JPS60128832A - 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] [Technical field to which the invention pertains] This invention relates to a rechargeable battery (hereinafter also referred to as J storage battery i).

), and relates to a charging device suitable for use in portable measuring instruments and the like. In general, such a charging device can be fully charged (100%
% charge). - [Prior art and its problems] Generally, there are two methods for charging storage batteries: a constant voltage charging method and a constant voltage charging method. The former is widely used because it can be charged in a short time, but overcharging shortens the life of the battery, so careful attention must be paid to overcharging. Therefore, in the constant voltage charging method, it is necessary to detect the voltage at the time of completion of charging, and the following methods, for example, are conventionally known as methods for this purpose.

In other words, the battery voltage at the end of charging depends on the charging current and battery temperature, but if the charging current is constant, you only need to pay attention to the temperature. This is a method of charging using a circuit using a temperature element (for example, a thermistor, etc.) with similar characteristics. However, with this method, adjustments must be made for each charger due to variations in parts, etc., and therefore, not only does it take time to make adjustments, but since it approximates the characteristics, it is difficult to reduce the error. The problem is that it is difficult to do so. Also, since it can only charge about 80% of the full charge (100% charge), the remaining charge (20%
% charge) does not result in overcharging.5 However, since supplementary charging is performed over a long period of time to bring the battery closer to full charge, there is a drawback that charging takes too long as a whole.

In other words, the relationship is like full charge time - quick charge time and supplementary charge time.For example, quick charge time is about 1 hour, while supplementary charge time is about 8 hours. It's normal.

[Object of the Invention] This invention was made under the above circumstances, and an object thereof is to provide a charging device that can fully charge a battery in a short period of time while suppressing overcharging. .

[Key points of the invention]

This invention provides a memory that stores the voltage at the completion of charging when a storage battery is charged with a predetermined current in relation to the temperature, and reads out the voltage at the completion of charging from the memory according to the temperature of the storage battery. is compared with the storage battery terminal voltage, and if the latter is smaller than the former, the predetermined current is applied to perform rapid charging until both voltages match, and after that, the charging current is sequentially reduced at regular intervals, This is designed to fully charge the battery in a short period of time while preventing overcharging. Note that after that, a supplementary charging current is supplied to supply self-discharge to maintain a fully charged state at all times.

[Embodiments of the invention]

FIG. 1 is a perspective view showing the appearance of a charging device according to the present invention;
FIG. 2 is a block diagram showing an example of the configuration of a charging device according to the present invention, and FIG. 2A is a detailed configuration diagram showing its details.

As is clear from FIG. 1, the charging device (charger) 10 according to the present invention has a plurality of charging insertion ports 20, into which the measuring device 30 is inserted, and the charging device 10 is electrically connected. By continuing, the storage battery inside the battery is charged. In addition, Ll.

L2 is an indicator lamp, and it is charged! The middle expansion lamp L1 lights up, and when charging is completed, the charging completion display lamp L2 lights up. When the measuring device 30 is pulled out from the insertion port 20, the lamp L2
Needless to say, the lights also go out.

Note that the voltage at the completion of charging when a certain current is passed through the storage battery depends on the temperature as described above, so in this invention, it is possible to know the voltage at the completion of charging according to the temperature. , a storage battery, that is, a temperature detector for detecting the temperature of the measuring device 30 is provided inside the charging device 10.

The charging device 10, as shown in FIG.
, a charging basic unit 1 and six sets of charging control units 2 to 4. Note that the number of control units is not limited to six, but can be any number.

-5-, - to 5, charging basic unit 1 as shown in detail in Figure 2A.
are a temperature detector 11 and an A/D (analog/digital) converter 12 as described above. EPROM (Erasable)
e Programmable Read OnlyM
memory 13, D/A (digital/analog) converter 14, and pulse generator 15
For example, the charging control unit 2 includes comparators 21, 22 . anime game) 23,2
4, counter 25, inverter gate 26, resistor R1~
R7, transistors TR1-TR3 and lamp L1.
It consists of Lx, etc.

The operation will be described below with reference to FIG. 2A and FIGS. 3 to 5. In addition, Figure 3 shows the voltage and temperature when the storage battery is fully charged! FIG. 4 is a characteristic diagram showing the relationship between charging time and charging current in a storage battery. The figure is the second
FIG. 4 is a waveform diagram of each part for explaining the operation shown in FIG.

The temperature detector 11 detects the temperature of the reed battery 51 inside the measuring device 5 when it is inserted, and outputs a voltage Vxi proportional to the temperature. This voltage Vll6 is converted into a digital signal by the A/D converter 12 and provided to the memory 13. The memory 13 includes a third
As shown in the figure, a characteristic curve A between a voltage Vli proportional to temperature and a voltage V2i at the completion of charging of the storage battery is approximated and stored as shown in B, and therefore, from the memory 13, it is detected by the temperature detector 11. A charging completion voltage V2i corresponding to the temperature is output. The reason for doing this is that, as mentioned above, storage batteries of the same type show the same voltage value when charging is complete, but if the ambient temperature or charging current differs, the voltage at the time of charging completion will differ. Therefore, by storing data in advance in memory when a battery of the same type is charged by flowing a constant current, it is possible to obtain the voltage at the completion of charging according to the temperature. It is intended to do so. In addition, since it is generally difficult to grasp the voltage at the time of full charge in a storage battery, the above-mentioned voltage at the completion of charge is about 80% of the full charge.

The output from the memory 13 thus obtained is converted into an analog signal by the b/A converter 14 and applied to the comparator 21 of the charging unit 2.

Hereinafter, a method of charging the storage battery 51 will be explained.

In FIG. 2A, when the measuring device 5 is inserted into the charging control unit 2, the storage battery voltage vB is detected by the comparator 2.
1,22. The comparator 21 compares the storage battery voltage vB with the voltage V2i read out through the memory 13 as described above, and outputs '1' when vB≧V2i.The comparator 22 converts the storage battery voltage VB into a predetermined voltage. It compares with VP and outputs 1# when VB > VP.If the voltage Vp is selected to be a predetermined voltage at which the storage battery 51 can be recharged, the above voltage will be reached within a very short time after the start of charging. If vB>Vp, the output of the AND gate 24 becomes 11#, and the lamp L1 lights up.

At this time, if the storage battery 51 is defective, the lamp L1 will not light up, thereby making it possible to detect a defect in the storage battery. Therefore, the output waveform of the comparator 22 becomes a waveform that rises to 1# almost at the same time as the insertion of the measuring instrument, as shown in FIG. 1” at the time ts
It is expressed as a waveform.

VB = V2t Tona? ) (r, c o, Vn <
When the output of the comparator 21 becomes ul, this output is given to the AND gate 23.
At this time, the AND gate 26 includes the inverter gate 2
Since the 11# signal via 6 and the clock pulse of a predetermined frequency from the pulse generator 15 of the charging basic unit 1 are provided, the p clock pulse is also provided to the counter 25 via the AND gate 23. As a result, the counter 25 and the pulse generator 15 start counting clock pulses. Output Q of counter 25. zQ
n+x t Qn0g are all '0' at the start of their operation.
”, and the count value of the counter 25 is QB a
Qn+ 1 s Qn+ 2 pieces.

When it becomes, it becomes ``1''. Output terminal Qny Q
n+tpQn+2 has a resistor Rs j R6p, respectively.
Transistors TR, TR2, TR, are connected via n7, and these are connected to terminals Qn p Qn+lp
"1 ON" until an output is obtained at Qn+z, and as a result, the storage battery 51 is charged via the resistors R1 to R4. At this time, the current given to the storage battery 51 is maximum, and its value is: 1. As shown in FIG. 4 or FIG. 5 (FIG. 5).

After that, the count value of the counter 25 reaches Qn and the terminal Qn
At time t6 when becomes "1#", the transistor TRI becomes "1#"
OFF", cutting the current through the resistor R2. As a result, the charging current decreases to 11 as shown in FIG. 4 or FIG. The frequency f of the clock pulse from the pulse generator 15 can be expressed as f=qn/Tt.Then, when the count value of the counter 25 reaches Qn+1, the terminal Qn+x At the time t1 when becomes "1", the transistor TR2 becomes "1 off" and the current passing through the resistor R3 is also cut, so the charging current becomes "I".
Reduced to 2. Similarly, the count value of the counter 25 is Qn+
At time t2 when the voltage reaches 2 and the terminal Qn+z becomes 11'',
Since the transistor TRs is turned off and the current passing through the resistor R4 is also cut, the current I3 is reduced to 3. Note that this current I3 is the current during conventional auxiliary charging of the storage battery, so this It can be seen that by doing as in the invention, the time for supplementary charging can be shortened.In addition, the output of the output terminal Qn+2 of the counter 25 is connected to the ant gate (23.2) via the inverter gate 26.
4 as a ``0'' signal, the counter 25
stops its operation, and the lamp L1 changes to the state shown in Fig. 5 (
The lamp L2 turns off as shown in (h), while the lamp L2 lights up as shown in (h). Thereafter, as long as the measuring instrument is electrically connected to the charging device, supplementary charging with the current I3 continues, but if the measuring instrument is removed, the counter 25 is reset by the signal R, so its output Qn p Qn +
* becomes “0” as shown in Figure 5), (e), and (e),
Lamp L2 also goes out. Incidentally, FIG. 5(c) shows the output waveform of the AND gate 23.

〔Effect of the invention〕

According to this invention, since the charging completion voltage, which changes depending on the temperature of the storage battery, is stored in the memory in advance, it is possible to automatically set the charging completion voltage at each temperature. Not only does it eliminate the need for adjustment for each unit, but it also prevents overcharging and reduces the auxiliary charging flow in stages after the rapid charging (approximately 80% charge) is completed to fully charge the storage battery. This has the advantage of shortening the charging time (100% charging can be achieved).

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the appearance of a charging device according to the present invention;
FIG. 2 is a block diagram showing a configuration example of a charging device according to the present invention, FIG. 2A is a detailed configuration diagram showing FIG. 2 in more detail,
Fig. 6 is a characteristic diagram showing the relationship between voltage and temperature when battery charging is completed, Fig. 4 is a characteristic diagram showing the relationship between charging time and charging current, and Fig. 5 explains the operation of Fig. 2A. It is a waveform diagram of each part for. Description of symbols 10... Charger, 20... Charging insertion slot, 30 (5, 6, 7)... Measuring device, 1...
... Charging basic unit, 2, 3, 4... Charging control unit, 11... Temperature detector,
12...A/D (analog/digital) converter, 16...memory, 14...D
/A (digital/analog) converter, 15...
...Pulse generation L21, 22...Comparator, 23, 24...And gate, 25...
...Counter, 26...Inverter gate,
51...Storage battery, 52...Load, L,
...Charging indicator lamp, I2...Charging completion indicator lamp, R1-R7...Resistor, TR1
~TRs...Transistor agent Patent attorney Akio Namiki Agent Patent attorney Kiyoshi Matsuzaki Figure 1 l. Fig. 2 0 -w +' + 卍

Claims (1)

[Claims] A charging device for supplying current to a storage battery inside a predetermined device and charging it when the device is inserted and electrically connected, comprising a detection means for detecting the temperature of the device, and a detection means for detecting the temperature of the device; A memory that stores the voltage at the completion of charging when charging with a predetermined charging current as a function of temperature, and the magnitude of the current supplied to the storage battery based on the relationship between the voltage read from the memory and the storage battery terminal voltage. Equipped with an i-controlled charging control unit, the control unit is
When the storage battery terminal voltage is lower than the charging completion voltage, rapid charging is performed by supplying the predetermined charging current to the storage battery until at least one voltage matches, and thereafter the charging current is sequentially supplied at predetermined time intervals. A charging device characterized in that it can perform full charging in a short period of time by lowering the voltage in stages.