JPS61177127A - Charge controller for 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] (Field of application in the pot industry) The present invention uses a storage battery voltage peak detection method, which is one of the rapid charging methods, to ensure charging and detection by eliminating malfunctions due to storage battery characteristics. The present invention relates to a charging control device for performing charging with higher sensitivity.

(Prior Art) As shown in FIG. 2, this type of charging control device conventionally connects dividing resistors (rl, r2) in parallel with the storage battery to be charged (31), and connects the dividing resistors (rl, r2) at the midpoint of the dividing resistors (rl, r2). Op amp (
The reverse input terminal (-) of OP) is connected, and its non-reverse input terminal (-1-1) is connected via a diode (Dl).

A capacitor fcl is connected between the non-reverse input terminal (the turret and the negative terminal of the storage battery to be charged (3)) to connect the storage battery to be charged (3).
Detects the peak voltage of the charging voltage of the operational amplifier (OP)
The control circuit +21 is operated by the output of the constant current power source fi+ to control the charging current by the constant current power source fi+ (for example, Japanese Patent Laid-Open No. 162140/1983).

(Problem to be solved by the invention) However, in this device, the initial setting sensitivity must be higher than the forward voltage (approximately 0.5 [V]) due to the diode connected to the non-reverse input terminal. It is requested that it be increased. Furthermore, when a sealed nickel-cadmium storage battery is charged after being left for a long period of time (approximately 10 days or more), its charging characteristics show a small first peak (Pl) at the beginning of charging, as shown in Figure 3, and then a second peak at the end of charging. Peak (P
2). Therefore, in the conventional control device, the control circuit may operate and control the charging current at the first peak (P,) at the initial stage of charging.

(Means for Solving the Problems) The present invention solves the problems in these conventional techniques and provides a charging control device with high sensitivity and no malfunction. This circuit is characterized by inserting a Zener diode into the circuit and using a voltage 7-orer circuit.

(Function) Therefore, by using the Zener diode connected to the 5-divided resistor circuit, it is possible to suppress the charging of the capacitor at the initial stage of charging.Therefore, the first peak in charging the storage battery after being left unused for a long time can be ignored, and at the same time, at the end of charging In the future, the initial setting sensitivity can be increased to several to several tens of mV using a voltage follower circuit.

(Example) FIG. 1 shows a circuit diagram of a charger using the charging control device of the present invention.

(1) is a constant current power supply section, which consists of a transformer (T) and a rectifier +51. ) transistor (Tr
).

The storage battery (3) to be charged, which is composed of a diode (Dl) and a diode (Dl), etc. and connected in series thereto, can be charged with a constant current. +21 is a control circuit, thyristor (SCR)
, a resistor (Rs), a capacitor (C2), etc., and a nuclear thyristor (SCR) is connected to the base of the transistor (Tr) of the constant current power supply section (1).
The charging current by the constant current power supply can be controlled by turning ON or OFF CR). (4) is a series circuit of a storage battery to be charged (resistors (R4, Rs, R6) connected in parallel with 31 and a Zener diode (ZD). Three operational amplifiers (op, , op2.
0P5) are connected as follows.

The non-reverse input terminal (→) of the first operational amplifier (OPl) is connected to the resistor (R5), and its output terminal is connected to the second operational amplifier (OP2) through a diode (D2) with low reverse leakage current. Non-reverse input terminal (connected to +1,
Furthermore, the output terminal of the second operational amplifier (op2) is the third operational amplifier (op2).
A voltage follower circuit was constructed by connecting the non-reverse input terminal of the operational amplifier (OP3) to the non-reverse input terminal of the first operational amplifier (OP3) and to the reverse input terminal of the first operational amplifier (OP1). and the reverse input terminal of the third operational amplifier (→ is the resistance (R4) of the series circuit (4)
) and a resistor (R5).

Furthermore, the output terminal of the third operational amplifier (op5) is connected to the gate of the thyristor (SCR) of the control circuit (21).

On the other hand, the non-reverse input terminal (-
A capacitor/(Cs) is connected between 1-1, the resistor (6) of the series circuit (4), and the Zener diode (ZD). In addition, (R7) (R8) (R9) (R10) in the figure
is a resistance, and (Ds) (D4) (Ds) is a diode.

In the charger constructed in this way, when the input terminal +61161 of the constant current power supply unit (1) is connected to a commercial AC power supply, it is rectified by the rectifier (5) through the transformer (conventional process) and connected to the transistor (Tr) and diode (Ds). ) The storage battery to be charged is charged with a constant current.In the initial stage of charging, the charging snow pressure of the storage battery to be charged (3) constantly increases, so the reverse input of the third operational amplifier (OPs) of the series circuit (4) Terminal C
The potential at the point (A) where → is connected is the first operational amplifier (
The voltage at the non-reverse input terminal (+1) of the non-reverse input terminal (OP1) of
Since it is equal to the potential applied to the non-reverse input terminal of p5), the third
No output signal is emitted from the operational amplifiers (OPs) and the thyristor (SCU) maintains the OFF state. The capacitor (C3) connected between the non-reverse input terminal (between the tower and the Zener diode (ZD) of the resistor (R6) of the second operational amplifier (op2) is the capacitor (C5) of the series circuit (4). Since the potential of the 01 point connected to the point 01 is lower than that of the point (b), it is charged.

As charging of the storage battery (3) to be charged progresses and reaches the final stage of charging, when the peak point of the light heavy voltage has passed, the potential at point (A) of the series circuit (4) becomes lower than the potential at the immediately preceding marked point. On the other hand, the non-inverting input terminal (+1) of the operational amplifier (OF2) in option 3 is held at its peak potential by the capacitor (C3), and the peak potential is applied, so the input of the third operational amplifier (OF2) is inverted. .Therefore, the third operational amplifier (OF2
) outputs an output signal from the output terminal of the control circuit (
Since the voltage is applied to the gate of the thyristor (SCR) No. 21, the thyristor (5CR) is turned on.

Then, the transistor (Tr) of the constant current power supply unit (1) connected to the thyristor (SCR) is turned off, and one current of charging to the storage battery to be charged (3) is controlled. MejIJt'
Mel*〆〆The voltage at this time of inversion is the point (B) because the output of the second operational amplifier (OPl) is fed back to the first operational amplifier (OPl) to form a so-called voltage follower circuit! The voltage is directly connected to the second operational amplifier (O
Since it can be used as the output of Pl), that is, the input snow pressure of a 1!3 operational amplifier (OPl), it can be several mV.

Note that the capacitor (C3) is discharged via the diode (D3).

On the other hand, when charging a charged lightning storage battery (3), for example, a sealed nickel-cadmium storage battery after being left for a long time, the first peak (Pl
), but the storage battery voltage at this point is low and the potential difference between point (B) and point 01 of the series circuit (4) is small, and the capacitor (C5) button is hardly charged, especially the diode (
D2) Since the resistor (R8) etc. are intervened, the capacitor (C5) is charged more reliably, and the sensitivity becomes extremely low and the storage battery voltage drops past the first peak point. However, as mentioned above, the capacitor (
Since the peak potential is not sufficiently maintained by C5), the peak detection at this point can be canceled, and the second peak at the end of charging is reliably detected and charging is controlled as described above.

(Effects of the Invention) As described above, according to the present invention, the detection potential difference at the peak time, that is, the initial setting sensitivity can be increased to several to several tens of mV, and the overcharging of the storage battery can be suppressed as much as possible with high sensitivity. In addition, it has excellent effects such as canceling the first peak at the initial stage of charging that occurs when the storage battery is left unused for a long period of time, preventing malfunctions, and resolving insufficient charge.

[Brief explanation of drawings]

Fig. 1 shows one embodiment of the present invention -F [air circuit diagram] Fig. 2 is a block diagram showing a conventional example, Fig. 3 shows one example of storage battery charging characteristics
Diagram showing an example

Claims (1)

[Claims] The storage battery to be charged includes a series circuit of a resistor and a Zener diode connected in parallel, a first operational amplifier whose non-reverse input terminal is connected between the resistors of the series circuit, and an output terminal of the first operational amplifier. a second operational amplifier connected to the non-reverse input terminal, whose output terminal is connected to the reverse input terminal of the first operational amplifier for feedback, and also connected to its own reverse input terminal; and the second operational amplifier. a third operational amplifier whose output terminal is connected to a non-reverse input terminal, whose reverse input terminal is connected between the resistors of the series circuit, and whose output terminal is connected to a control circuit that controls charging current;
comprising a capacitor connected between the non-reverse input terminal of the operational amplifier and the resistor and Zener diode of the series circuit;
A charging control device for a storage battery, which operates the control circuit according to an output signal of a third operational amplifier to control a charging current of a storage battery to be charged.