JP2003061258A - Electric equipment with built-in battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To install a charge control switch to quickly charge a battery and further make a light source to normally blink to allow charging of the battery to be restarted regardless of turn-on/off of the charge control switch. SOLUTION: Electric equipment is provided with a change-over switch 2 which switches the battery between the charging side and the load side; a light source 3 which indicates when the battery 1 is charged; a voltage detection switching circuit 4 which detects supply voltage supplied from a charger and causes the light source 3 to blink; and the charge control switch 5 which controls charging of the battery 1. When the change-over switch 2 is turned to the charging side, the electric equipment charges the battery 1 and turns on the light source 3. When the change-over switch 2 is turned to the load side, the electric equipment stops charging of the battery 1 and turns off the light source 3. Further, in the electric equipment, a voltage bypass resistor 12 is connected in parallel with the charge control switch 5. The voltage bypass resistor 12 bypasses the charge control switch 5 in off state and supplies voltage to the voltage detection switching circuit 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric device including a rechargeable battery and a light source for displaying the charge of the battery.

[0002]

2. Description of the Related Art FIG. 1 shows a circuit diagram of an electric device containing a battery. This electric device includes a changeover switch 2 that switches the battery 1 between a charging side and a load side. Changeover switch 2
To the charging side to charge the battery 1, and to the load side to supply power to the load. The electric device in this figure is an electric razor having a motor 7 as a load. Since this electric device does not drive the motor 7 while charging, it is suitable for a waterproof type electric razor. This is because the user cannot use the charger with the power cord connected because the motor 7 cannot be driven vigorously by the charger. That is, the motor 7 is always driven only by the battery 1, the rotation speed of the motor 7 does not change regardless of whether or not the power cord is connected, and the user has no merit of using the power cord in the connected state. For this reason, the power cord is detached and used, and it can be safely used in a bathroom or the like.

This electric device is provided with a light source 3 such as a light emitting diode for displaying the charging state of the battery 1. The light source 3 is blinked by the voltage detection switching circuit 4. The voltage detection switching circuit 4 detects the supply voltage supplied to the charging side of the changeover switch 2 and blinks the light source 3. The voltage detection switching circuit 4 includes a Zener diode 13
It has an input transistor 14 connected to the base and a switching transistor 11 which can be switched by the input transistor 14. Input transistor 1
4 connects the collector and the emitter between the base of the switching transistor 11 and the ground,
The input transistor 14 in the ON state connects the base of the switching transistor 11 to the ground so that the base current does not flow. The Zener diode 13 switches the changeover switch 2 to the load side, and when the supply voltage rises, a base current is passed through the input transistor 14 to switch it on. When the changeover switch 2 is switched to the charging side and the supply voltage becomes low, the Zener diode 13 does not flow the base current to the input transistor 14. Therefore, in this voltage detection switching circuit 4, when the changeover switch 2 is switched to the charging side and the supply voltage becomes low, the input transistor 14 is turned off, the switching transistor 11 is turned on, and the light source 3 is turned on.
Is switched to the load side, and when the supply voltage increases, the input transistor 14 turns on and the switching transistor 1
1 is turned off and the light source 3 is turned off. This is because the supply voltage becomes low when the changeover switch 2 is switched to the charging side and the battery 1 is charged, and becomes high when the changeover switch 2 is switched to the load side. The reason why the supply voltage drops when charging is that the voltage drop due to the charging current flowing through the battery increases.

[0004]

The electric device shown in FIG. 1 can be conveniently used because the light source 3 can be turned on to display the charge of the battery 1 in an easy-to-understand manner. However, this electric device
The battery 1 is always trickle charged while the changeover switch 2 is switched to the charging side. In order to limit the charging current for trickle charging, a current limiting resistor 9 is provided on the charging side of the changeover switch 2.
Are connected. The resistance value of the current limiting resistor 9 is set to a large resistance value so that deterioration can be reduced while continuously charging the battery 1. For example, in a nickel-hydrogen battery or a nickel-cadmium battery, the resistance value is set to a high value that provides a charging current of about C / 10.

An electric device having this circuit configuration cannot always be used in an ideal state. For example, when the battery is completely discharged and cannot be used, the battery cannot be rapidly charged in a short time, so that it takes time before it can be used. If the charging current is increased in order to shorten the charging time, the battery is continuously charged, which causes a serious deterioration of the battery. Further, trickle charging a battery continuously for a long time is not an ideal environment considering the battery life. This is because the battery is maintained in a state close to overcharge.

This drawback can be eliminated by connecting the charging control switch 5 to the charging side of the changeover switch 2 as shown in FIG. The charge control switch 5 is controlled by the charge control circuit 6 to charge the battery 1 until the battery 1 is fully charged, and then is switched from on to off to stop charging. Therefore, this electric device can be rapidly charged without degrading the battery 1. Therefore, even when the battery 1 is completely discharged, the battery 1 can be rapidly brought into a state in which it can be used in a short time.

However, the electrical equipment of this circuit diagram is
The light source 3 cannot blink normally. For example, when the changeover switch 2 is switched to the load side, the charging control circuit 6
Has a drawback that when the charging control switch 5 is switched on and off at a predetermined cycle, the light emitting diode is turned on at the moment of switching although the battery 1 is not charged. This is because the input transistor 14 cannot be forcibly turned on while the switching transistor 11 is turned off. At the moment when the charge control circuit 6 switches the switching transistor 11 on by switching the changeover switch 2 to the load side, the charge control switch 5 in the off state cannot supply the current to the zener diode 13 to turn on the input transistor 14. Therefore, after the switching transistor 11 is turned on, the charging control switch 5 is turned on,
Then, until the Zener diode 13 flows the base current of the input transistor 14 to turn on the input transistor 14, the light emitting diode is lit for a short time even though the battery 1 is not charged.

In order to eliminate this adverse effect, as shown in FIG. 3, when the voltage detection switching circuit 4 is connected to the connecting portion between the charging control switch 5 and the charger, the charging control switch 5 which has been turned off is turned on. Switching cannot be done and charging of battery 1 cannot be resumed. When the charging control switch 5 is turned off, it is in the same state as when the changeover switch 2 is switched to the load side, and the voltage detection switching circuit 4 always detects a high voltage and turns off the light source 3 and charges the battery 1. Is not restarted.

The present invention was developed to solve this drawback with a very simple circuit. An important object of the present invention is to provide an electric device with a built-in battery that can rapidly charge a battery by providing a charge control switch, and can normally recharge the battery by flashing the light source regardless of whether the charge control switch is on or off. To provide.

[0010]

An electric device according to the present invention has a built-in battery 1, a changeover switch 2 for switching the battery 1 between a charging side and a load side, and a light source 3 for displaying charging of the battery 1. , A voltage detection switching circuit 4 which detects the supply voltage supplied from the charger to the charging side of the changeover switch 2 and blinks the light source 3, and a charging which is connected to the charging side of the changeover switch 2 and controls the charging of the battery 1. And a control switch 5.
The electric device switches the changeover switch 2 to the charging side to charge the battery 1, and in this state, the voltage detection switching circuit 4 lights the light source 3. Further, the electric device switches the changeover switch 2 to the load side to stop the charging of the battery 1,
The voltage detection switching circuit 4 turns off the light source 3 in a state where the power is supplied to the load. Further, the electric device has a voltage bypass resistor 12 connected in parallel with the charging control switch 5. The voltage bypass resistor 12 bypasses the charge control switch 5 in the off state and supplies a voltage to the voltage detection switching circuit 4.

The electric device may be an electric razor. Further, the electric device can control the charging control switch 5 with the charging control circuit 6. The voltage detection switching circuit 4 is provided with a Zener diode 13 and an input transistor 14 connecting the Zener diode 13 to the base, and the base of the input transistor 14 is connected to the changeover switch 2 and the voltage bypass resistor 12 via the Zener diode 13. Can be connected to the connection part with. This voltage detection switching circuit 4 causes a current to flow from the Zener diode 13 to the base of the input transistor 14 to turn on the input transistor 14 when the voltage of the connection portion rises, and when the voltage of the connection portion decreases, a current flows to the Zener diode 13. It stops flowing. Further, in the electric device, the current limiting resistor 9 can be connected to the charging side of the changeover switch 2. The light source 3 can be a light emitting diode.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify electric equipment for embodying the technical idea of the present invention, and the present invention does not specify the electric equipment as follows.

Further, in this specification, in order to facilitate understanding of the claims, the numbers corresponding to the members shown in the embodiments are referred to as "claims column" and "to solve the problems". It is added to the members shown in "Means column".
However, the members shown in the claims are not limited to the members of the embodiment.

FIG. 3 is a circuit diagram showing the electric device as a waterproof type electric shaver. This electric razor charges a built-in battery 1 by connecting a charging power source 8. Therefore, a charging power supply circuit for converting 100 V of AC, which is a commercial power supply, into a charging voltage of a battery, which is DC, is not incorporated. However,
The electric device of the present invention may have a built-in charging circuit to directly connect AC 100V, which is a commercial power supply, to charge the battery. This electric device incorporates a power supply circuit that converts a commercial power supply into a charging voltage for a battery. This power supply circuit includes a transformer that steps down the alternating current to the charging voltage of the battery, a diode that rectifies the output of the transformer, and an electrolytic capacitor that smoothes the output of the diode.

The electric equipment has an inner blade (not shown) of a razor.
A reciprocating motor 7, a battery 1 for driving the motor 7, a changeover switch 2 for switching the battery 1 between the motor 7 and a charging power source 8, a light source 3 for indicating that the battery 1 is charged, and a light source 3, a voltage detection switching circuit 4 for blinking 3, a charging control switch 5 for controlling charging of the battery 1, and a charging control circuit 6 for controlling the charging control switch 5.

The battery 1 is a secondary battery such as a nickel-hydrogen battery, a nickel-cadmium battery or a lithium ion battery. The changeover switch 2 has a movable contact that is switched to the charging side when charging the battery 1 and to the load side motor 7 when driving the motor 7.
The change-over switch 2 is a manual switch, and switches a contact by operating a lever or a dial (not shown).

The charging control switch 5 is controlled by the charging control circuit 6 to control charging of the battery 1. The charge control switch 5 is a transistor, which rapidly charges the battery 1 in the on state and stops the rapid charge of the battery 1 in the off state. In the transistor shown in the figure, the emitter is connected to the charging power source 8 side, and the collector is connected to the charging side of the changeover switch 2 via the current limiting resistor 9. As shown in this figure, in the electric device in which the current limiting resistor 9 is connected between the charge control switch 5 and the changeover switch 2, the charging current of the battery 1 can be limited by the current limiting resistor 9. However, the circuits that use transistors and FETs for the charge control switch are transistors and FEs.
It is also possible to control the internal resistance of T or adjust the duty for turning them on and off at a predetermined cycle to control the current for rapidly charging the battery. Therefore, it is not always necessary to connect the current limiting resistor. In the electric shaver shown in the figure, the charge control switch 5 is a transistor, but a semiconductor switching element such as an FET can also be used for this.

The charging control switch 5 shown in the figure is controlled by the charging control circuit 6. The charging control circuit 6 switches the voltage of the output terminal 6a between "H" and "L", and the charging control switch 5
Control on and off. The output terminal 6a switches the charge control switch 5 on and off via the output transistor 10 and the switching transistor 11 of the voltage detection switching circuit 4. In this circuit, when the output of the output terminal 6a of the charge control circuit 6 becomes "L", the output transistor 10 is turned on, and the output transistor 10 turns into the switching transistor 11 of the voltage detection switching circuit 4.
Switch on. The switching transistor 11 that is switched on turns on the charging control switch 5 to charge the battery 1. When the output terminal 6a of the charge control circuit 6 becomes "H", the base current of the output transistor 10 stops flowing and the output transistor 10 is turned off. The off output transistor 10 is the switching transistor 11 of the voltage detection switching circuit 4.
Off, switching transistor 11 off
Turns off the charge control switch 5 to stop charging the battery 1.

The charging control circuit 6 has a built-in timer, and until the timer counts up, the output terminal 6
When a is set to "L" and the timer counts up, the output terminal 6a is switched to "L" and "H" at a constant cycle.
When the changeover switch 2 is switched to the charging side with the output terminal 6a set to "L", the battery 1 is charged. When the changeover switch 2 is switched to the charging side while the output terminal 6a is switched between "L" and "H", the battery 1 is pulse-charged. The average charging current in pulse charging is set to a value that can maintain the battery 1 in a fully charged state without deteriorating. On average, the charging current is adjusted in the cycle of "L" and "H". The average charging current can be increased by lengthening the time of "L" with respect to "H".

The charge control circuit 6 can detect the voltage of the battery 1 and control the charge control switch 5 without using a timer. The charge control circuit 6 turns off the charge control switch 5 when the voltage of the battery 1 rises to the full charge voltage. After switching off, the output terminal 6a is switched to "L" and "H" at a predetermined cycle to trickle charge,
The battery 1 is kept fully charged.

The charge control switch 5 has a voltage bypass resistor 12 connected in parallel. The voltage bypass resistor 12 is
When the charge control switch 5 is in the off state, the voltage is output to the output side of the charge control switch 5. Voltage bypass resistor 1
2 flows a base current for turning on the input transistor 14 through the Zener diode 13. In order to reliably turn on the input transistor 14, the voltage bypass resistor 12 has a small resistance value. However, since the voltage bypass resistor 12 supplies a charging current to the battery 1 in a state where the charging control switch 5 is turned off, the voltage bypass resistor 12 has a resistance value large enough not to charge and deteriorate the battery 1. In this circuit, since the voltage bypass resistor 12 is connected in parallel with the charge control switch 5, when the charge control switch 5 is off, it can be instantly detected that the changeover switch 2 has been switched to the load side.

The voltage detection switching circuit 4 turns on the light source 3 while the battery 1 is being charged. Changeover switch 2
Is switched to the load side, and when the battery 1 is no longer charged, it is turned off. Even if the changeover switch 2 is switched to the charging side, the light source 3 is turned off when the charging control circuit 6 turns off the charging control switch 5. Even when the changeover switch 2 is switched to the charging side, the light source 3 is turned off when the battery 1 is trickle charged. The voltage detection switching circuit 4 shown in the figure detects the supply voltage supplied from the charger to the charging side of the changeover switch 2 and blinks the light source 3. The supply voltage drops when charging the battery 1. This is because the output voltage of the charging power supply 8 drops due to the charging current.
When the battery 1 is not charged, the voltage drop of the charging power source 8 does not occur and the supply voltage increases.

The voltage detection switching circuit 4 shown in the figure comprises a Zener diode 13, an input transistor 14 having the Zener diode 13 connected to the base, and a switching transistor 11 having the base connected to the collector of the input transistor 14. The switching transistor 11 causes the light emitting diode, which is the light source 3, to blink.

The Zener diode 13 has a supply voltage lower than the Zener voltage when charging the battery 1,
The Zener voltage is set so that the supply voltage when the battery is not charged is higher than the Zener voltage. Therefore, the Zener diode 13 passes a current when the battery 1 is not charged and does not pass a current when the battery 1 is charged.

The voltage detection switching circuit 4 performs the following operation to blink the light emitting diode which is the light source 3. [When the battery 1 is being charged] The supply voltage becomes low and no current flows through the Zener diode 13. Therefore, the base current does not flow in the input transistor 14, and the input transistor 14 is turned off. The off-state input transistor 14 does not connect the base of the switching transistor 11 to ground.
The switching transistor 11 is turned on when the base current is supplied from the output transistor 10. The switching transistor 11 in the ON state energizes the light emitting diode which is the light source 3 to emit light.

[When the battery 1 is not charged] The supply voltage increases and a current flows through the Zener diode 13. Therefore, the base current flows through the input transistor 14, and the input transistor 14 is turned on. The input transistor 14 in the on state connects the base of the switching transistor 11 to the ground and turns off the switching transistor 11. The switching transistor 11 in the off state does not energize the light emitting diode which is the light source 3 and turns off the light emission.

[0027]

The electric equipment incorporating the battery of the present invention is provided with a charge control switch so that the battery can be rapidly charged, and
It has the feature that the light source can be blinked normally and battery charging can be resumed regardless of whether the charge control switch is on or off. that is,
The electric device of the present invention connects a voltage bypass resistor in parallel with a charge control switch that controls charging of the battery, and this voltage bypass resistor bypasses the charge control switch in the off state to supply a voltage to the voltage detection switching circuit. This is because the light is supplied to control the blinking of the light source. The electric device with this structure can light the light source while rapidly charging the battery when the charging control switch is on, and bypasses the charging control switch when the charging control switch is off and charging of the battery is stopped. The blinking of the light source is controlled by the voltage supplied from the voltage bypass resistor to the voltage detection switching circuit. Therefore, the light source can be normally blinked regardless of whether the charge control switch is on or off, although the battery can be rapidly charged by providing the charge control switch. Moreover,
The electric device of the present invention can realize this feature with an extremely simple circuit configuration.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a conventional electric device containing a battery.

FIG. 2 is a circuit diagram showing another example of a conventional electric device containing a battery.

FIG. 3 is a circuit diagram showing another example of a conventional electric device containing a battery.

FIG. 4 is a circuit diagram of an electric device containing a battery according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Battery 2 ... Changeover switch 3 ... Light source 4 ... Voltage detection switching circuit 5 ... Charge control switch 6 ... Charge control circuit 6a ... Output terminal 7 ... Motor 8 ... Charging power supply 9 ... Current limiting resistor 10 ... Output transistor 11 ... Switching transistor 12 ... Voltage bypass resistance 13 ... Zener diode 14 ... Input transistor

Claims (6)

[Claims] 1. An electric device containing a battery (1), comprising:
Changeover switch that switches the battery (1) between charging side and load side
(2), the light source (3) that displays the charge of the battery (1), and the voltage detection that blinks the light source (3) by detecting the supply voltage supplied from the charger to the charging side of the changeover switch (2) Switching circuit (4)
And a charging control switch (5) connected to the charging side of the selector switch (2) to control the charging of the battery (1) .The selector switch (2) is switched to the charging side to charge the battery (1). In this state, the voltage detection switching circuit (4) turns on the light source (3), switches the changeover switch (2) to the load side to stop charging the battery (1), and the battery (1) becomes the load. It is an electric device that turns off the light source (3) by the voltage detection switching circuit (4) in the state of supplying electric power, and connects the voltage bypass resistor (12) in parallel with the charging control switch (5). An electric device in which the voltage bypass resistor (12) bypasses the charge control switch (5) in the off state and supplies a voltage to the voltage detection switching circuit (4). 2. The electric device is an electric razor.
An electric device containing the battery described in. 3. The charge control switch (5) is a charge control circuit (6).
An electric device containing the battery according to claim 1, which is controlled by. 4. The voltage detection switching circuit (4) comprises a Zener diode (13) and an input transistor (14) connecting the Zener diode (13) to the base,
The input transistor (1
Switch the base of 4) switch (2) and voltage bypass resistor (12).
When the voltage of the connection part rises, a current flows from the Zener diode (13) to the base of the input transistor (14) to turn on the input transistor (14), and the voltage of the connection part becomes Zener diode when lowered
An electric device containing the battery according to claim 1, wherein an electric current is stopped from flowing in (13). 5. An electric device incorporating the battery according to claim 1, wherein a current limiting resistor (9) is connected to the charging side of the changeover switch (2). 6. An electric device containing a battery according to claim 1, wherein the light source (3) is a light emitting diode.