JPH05146087A - Charger - Google Patents

Abstract

PURPOSE:To prevent deterioration of battery and shortening of service life by preventing overcharge. CONSTITUTION:The charger 20 comprises a battery residual capacity detecting circuit 25, a standard charging circuit 26, a quick charge circuit 27 feeding high current in quick charge system, a circuit 28 discharging prior to start of quick charge, and a control section for switching between the standard charging circuit 26 and the quick charging circuit 27 based on a residual capacity of battery detected through the detecting circuit 25. Switching is made automatically among standard charge, discharge and quick charge depending on the residual capacity of battery.

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 a storage battery (secondary battery) whose function can be regenerated by charging after discharging, and more particularly to a handy terminal (portable terminal).
・ Cadmium (Ni
-Cd) relates to a charging device such as a battery.

[0002]

2. Description of the Related Art Ni-Cd batteries are characterized by good large current characteristics, excellent low temperature characteristics, long cycle life, strong overcharge, and easy maintenance. Therefore, it is used for applications requiring high reliability, for example, a backup power supply for communication or emergency. In addition, since the Ni-Cd battery can be used as a charging device with a relatively simple circuit as compared with a lead battery, it is often used for applications with a small battery capacity and is widely used as a general storage battery. .. As a conventional charging method for a storage battery, for example, there are one that performs standard charging using a standard charging device and one that uses a rapid charging device to flow a large current and complete charging in a short time.
4 to 6 are views showing a charging method for charging an electronic device such as a handy terminal using the standard charging device or the quick charging device. 4 is a side view showing a handy terminal and a charging adapter, FIG. 5 is a sectional view taken along the line AA ′ of FIG. 4, and FIG. 6 is a sectional view taken along the line BB ′ of FIG. 4 to 6, 11 is a handy terminal body, 12 is a communication adapter with a charging function, and the handy terminal body 11 is placed on the handy terminal placement surface 12a of the communication adapter 12 with a charging function during charging ( (Fig. 3). Charging contacts 13 and 14 are provided at predetermined positions on the back surface 11a of the handy terminal main body 11, and the charging surface 13a of the communication adapter is provided with a protrusion for charging so as to come into contact with the charging contacts 13 and 14. Contacts 15, 16 are provided. When attempting to charge, placing the handy terminal 11 on the communication adapter 12 with a charging function will start charging.

[0003]

However, in such a conventional charging device, since charging is performed by either standard charging or rapid charging, in the case of the standard charging device, It takes a long time to complete the charging, and in the case of the rapid charging device, the charging time is shortened, but there is a drawback that the overcharging and the memory effect which are likely to occur in the rapid charging occur. When the storage battery is overcharged, it not only shortens its life, but also may generate heat or break down. That is, in the case of a rapid charging device that rapidly charges by flowing a large current, in order to prevent overcharging, the so-called −ΔV detection method is used to detect the charging state and stop rapid charging, or a rapid protection timer or the like is used. Although charging is stopped, if you do not start charging after discharging once, it has the drawback of overcharging the battery and causing deterioration, reduction of battery capacity, and shortening of battery life. .. This is because the charging device is configured with a single function of standard charging or quick charging. If you try,
Obviously, if the charging method is automatically switched according to the state of the battery, overcharging can be prevented, and deterioration of the battery and shortening of the life can be prevented. An object of the present invention is to make it possible to automatically switch the charging system according to the state of the battery.

[0004]

The means of the present invention are as follows. The standard charging means 1 (see the functional block diagram of FIG. 1, the same applies hereinafter) is a standard charger that performs standard charging by the standard charging method. The quick charging means 2 is a quick charger that performs quick charging by a quick charging method, and has a discharging function that starts charging after discharging once in order to prevent overcharging and memory effect that tend to occur in rapid charging. Is preferred.
The remaining amount detection means 3 is a battery remaining amount detection circuit that detects the remaining amount of the battery. As the battery remaining amount detection circuit, for example, a circuit configured by a circuit that compares the battery voltage with a reference voltage may be used. The control means 4 controls switching between the standard charging means 1 and the quick charging means 2 based on the output of the remaining amount detecting means 3.

[0005]

The operation of the means of the present invention is as follows. Standard charging means 1 for performing standard charging by the standard charging method and rapid charging means 2 for performing rapid charging by the rapid charging method are provided, and when the remaining amount of the battery is detected by the remaining amount detecting means 3,
The standard charging means 1 and the quick charging means 2 are switched by the control means 4 based on the remaining amount detected by the remaining amount detecting means 3. Therefore, the charging method can be automatically switched according to the state of the battery.

[0006]

EXAMPLES Examples will be described below with reference to FIGS. 2 and 3 are views showing an embodiment of the charging device. First, the configuration will be described. FIG. 2 is a block diagram of the charging device 20. In this figure, a charging device 20 detects charging electrodes 21 and 22 electrically connected to an electronic device using a secondary battery such as a handy terminal, and a disconnect switch 23 to detect that the battery is installed at a predetermined position. Battery detection circuit 24 and a target battery (for example, charging electrodes 21 and 22) according to an instruction from a control unit 29 (described later).
Battery remaining amount detection circuit 25 for detecting the remaining capacity of the secondary battery in the electronic device connected to, a standard charging circuit 26 for performing standard charging by the standard charging method, and a rapid charging method for supplying a large current and rapidly A quick charging circuit 27 for charging, a discharging circuit 28 for discharging before the start of rapid charging in order to prevent overcharging and memory effect caused by the rapid charging, and a standard charging circuit
6 and a quick charging circuit 27 have a power supply unit for supplying a predetermined power, and the battery remaining amount detecting circuit 25 is operated by a detection signal from the battery detecting circuit 24 and the battery detected by the battery remaining amount detecting circuit 25. Standard charging circuit 2 based on the remaining amount
6 or a control unit 29 for controlling the quick charging circuit 27 to operate by switching.

Next, the operation of this embodiment will be described. FIG. 3 is a flow chart showing the charging method switching process of the control unit 29, and in the figure, the symbols Sn (n = 1, 2, ...) Show each step of the flow. First, in step S1, it is determined from the output from the battery detection circuit 24 whether or not the battery to be charged is installed in a predetermined position, and when the battery is installed in the predetermined position, the battery remaining amount detection circuit in step S2. 25, the remaining battery level of the target battery is detected. Next, it is determined whether or not the remaining battery level detected in step S3 is greater than or equal to the set value. When the remaining battery level is greater than or equal to the set value, the main unit can be continuously used without charging. And the standard charging circuit 26 is determined in step S4.
To start standard charging and end this flow process.

On the other hand, when the remaining amount of the battery is smaller than the set value in step S3, it is determined that the remaining amount of the battery is insufficient for operating the main body, and in order to perform quick charging, first in step S5. The discharge circuit 28 is operated to start discharging, and the remaining capacity of the battery after the start of discharging is detected in step S7. Next, in step S8, it is checked whether or not the discharged battery has a remaining capacity.
Returning to 6, the capacity detection is continued and the discharge is continued until the capacity is completely exhausted. When the remaining capacity is no longer detected, it is determined that the discharge has ended, the rapid charging circuit 27 is operated in step S8 to start rapid charging, and when the rapid charging is completed in step S9, the process proceeds to step S4 to start normal charging from the rapid charging. Switch to charging.

By executing the above flow, the following operation is performed on the circuit of FIG. First, the battery detection circuit 24 detects that a battery has been installed and notifies the control unit 29 of this detection signal. The control unit 29 receives the detection signal and operates the battery remaining amount detection circuit 25, the battery remaining amount detection circuit 25 detects the remaining amount of the target battery, and notifies the control unit 30 of the remaining amount detection result. ..

The control unit 29 operates the standard charging circuit 26 when the detected remaining battery amount is equal to or more than the set value because there is a capacity that can be continuously used without charging. When the value is smaller than the set value, the capacity is insufficient to operate the main body. Therefore, the discharge circuit 28 is once operated and then the quick charge circuit 27 is operated. When the rapid charging is completed, the standard charging is switched.

This prevents the rapid charging from being started when the battery has a sufficient remaining amount, and shortens the battery life caused by frequent repeated rapid charging including discharge operation, heat generation and operation. Instability can be prevented in advance. On the contrary, even if the user thinks that the battery has a sufficient remaining amount, when the battery is connected to the charging device 20, as a result, when there is no remaining amount, the battery is automatically switched to the quick charging. The charging time can be significantly shortened compared to a single-function type that only uses standard charging. Therefore, the user simply installs (connects) the battery (or the electronic device using the storage battery) to the charging device 20, and the optimal charging according to the state of charge of the battery is performed, which greatly improves the usability. Can be made

As described above, the charging device 20 is
A battery remaining amount detection circuit 25 that detects the remaining capacity of the battery, a standard charging circuit 26 that performs standard charging, a quick charging circuit 27 that flows a large current by the rapid charging method to perform rapid charging, and a discharge before the start of rapid charging. And a control unit 30 for controlling the standard charging circuit 26 or the quick charging circuit 27 to operate by switching based on the battery remaining amount detected by the battery remaining amount detecting circuit 25. Since standard charge, discharge and quick charge are automatically switched depending on the amount, it is possible to shorten the unusable state of the battery without shortening the battery life, and charge the battery of portable devices etc. It is suitable for use in a device.

In this embodiment, the charging system is switched by comparing the remaining battery level with the set value, but the mode of switching is not limited to this, and the remaining battery level is reflected in the control. Anything may be used as long as it can be used, for example, a timer function may be added.

Further, in the present embodiment, the installation (connection) of the battery is detected to start the operation, but the present invention is not limited to this, and the operation may be started by a switch or the like, and further appropriate. The operation may be automatically started at any timing.

[0015]

According to the present invention, the remaining battery level is detected,
Since standard charging and quick charging are switched according to the detected remaining amount, overcharging can be prevented, and deterioration of the battery and shortening of life can be prevented.

[Brief description of drawings]

FIG. 1 is a functional block diagram of the present invention.

FIG. 2 is a block diagram of a charging device.

FIG. 3 is a flowchart showing a charging method switching process of the charging device.

FIG. 4 is a diagram showing a handy terminal and a charging adapter.

5 is a cross-sectional view taken along the line A-A ′ of FIG.

6 is a cross-sectional view taken along the line B-B ′ of FIG.

[Explanation of symbols]

 20 Charging Device 24 Battery Detecting Circuit 25 Battery Remaining Detecting Circuit 26 Standard Charging Circuit 27 Quick Charging Circuit 28 Discharging Circuit 29 Control Section

Claims (1)

[Claims] 1. A standard charging unit for performing standard charging by a standard charging system, a quick charging unit for performing rapid charging by a quick charging system, a remaining amount detecting unit for detecting a remaining amount of a battery, and the remaining amount detecting unit. A charging device comprising: a control unit that controls switching between the standard charging unit and the quick charging unit based on an output.