JPS5967838A - Method of charging 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 method for charging a nickel-cadmium storage battery (hereinafter referred to as a battery) having similar characteristics.

Conventionally, when charging a battery in a short period of time, it is necessary to know when charging is complete by detecting various physical changes such as battery temperature and terminal voltage while charging the battery, and then reduce the charging current or stop charging. This prevents so-called overcharging of the battery.

However, such a method requires a sensor to detect physical changes in the battery, and therefore has the disadvantage that the charging circuit becomes complicated. Furthermore, depending on the method, detection of the above-mentioned physical changes under a wide range of environmental conditions is technically expensive, and therefore the manufacturing cost is high. On the other hand, when charging is controlled using a relatively simple method, it is difficult to accurately know when charging is complete because battery characteristics change depending on the battery condition and environment such as temperature. In many cases, charging became incomplete or overcharging caused battery deterioration.

In view of the above-mentioned drawbacks of the conventional charging method, the present invention has been developed by first discharging the battery to a predetermined voltage using a discharging load before charging the battery, and then charging the battery to a certain amount. The object of the present invention is to provide a battery charging method that can overcome the drawbacks mentioned above.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

In the embodiment shown in Figure 1, 1 is a nickel-cadmium storage battery or a storage battery with similar characteristics (the battery and
・U). 2 is a discharging load such as a resistor connected to this battery 1 via a switch SWI, and a forced air cooling fan 3 is connected in parallel to this discharging load 2 to prevent the temperature of the discharging load from rising. has been done. 4 is switch SW
This is a battery voltage detection circuit inserted between the battery 1 and the switch SW2 and connected to the battery 1. Reference numeral 5 denotes a charging timer connected to this battery voltage detection circuit, and this charging timer 5 is activated when the voltage at point A of the battery 1 decreases to a predetermined voltage and turns off the switch SWI.
1.6, which plays the role of a charging control member to turn on the switch SW2 for the required time after setting it to F, is a commercial AC power supply 7.
A rectifier 10 is connected to a secondary winding 9 of the transformer 6 through an outlet 8. 1
1 is a switch SW2 between the rectifier 10 and the battery 1.
This is a stable current circuit such as a charging control element connected in series via a

In the above configuration, first, before charging the battery 1, the switch SWI is turned ON (closed), and the grounded discharge load 2
The battery l is discharged. 1 When the voltage of the battery 1 at point A drops due to the discharge and reaches a predetermined voltage, for example, approximately IV/cell in the case of a nickel cadmium battery, the battery voltage detection circuit 4 is activated and the switch SW1 is set to 0FF (open circuit). do. Therefore, discharging of the battery stops at a predetermined voltage. After that, the charging timer 5 is connected to the battery voltage detection circuit 4.
It starts operating upon receiving a signal from the switch 8W2.
The secondary winding 9 of the transformer 6 connected to the commercial AC power supply 7 is turned on (closed) and energized for the required time 61
A rectifier 10 converts the voltage induced into direct current, and supplies power to the battery IK via a stable current circuit 11 to charge it.

Then, when charging for a short period of time is completed, the charging timer 5 stops operating and the switch SW2 becomes OFF (open circuit). Therefore, the entire charging operation of the battery 1 is completed. Note that during the discharge of the battery 1, the forced air cooling fan 3 operates, and the discharge load 2
prevents the temperature from rising.

Next, different embodiments shown in FIGS. 2 to 5 will be explained. The basic principles of these embodiments are substantially the same as those of the above embodiments, so the same reference numerals are used to omit redundant explanation.

The main difference between the embodiment shown in FIG. 2 and the previous embodiment is that in order to use the transformer 6A as a discharging load, a changeover switch S W i A consisting of three circuits is used as the primary winding of the transformer 6A. DC/AC
Converter 12 is inserted between transformer 6A and battery 10 via a switch on the secondary winding side of transformer 6.

In such a configuration, switch 5 is turned off when charging starts.
When the WIA is switched as shown, the transformer 6A is separated from the internal circuit, resulting in two discharge loads. Then, the battery l is once discharged to a predetermined voltage before being charged. That is, the battery 1 has its direct current converted to a transformed current by the DC/AC converter, and is discharged using the transformer 6A as the discharge load 2A. Due to the discharge, the voltage of the battery (point A) decreases, and when it drops to a certain predetermined voltage as described above, the battery voltage detection circuit 4 is activated, switches the switch 5WIA to the side opposite to that shown in the figure, and starts the charging timer 5. Start. The charging operation after the charging timer 5 starts is the same as that of the embodiment shown in FIG. 1 above. In the case of this embodiment, it is also conceivable to provide the transformer with a winding dedicated to discharge, as shown in FIG. 3 or FIG. 4. That is, in the case of a transformer having an outer iron core 13 as shown in FIG.
A copper plate 15 dedicated to discharge may be wound around the central outer circumferential portion around which the No. 3 coil 14 is wound. In addition, in the case of a transformer having an inner iron core 13A as shown in FIG.
A copper plate 15A dedicated for discharge may be wound around the outside of the secondary winding 14A of A. Furthermore, although not particularly shown in the drawings, in the case of FIG. 283, a copper plate exclusively used for discharge may be interposed between the chemical primary winding and the secondary winding.

Next, in the embodiment shown in FIG. 5, the main voltage difference from the embodiment shown in FIG. 2 is that the noise filter 16 is connected to the primary winding i side of the transformer 6B, and A changeover switch SW1-3 consisting of two circuits is provided on the side, and a thyristor chopper circuit 17 is inserted between the transformer 6B and the battery 10 via the switch 5W113.

In such melting, switch 5 is turned off when charging starts.
When WII3 is switched as shown, transformer 6B is connected to thyristor chopper circuit 17. Therefore, before charging, the battery 1 is synchronized with the power frequency range by a thyristor chopper, and is discharged by returning it to the commercial AC power source 7fiill via the transformer 6B. Due to the discharge, the voltage of the battery 1 (point A) decreases, and when it drops to a predetermined voltage as described above, the battery voltage detection circuit 4 is activated, switches the switch 5W113 to the side opposite to that shown in the figure, and starts the charging timer 5. . The charging operation after the charging timer 5 starts is the same as the embodiment shown in FIG. 1 described above.

As is clear from the above explanation, in the present invention, before charging the battery, the battery is discharged to a predetermined voltage using a discharging load, and then a charging timer is used to charge a certain amount. It is possible to obtain excellent effects such as those listed below.

(l) Since this method does not control charging by detecting physical changes in the battery during charging, there is no need for sensors.

(2) Therefore, according to the method of the present invention, the charging circuit structure can be easily constructed, so that cost reduction can be achieved.

(3) In addition, since a charging timer is used without performing complicated control during the charging process, the charging operation is stable and reliable, and therefore there is no risk of battery deterioration due to undercharging or overcharging. Does not occur.

(4) Furthermore, the present invention is not easily affected by the state of the battery or the environment (and can be discharged and charged in a short time).

(5) In the case of the embodiment in which the forced air cooling fan is connected to the discharge load, it is possible to prevent the temperature of the discharge load from rising and also to reduce its electric capacity.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, Figs. 2 and 5 are circuit diagrams showing different embodiments of the invention, and Figs. 3 and 4 are transformers used as discharge loads. It is a schematic explanatory view of the iron core which constitutes. 1...'warming pond, 2.2A...discharging load, 3...forced air cooling fan, 4...battery voltage detection circuit, 5...charging timer, 6.6
A, 6B...Transformer, 7...ktj', Source,
9, 14.14A...Secondary winding, 10.
... Rectifier, 11... Stable current circuit, 1
2...[DS/AC converter, 13.13A...iron core, 15.15A...copper plate, 16...noise filter, 17...thyristor chopper circuit.

Claims (1)

[Claims] - 1) A method for charging a battery, which is characterized in that before charging the battery, the battery is first discharged to a predetermined voltage using a discharging load, and then charged by a certain amount using a charging timer. 2) The method of charging a battery according to claim 1, wherein the discharging load is cooled by a forced air cooling fan while the battery is being discharged. 3) The method of charging a battery according to claim 1, wherein the discharging load is a resistor. 4) The discharge load is separated from the internal circuit by a plurality of changeover switches 5WIA, and is connected to the battery via a switch provided on the secondary winding side. A method for charging a battery according to claim 1, characterized in that: 5) Make sure that the transformer has a winding dedicated to discharge.
! 5. The method for charging a battery according to claim 1 or 4, wherein 6. Release. Charging of the battery according to claim 1, characterized in that the battery is synchronized with the source frequency and sent back to the power source via a transformer. Method.