JP2001095168A - Charger and electric cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized and low-priced charger which performs the charge, switching a plurality of batteries in order, and an electric cleaner using it. SOLUTION: A control circuit 6 outputs charge control signals A21 and B22 to turn on a transistor A11 and turn off a transistor B12. The power from the charge current output terminal 3 of a power circuit 2 is converted into a constant current for battery charge with a constant current circuit 4, and it charges a battery pack A9 through the current path returning to the power circuit 3 via a diode 8 for prevention of reverse flow of a charge current, a battery pack A9, and a transistor A11. The voltage detected by a battery voltage detection means 7 is outputted to a voltage detection terminal 20, and the control circuit 6 controls the charge current according to the signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for sequentially charging a plurality of batteries or battery packs and a vacuum cleaner using the same.

[0002]

2. Description of the Related Art In recent years, electric equipment (hereinafter referred to as battery equipment) using a rechargeable battery (including a battery pack) has become established in the market, and has been applied to various applications from electronic equipment such as mobile phones and personal computers to electric tools. Have been. Many battery charging schemes have been developed, and many of them are designed to detect a battery voltage or a change in voltage during charging with a voltage detection unit and charge the battery while controlling a charging current in accordance with the detection signal.

In a battery device, it is necessary to charge the battery when used for a certain period of time. To use the battery device for a long time, it is necessary to prepare a plurality of spare batteries. Although a charging method for charging a plurality of batteries has been developed, a charging device is provided for each battery or pack battery to be charged with the voltage detecting means.

[0004]

However, since the above-mentioned conventional charging device has a voltage detecting means for each battery or battery pack to be charged, there is a problem that the charging control circuit becomes large and expensive. Was.

[0005] For example, in the charging device described in Japanese Patent Application Laid-Open No. 7-87672, a technique (charging device) for charging two battery units is disclosed, but an A / D for detecting a battery voltage for each battery unit is disclosed. Since the voltage detecting means including the converter is used, the circuit scale is large and the price is high.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and a charging device for sequentially charging a plurality of rechargeable batteries and detecting a battery voltage to switch charging control.
It is an object of the present invention to provide a charging device capable of detecting the plurality of battery voltages with one voltage detecting means and a vacuum cleaner using the same.

[0007]

According to the present invention, there is provided a charging apparatus for sequentially charging a plurality of rechargeable batteries and detecting a battery voltage to switch charging control. It is detected by one voltage detecting means. When the number of the voltage detecting means is one, the control unit for controlling the charging current in accordance with the signal from the voltage detecting means can be made relatively small.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION
A charging device for sequentially charging a plurality of rechargeable batteries and detecting a battery voltage to switch charging control, wherein the plurality of battery voltages can be detected by one voltage detecting means.

According to a second aspect of the present invention, a plurality of rectifying means for preventing charging current backflow, a series connection circuit of a battery and a switch means are connected in parallel to a charging current supply power supply, and one of the switch means is provided. The charging device according to claim 1, wherein one of the batteries is sequentially closed to sequentially charge the batteries.

According to a third aspect of the present invention, the voltage detecting means is connected in parallel with the series connection circuit so as to detect a voltage between both ends of the series connection circuit of the charging current backflow prevention rectification means, the battery and the switch means. A charging device according to claim 2 disposed.

According to the first to third aspects of the present invention, the voltage detecting means of the charging device can be rationalized, and the entire control circuit can be simply configured, so that the charging device can be provided at a small size and at low cost.

According to a fourth aspect of the present invention, the switching device is a charging device according to the second or third aspect, wherein the switching device comprises a parallel connection circuit of a transistor and a resistor. During the charging of the battery, for example, when a battery is connected such that the user forgets to switch off the device and over-discharges the battery, a small current flowing through a resistor connected in parallel with the switch means is used for the battery. , It is possible to safely recover an over-discharged battery.

The invention according to claim 5 of the present invention is the invention according to claim 1.
By using the charging device described in any one of the items (4) to (4), a user-friendly vacuum cleaner can be provided.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in FIG. FIG. 1 is a block diagram illustrating a circuit configuration of the charging device according to the present embodiment. In FIG. 1, reference numeral 1 denotes a commercial power supply, which is a power supply source of the charging apparatus according to the present embodiment. Reference numeral 2 denotes a power supply circuit for supplying power from the commercial power supply 1 to the constant current circuit 4 and the control circuit 6. Reference numeral 3 denotes a charging current output terminal of the power supply circuit 2 for supplying battery charging power to the constant current circuit 4. Reference numeral 7 denotes a power supply terminal of a power supply circuit 2 for supplying power to the power supply 6. Reference numeral 7 denotes a voltage between both ends of a series connection circuit including a diode 8 for preventing backflow of charging current, a battery pack A9 serving as a battery to be charged, a battery pack B10, a transistor A11 and a transistor B12. , And a battery voltage detecting means 21 and 22 are charging control signals A and B for outputting a signal for turning on or off the transistor A11 and the transistor B12, respectively. 13 and 14 are resistors A and B connected in parallel with the transistor A11 and the transistor B12.

The operation of the charging device composed of the above components will be described.

First, how the battery pack A9 is charged will be described. The control circuit 6 turns on the transistor A11 and charges the transistor B to charge the battery pack A9.
Then, a charge control signal A21 and a charge control signal B22 are output so as to turn off the switch 12. The charging current at this time flows as follows. The power output from the charging current output terminal 3 of the power supply circuit 2 is converted to a constant current for battery charging by the constant current circuit 4, and the reverse current prevention diode 8 for the charging current and the battery pack A
9. The battery pack A9 is charged along a current path returning to the power supply circuit 3 via the transistor A11. Here, the voltage detected by the battery voltage detection means 7 is the sum of the ON voltages of the battery pack A9, the transistor A11 and the backflow prevention diode 8, and outputs a voltage signal relating to the battery pack A9 to the voltage detection terminal 20. . The control circuit 6 controls the charging current of the battery pack A9 according to the signal of the voltage detection terminal 20. By the way, needless to say, a small amount of current for charging the battery pack B10 always flows due to the resistor B14 connected in parallel with the transistor B12 which is turned off.

Next, how the battery pack B10 is charged will be described. The control circuit 6 outputs a charge control signal B22 and a charge control signal A21 to turn on the transistor B12 and turn off the transistor A11 in order to charge the battery pack B10. The charging current at this time flows as follows. The power output from the charging current output terminal 3 of the power supply circuit 2 is converted by the constant current circuit 4 into a constant current for battery charging, and a reverse current prevention diode 8 for charging current and a battery pack B
10. The battery pack B10 is charged along a current path returning to the power supply circuit 3 via the transistor B12. Here, the voltage detected by the battery voltage detection means 7 is the sum of the ON voltages of the battery pack B10, the transistor B12 and the backflow prevention diode 8, and outputs a voltage signal relating to the battery pack B10 to the voltage detection terminal 20. . The control circuit 6 controls the charging current of the battery pack B10 according to the voltage detection signal 20. By the way, needless to say, a small amount of current for charging the battery pack A9 always flows due to the resistor A13 connected in parallel with the transistor A11 which is turned off.

As described above, by controlling the control circuit 6 so that only one of the transistor A11 and the transistor B12 is turned on, the control circuit 6 uses one battery voltage detecting means 7 to connect the battery pack A9 to the battery pack A9. Pack B10
Each voltage can be detected.

By the way, in this embodiment, there are only two battery packs 9 and 10, but even if more battery packs are connected, one battery voltage detecting means 7 can detect all battery voltages. Needless to say, there is.

As described above, according to this embodiment, even when a plurality of battery packs are to be charged, only the transistors connected to the battery packs to be charged are turned off.
If N is set, only one battery voltage detecting means is required, and the circuit scale of the charging control circuit can be reduced. Therefore, the entire charging device can be configured to be small and inexpensive.

Since a small amount of current for charging the battery pack always flows due to the resistance connected in parallel with the transistor that is turned off, one switch is closed to charge the battery during charging. For example, even when a battery is connected that has been overdischarged by the user forgetting to switch off the device, the battery can be charged with a small current flowing through a resistor connected in parallel with the transistor. Therefore, the battery that has been deteriorated by overdischarge can be safely recovered.

[0022]

According to the first to third aspects of the present invention, the voltage detecting means of the charging device can be rationalized, and the entire control circuit can be simply configured, so that the charging device can be provided at a small size and at low cost.

According to the invention described in claim 4 of the present invention, 1
While the two switch means are closed and the battery is being charged, for example, when a battery is connected that has been overdischarged by the user forgetting to switch off the device, for example, through a resistor connected in parallel with the switch means Since the battery can be charged with a small amount of flowing current, the battery that has been deteriorated by overdischarge can be recovered safely.

According to a fifth aspect of the present invention, an easy-to-use vacuum cleaner can be provided by using the charging device according to any one of the first to fourth aspects for a vacuum cleaner. .

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a circuit configuration of a charging apparatus according to an embodiment of the present invention.

[Description of Signs] 1 Commercial power supply 2 Power supply circuit 3 Charging current output terminal 4 Constant current circuit 5 Power supply terminal 6 Control circuit 7 Battery voltage detecting means 8 Backflow prevention diode 9 Battery pack A 10 Battery pack B 11 Transistor A 12 Transistor B 13 Resistance A 14 Resistance B 20 Voltage detection terminal 21 Charge control signal A 22 Charge control signal B

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Seiji Yamaguchi 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 5G003 AA01 BA04 CA04 CA02 CA11 CC02 GA01

Claims (5)

[Claims] 1. A charging device for sequentially charging a plurality of rechargeable batteries, detecting a battery voltage, and controlling switching of a charging current in accordance with the battery voltage, wherein the voltages of the plurality of rechargeable batteries are changed to one voltage. A charging device characterized by detecting by a detecting means. 2. A charging current backflow prevention rectifier and a series connection circuit of a battery and a switch are connected in parallel to a plurality of charging current supply power supplies, and the battery is closed by sequentially closing any one of the switches. The charging device according to claim 1, wherein the charging is performed sequentially. 3. The circuit according to claim 2, wherein the voltage detection means is arranged in parallel with the series connection circuit so as to detect a voltage between both ends of the series connection circuit of the rectification means for preventing charging current backflow, the battery and the switch means. Charging device. 4. The charging device according to claim 2, wherein the switch means is constituted by a parallel connection circuit of a transistor and a resistor. 5. A vacuum cleaner using the charging device according to claim 1. Description: