JP2631844B2 - Battery capacity display - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device, particularly to a battery capacity display device, particularly to a device provided with a charging device for a secondary battery.

2. Description of the Related Art Conventionally, a display means used in a charging apparatus of this type displays a charging state by turning on a display element directly or indirectly using a commercial AC power supply as a driving source when a commercial AC power supply is turned on. What we did was common.

[Problems to be Solved by the Invention] However, as long as power is supplied to the primary side, all of the above-described display means perform display under the assumption that a normal charging operation is being performed. However, even if there is a charging abnormality due to a malfunction of the inverter circuit or the like, it is impossible to cope with the abnormality, and it is difficult to appropriately display the information.

The present invention has been made in view of the above disadvantages,
An object of the present invention is to display a proper and stable charge state by performing a display operation only after confirming that a charging operation is normally performed.

[Means for Solving the Problems] FIG. 1 is a schematic diagram showing a basic configuration of a charging device according to the present invention, in which an input voltage of a commercial AC power supply or the like is converted to a predetermined charging voltage by using an inverter circuit 20. In a battery capacity display device provided with a charging means for converting and charging the secondary battery 6, a detecting means for generating a signal corresponding to an operation state of the inverter circuit 20 and an input of a signal output from the detecting means are connected. And display means for performing a predetermined display operation.

[Operation] With the above configuration, when a predetermined voltage is input to the inverter circuit 20, the inverter circuit 20 raises the frequency of the input voltage to step down and replace the predetermined charging voltage, and then replaces the secondary battery 6.
To start the charging operation.

Since the detection means generates a predetermined signal at the same time as the charging operation is started, the display means performs a predetermined display operation after confirming that the charging operation is actually performed by inputting a signal. The display according to the actual state of charge is performed by the display means.

[Embodiment] 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 the same applies to various small electric appliances including a charging device alone or a charging unit in a power supply portion. Of course, it can be implemented.

As shown in FIG. 2, an electric shaver 1 embodying the present invention has an outer blade 2 detachably mounted on an upper portion of a main body case 3 and an inner blade 4 slidably disposed inside the outer blade 2. I do. Further, inside the main body case 3, a motor 5 for reciprocatingly driving the inner blade 4, a secondary power 6 for supplying a rotational driving power to the motor 5, a charge control for the secondary battery 6 or a An electric circuit 7 for performing various controls such as rotation control is housed. In addition, a knob 11 of a slide switch 10 for regulating the energization time to the motor 5 is provided in the center of the front of the main body case 3, and a first display element 12 for displaying a rotation control state is provided below the switch knob 11. Second and third display elements 13 and 14 for displaying a discharge state are provided. Further, the stock of the main body case 3 is provided with a power cord 16 provided with a power plug 15 at the tip thereof so as to be freely inserted and removed, so that the secondary battery 6 can be charged and the motor 5 can be directly sold by the commercial AC power supply 17. I have.

FIG. 3 is a block diagram schematically showing the entire electric circuit 7 built in the main body case 3 described above. The commercial AC voltage is converted into a predetermined charging voltage by the inverter circuit 20, and the power supply unit is turned on.
Apply to 21. The power supply unit 21 includes a main power supply including a secondary battery 6 such as a nickel-cadmium battery that can be charged and discharged by a plurality of parties.
22 and an auxiliary power supply 23 for rectifying the output voltage from the inverter circuit 20. Further, at the time of driving the motor with the switch 10 turned on, the rotation control unit 24 can maintain a substantially constant inner blade driving speed regardless of the fluctuation of the battery voltage or the magnitude of the load. Furthermore, the power supply unit 21 is detected by the detection unit 25 during charging.
The charge / discharge state of the
Regulate the operation time of 20 to 100 to 240 of commercial power supply voltage
The charging operation corresponding to the change of about V or the progress of charging is performed. Further, the state of the power supply unit 21 is detected by the detection unit 25 during charging and discharging, and a display corresponding to the charging and discharging state of the secondary battery 6 is performed on the display unit 27. Inform various information.

Hereinafter, based on the electric circuit diagrams shown in FIGS. 4 to 7,
The configuration of FIG. 3 will be described more specifically.

(Inverter Circuit) As shown in FIG. 4, the inverter circuit 20 is provided on the input side of a rectifier circuit 33 including a diode bridge 31 and a filter 32, and is input to the main body case 3 via a detachable power plug 15. After full-wave rectification of the commercial AC power supply 17 by the rectifier circuit 33, the commercial AC power supply 17 is applied to the inverter circuit 20 through the fuse.

The inverter circuit 20 includes, on the collector side of the transistor 35, a shock absorber 37 that is connected to both ends of the primary coil 36 and absorbs a shock voltage generated when the transistor 35 is turned off. And a feedback section 40 between the emitter and the emitter. Further, a feedback coil 41, an output coil 42, and a tertiary coil 43 are wound on the same iron core as the primary coil 36.

The feedback unit 40 connects one end of the feedback coil 41 to the base end of the transistor 35, and connects the other end of the feedback coil 41 to the transistor 35.
A capacitor 44 is connected between the emitters of the transistor 35 and a diode is connected in the reverse direction between the emitter and base of the transistor 35.
45, and the emitter end is connected to the positive side of the secondary battery 6 via the resistor 46. Further, the output voltage from the rectifier circuit 33 is connected to a connection point of the feedback coil 41 and the capacitor 44 with a resistor 47.
-The voltage divided by 48 can be applied via the resistor 49.

With the above configuration, a voltage is generated across the resistor 48 simultaneously with the application of the voltage to the inverter circuit 20, and the charging of the capacitor 44 is started by the voltage. When the voltage across the capacitor 44 rises and reaches near the turn-on voltage of the transistor 35, a current starts to flow through the primary coil 36 connected to the collector end of the transistor 35, and a voltage is generated in the feedback coil 41 due to the increase in the current. I do. This voltage flows between the base and the emitter of the transistor 35, turning on the transistor 35 and simultaneously charging the capacitor 44 in the opposite direction. Here, when the primary current becomes stable and the voltage across the feedback coil 41 decreases, a current flows in the opposite direction through the diode 45 due to the charging voltage of the capacitor 44, and the voltage across the diode 45 becomes a blocking voltage. The transistor 35 is rapidly turned off. After the transistor 35 is turned off, the voltage output from the feedback coil 41 and the diode
After the capacitor 44 is rapidly discharged by the resistor 50 selectively connected to the base end at 55, the voltage across the resistor 48 is again applied to the capacitor 44 through the resistor 49, and the capacitor 44
Is charged in the positive direction, and the above ON / OFF operation is repeated. Here, the energy stored in the primary coil 36 when the transistor 35 is turned on is selectively supplied to the load connected to the output coil 42 and the tertiary coil 43 by the rectifying diodes 51 and 52 during the off period of the transistor 35. Taken out.

The tertiary coil 43 has a number of turns several times larger than that of the output coil 42, and therefore can output a higher voltage than that of the output coil 42, and further smoothes the output by using a rectifying diode 52 and a large-capacity capacitor 53 to assist. The power supply 23 is configured. Accordingly, even when the output from the inverter circuit 20 is reduced due to the inverter circuit 20 being operated but the inverter circuit 20 being sufficiently controlled, various circuits can be supplied from the auxiliary power source 23. auxiliary voltage V ₂ drive and control of the necessary and sufficient size capable of, and the like can be supplied to each circuit in the following as a circuit drive voltage or control signal.

(Detection Unit) As shown in FIG. 5, the detection unit 25 includes first to fourth detection circuits 61, 62, 63, 64 and a switch circuit 80, and performs control corresponding to the charge / discharge state of the secondary battery 6. It outputs a signal and a detection signal.

The first detection circuit 61, there is connected to the output side of the auxiliary power supply 23, by dividing the output voltage V ₂ of the auxiliary power supply 23 by the resistors 65, 66, the inverter circuit 20 the secondary battery 6
The detection voltage V ₃ , which changes in proportion to the increase or decrease in the average value of the charging voltage on the pulse output toward, is extracted, and the reference voltage using the voltage V ₃ and the forward voltage of the diode 67 is extracted.
The magnitude of the V ₄ compared in comparator 68 with OP amplifier, when the detected voltage V ₃ exceeds the reference voltage V _4, it sends a control signal Sa to the output control section 26 described later from the comparator 68, an inverter Circuit 20
Output is intermittently stopped to enable output control.

Incidentally, when the drive motor 5 while actuates the inverter circuit 20, while the detected voltage V ₃ as described above is decreased,
Reference voltage V ₄ is kept substantially constant value. So switch
Turns on the 10 parallel resistor 69 for simultaneously detecting voltage generated when driving the motor 5 is turned off at the switch contacts 10a and performs the correction of the detected voltage value by raising the detection voltage V _3, the output from the inverter circuit 20 Can be maintained substantially constant.

The second detection circuit 62 takes out the detection voltage V ₆ from both ends of the large diode 70 of the temperature coefficient, the control signal corresponding to the magnitude of both by comparing the reference voltage V ₄ obtained by the this voltage V ₆ by the comparator 71 Sb is output, and when the output control by the above-described first detection circuit 61 is malfunctioning and the battery temperature is abnormally increased by continuing charging after full charge, the control signal Sb is changed from Low to High. By inverting and forcibly restricting the operation of the inverter circuit 20, overcharging of the secondary battery 6 is avoided and battery deterioration is prevented.

The third detection circuit 63 includes a voltage dividing resistor 56 in parallel with the main power supply 22.
· 57 connects, take out the detection voltage V ₆ of the voltage value proportional to the change in the terminal voltage V ₁ of the rechargeable battery 6. Auxiliary power supply for resistor 57
Transistor 73 is turned on by the output voltage V ₂ from the 23 is connected, together with the transistor 73 inverter circuit 20 only during operation reduce power by outputting a detection voltage V ₆ turns on, inverter circuit 20 and the manner and outputs a detection signals S ₁ corresponding to the operation timing. The detection voltage V ₆ is further increased by OP
The comparator 74 with the amplifier is compared with a reference voltage V ₇ formed by the diode 75, the terminal voltage V ₁ of the secondary battery 6,
Inverted from the output terminal fully charged exceeds the upper limit voltage V _H that is set in advance that is close is detected Low to High, the third sends a detection signal S ₃ of the display unit 27 to be described later By turning on all the display elements 14 and forcibly displaying the full charge, the display of the display unit 27 can be corrected.

Fourth detection circuit 64, has been made to operate only during the motor driving period in tandem with the switch-on operation of the switch knob 11, divides the detected voltage of the terminal voltage V ₁ of the secondary battery 6 by resistors 76 & 77
Removed V _8, usually compared with a reference voltage V ₉ by the diode 78 is outputs the detection signal S ₄ of the High state, voltage
Changes to Low if the lower limit voltage V _L which V ₁ is set in advance,
By turning off all the third display elements 14 in the display unit 27 and blinking the second display element 13, the display is returned to a state in which the battery capacity is 20% or less, and the display correction at the time of discharging is performed.

Incidentally, the ambient temperature of the battery 6 during discharge is reduced and the output voltage V ₁ of the apparent from that the secondary battery 6 rises, the detected voltage V ₈ is also decreased. Therefore, a thermistor 79 is connected in series with the reference voltage generating diode 78, which tends to decrease more than necessary, and when the temperature rises, the divided voltage ratios of the diode 78 and the thermistor 79 have the same tendency before the temperature rise. with connection to be to increase the current flowing through the diode 78, and the like to correct the reference voltage V ₉ itself.

The switch circuit 80 is a two-circuit two-contact switch contact 10a.
The switching transistor 81 is provided when the switch 10b is turned on in connection with the ON operation of the switch knob 11. The transistor 81 is provided with a CR charge / discharge circuit 82 on the base side, and can be turned on and off between the base and the emitter by the switch contact 10b.When the switch knob 11 is off, both ends of the capacitor 83 are short-circuited. Set the base voltage to zero, turn off transistor 81, and set the collector end to High
Although it is in the state, when the switch knob 11 is turned on,
A charging current flows through the capacitor 83 through the resistor 84, and the transistor 81 is turned on a predetermined time after the switch is turned on, so that a stable low state detection signal ₂ without chattering is sent to the display unit 27.

(Output control section) the output control unit 26 includes a control signal generating circuit 85 the oscillation period is regulated by the detection signal S ₃ output from the third detection circuit 63,
When a control signal Sa, Sb, or Sc is input from any one of the first detection circuit 61, the second detection circuit 62, and the control signal generation circuit 85, the control circuit is turned on, and the base end of the inverter circuit 20 is grounded so that the inverter circuit And an output control circuit 86 for stopping the operation of the control circuit 20.

The output control circuit 86 includes a collector and an emitter of the transistor 87 between the base end of the transistor 35 in the inverter circuit 20 and the ground, and includes a Zener diode 88 at the base end. Through
When the control signals Sa, Sb, and Sc in the high state are input, the zener diode 88 is turned on, the transistor 87 is turned on, the base end of the transistor 35 is grounded, and the oscillation of the inverter circuit 20 is stopped.

In the control signal generation circuit 85, the third detection circuit 63 determines that the upper limit voltage V _H
Until detected has stopped operating, it starts oscillation and outputs a detection signal S ₃ by detecting the upper limit voltage V _H, to stop the inverter circuit 20 intermittently. That is, the secondary battery 6
Is a terminal voltages V ₁ of the state close to the full charge exceeding the upper limit voltage V _H, the control acts in the first detection circuit 61, frequently inverter circuit 20 starts and stops oscillation of the secondary battery 6 terminals with an adverse effect on the detection operation of the voltages V ₁ also detecting unit 52 repeats the copper to a relatively large, joined as noise to the digital circuit constituting the display unit 27, also cause a malfunction. Therefore, the control signal generation circuit 85 causes the inverter circuit 20 to be forcibly stopped at a period sufficiently longer than the control period of the first detection circuit 61 to quickly shift to a state in which the charging current is narrowed down. The occurrence of control with a short repetition cycle in 61 is prevented as much as possible.

By connecting the resistor 89 in parallel with the resistor 91 via the diode 90, the time constant at the time of discharging the capacitor 92 is smaller than that at the time of charging, and the ratio of the inverter stop period in one cycle is increased. On the other hand, when the motor is driven, the power consumption is large, and the control in the vicinity of the full charge is not necessary. Therefore, the plus input terminal of the OP amplifier 93 is grounded by the low resistance 94 and the switch contact 10b to stop the oscillation. .

(Rotation control unit) The rotation control unit 24 normally stops its operation as shown in FIG. 6, but operates in conjunction with the ON operation of the switch contact 10a. The movement is detected using a photointerrupter 100 including a light emitting diode and a phototransistor, and a signal having a frequency corresponding to the rotation speed of the motor 5 is generated. This signal is input to the further filter circuit 101, and selectively sends only the AC signal of the frequency component corresponding to the rotation cycle of the motor 5 to the waveform shaping circuit 102. Waveform shaping circuit 102, while an output signal from the filter circuit 101 to the negative input terminal of the comparator 103, a reference voltage obtained by dividing the secondary battery voltages V ₁ by resistors 104 · 105 to the positive terminal Voltage, and a resistor 106
And a positive feedback is applied by a resistor 108. The peak value of both ends of the diode 107 is regulated by the forward voltage of the diode 107. A rectangular wave-like detection signal is extracted. This signal is converted into a detection signal having a magnitude corresponding to the frequency by a DA converter 110, and is compared with a reference voltage by a comparator 111. If a difference occurs between the two, a control corresponding to the value of the difference is performed. The signal is sent to the control circuit 112. The control circuit 112 is interposed in an energizing circuit for the motor 5, and controls a voltage drop in the control circuit 112 by a control signal to increase or decrease the voltage applied to the motor 5, thereby reducing the load applied to the motor 5. regardless or secondary battery 6 level of the terminal voltage V ₁ of the rotational speed control is performed to maintain a substantially constant rotational speed.

(Display Unit) As shown in FIG. 7, the display unit 27 operates at the time of charging / discharging and displays a charging / discharging state display circuit 120 corresponding to the charging / discharging state.
And a rotation state display circuit 121 that operates when the motor is driven to indicate that rotation speed control is being performed, and constantly applies a voltage V ₁ ′ that further stabilizes the output voltage V ₁ from the main power supply 22. In the active state.

The charge / discharge state display circuit 120 includes the second and third display elements 1.
Sixteen light emitting diodes 13a, 13b, 14a to 14d are provided at 20% intervals from 0 to 100% charged state as 3.14, and when the switch knob 11 is in the off position and in the standby state, the second and third light emitting diodes are provided. Only when the display elements 13 and 14 are turned off to stop the display operation and the detection signal ₁ or ₂ is in the Low state, and it is confirmed that the inverter circuit 20 is operating or the motor 5 is on. Then, the light emitting diode corresponding to the current capacity of the secondary battery 6 is turned on.

That is, the charge / discharge display maintains the current display state because the battery capacity hardly changes during the period when the motor is driven while the inverter circuit 20 is operating.
If only the charging is stopped and the charging is completed, the charging is completed in about 1 hour from the fully discharged state. Conversely, the motor 5
During direct drive, the number of illuminated display elements is reduced by 1 every about 8 minutes.
Decrease by one. Further, during charging, the terminal voltage V ₁ of the secondary battery 6 exceeds the upper limit voltage V _H and the detection signal
When S ₃ is output, all the light emitting diodes light up the third display element 14, forces a full charge display off the second display device 13, the fourth detection circuit 64 is a lower limit voltage V _L Upon detection, the third display element 14 is turned off and the second display element 13 is turned off.
Blinks to display the empty state of the secondary battery 6 to urge the user to charge.

More specifically, the detection signals ₁ and ₂ are applied to the base end of the switching transistor 131 and the clock signal generation circuit 132 in parallel via the NOT circuit 130. The collector end of the transistor 131 is the second
And the light emitting diodes constituting the third display elements 13 and 14 are connected to the cathode side, and the display elements 13 and 14 are normally turned off by applying a high signal, but the inverter circuit 20 or the motor 5 operates. Then, the transistor 131 is turned on, and the cathode sides of the display elements 13 and 14 are grounded to turn on.

At the same time, the clock signal generation circuit 132 starts, and
Clock signal S _A of 5m sec cycle is generated, the clock signal S _A is 1 frequency division of 1 and 2 ¹² min 2 ¹³ min dividing circuit 133, the timer signal of about 1 minute 30 second period S to form a _{B-S C,} input to the first and second 2NAND circuit 134, 135 respectively.

On the other hand, the detection signals ₁ and ₂ and their inverted outputs are
AND with the second AND circuits 136 and 137
The outputs of AND circuits 136 and 137 are connected to first and second NAND circuits 134
- by inputting 135, and the inverter circuit 20 operates the motor 5 is stopped removed timer signal S _B of the 1NAND circuit 134 about one minute period, while the inverter circuit 20 is stopped motor 5 ON The second NAND circuit 135 takes out a timer signal S _C having a period of about 30 seconds, and the timer signals S _B and S _C are individually input to the clock input terminals I ₁ and I ₂ of the up / down counter 138.
Is applied to

Up-down counter 138, is used as the up-counting and C-MOS type low power clock signal input terminal I ₁ · I ₂ provided separately for down-counting. Such counter 138 is a hexadecimal counter, when the input terminal I ₁ for counting up 16 timer signal S _B is input, a carry signal from the carry signal output terminal O ₁ S _D
Indicates that about 15 minutes have passed since the output of one. Conversely, when the input I ₂ to 16 timer signal S _C of the down-counting is input, a borrow signal output terminal O ₂ or borrow signal S _E is output. This indicates that about 8 minutes have elapsed. The signals S _D and S _E are further ORed and then input to the shift register 139.

The shift register 139 is a binary 4-digit parallel output terminal Q _{1 to} Q
₄ CM, which enables bit shifting in both left and right directions
OS type is used. The shift register 139
Have first and second AND circuits 136 and 137 connected to their control terminals C ₁ and C ₂ .
Of which the output signal is applied separately, when the control terminal C ₁ is High state, the register each time the carry signal S _D is outputted one
The third display element 14 connected to the output terminals Q _{1 to} Q ₄ of the register 139 by shifting each bit of 139 one step at a time in the left-right direction.
Are increased by one each of the light emitting diodes 14a to 14d. Conversely, when the control terminal C ₂ is High, reduced by one lighting number of light emitting diodes of the third display element 14 each time the borrow signal S _E is shifted leftward is entered one, have been The current capacity of the secondary battery 6 is indicated by the number of light-emitting diodes in the third display element 14.

By the way, the above-mentioned charge / discharge display assumes that conditions such as a charge current or a load current are always constant, and therefore, if charge / discharge is repeated, occurrence of an error between the display and the actual capacity can be avoided. Absent. Therefore, in this embodiment,
Presetting an upper limit value V _H and the lower limit value V _L of the terminal voltage V ₁ of the secondary battery 6, to force a 100% display exceeds the upper limit value V _H,
When the value falls below the lower limit value V _L , 20% display is performed.

That is, the upper limit value correction is performed by keeping the 4-bit parallel input terminals P _{1 to} P ₄ of the counter 138 all in the High state and applying the detection signal S ₃ output from the third detection circuit 63 to the control terminal C. sets all bits immediately counter 135 when the upper limit voltage V _H is detected, to such outputs a carry signal S _D with a timer signal S _B to be inputted within then 1 minute. On the other hand, the parallel input terminals P _{1 to} P _{4 of the} shift register 139
Is also set to the high state, and the detection signal S ₃ can be input to the control terminal C _2.
After the S ₃ is output, is all bits are set carry signal S _D at the same time the shift register as output from the counter 138 139 and the output terminal Q ₁ to Q ₄ become all High state 4
All the three light emitting diodes 14a to 14d are turned on.

On the other hand the lower limit voltage correction is carried out by resetting the shiftless register 139 by the reset signal S _F, the reset is not to reset directly by the detection signal ₄ output from the fourth detection circuit 64, the following reset Indirectly through circuit 140. That is, the reset circuit 140 includes the frequency divider 141 of the clock signal S _A , and always applies the High signal of the detection signal ₄ to the reset terminal Re of the frequency divider 141 to continue the stop state. 64 detects the lower limit voltage and when the detection signal ₄ becomes low, the frequency dividing circuit 141
Starts the frequency division of the clock signal S _A after the reset, and after a few seconds, resets the reset signal _SF to the counter 138 and the shift register 1
Send to 39. With this configuration, if the inversion of the detection signal ₄ is a short-time voltage change due to noise or the like, the detection signal is set to High again by the time the reset signal _SF is output.
Since it returns to the state and stops counting by the frequency divider 141,
This prevents the reset signal _{SF from} being output by mistake.

Resetting shift register 139 by the reset signal S _F which is generated as described above, all the four output terminals Q ₁ to Q ₄ become Low state, four light emitting diodes 14a~14d tethered to the output end off Then simultaneously, sends a High signal to the second display device 13 via the NOT circuit 142, a timer signal S _G of about 0.25 second intervals sent from the frequency divider 133 the second display element
13 blinks to indicate that the capacity of the secondary battery 6 has decreased and charging is required.

Even if the switch knob 11 is returned to the OFF state during the above-described display, a small amount of power is always supplied from the secondary battery 6 to the display unit 27, and the display content at the time of the OFF is stored.

However, when the rechargeable battery 6 drops significantly below the lower limit voltage value _VL , the operation of the circuit is completely stopped and the stored value disappears, and the display becomes indefinite when the inverter circuit 20 is operated again to start charging. . Further, before the above-described reset by the fourth detection circuit 64 and the reset circuit 140 operates, the motor 5
When you run, despite having little battery capacity,
The third display element 14 may be lit. So, the battery voltage
When exerting inverter circuit 20 in a state in which the transistor 143 is turned off in the reset circuit 140 V ₁ is lowered, the display by turning the transistor 143 is forcibly reset circuit outputs the reset signal S _F ' The correction is made to indicate that the battery capacity is running out.

Rotation state display circuit 121, the light emitting diodes 12a, comprises a first display element 12 and a transistor 123 for switching having a 12b in parallel, as well as connecting the base of transistor 123 to Q ₁ terminal of the shift register 139, A detection signal ₂ output from the switch circuit 80 when the motor 5 operates is applied to the emitter terminal. With this configuration, when the motor 5 switch 10 is turned off is stopped, the detection signal ₂ and Q ₁ terminal both transistors in the High state 12
When the switch 3 is turned off and the first display element 12 is turned off, when the switch 10 is turned on, the detection signal ₂ becomes Low, the transistor 123 is turned on and the first display element 12 is turned on to perform rotation control. To indicate that Here the secondary battery 6 is exhausted, the terminal voltage V ₁ is within the scope of the rotation control does not work below the lower limit voltage V _L, Q ₁ terminal also becomes Low state reset circuit 140 is activated, the transistor 123 It turns off and the first display element 12 is turned off.

The fourth detection circuit 64 is connected to the base end of the transistor 123.
Even if the detection signal ₄ output from is directly applied, a display operation substantially similar to the above can be performed.

[Effects of the Invention] As described above, according to the present invention, the display means performs a predetermined display operation after the detection means confirms that charging is actually being performed. The charge indication can be displayed.

Furthermore, by using the auxiliary power supply 23 that rectifies and smoothes the output voltage from the tertiary coil 43 of the inverter circuit 20 for detecting the state of charge, power supply to the detection unit 25 and detection operation can be performed simultaneously, thereby simplifying the circuit configuration. Can be achieved.

Further, since the display on the display unit 27 is corrected by the upper and lower limit voltage values of the secondary battery 6, there are many advantages such as accurate charge / discharge display with a relatively simple configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an outline of the present invention. 2 and 3 show an example in which the present invention is applied to an electric shaver. FIG. 2 is an overall front view, and FIG. 3 is a block diagram schematically showing an electric circuit. 4 to 7 are specific electric circuit diagrams of FIG. 3, wherein FIG. 4 is a power supply section, FIG. 5 is a detection section and an output control section, FIG. 6 is a rotation control section, FIG. The figures each show a display unit. 5 ... motor, 6 ... rechargeable battery, 10 ... switch, 20 ... inverter circuit 22 ... main power supply, 23 ... auxiliary power supply, 25 ... detection unit, 26 ... output control unit, 27 ... Display section.

Claims (2)

(57) [Claims] An inverter circuit for converting an input voltage to a predetermined charging voltage to charge a secondary battery; a load fed from the secondary battery in conjunction with a switch-on operation; Detecting means for generating a detection signal corresponding to an operation state of the circuit; and simultaneously detecting the terminal voltage of the secondary battery while integrating the charge / discharge time of the secondary battery, and detecting a preset upper limit voltage and lower limit voltage. A display means for correcting the integrated value in conjunction with the display signal and performing a predetermined display operation in conjunction with the input of the detection signal. The detection means is capable of detecting whether the inverter circuit is on or off and whether a load is supplied from the inverter circuit side, and sends a detection signal corresponding to the detected content to the display means. Therefore, the detection signal corresponding to the power supply timing for the load described above is
2. The battery capacity display device according to claim 1, wherein the battery capacity display device is sent to the display means a predetermined time after power supply is started.