JPH01268430A - Charger - Google Patents

Abstract

PURPOSE:To ensure a predetermined charge capacity even when a battery is overdischarged by detecting whether the battery to be charged is overdischarged and performing charge control. CONSTITUTION:A circuit 6 for detecting overdischarged state of a battery 3 is provided and the setting times of timer circuits 2, 4 are controlled based on an output from the circuit 6. The overdischarge detection circuit 6 is provided with a timer circuit 7 which starts operation at a time point when a power source is thrown in. When the power source is thrown in, contact 8a of a relay 8 is connected to the side (b) by an output fed from the timer circuit 7 and a discharge resistor 9 is connected temporarily to the battery 3. If the battery 3 is overdischarged, the voltage thereof drops and a comparator 10 detects the voltage drop and provides signals through a latch circuit 12 to the timer circuits 2, 4 thus setting a relatively long charge time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a charging device for charging a storage battery.

[Prior art 1] Conventionally, this type of charging station for charging storage batteries has been used commercially as shown in Figure @6. @AC to Guiode Bridge DB
The DC power supply DC obtained by rectifying the DC power and smoothing it with the capacitor C1 is connected to the storage battery 3 via the switching power supply circuit 1
is applied, and the operation of the switching power supply circuit 1 is controlled by the timer circuit 2 to perform charging control. During t1, the switching power supply circuit 1 was operated to prevent the storage battery 3 from being overcharged. In Figure 7, the capacity of storage battery 3 is 0%.
It shows the charging current and the change in charging capacity when charging is started from the state of .Charging is performed for a certain period of time from the start of charging, and after a certain period of time t1, the charging capacity (
By controlling the charging of the storage battery 3 using the timer circuit 2 in this way, stable charging control can be performed without being affected by battery temperature and battery voltage, and the circuit configuration is simple. It has the advantage of becoming

Further, the timer circuit 4 operates when charging is started with commercial 1 [Ac applied, and the timer contact is turned on at a certain time t2 to light the light emitting diode 5, so that the amount of S' in the storage battery 3 is When the load recovers to some extent and becomes usable, the light emitting diode 5 is turned on to indicate that it is ready for use.0For example, if the load is an electric shaver, the light emitting diode 5 is turned on once. It's possible to shave! ! If the time t2 for charging the storage battery 3 to L (A in Fig. 7) is set in the timer circuit 4, the time t2 for charging the storage battery 3 to L (A in Fig. 7) can be set in the timer circuit 4. The light emitting diode 5 lights up to indicate that it is ready for use.

[Problem to be Solved by the Invention 1] However, in the above-mentioned conventional example, when the storage battery 3 is in an over-discharge state, as shown in FIG.
Since it takes time t to recover from the over-discharge state to the normal discharge state fi (charging capacity! lO%) charge state, when charging is stopped after a certain period of time set by the timer circuit 2, the storage battery 3 is fully charged (predetermined charging capacity IL)
There was a problem that the predetermined charging capacity could not be secured. Further, as a matter of course, the usable indication will also be displayed at the wrong time (charging capacity fiA').

The present invention has been made in view of the above-mentioned α, and its purpose is to provide a charging device that can secure a predetermined charging capacity even when a storage battery is in an over-discharge state. It is in.

[Means for Solving the Problems] The charging i1e of the present invention includes an overdischarge detection circuit that detects an overdischarge state of a storage battery to be charged, and a charging control circuit that controls charging based on the output of the overdischarge detection circuit. This is what I did.

[Function J] The present invention is made by NII as described above, and since it detects whether the storage battery to be charged is in an over-discharge state and performs charging control, even if the W battery is in an over-discharge state, the predetermined It is now possible to secure a charging capacity of .

[Embodiment] Fig. 1 shows an embodiment of the present invention, and Fig. 6 shows an over-discharge detection circuit 6 for detecting an over-discharge state of a storage battery 3 in a charging device similar to the conventional example. The setting time of the timer circuit 2.4 is controlled based on the output of the circuit 6 to control charging and also to control the usable display.

In the embodiment, the overdischarge detection circuit 6 operates through a timer circuit 7 that operates from the time the power is turned on, a switching relay 8 controlled by the timer circuit 7, and a relay contact 8a of the switching relay 8. A discharge resistor 9 connected to the storage battery 3
, a comparator 11 that compares the terminal voltage VD of the storage battery 3 with a reference voltage VS to detect an overdischarge state, and a latch circuit 12 that latches the output of the comparator 11. During this period, over-discharge detection is performed, and charging is started when the timer circuit 7 times out. Note that 11 is a base power supply that generates the reference voltage Vs.

The operation of the embodiment will be described below. Now, when the power is turned on and commercial power AC is applied, the timer circuit 7 of the over-discharge detection circuit 6 operates, the contact 8a of the switching relay 8 is switched to the b side, and the discharging resistor 9 is connected to the storage battery 3.
for a short time t.

During this period, forced discharge is performed via the discharging resistor 9, and the terminal voltage VD of the storage battery 3 decreases due to this forced discharge. At this time, if the '1stfL battery 3 is not in an over-discharge state, the terminal voltage vo will not fall below the reference voltage Vs, and the comparator 10 output will remain "L", as shown in Figure 2. , the output of the latch circuit 11 also becomes "I-" and no overdischarge detection signal is output. Therefore, the set time tllL2 of the timer circuits 2 and 4 is not changed, and the contact of the switching relay 8 is closed at the time of time up of the timer circuit 7. a
Charging is started by switching to the side, and the charging control circuit operates in the same manner as in the conventional example.

On the other hand, when the storage battery 3 is in an over-discharge state, as shown in FIG. 3, the terminal voltage VB decreases significantly due to forced discharge via the discharging resistor 9 and becomes below the reference voltage Vs. Therefore, the output of the comparator 11 becomes "H" and is latched by the latch circuit 12, and an overdischarge detection signal is output. This over-discharge detection signal changes the set time of the timer circuits 2 and 4 to a longer time than in the case of normal discharge (t+'
yh°) to compensate for insufficient charging Wl capacity due to overdischarge. Figure 4 shows the changes in the charging current and the amount of charging ¥1.
If the setting is set to 3, a predetermined charging capacity can be secured and an appropriate usable display can be performed.

FIG. 5 is an explanatory diagram of the operation of another embodiment. When the storage battery 3 becomes over-discharged and the output of the latch circuit 11 becomes H",
The output voltage of the switching power supply circuit 1 is increased for a certain period of time ts (set to j, = t in the embodiment) after the start of charging to increase the charging current, and the over-discharged storage battery 3 is connected to the timer circuit 2. In addition to compensating for insufficient charging '81 when the battery is charged for a certain period of time t1 set in accordance with the present invention, it is possible to display an appropriate usable status.

[Effects of the Invention] The present invention is configured as described above, and since the charging control is performed by detecting whether or not the storage battery to be charged is in an over-discharge state, even if the storage battery is in an over-discharge state, a predetermined operation is performed. This has the effect of ensuring charging capacity.

[Brief explanation of the drawing]

Fig. m1 is a circuit diagram of one embodiment of the present invention, Figs. 2 to 4 are explanatory diagrams of the same operation as above, and Fig. 5 is an explanatory diagram of operation of another embodiment.
FIG. 6 is a circuit diagram of a conventional example, and FIGS. 7 and 8 are operation explanatory diagrams of the same. 1 is a switching power supply circuit, 2 is a timer circuit, 3 is:
II battery, 6 is an over-discharge detection circuit. Agent Patent Attorney Ishi 1) Ai Seventy-six... Overdischarge detection circuit Figure 1 Figure 2 Figure 3 Electrical input tt Yami Figure 4 Figure 5 Figure 6 Figure 7 Ahead i Figure 8

Claims (1)

[Claims] (1) A charging device comprising: an overdischarge detection circuit that detects an overdischarge state of a storage battery to be charged; and a charge control circuit that controls charging based on the output of the overdischarge detection circuit.