltage match at a preset temperature, the surface temperature of the transistor 89 is lower than the set value. The reference voltage is higher than the set voltage during the interval, the output terminal of the comparator 93 is opened, and the “H” level signal is applied to the control terminal of the transistor 89 through the resistor 90, and the transistor 89 is turned on to turn on the motor. The energization state of 15 is maintained. However, when the surface temperature of the transistor 89 rises above the set value, the detection voltage drops below the reference voltage, and as a result, the output terminal of the comparator 93 is grounded and inverted to the "L" level, turning off the transistor 89 and turning on the motor. The power supply to 15 is forcibly stopped. When such a stop state of energization continues, the surface temperature of the transistor 89 also drops, and the detection voltage accordingly drops. Therefore, the output side of the comparator 93 returns to the “H” level again, turning on the transistor 89 to turn on the motor 15. Re-energize to.

That is, the inner blade 1 like the rotary type
In an electric shaver having a relatively large contact resistance between the outer blade 10 and the outer blade 10, if the outer blade 10 is pressed against the skin surface more than necessary and shaving is performed, the rotation of the inner blade 14 is locked or close to it. There is a risk of becoming. In such a case, the rise in the temperature of the transistor 89 is detected and the rotation of the motor 15 is once stopped to notify the operator of the defect in the usage state. When the user who knows such a motor stop moves the outer blade 10 away from the skin surface or weakens the pressing force,
If the temperature of the transistor 89 falls below the set value, the motor 15
After the rotation of is restarted, an appropriate load current is maintained,
Motor rotation continues.

On the other hand, the circuit configuration for detecting an abnormality by the voltage is such that the emitter / collector terminal of the switching transistor 96 is connected to both ends of the resistor 95 while the base terminal is connected to the transistor via the resistor 97 and the diode 98. It is connected to the collector end of 89.

Here, the collector-emitter voltage of the transistor 89 shows only a voltage change about twice as much as in the steady operation at the time of overload such as when the rotation of the motor 15 is locked. If a short circuit occurs between windings, the voltage will rise rapidly to near the power supply voltage.

Therefore, the collector-emitter voltage generated by the collector current flowing through the transistor 89 when the motor 15 is locked does not turn on the switching transistor 96, and when the motor 15 is short-circuited. The ON voltage of the switching transistor 96 is set in advance so that it is turned on for the first time by the voltage generated by the flowing current.

With such a configuration, when the outer blade 10 is overloaded and the rotation of the motor 15 is locked, the abnormality detection by the voltage does not work, and the abnormality detection by the temperature causes the motor 15 to be detected. Restrict energization. However, when the motor 15 is short-circuited, the voltage detection works before the above-mentioned temperature detection works, and the switching transistor 96 is turned on to forcibly stop the power supply to the motor 15. This stopped state is maintained as it is by the voltage Vm sent from the main power source 29 side via the motor 15 and informs the operator that the circuit is abnormal, not just a problem in use.

When the motor 15 is short-circuited as described above, it is required to stop the power supply to the motor 15 more quickly. In the present embodiment, the temperature detection means works in the direction of increasing the detection voltage input to the comparator 93 due to the temperature rise of the transistor 89, and cooperates with the voltage detection means which operates to decrease the reference voltage. Thus, the output of the comparator 93 is inverted more rapidly than in the case where the voltage detecting means is independent.

Further, in the present embodiment, the transistor 8
The base end of 9 is provided with a normally open switch 99 which is closed in conjunction with the removal of the outer blade holder 11, and the base end of the transistor 89 is grounded and turned off by the ON operation of the switch 99, forcing the rotation of the motor 15. By stopping the inner blade 14 from occurring, it is possible to prevent the inner blade 14 from being continuously driven when the outer blade 10 is removed.

Further, a motor-off state detection circuit 100 is provided in parallel with the base end of the transistor 89, and the transistor 101 is turned on / off at the same time by the voltage applied to the base end of the transistor 89, so that the power supply to the motor 15 can be stopped. "H" level detection signal Sm
Is sent to the central control unit 28 to inform that the motor 15 is stopped.

By the way, the rotation speed of the motor 15 increases / decreases according to the magnitude of the applied voltage, and the temperature of the inner blade 14 changes according to the rotation speed of the motor 15 and thus the inner blade 14 and the outer blade 10.
Increase or decrease according to the relative speed of. The blade temperature detection circuit 45 utilizes this, and when the drive voltage of the motor 15 exceeds the set value, it sends a predetermined control signal S3 to the above-mentioned third control circuit 34 to lower the output of the inverter circuit 22. .

That is, when the inverter circuit 22 is in operation, the output voltage Vm from the main power supply 29 is not only the secondary battery voltage having a steady value but also the pulse-shaped charging voltage generated from the inverter circuit 22. Are superimposed. on the other hand,
If the load applied to the motor 15 is light, such as when the electric razor is idled, the load current is also small, so the output voltage from the main power supply 29 is also high, and the motor 15 will rotate at a higher speed than during steady shaving. And

Therefore, the voltage V output from the main power supply 29 is
m is divided by resistors 102 and 103 to form a detection voltage,
The detected voltage is compared with a reference voltage sent from a lower limit voltage detection circuit 47, which will be described later, in the comparator 104, and the control signal S3 is supplied to the third control circuit 34 corresponding to the period in which the detected voltage having a value exceeding the reference voltage is applied. send. Then, the oscillating operation of the inverter circuit 22 is intermittently stopped, and the pulsed charging voltage in the thinned state is superimposed on the secondary battery voltage via the main power source 29 and applied to the motor 15. The motor 15 is rotationally driven at a rotational speed reduced as compared with the case where the control is not performed. This suppressed rotation state is
When the normal shaving operation is started, the peak value of the output voltage from the main power supply 29 is also lowered, and as a result, the inverter circuit 22 returns to the normal driving state.

[0057]

[Display control unit] The charge amount is displayed by the central control unit 28 described later.
Always check the charging / discharging state with respect to the secondary battery 16,
The battery capacity indicator 20 displays the current capacity. Here, in the display control unit 26, the load amount detection circuit 46 that outputs the detection signal Sc corresponding to the weight of the load on the motor 15, and the detection signal Sb when the battery capacity falls below the set value. A lower limit voltage detection circuit 47, a reset circuit 48 that generates a reset signal Sr when the battery capacity falls below the operable lower limit of the circuit, and an AC input detection circuit 49 that outputs a detection signal Sa indicating the charging time. Every time the charging / discharging state of the secondary battery 16 is detected together with the detection signals Sh and St output from the charging control unit 25, each signal is sent to the central control unit 28 to enable correction of the capacity display.

The load amount detection circuit 46 is used in the motor control section 27.
Using the fact that the collector-emitter voltage of the transistor 89 in the rotation timing control circuit 43 of FIG. 1 increases or decreases according to the magnitude of the load applied to the motor 15,
In this case, the amount of power consumption is detected in two steps, large and small. As shown in FIG.
The value divided by 06 and the forward voltage of the diode 107 are compared by a comparator 108 using an OP amplifier, and an “H” or “L” level detection signal Sc corresponding to the magnitude of the two is compared with the central control unit 28. Send to.

As shown in FIG. 6, the lower limit voltage detection circuit 47 is energized from the main power source 29 by the ON operation of the switching transistor 109 which is turned on in association with the ON operation of the main switch 42, and operates only during the motor driving period. To do. Further, the output voltage Vm from the main power supply 29 is divided by the resistors 110 and 111 to extract the detected voltage, and the thermistor 112 connected in series adjusts the amount of energization to adjust the temperature to obtain a reference voltage based on the voltage across the diode 113. Is normally maintained at the “H” level by comparing with the comparator 114, but a detection signal Sb that changes to the “L” level when the voltage falls below a preset lower limit voltage is sent to the central control unit 28. Then, the fact that the terminal voltage of the secondary battery 16 has fallen below the lower limit voltage is notified.

The reset circuit 48 controls the central control unit when charging is restarted and the terminal voltage rises after the operation of the central control unit 28 is stopped after the terminal voltage of the secondary battery 16 is lower than the lower limit voltage described above. By sending a reset signal Sr to the central control unit 28, the central control unit 28 is returned to the initial state, and the oscillation circuit 115 that self-oscillates when a voltage is applied from the secondary battery 16 and the secondary battery 16 are provided. When the terminal voltage exceeds a predetermined value, the switching circuit 116 stops the oscillation operation of the oscillation circuit 115.

The oscillator circuit 115 includes two transistors 1
In the multivibrator using 17 · 118, both transistors 117 · 118 are alternately turned on / off by applying a voltage Vm from the main power supply 29, and a rectangular wave reset signal Sr is supplied to the reset terminal of the central control unit 28. Can be applied continuously.

The switching circuit 116 divides the output voltage Vm of the main power supply 29 by the resistors 119 and 120 and turns on / off the transistor 121 by the divided voltage.
The voltage applied to the transistor 118 of the oscillation circuit 115 is bypassed between the collector and the emitter.

With such a configuration, when the secondary battery 16 is completely discharged and the terminal voltage is low, and therefore the charging is started when the transistor 121 is in the off state, first, the oscillation circuit 1
15 starts an oscillating operation, and a rectangular wave reset signal S
r is sent to the central control unit 28 to continue the reset operation.

When charging progresses and the output voltage Vm of the main power supply 29 rises and approaches the turn-on voltage of the transistor 121, the voltage applied to the oscillation circuit 115 decreases, and as a result, the oscillation circuit 115 stops and resets. The input of the signal Sr to the central control unit 28 is stopped, and the central control unit 28 starts the operation described in detail later.

As shown in FIG. 4, the AC input detecting circuit 49 is connected in parallel to the inverter circuit 22 on the output side of the rectifying circuit 53, and the power plug 54 is inserted into the outlet so that the electric razor can be used in the commercial AC power source 21 in the operating mode. The voltage of "H" level is normally applied from the main power supply 29, but when the commercial AC power supply 21 is input, it is output from the rectifier circuit 53. The full-wave rectified voltage Vh is divided by the resistors 71, 123, and 124,
The voltage generated across the resistor 124 causes the transistor 122 to
Is turned on and grounded, the detection signal Sa of "L" level is sent to the central control unit 28.

Further, as shown in FIG. 6, the main switch 4
2 is turned on, the output voltage Vm of the main power supply 29 is set to the diode 1
By taking out through 40, the detection signal Ss corresponding to the driving of the motor 15 is sent to the central control unit 28.

[0067]

[Central Control Unit] FIGS. 7 and 8 are flowcharts showing an outline of a control procedure by a program stored in the ROM 38 of the central control unit 28 shown in FIG. 3, and FIG. 9 shows an internal register at the time of control by the program. Alternatively, it is an explanatory view showing a correspondence relationship of counters that are pseudo-configured on the RAM 37, and the configuration of the central control unit 28 will be described below with reference to both drawings.

The central control unit 28 has a single basic circuit configuration as shown in FIG. 9, and changes the count value of the counter each time the usage mode of the electric shaver and the detection conditions in the mode change. The circuit configuration can be changed for each mode and for each detection condition in each mode so that control processing of different modes can be performed using the same circuit. 15
A signal output from the millisecond timer 125 about every 15 milliseconds is used as a trigger to read a detection signal into the central processing unit 39 from each port of the I / O device 40 shown in FIG. After determining the mode of use and performing predetermined mode processing such as initial setting of the counter value, a series of processing such as counter integration is performed.

That is, the output end of the 15-millisecond timer 125 is connected to the 1-second counter 126, and a signal is sent to the mode counter 127 every time 1 second has elapsed after the 1-second counter 126 has counted over.

The mode counter 127 is the first and second mode counters 128 and 12 used in the modes of charging the secondary battery 16, driving the motor 15 in an alternating current and driving the battery.
9 and a standby mode counter 130 used in the standby mode
The count value is reset each time the mode is changed, and the first and second mode counters 128 and 129 are used according to the detection condition in each mode to correspond to the use mode. It is possible to perform integrated calculation of battery capacity with the increased or decreased rate.

That is, during a series of step processing performed every 15 milliseconds, only one mode counter that is uniquely determined by the detection condition becomes active, counts down the corresponding counter, and further counts the mode counter. When the count value reaches zero after finishing counting, the main counter 131 is sent a signal and
Reset the initial counter value in the corresponding mode.

The main counter 131 is a 128-base up / down counter, which stores the count value as it is even when the mode is changed, and upcounts the count value in the charging mode and downcounts it in the other modes. Thus, the current battery capacity is specified by the subsequent value of the display counter 132 and the count value of the main counter 131, so that the display operation of the battery capacity indicator 20 can be made continuous regardless of the mode change. Every time the main counter 131 counts a predetermined number, an up or down signal is sent to the display counter 132 to change the value of the display counter 132.

The display counter 132 has a configuration substantially equivalent to that of a 4-bit shift register, and corresponds to each bit and is a green light emitting diode 19a for displaying 100 to 40%.
.About.19d are connected, and the number of light emitting diodes to be turned on is increased or decreased by bit shifting each time a signal is input from the main counter 131, 40% to 10%
Battery capacity up to 0% can be displayed stepwise at 20% intervals. In addition, the count value of the display counter 132 becomes zero and the light emitting diodes 19a to 1 of 40 to 100%
When all 9d are turned off, the light emitting diodes 19e and 19f for displaying 20% and 0% of red are blinked.

Next, the outline of the above-mentioned circuit operation will be described according to the programs shown in FIGS. 7 and 8. Reset signal Sr with main power supply 29 connected to central control unit 28
When is applied, a reset is applied at the same time, and each unit is initialized in step ST1 and then the 15-millisecond timer 125 is started (step ST2). The timer 12
5 always keeps the clocking operation even while the program is running,
An interrupt signal is generated every time a millisecond elapses. When such an interrupt occurs, a series of steps described below are executed, and then the process returns to step ST3 to wait for the next interrupt.

When an interrupt occurs in step ST3,
The detection signal S output from the AC input detection circuit 49 through the corresponding input port of the I / O device 40 shown in FIG.
a, the value of the detection signal Ss output when the motor is fed or the value of the detection signal Sm that indicates that the motor rotation is forcibly stopped when the motor is fed (step ST
4) In step ST5 to step ST9, depending on the presence or absence of the input of each detection signal, after branching into five modes of charging, AC drive, motor forced stop, battery drive and standby (steps ST10 to 14), When it is confirmed that is different from that at the time of the previous interruption, the setting corresponding to each mode is performed as shown in FIG.

For example, when there is an AC input and the main switch 42 is off, the inverter circuit 22
From the main power source 29 to the secondary battery 16 is a "charge mode". Therefore, further step ST3
When it is confirmed that the detection signal St is not output from the upper limit temperature detection circuit 36 at 0 and thus the charging is not completed, the setting common to the charging mode, that is, the output request to the inverter circuit 22 is issued in step ST31. , Set the main counter 131 in the up direction,
A request is issued to cause the battery capacity indicator 20 to perform a display corresponding to the value of the display counter 132.

Further, in step ST32, the I / O device 40
The detection signal Sh of the upper limit voltage detection circuit 35 is read from
When it is confirmed that the terminal voltage Vm of the secondary battery 16 has not reached the upper limit voltage, the first mode counter 128 is set to an octal counter in step ST33, and the main counter 131 can be up-processed every 8 seconds. By doing
Battery capacity indicator 2 every 8 × 128 = 1024 seconds
The number of 0 emission displays is increased by one.

Contrary to the above, if it is detected in step ST32 that the upper limit voltage has been reached, it is determined that the secondary battery 16 is in a state of being almost fully charged. ~ 80% of light emitting diode 19b ~
A request to display that all of 19d are turned on to indicate that the battery is almost fully charged is issued, the second mode counter 129 is set to the quaternary counter, and the count value of the main counter 131 is set to zero. As a result, after performing additional charging for about 8 minutes after reaching the upper limit voltage, the main counter 1
When 31 is counted over and the light emitting diode 19a is turned on, 100% charge is displayed.

When it is detected that the upper limit voltage has been reached, a flag is set and the above-mentioned upper limit voltage re-reading process is not performed while the battery capacity display on the display counter 132 is 100%. By this processing,
For example, when charging is interrupted due to a power failure or the like during charging, the terminal voltage may fall below the upper limit voltage without decreasing the battery capacity. Even in such a case, when charging is restarted, the main counter 131 Since the count value of the main counter 131 is stored without resetting and the count-up operation is continuously performed starting from the count value at the time of interruption of charging, overcharge is prevented in advance.

On the other hand, when the output of the detection signal St is confirmed in the above-mentioned step ST30, it is judged that the charging of the secondary battery 16 is in the overcharged state or is close to it. Therefore, the full charge process in step 35 is started,
The display counter 132 is set to light all 0 to 100% of the light emitting diodes 19 in the battery capacity indicator 20 to indicate that charging is completed, and the output request to the inverter circuit 22 is stopped.

When the secondary battery 16 is repeatedly charged and discharged a number of times, the terminal voltage of the secondary battery 16 may not reach the upper limit voltage even when fully charged. In such a case, 1C charging is performed only on the basis of time until the time when 100% of the light emitting diode 19a is turned on without performing the absolute correction and the charging control by the upper limit voltage, and the trickle charging is started.

Next, in step ST5, the commercial AC power source 21
Is input, the motor 15 is supplied with power in step ST6, and when it is determined in step ST7 that the motor is not forcibly stopped, the motor 15 is driven using the commercial AC power supply 21. AC drive mode "
Therefore, in step ST40, a setting common to the AC drive mode, that is, an output request for the inverter circuit 22 is issued, the main counter 131 is set in the down direction, and a lighting request for the battery capacity indicator 20 is issued.

Further, in step ST41, it is determined whether or not 15 minutes have continuously passed since the AC drive mode was entered, and if "YES", the battery drive mode described later is entered and the inverter circuit 22 is stopped for 30 minutes. However, the inverter circuit 22 is prevented from overheating.

However, the determination in step ST41 is "NO".
If so, in step ST42, the detection signal Sc of the load amount detection circuit 46 is read from the I / O device 40, and the motor 15
If the current consumption at is smaller than the reference value, step S
At T43, the first mode counter 128 is set to hexadecimal. On the contrary, if it is large, at step ST44 the second mode counter 129 is set to decimal, and the main counter 13
The reduction rate of 1 is corrected so as to be proportional to the current consumption.

Next, when it is detected that there is no AC input in step ST5, that the main switch 42 is turned on in step ST8, and that the motor is not forcibly stopped in step ST9, respectively. , Motor 1
5 is driven by the secondary battery 16 "battery drive mode"
Therefore, in step ST50, a common setting for the battery drive mode, that is, the main counter 131 is set in the down direction, and a lighting request for the battery capacity indicator 20 is issued.

Further, in step ST51, the detection signal Sc of the load amount detection circuit 46 is read in the same way as in the AC drive mode, and if the current consumption of the motor 15 is small, step ST51.
At 52, the first mode counter 128 is set to quaternary and 4
The signal is output from the mode counter 127 once a second.
On the other hand, when the current consumption is large, it is set to the ternary in step ST53 to increase the decrease rate of the main counter 131, and the setting corresponding to the battery drive mode is performed.

Next, in the "standby mode" in which it is determined in step ST5 that there is no AC input and in step ST8 that the motor is not being driven, a lighting request to the display 20 is issued in step ST60. Stop, set the main counter 131 to the down side,
In step ST61, the count value of the standby mode counter 130 is set to 16000.

Although it is determined in step ST6 or ST8 that the main switch 42 is turned on and the detection signal Ss is generated, step ST7
Alternatively, in ST9, the motor abnormality detection circuit 44 causes the motor 15
When it is determined that the detection signal Sm for notifying the rotation stop of is output, whether the outer blade holder 11 has been removed,
It is estimated that there was some abnormality in the rotary drive system for the motor 15.

In this case, the motor forced stop mode of step ST12 is entered, and the operation state is equivalent to the above-mentioned "standby mode", for example, the output stop request of the inverter circuit 22 and the display stop request of the battery capacity indicator 20 are issued. By setting to such a state, the residual amount error due to the integration of the battery capacity is reduced as much as possible.

After the predetermined mode setting operation is performed as described above, the lower limit voltage detecting process is performed in step ST15. By this processing, when the lower limit voltage detection signal Sb is output in the battery drive mode, the values of the main counter 131 and the display counter 132 are set to predetermined values, and the battery capacity display value is absolute corrected with the lower limit value.

Next, in step ST16, the 1-second counter 12
When 6 is counted down and the 1-second counter 126 counts over, the mode counter 127 designated by the above-described mode detection is counted down in step ST17.

When it is determined in step 18 that the mode counter 127 has exceeded the count, the main counter 131
Counting up or down (step ST19)
Then, in response to the determination that the count value of the main counter 131 has reached 0 or 128 in step ST20, the display counter 132 is counted up or down in step ST21.

Then, in step ST22, the display 20
The display corresponding to the presence / absence of a display request and the value of the display counter 132 is performed, output processing is performed to the inverter circuit 22 in step ST23, and a series of processing is ended.

[0094]

[Other Embodiments] FIG. 10 shows another embodiment of the present invention.
An example in which the central control unit 28 does not perform overall control will be described. Since most of the configuration of this embodiment is the same as that of the above-described embodiment, the same parts are denoted by the same names and reference numerals, and the disclosure of the specific circuit configuration is omitted.

In the present embodiment, the commercial AC power supply 21 is applied to the inverter circuit 22 by the timer means provided in the charging control section 25a, and the secondary battery 16 in the main power supply 29 is supplied.
The control signal S4 is sent to the inverter circuit 22 a predetermined time after the charging is started, so that the charging control by time is performed.

Furthermore, when the terminal voltage of the secondary battery 16 exceeds a preset upper limit value, the upper limit voltage detection circuit 35 which generates a predetermined signal Sh, and the surface temperature of the secondary battery 16 exceeds the preset upper limit value. And an upper limit temperature detection circuit 36a that generates a predetermined signal St ', and when either one of the detection circuits 35 and 36a performs a detection operation, the charge control unit 25a sends a control signal S4 to the output control unit 24a, Overcharging of the secondary battery 16 is prevented by turning on the base-emitter of the output transistor 55 of the inverter circuit 22 to regulate the oscillation operation.

The upper limit temperature detection circuit 33a is used for the secondary battery 16
The temperature change of the secondary battery 16 is detected by the first thermistor 84 provided on the surface of the battery, and the detection voltage is taken out from both ends of the resistor 86, while the reference voltage is output from both ends of the resistor 87, which is provided in the charge control unit 25a. When the detected voltage exceeds the reference voltage by the comparator (not shown), the control signal S4 is output to the inverter circuit 22. Further, the detection signal Sh output from the upper limit voltage detection circuit 35 is connected to both ends of the resistor 87, and when the upper limit voltage is detected, both ends of the resistor 87 are short-circuited to lower the reference voltage so that the above-mentioned detection voltage becomes the reference. The control signal S4 is output in excess of the voltage.

Further, the main switch 42 is constituted by two circuits and two contacts, and the charge display portion 133 is connected to the off side contact of the first switch 42a. Charge display 133
Is a series connection of a light emitting diode 134 and a switching transistor 135.
The signal S5 generated when the charging control unit 25a is in the off state and the charging control unit 25a is charging the switching transistor 1 is
The light-emitting diode 134 is energized according to the time when it is input to the base end of 35, thereby displaying that the secondary battery 16 is being charged.

The blade temperature detecting circuit 45a is connected to the first auxiliary power source 3
By supplying the driving power from 0, the inverter circuit 22 basically operates in response to the operation, but the OFF side contact of the second switch 42b of the main switch 42 is connected to the plus side of the comparator 104 shown in FIG. By connecting to the input end, when the main switch 42 is off, the input end is grounded so as not to operate. Further output signal S
3 is sent to the output control section 24a to regulate the operation of the inverter circuit 22.

By connecting the ON side contact of the first switch 42a to the input side of the second auxiliary power supply 31 via the diode 136, the power supply to the charging control unit 25a is cut off when the main switch 42 is turned ON. The output control for the circuit 22 is not performed.

Further, the ON-side contact of the second switch 42b is connected to the ground side of the motor control section 27, and in conjunction with the ON operation of the main switch 42, energization of the motor 15 and detection of abnormal rotation are performed. . Here, the operation of the inverter circuit 22 is directly regulated by sending the detection signal Sm notifying the stop timing of the motor 15 to the output control section 24a.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a basic configuration of the present invention.

FIG. 2 is a partially cutaway front view showing an external shape.

FIG. 3 is a block diagram schematically showing an overall configuration of an electronic circuit.

FIG. 4 is an electric circuit diagram specifically showing a configuration of a power supply part in FIG.

FIG. 5 is an electric circuit diagram specifically showing a configuration of a motor control portion in FIG.

FIG. 6 is an electric circuit diagram specifically showing a configuration of a central control portion in FIG.

FIG. 7 is a flowchart illustrating a processing procedure according to a program in a central control unit.

FIG. 8 is a flowchart showing details of a mode setting portion in FIG. 7;

FIG. 9 is a block diagram showing a configuration corresponding to each procedure shown in FIGS. 7 and 8;

FIG. 10 is a block diagram showing another embodiment without control by the central control unit.

[Explanation of symbols]

 14 Inner blade 15 Motor 16 Secondary battery 20 Battery capacity indicator 22 Inverter circuit 23 Power supply unit 24 Output control unit 25 Charging control unit 26 Display control unit 27 Motor control unit 28 Central control unit 29 Main power supply 30 First auxiliary power supply 31st 2 Auxiliary power supply 35 Upper limit voltage detection circuit 36 Upper limit temperature detection circuit 42 Main switch 43 Rotation timing regulation circuit 44 Motor abnormality detection circuit 45 Blade temperature detection circuit 49 AC input detection circuit 89 Switching transistor 91 Thermistor 92 Fixed resistance

Claims (3)

[Claims] 1. A motor, and a switching element that is connected in series with the motor and regulates the timing of energization to the motor. At least one of the voltage and the amount of heat generated corresponding to the magnitude of the current flowing through the motor is provided. A small electric device, wherein the switching element is automatically turned off when a set value is exceeded. 2. A motor (15), a switching transistor (89) which is connected in series with the motor (15) and regulates energization timing, and a signal corresponding to a change in surface temperature of the transistor (89). A temperature detecting means capable of outputting, a voltage detecting means capable of outputting a signal corresponding to a change in the emitter-collector voltage of the transistor (89), and a temperature detected by the temperature detecting means is lower than a set value or the above voltage. An ON signal is output to the switching transistor (89) while the voltage detected by the detection unit is lower than a set value, and an OFF signal is output when the detected temperature exceeds the set value or the detected voltage exceeds the set value. Means and a small electric device. 3. The motor (15) drives an inner blade (14) of an electric razor, and the temperature detecting means includes a thermistor (91) arranged on the surface of the transistor (89) and a fixed resistor. (92) divides the motor drive voltage and outputs the detection voltage from both ends of the fixed resistor (92). The voltage detection means divides the motor drive voltage by the two fixed resistors (94) and (95). By doing so, the reference voltage is formed, and the resistor (95) for generating the reference voltage is short-circuited by the switching element which is turned on when the emitter-collector voltage of the transistor (89) exceeds the set value. In the OP amplifier, the reference voltage output from the voltage detecting means is input to its positive terminal, while the detection voltage output from the temperature detecting means is input to its negative terminal. The small electric device according to claim 2, which applies force.