JPH087793Y2 - Charger charge current control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a charging current control device, and more particularly, to prevent the life of a storage battery from being shortened due to overcharging and to fully charge the battery at a desired time. The present invention relates to a charging current control device for a charger.

[Prior Art] Conventionally, the use ratio of rechargeable storage batteries has been increasing year by year due to the widespread use of small audio equipment such as cassette tape players. Accordingly, it has been demanded to shorten the charging time. Widely used. The quick charger charges at a current several times as high as the normal charging current, and stops charging when the completion of charging is detected by the full-charge detection circuit. Further, in order to further shorten the charging time, it is also known to use ultra-fast charging with a larger current for about 10 to several tens of minutes. It has not been established and the timer stops charging after a certain period of time.

The rapid charger and the ultra-quick charger described above charge with a large current while keeping the required charging time constant, and therefore the effect on the life of the storage battery cannot be ignored. Further, even in the case of no urgent need, the battery is charged in a short time, and the shortening of the life is promoted. Therefore, there is a demand for a charger in which the shortening of the life is prevented by controlling the charging current.

[Problems to be solved by the invention] Generally, storage batteries such as nickel cadmium battery are 300 to 5
It is said that the battery has a repeated charge life of about 00 times, and the life varies depending on the usage conditions and charge conditions, and a certain battery life cannot be specified. However, the charging current has a great influence on the life, and when charging with a large current, the reduction of the charging capacity is accelerated, and as a result, the life of the storage battery is short-circuited. Therefore, it is preferable to set the charging current to a small current from the viewpoint of battery life, but as described above, there is a great demand for shortening the charging time.

Therefore, a charging current control device for a charger that can charge within a user's desired time and that satisfies the contradictory conditions of shortening charging time and extending battery life as much as possible by minimizing the charging current. A technical problem to be solved in order to provide is created, and the present invention aims to solve the problem.

[Means for Solving the Problems] The present invention has been proposed in order to achieve the above object, and includes a control circuit for controlling a charging current of a charger, a timer circuit capable of arbitrarily setting a charging time, A charging current control device comprising a storage battery remaining capacity detection circuit,
It is intended to provide a charging current control device for a charger, characterized in that the charging current is controlled by calculating a required current value based on the set time of the timer circuit and the remaining capacity.

[Operation] According to this invention, the charger having the control circuit for the charging current is provided with the remaining capacity detection circuit of the storage battery and the timer circuit that can set the time arbitrarily, and each is connected to the control circuit. Then, when the user connects the storage battery to be charged to the charger and sets the desired charging time in the timer circuit, the control circuit measures the remaining capacity of the storage battery, and the measured value and the set charging time are satisfied. The current value required for charging is calculated and the charging current is controlled to the calculated value, so that quick charging can be performed according to the user's request and the charging current is controlled to the minimum required. Therefore, in an urgent case, if the charging time is set to a long time, the battery is charged with a small current, and the life of the storage battery is prevented from being shortened as much as possible.

[Embodiment] An embodiment of the present invention will be described below in detail with reference to the attached drawings. Fig. 1 shows 1.2V with charging current controller (1)
It is a circuit block diagram of a nickel cadmium battery charger (2). The charger (2) rectifies the AC power supply (3) into a direct current by the rectifier circuit (5) after the line filter (4) and intermittently turns the direct current into a pulse current by the switching element (6). The pulse current is transformed by the transformer (7) at a predetermined transformation ratio and is output to the output terminals (9) and (10) through the rectifier circuit (8). ON / OFF of the switching element (6) is controlled by a control circuit (12) built in the microprocessor (11), and the duty ratio of ON / OFF is formed to be continuously variable.

The charging current control device (1) forms a storage battery remaining capacity detection circuit (16) from a discharge circuit (13), an A / D converter (14), and a voltage measuring unit (15) incorporated in a microprocessor (11). In addition, the set time input section (17) such as a switching switch is connected so that the set time is input to the timer circuit (18). Moreover, the control circuit (12)
Calculates the required charging current value for fully charging the storage battery from the measured voltage of the remaining capacity detection circuit (16) and the set time of the timer circuit (18), and the switching element (6) according to the calculated value. Control the duty ratio of. That is, even for storage batteries having the same remaining capacity, the charging current changes depending on the charging setting time, and the charging current is controlled to be fully charged at the setting time. Will decrease proportionally.

Next, the procedure for controlling the charging current will be described with reference to FIGS. 1 and 2. First, the set time input section (17) is manually operated to set a desired charging time (step 101). The configuration of the set time input unit (17) is not particularly limited, but, for example, ultra-fast charging of about tens of minutes, rapid charging of about 1 hour and normal charging of several hours are set in advance, and the switch is set. If it is formed so as to be selected by switching, the operation is easy. Then, a storage battery is connected to the output terminals (9) and (10) (step 102). Then, the control circuit (12) turns on the transistor (19) of the discharge circuit (13) to discharge the current of the storage battery to the ground (21) through the resistance element (20) (step 103). The resistance value of the resistance element (20) is
It is set to 2.7Ω, and after 5 seconds have elapsed in the discharging state (step 104), the control circuit (12) measures the voltage of the storage battery converted into a digital signal through the A / D converter (14) (step). 105).

Then, the transistor (19) of the discharge circuit (13) is turned off to stop the discharge (step 106), the remaining capacity of the storage battery is judged from the measured voltage, and the control circuit (12) is set as the remaining container. A required charging current value is calculated and determined based on the charging time (step 107). Here, when the storage battery is discharged and there is no remaining capacity and the charging time is set to ultra-rapid charging, the control circuit (12) sets the duty ratio of the switching element (6) to a large value, and the output terminal (9) ( Apply a large current of about 2A to 10) and charge it in an extremely short time.

On the other hand, when the storage battery is not completely discharged and the capacity remains, the charging current required to fully charge at the same time is small, and the longer the charging setting time is, Since the required current is small, the charging current determined by the control circuit (12) based on the remaining capacity and the set time is in the range of 2 A to hundreds of tens mA. Then, after the set time elapses with the determined charging current, the battery is fully charged and the timer circuit (18) stops charging (step 108), and thereafter, trickle charging that supplements self-discharge with a small current until the storage battery is removed (step 108) 109).

In the above-mentioned one embodiment, the charger for the small nickel cadmium battery has been described, but it is not particularly limited to this, and can be applied to general storage batteries by appropriately setting the charging current and voltage. The invention can be variously modified without departing from the spirit of the invention, and it goes without saying that the invention extends to the modified one.

[Advantage of the Invention] As described in detail in the above-mentioned position embodiment, the present invention provides the charging current control device of the charger with the timer circuit capable of arbitrarily setting the charging time. Further, a storage battery remaining capacity detection circuit is provided, the remaining capacity is measured at the start of charging, a charging current value required for full charge is calculated from the measured value and a set time, and charging is performed at the current value. ing. Therefore, regardless of the remaining capacity, it will be fully charged in the set time and overcharge can be prevented, and the charging current will be controlled to the minimum necessary.In case of emergency, set the charging time to a long time to set the charging current. The reduction reduces the life of the storage battery as much as possible.

In addition, compared to a quick charger that always charges with a constant large current, deterioration of the electrolytic capacitor and the like due to heat generation of the charger body can be reduced, and the durability and reliability of the charger are improved along with the extension of the life of the storage battery. It is truly a device of practical value.

[Brief description of drawings]

1 shows an embodiment of the present invention, FIG. 1 is a circuit block diagram of a charger, and FIG. 2 is a flow chart for explaining the operation of a charging current control device. (1) …… Charging current control device (2) …… Charger, (12) …… Control circuit (16) …… Remaining capacity detection circuit (18) …… Timer circuit

Claims (1)

[Scope of utility model registration request] 1. A control circuit for controlling a charging current of a charger,
A charging current control device comprising a timer circuit capable of arbitrarily setting a charging time and a storage battery remaining capacity detection circuit, wherein a required current value is calculated based on the set time and remaining capacity of the timer circuit to control the charging current. A charging current control device for a charger, characterized in that