JP2627259B2 - Small electrical equipment - Google Patents

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 having a charging circuit for a secondary battery, and more particularly to a device for controlling a charge amount by detecting a terminal voltage of the battery.

[0002]

2. Description of the Related Art Conventionally, this type of charge amount control utilizes the fact that the terminal voltage rises with the charging of a secondary battery, but conversely decreases as it approaches a fully charged state. In general, the charge amount control is performed by detecting the peak value of or a point when the voltage further decreases by a predetermined voltage.
However, this type of secondary battery may not reach the original full charge voltage after repeated charging and discharging, and if the charging environment temperature is high, the internal resistance is low and the terminal voltage is low, so the preset upper limit value is set. May not be detected and sufficient control may not be performed. In view of this, there is also disclosed an apparatus which includes a timer means in addition to the terminal voltage detection means, and forcibly stops charging by the timer means when the upper limit voltage detection is not performed (for example, Japanese Patent Application Laid-Open No. Sho 62-10013).
No. 9). Further, in this disclosed example, it is also found that once the peak voltage is detected, the setting time in the timer means is shortened.

[0003]

However, for example, when a secondary battery in a fully charged state is charged again, a peak voltage is detected and the charging operation is started. However, since the time since the start of charging is short, the charging time is short. , The timer means has not yet reached the set time. At this time, if the charging is interrupted, the peak value decreases, so that the charging is continued by the timer means without detecting the peak voltage, which may result in overcharging.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides a small-sized electric device having a charging means capable of preventing overcharging by detecting the upper limit voltage and holding the output once the upper limit voltage is detected. The purpose is to do.

[0005]

As shown in FIG. 1, a small electric apparatus according to the present invention includes a means for integrating the amount of charge / discharge for a secondary battery 6, and an upper limit for the secondary battery 6. Means for detecting a voltage; charge control means for performing a predetermined charge regulating operation when the upper limit voltage detecting means detects the upper limit voltage or when the count value in the integrating means reaches a set value; and changing the mode of charging or discharging. Means for detecting

Further, the charging control means holds the output when the upper limit voltage is detected by the upper limit voltage detecting means, and holds the output until the mode change detecting means detects a change to another mode. It is characterized by doing. When the upper limit voltage detecting means detects the upper limit voltage before the value reaches the set value, the set value is set, and the integrated value is displayed in accordance with the value. preferable.

[0007]

With this configuration, the amount of charge of the secondary battery 6 is accumulated and stored in the integrating means as the charging proceeds. Here, if the accumulation means reaches the set value before the detection means detects the set state, the charge control means operates to start the operation of regulating charging of the secondary battery. Conversely, if the detecting means performs a predetermined detecting operation before the integrating means reaches the set value, the value of the integrating means is set to the set value, and the charging operation for the secondary battery is started. At this time, as a result of holding the detection state of the upper limit voltage as it is, even if the charging is stopped and the terminal voltage of the battery falls below the upper limit value, the charging regulating operation is maintained as it is. At this time, the display means displays the display corresponding to the integrated value to inform the operator of the stage of charging.

[0008]

As described above, the present invention is configured such that when the upper limit voltage of the secondary battery 6 is detected, it is maintained unless another mode is detected, so that the fully charged battery is repeatedly charged. In addition, overcharging can be prevented. Further, the integrated value of the charged amount is set to a predetermined value in conjunction with the detection of the completion of charging by the detecting means, and a display corresponding to the integrated value is performed, so that the state of charge of the secondary battery 6 is changed. It can be grasped accurately.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on an example in which the present invention is applied to an electric shaver. However, the present invention is not limited to this, and it is needless to say that the present invention can be applied to various small electric appliances equipped with a secondary battery.

An electric shaver 1 embodying the present invention is shown in FIG.
As shown in FIG. 1, the outer blade 2 is detachably mounted on the upper part of the main body case 3, and the inner blade 4 is slidably disposed inside the outer blade 2. Further, inside the main body case 3, a motor 5 for reciprocatingly driving the inner blade 4, a secondary battery 6 for supplying electric power for rotational driving to the motor 5, a charge control for the secondary battery 6, or a motor An electronic circuit 7 for performing various controls such as rotation control is housed. In addition, a switch knob 9 of a slide switch 8 for regulating the timing of energizing the motor 5 is provided at the center of the front of the main body case 3, and below the switch knob 9 it is determined whether or not the rotation of the motor 5 can be controlled. A rotation control display 10 composed of two light emitting diodes for displaying, and a battery capacity display 11 composed of six light emitting diodes for performing display corresponding to the charge / discharge state of the secondary battery 6
And are arranged. Further, a power cord 13 having a power plug 12 provided at a tip thereof is detachably provided at a lower portion of the main body case 3 so that the motor 5 can be directly driven by a commercial AC power supply in addition to charging the secondary battery 6. I have.

FIG. 3 is a block diagram schematically showing the entire electronic circuit 7 built in the main body case 3 described above.
Inverter circuit 15 for converting an AC voltage of 100 to 240 V supplied from commercial AC power supply 14 to a predetermined charging voltage
A power supply unit 16 for supplying power to the entire electronic circuit 7,
A rotation control unit 17 for controlling the rotation state of the motor 5, a detection unit 18 for constantly detecting the operation state of the electric shaver 1, and an output control of the inverter circuit 15 based on various detection signals taken out from the detection unit 18. A central control unit 19 that performs display control of the current capacity of the secondary battery 6 and an output control unit 20 that forcibly stops oscillation of the inverter circuit 15 by inputting a control signal from the detection unit 18 or the central control unit 19. Be composed.

The power supply section 16 comprises a main power supply 21 having a secondary battery 6 such as a nickel-cadmium battery which can be charged and discharged a plurality of times, and an auxiliary power supply 22 which rectifies and smoothes the output voltage from the inverter circuit 15. Thus, power is supplied to the motor 5 and the electronic circuit 7.

The motor 5 is connected to a main power supply 21 via a switch 8.
The power is supplied from the side, and the rotation control unit 17 provided with the rotation detection circuit 23 and the rotation control circuit 24 operates to keep the motor rotation speed substantially constant regardless of the fluctuation of the battery voltage or the lightness of the load applied to the motor 5. Is maintained.

The central control unit 19 has a RAM 25 or R
A so-called "one-chip type microprocessor" in which various peripheral circuits such as the OM26 are integrally formed is used.
It operates in synchronization with the input of the clock signal,
The central processing unit 27 and the I / O device 28 are connected via various buses 29, and the detection information output from the detection unit 18 is
The information can be taken in through an input port on the I / O device 28, and such information can be used as control data in the ROM 2.
6 to perform a control operation according to the program stored in the inverter circuit 15 and the display 10.
1 to output a control signal.

The detection section 18 determines whether or not the commercial AC power supply 14 is connected to the inverter circuit 15 by the AC input detection circuit 30 and whether or not the switch 8 for driving the motor is turned on by the motor power supply detection circuit 31. Are each detected and used as basic information for determining the operation mode of the electric shaver 1.

Further, the auxiliary power supply 22 is
, And controlling the inverter circuit 15 so as to maintain the voltage Vs constant, the inverter circuit 15 can be operated despite the difference in the commercial power supply voltage used between 100 and 240 V. Can be maintained substantially constant.

Further, the rotation abnormality detecting circuit 33 detects a state in which the motor 5 remains locked even though the motor 5 is energized. In such a case, the inverter circuit 15 is forcibly stopped, and The circuit 15 is prevented from being damaged due to a rise in temperature.

Further, a load amount detection circuit 34 detects the magnitude of the current consumption in the motor 5 and relatively corrects the battery capacity display when the motor is driven, while the upper limit voltage detection circuit 35
And the lower limit voltage detection circuit 36 detects that the terminal voltage Vm of the secondary battery 6 has reached the upper limit value or the lower limit value during charging and discharging, and absolutely corrects the display value of the battery capacity indicator 11 by such detection. I have.

The secondary output detection circuit 32 and the rotation abnormality detection circuit 33 input the detection signals to the output control section 20 as control signals S1 and S2, and directly control the inverter circuit 15. It is also possible to use the detection signal for the central control unit 19 and indirectly control the output of the inverter circuit 15 via the central control unit 19.

Each of the components schematically shown in FIG. 3 will be described more specifically with reference to the electric circuit diagrams shown in FIGS. 4 to 6.

[0021]

[Inverter Circuit] As shown in FIG. 4, the inverter circuit 15 is provided with a rectifier circuit 39 having a diode bridge 37 and a filter 38 on the input side. After full-wave rectification of the AC power supply 14 by the rectifier circuit 39, the temperature fuse 4
0 is applied to the inverter circuit 15.

The inverter circuit 15 includes a primary coil 42 and the primary coil 4 on the collector side of the output transistor 41.
A shock absorber 43 connected to both ends of the transistor 2 for absorbing a shock voltage generated when the transistor 41 is turned off is provided, and a feedback unit 44 is provided between the base and the emitter. Further, a feedback coil 45, an output coil 46, and a tertiary coil 47 are wound on the same iron core as the primary coil 42.

The feedback section 44 connects one end of the feedback coil 45 to the base end of the output transistor 41, and
A capacitor 48 is connected between the other end of the output transistor 41 and the emitter of the output transistor 41, and a diode 49 is connected between the emitter and base of the output transistor 41 in the opposite direction.
The emitter terminal is connected to the positive side of the secondary battery 6 via the resistor 50. Further, the output voltage from the rectifier circuit 39 is connected to the connection point of the feedback coil 45 and the capacitor 48 with the resistor 51.
The voltage divided at 52 can be applied via a resistor 53.

With the above configuration, a voltage is generated across the resistor 52 simultaneously with the application of the voltage to the inverter circuit 15, and the charging of the capacitor 48 is started by the voltage. The voltage across the capacitor 48 rises and the output transistor 41
Of the transistor 41
A current starts to flow through the primary coil 42 connected to the collector end of the feedback coil 45, and a voltage is generated in the feedback coil 45 due to the increase in the current. This voltage flows between the base and the emitter of the transistor 41, turning on the transistor 41 and simultaneously charging the capacitor 48 in the opposite direction.

Here, when the primary current is stabilized and the voltage across the feedback coil 45 decreases, a current flows in the opposite direction through the diode 49 due to the charging voltage of the capacitor 48, and the voltage across the diode 49 becomes the blocking voltage. As a result, the output transistor 41 is rapidly turned off. After the output transistor 41 is turned off, the capacitor 48 is rapidly discharged by the voltage output from the feedback coil 45 and the resistor 55 selectively connected to the base end by the diode 54. The voltage is applied to the capacitor 48 through 53, the capacitor 48 is charged in the positive direction, and the above-mentioned ON / OFF operation is repeated.

During a series of operations of the inverter circuit 15 described above, when the output transistor 41 is turned on, the energy stored in the primary coil 42 is output to the output transistor 4.
The power is selectively extracted from the power supply unit 16 during the off period of one.

[0027]

[Power Supply] The power supply 16 comprises a main power supply 21 and an auxiliary power supply 22. The main power supply 21 has a rectifier diode 56 and a secondary battery 6 connected to the output terminal of the output coil 46. When the inverter circuit 15 is stopped, the secondary power supply 6
While the inverter circuit 15 is operating, the output from the output coil 46 is added thereto to extract the voltage Vm, and the electronic circuit 7 is always operable.

On the other hand, the auxiliary power supply 22 has a rectifying diode 57 and a large-capacity smoothing capacitor 58 connected to the output side of the tertiary coil 47, and outputs the auxiliary voltage Vs only when the inverter circuit 15 operates. The drive power is supplied to each electronic circuit for exclusively controlling the inverter circuit 15.

By setting the number of turns of the tertiary coil 47 to be several times larger than that of the output coil 46, a voltage higher than that of the output coil 46 can be output. However, even when the output from the inverter circuit 15 is reduced because the inverter circuit 15 is sufficiently controlled, an auxiliary voltage having a sufficient and sufficient magnitude to drive and control various circuits is provided. Vs can be taken out.

[0030]

[Output control unit] The output control unit 20 includes the inverter circuit 15
The base of the output transistor 41 and the collector of the switching transistor 59 are connected to the diode 6
0, and the emitter end is grounded. The signal "H" is output from one of the secondary output detection circuit 32, the rotation abnormality detection circuit 33, and the central control unit 19.
When the level control signals S1, S2, and S3 are input to the base terminal of the transistor 59 via the OR circuit 61, the transistors are turned on, and the output transistor 41 of the inverter circuit 15 is turned on.
To ground the base end of the inverter circuit 15 to forcibly stop the oscillating operation of the inverter circuit 15.

[0031]

[Rotation control unit] As shown in FIG. 5, the rotation control unit 17 always stops its operation, but operates in conjunction with the ON operation of the switch contact 8a. And a rotation control circuit 24 that controls the motor applied voltage according to the detected rotation speed to make the motor rotation speed substantially constant.

The rotation detecting circuit 23 detects the movement of the motor rotating shaft using a photo interrupter 62 including a light emitting diode and a phototransistor, and generates a signal having a frequency corresponding to the rotating speed of the motor 5. This signal is further input to a filter circuit 63, and only an AC signal having a frequency component corresponding to the rotation cycle of the motor is selectively sent to a waveform shaping circuit 64. The waveform shaping circuit 64 includes a comparator 65
, The output signal from the filter circuit 63 is input to the negative input terminal, and the secondary battery voltage Vm is input to the positive terminal.
A reference voltage obtained by dividing the reference voltage by resistors 66 and 67 is applied. Further, a diode 69 connected to the secondary battery 6 via a resistor 68 is connected to the output terminal, and positive feedback is applied by a resistor 70. From both ends of the diode 69, a detection signal in the form of a rectangular wave whose peak value is regulated by the forward voltage of the diode 69 is output to the rotation control circuit 24.

The rotation control circuit 24 converts an input signal having a frequency corresponding to the rotation speed of the motor 5 into a detection signal having a magnitude corresponding to the frequency by a DA converter 71, and then outputs a reference voltage by a comparator 72. If a shift occurs between the two, a control signal corresponding to the value of the shift is sent to the motor control circuit 73.
Send to The motor control circuit 73 is a transistor 74 connected in Darlington, which is interposed in a circuit for supplying power to the motor 5, and which is controlled by a control signal.
And the collector voltage of the transistor 74
The voltage applied to the motor 5 is increased or decreased by controlling the voltage drop between the emitters, and regardless of the magnitude of the load applied to the motor 5 or the terminal voltage Vm of the secondary battery 6,
A rotation speed control for maintaining a substantially constant rotation speed is performed.

[0034]

[Detection Unit] As shown in FIG. 4, the AC input detection circuit 30 is connected in parallel with the inverter circuit 15 on the output side of the rectifier circuit 39, the power plug 12 is inserted into the outlet, and the electric shaver 1 uses the commercial AC power supply 14. This is for detecting whether or not the mode is set, and the “H” level voltage is normally applied from the main power supply 21 via the transistor 121 connected to the output port of the central control unit 19. When the commercial AC power supply 14 is input, the full-wave rectified voltage output from the rectifier circuit 39 is divided by the resistors 75 and 76, and the voltage generated at both ends of the resistor 76 at the time of AC input is used as the transistor 7
By turning on and grounding 7, an “L” level detection signal Sa is sent to the central control unit 19.

The secondary output detection circuit 32 is connected to the output side of the auxiliary power supply 22, as shown in FIG.
By dividing the output voltage Vs of the auxiliary power supply 22 by the resistors 78 and 79, the output voltage Vs of the value that changes in proportion to the increase or decrease of the average value of the pulsed charging voltage output from the inverter circuit 15 to the secondary battery 6 is increased. Take out the detection voltage. Further, the magnitude of the voltage and the reference voltage using the forward voltage of the diode 80 are compared by a comparator 81 using an OP amplifier, and when the detected voltage exceeds the reference voltage, the comparator 81 sends the signal to the output control unit 20. By transmitting the control signal S1 and intermittently stopping the oscillation of the inverter circuit 15,
Is within the range of 100 to 240 V, the output of the inverter circuit 15 is controlled such that the amount of power output from the inverter circuit 15 toward the secondary battery 6 becomes substantially constant.

When the motor 5 is driven while the inverter circuit 15 is operated, the above-described detection voltage decreases, while the reference voltage maintains a substantially constant value. Therefore,
At the same time as turning on the switch contact 8a for energizing the motor 5 to drive the motor 5, the parallel resistor 82 for generating the detection voltage
Is turned off at the switch contact 8b, the detected voltage is raised to correct the detected voltage value, and the output power from the inverter circuit 15 can be maintained substantially constant regardless of the magnitude of the load current in the inverter circuit 15. In addition, a capacitor 83 is connected in parallel with the detection voltage generating resistor 79 to suppress the peak voltage, delay the time when the control starts to be applied, and reduce the control error as much as possible. Further, a thermistor 84 is connected in series with the diode 80 for generating a reference voltage, and a current flowing through the diode 80 is finely adjusted in response to a rise in circuit temperature, thereby stabilizing the reference voltage.

The abnormal rotation detection circuit 33 is connected to the output side of the rotation detection circuit 23 as shown in FIG. 5 so that the motor 5 is energized when the inverter circuit 15 is operating and the switch 8 is turned on. Nevertheless, for example, when the motor 5 fails to start due to insufficient capacity of the secondary battery 6, the control signal S2 is sent to the output control unit 20 to forcibly stop the inverter circuit 15, and the inverter circuit 15 From flowing an excessive current to the motor 5.

That is, the output voltage Vm of the main power supply 21 is applied to the collector of the transistor 85 through the switch contact 8a.
By applying the signal between the emitters and applying the output signal from the rotation detection circuit 23 to the base end, the motor 5
Of the secondary battery voltage Vm in accordance with the rotation of
And a rectangular wave signal is taken out at the collector end. This signal is further smoothed by the rectifier circuit 86 to make the ON voltage of the transistor 87, while the output voltage Vs from the auxiliary power supply 22
Is applied to the output control unit 20 so that the input side of the output control unit 20 can be grounded by the transistor 87 when the transistor 87 is turned on.

With such a configuration, the output voltage Vs from the auxiliary power supply 22 is not provided while the inverter circuit 15 is not operating, and the transistor 87 is provided while the motor 5 is rotating normally.
Are turned on and the control signal S2 to the output control unit 20
, The inverter circuit 15 continues the normal operation. However, if the rotation of the motor 5 is locked while the inverter circuit 15 is operating, the auxiliary power supply 2
Output voltage Vs from the secondary output detection circuit 3
2 controls the direction in which the output from the inverter circuit 15 increases so that a large current tends to flow from the inverter circuit 15 to the motor 5, but the transistor 87 is turned off and the output voltage Vs from the auxiliary power supply 22 is output controlled. A control signal S2 is applied to the unit 20 to forcibly stop the inverter circuit 15 to prevent the inverter circuit 15 from being damaged by an overload.

The load amount detection circuit 34 includes a motor control circuit 7
3, the power consumption of the motor 5 is detected in two levels, utilizing the fact that the base voltage of the transistor 74 in 3 increases or decreases in accordance with the magnitude of the load applied to the motor 5. As shown in FIG. 5, a value obtained by dividing the base voltage by the resistors 89 and 90 and a value obtained by dividing the secondary battery voltage Vm by the resistors 91 and 92 are compared by a comparator 88 using an OP amplifier. The detection signal Sc of “H” or “L” level corresponding to the magnitude is sent to the central control unit 19.

As shown in FIG. 6, the upper limit voltage detection circuit 35 connects the voltage dividing resistors 93 and 94 in parallel with the main power supply 21 and detects a detection voltage having a value proportional to a change in the terminal voltage Vm of the secondary battery 6. From both ends of the resistor 94. A transistor 95 that is turned on by the output voltage Vs from the auxiliary power supply 22 is connected in series to the resistor 94, and only when the inverter circuit 15 is operating, the transistor 95 is turned on to output a detection voltage to save power. At the same time, a detection signal corresponding to the operation timing of the inverter circuit 15 is output.

The detected voltage is further compared with a reference voltage formed by a diode 97 in a comparator 96 using an OP amplifier, so that the terminal voltage of the secondary battery 6 exceeds a preset upper limit voltage and is fully charged. When it is detected that the state is approaching, the output terminal is inverted from "L" to "H" level, a signal is sent to the transistor 98 connected to the input port of the central control unit 19, and the transistor 98 is turned on to input. The port is grounded and a detection signal Sh is sent to notify the central control unit 19 that the secondary battery 6 has reached the upper limit voltage.

The lower limit voltage detecting circuit 36 is provided with a switch contact 8
c, which operates only during the motor driving period in conjunction with the ON operation of the terminal c.
・ Divided by 100 and take out detection voltage, diode 1
The comparator 102 normally outputs a “H” level detection signal by comparing the reference voltage with the reference voltage of “01”, but changes to “L” level when the voltage falls below a preset lower limit voltage. To notify that the terminal voltage Vm of the secondary battery 6 has fallen below the lower limit voltage.

When the ambient temperature of the secondary battery 6 rises during discharging, the apparent output voltage from the secondary battery 6 decreases and the detection voltage and the reference voltage also decrease, but the detection voltage is proportional to the output voltage. Whereas the reference voltage decreases exponentially. Therefore, the thermistor 1 is connected in series with the diode 101 for generating a reference voltage, which tends to be reduced more than necessary.
03 is connected, so that the divided voltage ratios of the diode 101 and the thermistor 103 at the time of temperature rise have the same tendency as before the temperature rise.
03 is increased to correct the value of the reference voltage itself.

The motor power supply detection circuit 31 informs the central control unit 19 of the operation status of the switch knob 9, and in this embodiment, as shown in FIG. 6, detects the output voltage Vm from the main power supply 21 as a lower limit voltage. Thermistor 103 of circuit 36
By always applying the voltage to the input port of the central control unit 19 through the diode 101 and grounding the input port with the switch contact 8c when the switch knob 9 is operated,
A detection signal Ss that changes from “H” to “L” level is sent to the port to notify the central control unit 19 of the timing of energizing the motor 5.

[0046]

[Central Control Unit] FIGS. 7 and 8 are flow charts showing an outline of a control procedure by a program stored in the ROM 26 of the central control unit 19 shown in FIG. 3, and FIG. Alternatively, it is an explanatory diagram showing a correspondence relationship of counters configured in a pseudo manner on the RAM 25. Hereinafter, the configuration of the central control unit 19 will be described with reference to both drawings.

The central control unit 19 has a single basic circuit configuration as shown in FIG. 9, and changes the count value of the counter every time the use mode of the electric shaver 1 and the detection conditions in the mode change. The circuit configuration can be substantially changed for each mode and for each detection condition in each mode, thereby enabling control processing of different modes using the same circuit. Oh, 15
The detection signal is read from each port of the I / O device 28 shown in FIG. 3 to the central processing unit 27 by using a signal output about every 15 msec from the msec timer 104 as a trigger, and the current use mode is determined from the value of the detection signal. After making a determination and performing a predetermined mode process such as initial setting of a counter value, a series of processes such as counter integration are performed.

That is, the output terminal of the 15-ms timer 104 is connected to the one-second counter 105, and sends a signal to the mode counter 106 every time one second elapses after the one-second counter 105 counts over.

The mode counter 106 includes first and second counters 107 and 108 used in each mode of charging the secondary battery 6, AC drive of the motor 5, and battery drive, and a standby mode counter 109 used in the standby mode. , The counter value is reset every time the mode is changed, and in each mode, the first and second mode counters 107 and 108 are selectively used in accordance with the detection conditions, thereby corresponding to the use mode. It is possible to calculate the integrated battery capacity at the rate of increase or decrease.

That is, during a series of step processing performed every 15 msec, only one mode counter uniquely determined by the detection condition becomes active, the corresponding counter is counted down, and the mode counter 106 which has performed the count processing is further processed. When the counter has counted down to a predetermined value and becomes zero, a signal is sent to the subsequent main counter 110 and the initial counter value of the corresponding mode is set again.

The main counter 110 is a 128-digit up / down counter which stores the count value as it is even when the mode is changed, and counts up the count value in the charging mode and down counts in other modes. Thus, the current battery capacity is specified by the subsequent value of the display counter 111 and the count value of the main counter 110, so that the display operation on the battery capacity display 11 has continuity regardless of the mode change. Each time the main counter 110 counts a predetermined number, it sends an up or down signal to the display counter 111 to change the value of the display counter 111.

The display counter 111 has a configuration substantially equivalent to a 4-bit shift register, and corresponds to each bit and emits 100 to 40% of a green light emitting diode 11a.
To 11d, and the number of light-emitting diodes to be lit is increased or decreased by shifting the bit every time a signal is input from the main counter 110, so that 40% to 100%
% Can be displayed stepwise at 20% intervals. In addition, the count value of the display counter 111 becomes zero and the light emitting diodes 11 a to 11
When all d are turned off, the light emitting diodes 11e and 11f for displaying 20% and 0% of red light are blinked.

Next, the outline of the above-mentioned circuit operation will be described with reference to the programs shown in FIGS. With the main power supply 21 connected to the central control unit 19, the reset signal Sr
Is applied, a reset is applied at the same time, each part is initialized in step 1, and then a 15 msec timer 1
04 is started (step 2). The timer 104
During the execution of the program, the timer operation is always continued, and an interrupt signal is generated every elapse of 15 msec. When such an interrupt occurs, a series of steps described below are executed, and the process returns to step 3. Wait for the next interrupt to occur.

When an interrupt is generated in step 3, FIG.
Through the corresponding input port of the I / O device 28 shown in
Detection signal Sa output from AC input detection circuit 30 and detection signal Ss output from motor power supply detection circuit 31
Are read (Step 4), and in Steps 5 to 7, the operation branches into four modes of charging, AC driving, battery driving, and standby (Steps 8 to 11) in accordance with the presence or absence of input of Sa and Ss. After that, when it is confirmed that the mode 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, if there is an AC input and the switch 8
Is off, it is a "charge mode" in which only charging is performed from the inverter circuit 15 toward the secondary battery 6 of the main power supply 21, so that the setting common to the charging mode in step 21, that is, the inverter circuit 15 , The main counter 110 is set in the up direction, a request to turn off the rotation control indicator 10 is issued, and a request to cause the battery capacity indicator 11 to perform a display corresponding to the value of the display counter 111 is issued.

Further, in step 22, the detection signal Sh of the upper limit voltage detection circuit 35 is read from the I / O device 28, and it is confirmed that the terminal voltage Vm of the secondary battery 6 has not reached the upper limit voltage. And the first mode counter 10
7 is set in the octal counter, and the main counter 110 can be up-processed every 8 seconds, so that 8 × 128
Each time 1024 seconds elapse, the number of light emission indications of the battery capacity display 11 is increased by one.

Conversely, if it is detected in step 22 that the voltage has reached the upper limit voltage, it is determined that the secondary battery 6 is almost fully charged.
Then, a request is made to light up all the light emitting diodes of 40 to 80% to indicate that the battery is approaching full charge.
The mode counter 108 is set to a quaternary counter, and the count value of the main counter 110 is set to zero. As a result, the main counter 110 counts over after performing additional charge for about 8 minutes after reaching the upper limit voltage, and a display of 100% charge is displayed.

It is to be noted that once detection has been made that the upper limit voltage has been reached, a flag is set, and the above-described upper limit voltage re-reading process is not performed while the battery capacity display on the display counter 111 is 100%. By such processing, for example, when charging is interrupted due to a power failure or the like during charging, the terminal voltage may be lower than the upper limit voltage without a decrease in battery capacity. The count value of the main counter 110 is stored without resetting the counter 110, and the count-up operation is continuously performed starting from the count value at the time of interruption of charging, thereby preventing overcharging.

Next, when there is an input from the commercial AC power supply 14 and power is being supplied to the motor 5, the motor 5 is driven using the commercial AC power supply 14 in the "AC drive mode". , Common settings for AC drive mode,
That is, an output request is issued to the inverter circuit 15, the main counter 110 is set in the down direction, and a lighting request is issued to the rotation control display 10 and the battery capacity display 11.

Further, at step 26, it is determined whether or not fifteen minutes have elapsed continuously after entering the AC drive mode.
If “YES”, the operation proceeds to the battery driving mode described later, and the inverter circuit 15 is stopped for 30 minutes.
5 prevents overheating.

However, if the determination in step 26 is "NO", the detection signal Sc of the load amount detection circuit 34 is read from the I / O device 28 in step 27, and if the current consumption in the motor 5 is smaller than the reference value. For example, in step 28, the first mode counter 107 is set to hexadecimal, and when it is larger, in step 29, the second mode counter 108 is set to decimal, and the decreasing rate of the main counter 110 is proportional to the current consumption. Correct as follows.

Next, when there is no AC input and the switch 8 is turned on, the motor 5 is driven by the secondary battery 6 in the "battery drive mode".
To set the common mode for the battery drive mode, that is, set the main counter 110 in the down direction, and set the rotation control display 10
Then, a lighting request of the battery capacity indicator 11 is issued.

At step 31, the detection signal Sc of the load amount detection circuit 34 is read in the same manner as in the AC drive mode. If the current consumption of the motor 5 is small, the first mode counter 107 is set to quaternary at step 32. A signal is output from the mode counter 106 once every four seconds. If the signal is large, the value is set to ternary in step 33 to increase the rate of decrease of the main counter 110 and perform setting corresponding to the battery driving mode.

Next, in the "standby mode" in which there is no AC input and the motor is not driven, the lighting request to the display is stopped in step 34 and the main counter 1 is turned off.
10 is set to the down side, and in step 35, the count value of the standby mode count 109 is set to 16000.

After the predetermined mode setting operation is performed as described above, the process of detecting the lower limit voltage is performed in step S12. By this processing, when the lower limit voltage is detected in the battery driving mode, the values of the main counter 110 and the display counter 111 are set to predetermined values, and the battery capacity display value is absolutely corrected with the lower limit value as described later.

Next, at step 13, the one-second counter 105 counts down. When the one-second counter 105 counts over, at step 14, the mode counter 106 specified by the mode detection is counted down.

If it is determined in step 15 that the mode counter 106 has counted over, the main counter 110
Is incremented or decremented (step 16), and in response to the determination that the count value of the main counter 110 has reached 0 or 128 in step 17, the display counter 111 is incremented or decremented in step 18. .

Thereafter, at step 19, the display 10.1
A display corresponding to the presence / absence of a display request for 1 and the value of the display counter 111 is performed, output processing to the inverter circuit 15 is performed in step 20, and a series of processing ends.

Next, the lighting states of the indicators 10 and 11 and the changes in the inverter control signal So and the count value of the main counter 110 in each mode will be described in detail with reference to FIGS.

First, in the charging mode, as shown in FIG. 10 (c), the rechargeable battery 6 is stopped for about 60 ms and then stopped for 15 ms until the charged capacity reaches 20% to 100%. 1 due to the control signal So whose duty ratio is 4/5
C charging is performed.

That is, as shown in FIG. 4, while the control signal So at the “H” level is being output from the central control unit 19, the transistor 121 is turned on, and the transistor 77 of the AC input detection circuit 30 is also turned on. Therefore, the control signal S3 maintains the "L" level, and the inverter circuit 15 performs a normal oscillation operation. However, while the control signal So is at the "L" level, the transistor 121 is turned off and the main power supply 16 Is output to the output control unit 20 as the control signal S3, the inverter circuit 15 is stopped for 15 ms, and the output voltage Vm in the case where the inverter circuit 15 operates for the entire period is
At 1% output, the secondary battery 6 is charged by 1C.

Such 1C charging corresponds to a charge increase of 20% in about 16 minutes, and as a result, as shown by the solid line in FIG. Be raised.

The current capacity of the secondary battery 6 is specified by the lighting position of the light emitting diode, that is, the count value of the display counter 111 and the count value of the main counter 110. The battery capacity itself is based on the charging time. As long as the relative calculation is performed, the error caused by repeating the charging and discharging over a long period of time cannot be avoided. Therefore, at the time of charging, when it is detected that the terminal voltage Vm of the secondary battery 6 has exceeded a preset upper limit voltage value, the charging amount is absolutely corrected at such a time.

That is, when the upper limit voltage is detected at time t1 when the charge is continued and, for example, 60% charge is displayed, all the displays of 40 to 80% are immediately turned on as indicated by the solid line, and the main counter is turned on. The count value of the counter 110 is set to 0, and the mode counter 106 is further changed from the first mode counter 107 to the second mode counter 108 to double the advance rate of the main counter 110, and about half of the previous eight minutes. , The count value of the main counter 110 is set to count 128, and the additional charge is performed for 8 minutes.

With this configuration, the maximum count of the main counter 110 from when the 80% display light emitting diode is turned on to when the 100% display is turned on is also 128.
In response to 28 counts, the battery capacity at the time of charge / discharge can be continuously calculated through the main counter 110, and 1
It is set so that 80% display is always performed for a predetermined time before 00% display.

After the additional charge is completed, at time t2, the 100% light-emitting diode 10a is turned on, the count value of the main counter 110 is returned to zero, and the inverter control signal So is inverted to change the duty. The ratio is reduced to 1/5 and trickle charging with 0.25C is started. At this time, the main counter 110 stops counting up at a count value of 64, which is half of 128, and waits for a change of the use mode while maintaining this value.
When shifting from the 100% charge display state to the drive mode of the motor 5, the 100% display is reduced to about half of the display time of 40 to 80%, and the 100% display is prevented from continuing more than necessary. I try not to make you feel uncomfortable.

If the charging / discharging of the secondary battery 6 is repeated many times, the terminal voltage Vm of the secondary battery 6 may not reach the upper limit voltage even when fully charged. In such a case, without performing the absolute correction using the upper limit voltage, as shown by the dashed line in FIG. 10A, 1C charging based on only the time is performed until time t3 at which 100% of the light emitting diodes 10a are turned on. After that, it will shift to trickle charging.

Next, when the motor switch 8 is turned on in the above-mentioned charged state, the apparatus enters the AC drive mode.
In such a mode, since a larger amount of power is required than in the above-described charging mode, the duty ratio of the control signal So is set to 1
The inverter circuit 15 is always operated to supply a larger current to the load side than at the time of charging. On the other hand, if the motor is driven continuously for 15 minutes or more, the inverter circuit 15
For 30 minutes, the inverter circuit 15 is stopped for 30 minutes to prevent overheating.

Also, the display in this mode is as shown by a solid line in FIG. 11 (a) about every 32 minutes when the load is small, such as when the motor is idling, and as shown by a dashed line when the load is large. Every 20 minutes, the lighting position is lowered by 20%, and when the lighting position is lowered to the 20% position, the 0% and 20% displays blink.

In practice, however, the charging mode is entered immediately after the motor 5 is stopped, and charging is performed. In the AC driving mode, most of the consumed current is supplied from the inverter circuit 15 and the secondary battery 6 Since the amount of current consumed by itself is extremely small, the rate of decrease in battery capacity is smaller than the above graph, and the absolute value is not corrected because the battery capacity does not decrease until the lower limit voltage is detected.

Next, in the battery driving mode, since all the consumed current is supplied from the secondary battery 6, even if the load is light, the reduction by 20% is reduced by about 8% as shown by the solid line in FIG.
Minute, and in the case of a heavy load, it is set as short as 6 minutes as indicated by a chain line. Further, in the present mode, at the time t4, the 40% capacity is turned on, and at the same time, the counting of the main counter 110 is stopped, and the detection of the lower limit voltage is waited while the count value is kept at zero. The lower limit of the charge amount is corrected.

When the detection state of the lower limit is entered at time t5, the correction processing is not immediately performed, but first, the confirmation processing of the lower limit voltage is started. That is, the fluctuation of the secondary battery terminal voltage at the time of driving the motor is relatively large, and the malfunction of detecting the lower limit voltage easily occurs even when the battery capacity is sufficient. Therefore, in the present embodiment, the 10-second counter 112 shown in FIG. 9 is started at the same time as the detection of the lower limit voltage, the counter 112 counts 10 seconds, and the lower limit voltage is detected continuously for 10 seconds. If confirmed, the process proceeds to the next lower limit voltage correction process.

For example, when the detection of the lower limit voltage is determined at time t6, a count value for 20 seconds is set in the main counter 110, this value is counted down, and it is first confirmed that the value has become zero at time t7. The 40% display is turned off, the 20% display blinks, and FIG.
As shown in (c), the display of the rotation control display 10 is stopped to indicate that the rotation control of the motor 5 is not performed, and furthermore, 128 is set in the main counter 110 to continue the countdown, and the count value becomes zero. Then, stop counting and save this value.

Further, when the lower limit voltage is detected during the display of the stable operation state, such as the 60% display at the time t8, the display does not immediately shift to the 20% display but the above-mentioned lower limit for 10 seconds. After waiting for the voltage confirmation, the display is shifted from the time t9 to the 20% display after the display for 40% is continued for a predetermined time, for example, about 20 seconds.

That is, in any case,
By setting to shift to the warning by the 20% display after passing the 40% display which is the display immediately before the warning state, the user can suddenly shift from the display state with sufficient battery capacity to the warning display. As much as possible.

Note that once the lower limit voltage is detected, a flag is set so that the lower limit voltage is not read again unless the charging mode is passed. Even if the lower limit voltage is detected and the battery capacity is extremely low, once the motor 5
Is stopped, the terminal voltage Vm self-returns and rises, sometimes exceeding the lower limit voltage. Also, the display time of the 40% display can be appropriately changed and implemented according to the usable time after the detection of the lower limit voltage.

Next, even when the electric shaver 1 is left without being used, the secondary battery 6 itself is self-discharged and the electric power is always supplied to the internal electronic circuit 7. The capacity of the secondary battery 6 is constantly decreasing.
Therefore, the displays on the display units 10 and 11 are turned off for power saving, but as shown in FIGS. 13 (a) and 13 (b),
Inside the central control unit 19, the countdown process of the main counter 110 is continued, and the current capacity of the secondary battery 6 is always stored.

However, the terminal voltage Vm of the secondary battery 6
When the voltage falls below the lower limit voltage and further falls below the voltage value at which the operation of the central control unit 19 is guaranteed, the circuit operation is completely stopped and the stored value described above is also lost. When charging is started in such a state, the circuit itself resumes operation, but since the initial setting to be performed in step 1 of FIG. 8 is not performed,
The displayed value is in an undefined state.

The reset circuit 113 shown in FIG. 6 sends a reset signal Sr to the central control unit 19 in such a case, and the light emitting diodes 11e for displaying 0% and 20%.
11f blinks and the counter value of the main counter 110 is reset to an initial state of 0. The oscillation circuit 114 self-oscillates by applying a voltage from the secondary battery 6, and the terminal voltage Vm of the secondary battery 6. Is greater than a predetermined value, the switching circuit 115 stops the oscillation operation of the oscillation circuit 114.

The oscillation circuit 114 has two transistors 1
This is a multivibrator using the 16/117, and by applying the voltage Vm from the main power supply 21, the two transistors 116 and 117 alternately turn on and off alternately, and the reset signal Sr Can be continuously applied.

The switching circuit 115 divides the output voltage Vm of the main power supply 21 by the resistors 118 and 119, turns the transistor 120 on and off with the divided voltage, and switches the transistor 1 of the oscillation circuit 114 between the collector and the emitter.
17 is bypassed.

With this configuration, when charging is started when the secondary battery 6 is completely discharged and the terminal voltage Vm is low and the transistor 120 is off, first, the oscillation circuit 1
14 starts an oscillating operation and generates a rectangular reset signal S
r is sent to the central control unit 19 to continue the reset operation.

Here, when the charging proceeds and the output voltage Vm of the main power supply 21 rises and approaches the turn-on voltage of the transistor 120, the voltage applied to the oscillation circuit 114 gradually decreases, and as a result, the oscillation circuit 114 stops. Thus, the input of the reset signal Sr to the central control unit 19 stops, and the central control unit 19 starts the above-described operation from step 1 shown in FIG.

If the test signal St is input at the time of reset, the test mode is entered. In this mode, it is possible to check the charge amount display operation by the counter in a short time.
Bypass the 1 second counter 105 shown in
The counter operation of the counter is directly performed by the output signal of the timer 104. For example, when the charging mode is selected during the test mode, 15 ms × 8 × 128 = 16 seconds,
A charge check for 20% is performed in about 16 seconds.

[Brief description of the 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 an explanatory diagram showing an operation corresponding to the configuration of the charging mode in FIG. 8;

FIG. 11 is an explanatory diagram showing an operation corresponding to the configuration of the AC drive mode in FIG. 8;

FIG. 12 is an explanatory diagram showing an operation corresponding to the configuration of the battery drive mode in FIG. 8;

FIG. 13 is an explanatory diagram showing an operation corresponding to the configuration of the standby mode in FIG. 8;

[Explanation of symbols]

 Reference Signs List 5 motor 6 secondary battery 8 switch 11 battery capacity indicator 14 commercial AC power supply 15 inverter circuit 16 power supply unit 17 rotation control unit 18 detection unit 19 central control unit 20 output control unit 21 main power supply 22 auxiliary power supply 30 AC input detection circuit 31 Motor power supply detection circuit 32 Secondary output detection circuit 33 Rotation abnormality detection circuit 34 Load amount detection circuit 35 Upper limit voltage detection circuit

Claims (2)

(57) [Claims] 1. A means for integrating a charge / discharge amount for a secondary battery (6); a means for detecting an upper limit voltage of the secondary battery (6); When the count value of the means reaches a set value, the charge control means includes a charge control means for performing a predetermined charge regulating operation, and a means for detecting a change in the mode of charging or discharging. A small-sized electric device which holds this output when a voltage is detected, and holds the output until the mode change detecting means detects a change to another mode. 2. The method according to claim 1, further comprising the step of: setting the set value when the upper limit voltage detecting means detects the upper limit voltage before the value reaches the set value, and displaying the integrated value corresponding to the set value. 2. The small electric device according to claim 1, wherein: