JPS6188732A - 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] The original F! A relates to a charger for storage batteries, particularly a quick charger for sealed nickel-cadmium storage batteries.

Traditionally, this type of charger either directly detects the battery voltage or
Alternatively, a resistive voltage divider circuit is connected in parallel with the storage battery, and by detecting a predetermined divided voltage proportional to the storage battery voltage appearing at the partial voltage detection point, the R1 constant charging state of the storage battery is fully detected and the charging of the storage battery is controlled. However, the voltage of the nickel-cadmium storage battery ("i As shown by 1a and 1b in Fig. 1, there are variations Vo and Vo' in the charge end voltage of two different storage batteries. Therefore, Vo
If charging is performed based on f, the other storage battery will be overcharged. Also, if charging is performed based on Vq'i, the other storage battery will be insufficiently charged. Furthermore, as shown in FIG. 2, even when the same storage battery has a different end-of-charge voltage, depending on the ambient temperature of the storage battery during charging, there is a custom-made model that shows a different end-of-charge voltage.

Therefore, in conventional quick chargers, in order to prevent deterioration of the storage battery due to overcharging, as shown in FIG.
', and in order to prevent the other storage battery from being insufficiently charged, after the storage battery voltage reaches Vo', it is charged with a second charging current I2, and the charging end voltage Vo' is corrected according to the ambient temperature. I was taking it.

The present invention provides a charger that can rapidly and properly photoelectrically charge a storage battery regardless of such variations in photoelectric termination voltage and changes in ambient temperature.

The charging voltage of nickel-cadmium storage batteries is shown in Figures 1 and 2.
It has the characteristics shown in the figure. To explain 1a in FIG. 1, the storage battery voltage rises quickly in the initial stage of charging, and after reaching a predetermined value, gradually rises. When the end of charging approaches, the storage battery voltage has a characteristic of rising steeply, reaching the photovoltaic end voltage Vp, and then dropping.

The present invention improves the drawbacks of conventional chargers by providing means for detecting the drop in battery voltage that occurs after the end-of-charge voltage Vp and controlling the charging of the battery.

An embodiment of the invention will be described with reference to FIG. In the figure, 1 is a source device, 2 is a storage battery to be charged, 3 is a detection circuit that detects the drop in storage battery voltage that occurs after the photovoltaic termination voltage Vp, and 4 is a signal from the detection circuit 3 that controls the entire power supply device 1. It is a control circuit.

Next, a specific configuration of the detection circuit 3 shown in FIG. 4 will be explained with reference to FIG. Terminal a has a resistor of 5 and a Zener diode of 10.
Connected to the terminal via. The terminal a side of the resistor 5 is connected to the anode of the capacitor 7 and diode 8 connected in series.
It is connected to the other end of the resistor 5 via the cathode. The anode and cathode of the diode 8 are connected to the two input terminals of the operational amplifier 9 when the cathode voltage is higher than the anode voltage.
Ma is arranged so that an output signal is output to output terminal C.

The operation of the detection circuit 3 in such a configuration will be explained with reference to FIG. In FIG. 6, a 171M core battery is shown with a characteristic that it gradually increases until the charging time tp and then decreases. On the other hand, the anode direct voltage characteristics based on the cathode voltage of the diode 8 shown in FIG. 5 are as shown in 2.2 of FIG. 6. That is, until the charging time tp, the capacitor is charged, so that the same pressure is applied to the diode 8, and the voltage between the anode and the cathode exhibits a constant value. Further, after the charging time tp, the capacitor 7 is not charged, the voltage of the capacitor 7 becomes higher than the voltage of the resistor 5, and the capacitor 7 attempts to discharge via the resistor 5. However, this discharge is blocked by the reverse characteristic of the diode 8. Therefore, the anode voltage drops after the charging time tp, becomes zero at +alte during charging, and thereafter becomes smaller than the cathode voltage. Therefore, the fifth
The output terminal of the arithmetic unit 9 shown in the figure is
An output signal will be output at one optical time t8 as shown in FIG.

Charging can be controlled by driving the control circuit 4 shown in FIG. 4 with this output signal.

The 1d pressure detection circuit shown in FIG. 45 is an improved circuit consisting only of resistors. That is, the terminal a is connected to the terminal A via the resistor 5 and the Zener diode 1o. The operation of exploiting the drop in the storage battery voltage at the completion of photovoltaic operation is stable because the input bias voltage of the amplifier circuit 9 is kept constant by the Zener voltage of the Zener diode 10. Also, the amount of T added to terminal a and terminal
If the JL cell voltage is lower than the Zener diode 100 Zener voltage, no current will flow through the detection circuit. Therefore, the seventh
When an abnormal peak curve appears in the initial stage of charging as shown in the figure, a detection circuit consisting only of resistors extracts this abnormal peak voltage and malfunctions, but in the detection circuit of Fig. 5, the Zener voltage of the Zener diode 10 is Malfunctions can be prevented by selecting a voltage higher than this abnormal peak voltage. Note that the customization shown in FIG. 7 may appear when the storage battery is left unused for a long period of time, or when multiple storage batteries are combined and overcharged.

The detection accuracy of the detection circuit shown in FIG. 5 varies greatly depending on the forward voltage of the diode 8. Figure 288 shows the method for reducing the forward I & pressure, and by thermally coupling the diode 8 to the heating element 11, the accuracy can be improved.

Further, according to the present invention, when the four-source device 1 of FIG. 4 is disconnected, or when it is disconnected, it is necessary to quickly discharge the charges accumulated in the co/dancer 8 of FIG. FIG. 9 is a circuit diagram showing the configuration of this 1-7 node circuit. The configuration will be explained with reference to FIG. FIG. 9 shows a block field effect transistor 12 at both ends of the circuit board 7 of the detection circuit shown in FIG.
The drain and source of the transistor 12 are connected through a resistor 13, and the gate of the transistor 12 is connected to a terminal.

With such a configuration, when a voltage is applied between the terminals a and b, the gate and source of the transistor 12 are reverse biased by the voltages of the diode 8 and the Zener diode 1o, so that the voltage of the transistor 12 is reverse biased. 1
2 is disconnected between the drain and source, and the reverse output circuit 3 performs the operation described above.

On the other hand, when the voltages at terminals A and S are removed, the reverse bias between the gate and source of the transistor 12 disappears, so the resistance between the drain and source of the transistor 12 decreases, and the capacitor shown in FIG. 7 is discharged through the drain and source of the transistor 12.

Therefore, even if the power supply circuit 1 shown in FIG. 4 is temporarily cut off and then turned on again, the above-described Φ operation can be performed automatically and smoothly.

As described above, the optical ζ device of the present invention has a simple configuration and can detect the voltage drop after the charging end voltage of a wave photoelectric storage battery, thereby making it possible to appropriately utilize the photoelectricity of the storage battery.

[Brief explanation of drawings]

Figures 1 and 2 are diagrams showing the charging characteristics of nickel-cadmium synthesis ability, Figure 3 is a diagram of photoelectric characteristics in the conventional photoelectric system, Figure 4 is a circuit diagram of the charger of the present invention, and Figure 61A is a diagram showing the charging characteristics of the nickel-cadmium synthesis ability. 6 is an explanatory diagram of the operation of the detection circuit of FIG. 5, FIG. 7 is a diagram showing the photoelectric characteristics of an abnormal storage battery, and FIG. 8 is a diagram showing the improvement of the forward voltage characteristics of the diode. 913 is a diagram showing a beam cent circuit. DESCRIPTION OF SYMBOLS 1... Photoelectric power supply device, 2... Source battery, 3... Voltage detection circuit, 4... Control circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 to Figure 5 Figure 6 Open when charging Figure 7 Figure 8 Figure 9

Claims (2)

[Claims] (1) A charging power supply device that charges a storage battery, a voltage detection circuit having a Zener diode and a resistor whose voltage at both ends changes depending on the voltage of the storage battery, and at least a capacitor and a diode connected to both ends of the resistor. a series circuit, an amplifier that compares the anode side voltage and cathode side voltage of the diode, detects that the cathode side voltage has become higher than the anode side voltage, and generates an output signal; A charger comprising a control circuit that controls a power supply device. (2) The charger according to claim 1, wherein the diode is thermally coupled to a heating element.