JPS63242140A - Charger - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Industrial applications The present invention relates to improvements in chargers.

BACKGROUND OF THE INVENTION Conventionally, a problem with chargers for lead-acid batteries has been their ability to charge lead-acid batteries that have been left unattended after being over-discharged (hereinafter referred to as "over-discharged batteries"). This is because the internal resistance of the overdischarged battery is high, making it difficult for charging current to flow. As a method to solve this problem, overdischarge fft! There is a method in which a current is passed through the battery in the opposite direction to the normal one (hereinafter referred to as "reverse current"), and then normal charging is performed.

Problems to be Solved by the Invention When the above charging method is applied to a charger, reverse charging must be performed only when charging an over-discharged battery, and a function to detect an over-discharged battery is required. .

One way to achieve this function is to detect an AC voltage component included in the charging voltage. This is an application of the fact that the AC voltage component included in the charging voltage increases when charging a battery that has been left over-discharged.

However, in this method, when a charging Fi power source with a small AC current component is used, there is a problem that it is difficult to detect an over-discharged battery because the AC voltage component included in the charging VL voltage is small. ing.

Means for Solving the Problems The present invention solves the above problems and makes it possible to detect over-discharged batteries even when using a charging power source with a small alternating current component. It is characterized by superimposing alternating current components including frequencies.

By having the above-described configuration, the present invention further superimposes an alternating current even when a charging power source with a small alternating current component is used, so that overdischarged batteries can be prevented by detecting the alternating current voltage component included in the charging voltage. It is possible to detect this and perform reverse charging.

Furthermore, by superimposing alternating current for only a certain period of time after the start of charging, it is possible to detect over-discharged batteries immediately after starting charging, and to perform subsequent charging without superimposing alternating current.

Furthermore, by intermittent charging current, it is possible to superimpose alternating current components.

Example An embodiment of the present invention will be described with reference to FIG.

Charging [The output of current 1 is the current control unit 4, relay contact lO
It is connected to the sealed lead-acid battery 12 through.

The current control unit 4 controls the charging current on and off, and when charging starts, the first timer 2 operates to control the oscillation unit 3.
The output of the oscillator 3 controls the current controller 4 to intermittent the snow flow.

Charge 1) The AC voltage component included in the voltage becomes an input to the AC voltage detection section 7 through the capacitor 9 and the resistor 8, and when the AC voltage component exceeds a certain value, the second timer 6 operates.

When the timer 6 operates, current flows through the coil 5 of the relay, and the contacts 10 of the relay are switched to perform reverse charging for a certain period of time. With this kind of operation, it is possible to charge an over-discharged battery.

Fig. 2 shows the charging characteristics of an over-discharged battery (4V, 4Ah, internal resistance 300Ω). The intermittent frequency is l0Hz,
The AC component detection voltage is 1.0y+)-p, the setting time of the first timer 2 is 5 seconds, and the setting time of the second timer 6 is 60 seconds.
− is. As shown in Figure 2, after reverse charging, a light flow of 1 kg flowed, and the battery entered normal charging and was able to recover.

Note that in FIG. 1, 1) is a diode.

Effects of the Invention As described above, in the present invention, an over-discharged battery is detected by superimposing an alternating current component on the charging current, and reverse charging is performed. According to the present invention, it is possible to detect over-discharged batteries even when using a charging power source with a small alternating current component. Furthermore, when using a switching power supply, which has been widely used in recent years, it was previously difficult to detect because the frequency of the AC voltage component included in the charging voltage was high (the internal resistance of the battery decreases as the frequency increases). ), the industrial value that can be detected by using the charger of the present invention is extremely great.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a charging characteristic curve diagram when the charger of the present invention is used. 2 is a first timer, 3 is an oscillation unit, 4 is a current control unit, 5 is a relay coil, 6 is a second timer, 7 is an AC voltage detection unit,
10 is a relay contact, 12 is a sealed lead acid battery

Claims (3)

[Claims] (1) It is characterized by comprising a means for adding an alternating current component including an arbitrary frequency to the charging current, and flowing a charging current in the opposite direction to the normal direction when the alternating current voltage component included in the charging voltage is equal to or higher than a certain value. charger. (2) The charger according to claim (1), wherein an alternating current component including an arbitrary frequency is superimposed on the charging current only for a certain period of time after the start of charging. (3) Claim (1) characterized in that alternating current is superimposed on the charging current by continuing the charging current.
or the charger described in paragraph (2).