JPS6126437A - Charger of storage battery - 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 The present invention relates to a charging device for a storage battery, particularly a sealed storage battery.

As shown in FIG. 6, as a conventional charging device for a sealed type nickel cadmium storage battery, a sealed type 2 battery as a storage battery to be charged is connected to a power supply (1) via a charging current control circuit (2) consisting of a transistor (Tr), etc. Connect the charging terminal (4) for charging the Nocle Cadmium storage battery (3), connect the dividing resistor (R1) (R2) between the charging terminals +41 and +4+, and connect one of the resistors (R2) to the quioto (Dl and Container). The voltage detection circuit (5) consisting of a series circuit of C1 is connected in parallel, and the midpoint of the dividing resistor and the
) and the capacitor (C1) are each connected with a comparator (6
) input terminal is connected. Also, a transistor (Tr
) is connected to the power supply (1) via the thyristor (7).
is connected to one side of the

The output end of the comparator (6) is connected to the gate of the sirisk (7).

The charging device configured in this way has its charging terminal +41
When the F4FIC sealed nickel-cadmium storage battery (3) is connected and charged, the terminal voltage of the storage battery increases with each hour of charging, as shown in the charging characteristic diagram of the sealed storage battery shown in FIG. During this time, the diode (D) and capacitor (
The voltage at the connection point of C1, that is, the voltage at the output end of the voltage detection circuit is lower than the voltage at the midpoint of the dividing resistor, and Funde/Sfc) is charged. When the terminal voltage of the storage battery (3) passes the peak point fP in the charging characteristic diagram and begins to fall, the capacitor (
Since the charge stored in C) is blocked by the polarizing characteristic of the diode (D), the output voltage of the voltage detection circuit becomes higher than the midpoint of the dividing resistor, and as a result, the input of the comparator (6) becomes The inverting comparator (6) sends a conduction signal to the thyristor (7) to make the thyristor (7) conductive and cut off the transistor (Tr), thereby controlling the charging current.

However, the voltage at the output terminal of the voltage detection circuit decreases due to the self-leakage current of the capacitor, the reverse current of the diode, the input bias current of the comparator, etc., so it takes some time until the input of the comparator is reversed and the charging current is controlled. This caused a delay in performance and had an unfavorable effect on storage and batteries.

It is an object of the present invention to overcome these conventional drawbacks and provide a charging device that can reverse the charging current as soon as it passes the peak point (P) of the charging characteristic diagram.

a first heavy pressure detection circuit comprising a power supply device, a charging terminal for a storage battery to be charged connected to the power supply device via a charging current control circuit, and a first capacitor connected between the charging terminals; a second voltage detection circuit comprising a second capacitor connected in parallel with the heavy pressure detection circuit and having a smaller capacitance than the first capacitor of the first voltage detection circuit;
．． The present invention is characterized in that it includes a comparison circuit that filters the output voltage of the second voltage detection circuit using a comparator, and the charging type current control circuit is controlled by the output of the comparison circuit to control the charging current.

An embodiment of the present invention will be described in detail below with reference to FIG.

(1) In the quay power supply device, an AC input terminal (81 (Elf) is connected to the primary side of the transformer (Tl), and a rectifier (9) consisting of a tie auto bridge circuit is connected to the secondary side.

(C5) is a smoothing capacitor. (2) is the power supply f
A charging current control circuit connected to i+, connected to two Turlington-connected transistors (Try) (Tr2), a transistor (Trs) connected to the base of the transistor (Try), and the emitter of that transistor (Try). The transistor (Tr5) is quickly cut off by the conduction of the thyristor (7), and the two transistors (Trl) (Tr) are connected in a Darlington manner.
2) The car is shut off, and charging of the storage battery is switched from quick charging to trickle charging via a resistor (R5) connected between the collector and emitter of the transistor (Trl). Further, as is clear from the figure, a constant current function is provided to make the charging current a constant current by connecting a noenada and an iode (zD2) between the eminox base of the transistor (Tr2). A charging-only terminal +41 to which the storage battery to be charged (3) is connected is connected to the power supply device (1) via this circuit.

(D3) This is a backflow prevention quiode. A first voltage detection circuit (5) consisting of a series circuit of a first voltage IJ (D) and a first capacitor (C1) is connected to a resistor (R1).
between the charging terminal +4+ +4)
The storage battery (3) connected to [4] is connected in parallel, and the first voltage detection circuit (5) is further connected with a second diode having the same rating as the first diode (Dl). (D2) and its second capacitor (C
2) A second heavy pressure detection circuit consisting of a series circuit (5 of them are connected in parallel. (R2) is a resistor connected in parallel to these first and second voltage detection circuits +51[5'l. The first diode-1 of the first voltage detection circuit (5); (D
+) and the first capacitor (C1) connection point fa) and the second voltage detection circuit (five second diodes (D2)
The connection point fbl between the capacitor and the second capacitor (C2) is connected to the input terminal of a comparator (6) constituting a comparison circuit. The output terminal of the comparator (6) is connected through a resistor (R4) to the gate of the cyrisk (7).

Charging terminals (4) (4) of the charging device configured in this way
) When a sealed nickel-cadmium storage battery (3) is connected to the battery (3) and charged, the battery terminal voltage increases as shown in the charging characteristic diagram of FIG. 2, as in the conventional case. During this time, both the first and second capacitors (C+) (C2) are charged, but since the second capacitor (C2) has a smaller capacity, the connection point (bi) of the second voltage detection circuit (5) The voltage at the connection point (al) of the first voltage detection path (5) is higher than the voltage at the connection point (al), so it is rapidly charged via the transistor at the output terminal of the comparator (6).Then, the terminal of the storage battery (3) As soon as the voltage passes the peak point fp in the charging characteristic diagram in Figure 2 and begins to fall, the first and second capacitors (
C+) (C2) each start to discharge due to the self-leakage current of the capacitor, etc., but the second capacitor (C2), which has a smaller capacitance, discharges more than the first capacitor (C1), which has a larger capacitance. Therefore, the voltage at the second voltage detection circuit (5 connection points (bi) decreases faster than the voltage at the connection point (a) of the first voltage and pressure detection circuit (5), and the voltage is reversed, and the input of comparator (6) is reversed, and the input of comparator (6) is reversed.
outputs a conduction signal for the cyrisk (7) to make the cyrisk (7) conductive.

The transistor (Tr3) is turned on by the conduction of the thyristor (7).
) is blocked. Therefore Darlington connected 2
The two transistors ('Try) (Tr2) are also cut off, and the charging current becomes a very small current flowing through five resistors (R), and is switched to trickle charging.

In the above embodiment, the first and second voltage detection circuits are each made up of a series circuit of a diode and a capacitor, but the invention is not limited to this. For example, the second diode (D2) may be replaced with a resistor. You can also use it.

As described above, according to the present invention, since the charging current is controlled by comparing the first and second voltage detection circuits each having a capacitor with a different capacity, the terminal voltage of the storage battery during charging exceeds the peak point. According to the capacitor characteristics, the input of the comparator is immediately reversed, and charging control can be performed in a short time.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the charging device of the present invention, FIG. 2 is a charging characteristic diagram of a storage battery, and FIG. 3 is a circuit diagram of a conventional charging device. (1)...power supply device, (2)...charging current control circuit, (
3)...storage battery, (4)...charging terminal, (5)...first
voltage detection circuit. (5...Second voltage detection circuit, (6)...Comparator, (
7) Thyristor, (C+) First capacitor, (C2) Second capacitor Patent applicant Furukawa Battery Co., Ltd. Toyo Denpa Co., Ltd.

Claims (1)

[Claims] a first voltage detection circuit comprising a power supply device, a charging terminal for a storage battery to be charged connected to the power supply device via a charging current control circuit, and a first capacitor connected between the charging terminals; a second voltage detection circuit comprising a second capacitor connected in parallel with the voltage detection circuit and having a smaller capacitance than the first capacitor of the first voltage detection circuit;
, a comparison circuit that compares the output voltage of the second voltage detection circuit, and the charging current control circuit is controlled by the output of the comparison circuit to control the charging current.