KR100194644B1 - Rechargeable Battery Charger - Google Patents

Abstract

The present invention relates to a charging device capable of charging a non-rechargeable rechargeable battery or battery pack among rechargeable batteries or battery packs used as a power source for a cordless phone or a camcorder. The purpose is to implement a charging device capable of charging a rechargeable battery that is degraded by overcharge or completely discharged due to long periods of nonuse by adding a high voltage and a small additional circuit that is 5 to 10 times. The configuration includes power source generating means, power source driving means, residual voltage detecting means, and charging method selecting means. The power generating means generates two types of charging voltages, a first charging voltage for initial charging of a degraded or naturally discharged abnormal battery, and a second charging voltage for fast charging and standard charging of a normal battery. The power supply driving means supplies one of the first charging voltage and the second charging voltage to the rechargeable battery from the power generating means according to the control signal. The residual voltage detecting unit detects the residual voltage of the rechargeable battery and outputs a residual voltage signal for determining whether the initial charging is necessary. The charging method selecting means selects the charging method by determining whether the initial charging is necessary according to the residual voltage signal, and supplies a control signal to the power supply driving means.

Description

Rechargeable Battery Charger

The present invention relates to a charging device for a rechargeable battery, and more particularly to a charging device capable of charging a non-rechargeable rechargeable battery or battery pack among rechargeable batteries or battery packs used as a power source for a cordless phone or a camcorder.

Hereinafter, a battery or a battery pack is called a battery in this specification. In general, charging methods for rechargeable batteries include a constant voltage charging method, a constant current charging method, a mode switching charging method, and a charging time variable charging method. The mode switching charging method is a charging method that can be charged while switching between two modes, a constant voltage charging method and a constant current charging method. The charging time variable charging method is a charging method that detects a change in terminal voltage drop while discharging a constant current in a rechargeable battery, and determines the time for fast charging according to the already programmed contents.

An example of a conventional charging device will be described with reference to the accompanying drawings. 1 is a circuit diagram of a conventional two-stage charging device for a rechargeable battery. Referring to FIG. 1, a conventional two-stage charging device for a rechargeable battery is as follows.

This device is already patented patent No. 059789. It adopts a constant voltage charging method and consists of a single VCC power supply. When the push switch SW on the left side of the drawing is not pressed, the standard charging or the extra charging (creele charging) is performed by the resistor R5. When the push switch SW is pressed, fast charging is performed through the resistor R3. Such a constant voltage charging method has been widely applied to a general charging device such as a charger for a handset telephone or a camcorder because it can be inexpensively configured using a small number of devices. On the other hand, the deteriorated performance of the rechargeable battery has a disadvantage that can not be recharged because the charging start (initiation of reversible reaction) does not start even if the charging current slightly higher than the rapid charging standard value suggested by the manufacturer.

As another example, the variable charging time method is regarded as an effective way to charge the battery while protecting the life of the battery, but this method is difficult to always charge the same without including the prediction of the change in the battery's climacteric change. Even if the prediction is included, it is difficult to apply when the battery is not the model. Furthermore, in order to implement such a device, a circuit must be configured including a computing device such as a CPU and a memory device such as a ROM, thereby increasing the manufacturing cost of the charging device.

Moreover, even if the charging device is configured in the conventional manner as described above, if the rapid charging is continued for several tens to hundreds of times, the rechargeable battery is deteriorated by overcharging. Therefore, there is no problem in that there is no proper charging method for a rechargeable battery deteriorated by overcharging, a rechargeable battery that cannot be recharged because it is completely discharged due to long periods of non-use, or a rechargeable battery whose charging capacity is decreased due to menopausal change. there was.

In addition, in the conventional charging device to satisfy the charging current by setting the charging time according to the fast charging or standard charging standard suggested by the rechargeable battery manufacturer, this method is also different for the charging of the deteriorated rechargeable battery There was another problem that it did not work.

That doesn't mean you can't completely use the degraded rechargeable batteries. According to the experimental results, among the deteriorated rechargeable batteries, especially nickel cadmium battery is very resistant to overcharging, and when the current flows 5-10 times higher than the rapid charging current, the reversible reaction starts and charging starts. . Once charging is started, it can be quickly charged and can be reused almost identical to regular products if used continuously.

The present invention devised to solve the above problems is a charging device that can be charged even for a rechargeable battery that is degraded by overcharge or completely discharged due to unused for a long time by adding a high voltage and a small additional circuit corresponding to 5 to 10 times The purpose is to implement

A characteristic of the present invention for achieving the above object is to generate two types of charging voltages for the initial charge of the degraded or naturally discharged abnormal battery, the first charge voltage for the rapid charging of the normal battery and the second charge voltage for the standard charging Power supply means for supplying one of said first charging voltage and said second charging voltage to said rechargeable battery from said power generating means in accordance with a control signal; Residual voltage detection means for outputting a residual voltage signal for determining whether charging is necessary and charging for selecting a charging method by determining whether the initial charging is necessary according to the residual voltage signal and supplying the control signal to the power driving means. It consists of a method selection means.

1 is a circuit diagram of a conventional two-stage charging device for a rechargeable battery.

2a is a circuit diagram of a charging device for a rechargeable battery according to the present invention.

2b is a circuit diagram of a charging method selection unit of a charging device for a rechargeable battery according to the present invention;

3 is a detailed circuit diagram of a selection unit of a charging device for a rechargeable battery according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail one of the preferred embodiments according to the present invention.

2a is a circuit diagram of a charging device for a rechargeable battery according to the present invention, and FIG. 2b is a circuit diagram of a charging method selector of the charging device for a rechargeable battery according to the present invention. Referring to Figures 2a to 2b it will be described the circuit of the charging device of the rechargeable battery according to the present invention.

2A, 3, 4, and 2B which are left after cutting off part 1 of FIG. 1 and leave it unchanged, 12B, 13, 14 of FIG. 2A at points 5 and 6 By connecting the points 15 and 16, it is possible to add the high voltage HVCC suitable for the initial charging and to add the detection circuit 24 that can determine whether to perform the initial charging, while still exhibiting the same function as the first diagram. . In FIG. 2A, the dotted line portion to the right of points 12B and 16 and the SW in the dotted line to the left of points 13 and 15 represent a part of FIG. In addition, part A omits the constant voltage circuit part to match the operating voltage of the IC in the circuit according to the present invention. This means that in case of 4 4.8 volt battery to be charged, VCC may be applied to 5 volts, so a separate constant voltage circuit is not necessary, and it may be directly connected as shown in FIG. 2a, but the battery to be charged is less than or equal to that. If this is the case, a separate 5-volt constant voltage circuit must be made and inserted. In this description, it is assumed that there are four batteries to be charged, and a part A is directly connected as in the example of FIG. 2A. The values and specifications of all the other elements are variable according to the number of batteries and the charging current, and thus, are not specified.

In FIG. 2B, when the AC power is input to the charger, the power supply unit 21 outputs secondary power from the power transformer 11. This secondary power source varies depending on whether onion rectification or half-wave rectification is performed. However, in this embodiment, since the performance can be exhibited regardless of the case, it is assumed that half-wave rectification is performed. heard. The start of the secondary side decoupling is connected to the GND terminal of the charger as a reference for 0 volts AC. The middle tap generates a reasonable AC to apply a standard voltage for quick charging after passing through the rectifier circuit (for example, to apply 5 volts DC for fast charging, divide 1.2 to 1.4 from the required 5 volts after rectification). Generates 4 volts AC). In addition, at the end of the sense, after passing through the rectifier circuit, a proper AC is generated so that a high voltage for initial charging can be applied (for example, when 5 volt DC is applied for fast charging, Generates AC which can apply 50 volts DC). Afterwards, HVCC for initial charging and VCC for rapid and standard charging are generated through rectifying circuits. The power supply unit 21 may be configured in the same manner as in the embodiment as long as the circuit can generate 5 to 10 times the initial charge HVCC separately from the circuit for generating the DC voltage for fast and standard charging. The core of this power supply 21 is to make an additional HVCC to start reversible reaction and start charging even if the rechargeable battery is degraded by applying HVCC for 5-10 times faster than the rapid charging and standard charging voltage. .

In FIG. 2A, the power supply driving unit 22 is composed of a part for driving the HVCC for initial charging and a part for driving the VCC for rapid and standard charging. These driving parts output HVCC or VCC according to the base-side input signals of the transistors TR11 and TR13. The driving part in the form of an emitter follower of a multi-arlington connection allows the charging current to flow sufficiently, and the value of R12 and the voltage of the main power supply are taken into consideration since the value of the resistor R12 determines whether the charging voltage drops. You just need to decide. However, it is important to apply the rapid and standard voltages according to the conditions required for charging, and apply an initial charging voltage of 5 to 10 times to it. If such a function can be provided, the power driver 22 may be configured in another form. Do.

The residual voltage detector 24 is composed of a transistor TR15, a resistor R14, and a resistor R13. This part detects the residual voltage through terminal 16 and sends the output signal to the collector side of TR15. The value of R14 can be determined as a value that can detect whether a battery that needs fast charging or standard charging is inserted. In this case, TR15 is turned on, so that the collector side is low and performance is degraded. When the battery is inserted, TR15 is turned off and the collector side is high.

The charging method selector 23 is composed of an RS-flip-flop IC11, an additional circuit is added so that the HVCC and the VCC do not collide, and the open collector type is configured to drive a high voltage. The R-input is received from the collector side of TR15 and the S-input is received from the fast switch push switch SW of FIG. The specific operation will be described by the circuit diagram of FIG. 3 and the truth table of Table 1. FIG.

3 is a detailed circuit diagram of a selection unit of a charging device of a rechargeable battery according to the present invention. Referring to Figure 3 will be described in detail the selection of the charging device of the rechargeable battery according to the present invention.

This RS-flip-flop is S-first, so that no matter what R is, that is, the fast-switching push switch SW of FIG. 1, regardless of whether a fast-charged or standard-charged battery is inserted, High is input to S by pressing, so Q of IC11 in FIG. 2a becomes high and QN becomes low. As a result, the power driver consisting of TR13 and TR14 is opened, and the power driver consisting of TR11 and TR12 is switched to apply a voltage suitable for the fast and standard charging modes.

The overall operation principle will be described with reference to Table 1 below for a series of operations for charging a degraded battery and a normal charging battery.

First, a case where a battery having a degraded performance (including a deteriorated or completely discharged battery) is inserted is as follows. In this case, the voltage between terminals 12 and 16 of FIG. 2A, which is both ends of the battery, is zero or close to zero, and the push switch SW for rapid charging is not pressed. Therefore, TR15 is turned off, IC11's R-input is high, and S is low, so the final output Q is low, turning off the power driver consisting of TR11 and TR12, as in No. 3 of the truth table of Table 1, and the final output QN is high. Turn on the power driver consisting of TR13 and TR14. Therefore, 5 ~ 10 times of charging current flows between both ends of battery, and reversible reaction starts within 1 ~ 10 seconds, and voltage of terminal 16 rises to the proper value for fast charging, and then TR15 turns on and R- input is low. Changes to. Therefore, as R and S are both low, as in No. 1 of the truth table of Table 1, the output of 2NAND4 in FIG. 3 is low, so the output of 2AND1 is low and the intermediate output A is Regardless of the value, the output of 2OR1 goes high. Eventually, the final output QN goes low to cut off the HVCC, the initial voltage during charging, and the final output Q goes high to apply VCC to start standard charging through R5.

At this time, if the push switch (SW) for fast charging is pressed, the capacitors C, resistors R1, R3, R4, buffer B, transistors TR1, TR2 of FIG. 1 operate, while S remains high while C is discharged, and the truth table of Table 1 As in No. 2, QN goes low to cut off HVCC, which is the initial voltage during charging, Q goes high to apply VCC, and fast charging continues until C goes low through R3, R4, and R5. In this case, only R5 passes the standard charging current. The operation of a battery that is a normal battery but has been completely discharged due to being unused for a long time also operates in the same manner as the above, and thus description thereof will be omitted.

The following is an example of inserting a normal battery (which means that the battery is not used for full discharge because it is still in use and that requires rapid or standard charging). In this case, the voltage between terminals 12 and 16 of FIG. 2A, which is both ends of the battery, is 1 or close to 1, and the quick switch push switch SW is not pressed yet. Therefore, TR15 is turned on, R11 input of IC11 is low, and output of 2NAND2, which is the middle output A of FIG. 3, is low, but the output of 2AND1 in the additional circuit part of FIG. 3 is because R and S are simultaneously low. Is low, and the INV2 to which this output is connected is high, resulting in Q being 2OR1 output high. Therefore, as in No. 1 of the truth table of Table 1, the output Q is high to apply VCC, and the output QN is low to cut off HVCC which is an initial voltage during charging, and the applied VCC starts standard charging through R5. At this time, if the push switch SW for fast charging is pressed, C, R1, R3, R4, B, TR1, and TR2 of FIG. 1 are operated, while S is kept high while C is being discharged, and QN is low as in No. 2 of the truth table of Table 1 HVCC, which is the initial voltage at the time of charging, is cut off, Q becomes high, and VCC is applied to continue fast charging until C is low through R3, R4, and R5. When C is low, standard charging current passing through R5 is applied. Shed.

As described above, the present invention can be recharged not only for a normal battery capable of quick charging or standard charging, but also for a rechargeable battery that is degraded by overcharging or completely discharged due to unused for a long time, thereby extending the number of reuse of the rechargeable battery. Better yet, it has the effect of making rechargeable batteries economical.

Claims (4)

Power generation means for generating two types of charging voltages, a first charging voltage for initial charging of a degraded or spontaneously discharged abnormal battery and a second charging voltage for fast charging and standard charging of a normal battery; Power supply driving means for supplying one of the first charging voltage and the second charging voltage to the rechargeable battery according to the control signal; Residual voltage detection means for detecting a residual voltage of the rechargeable battery and outputting a residual voltage signal for determining whether initial charging is necessary; And a charging method selecting means for selecting a charging method by determining whether the initial charging is necessary according to the residual voltage signal, and supplying the control signal to the power driving means. The control signal according to claim 1, wherein the charging method selection means is configured to charge the second charging voltage capable of comfortable charging or standard charging when the normal rechargeable battery is inserted and the rechargeable battery does not require initial charging. Supplying the power supply means; When an abnormal rechargeable battery is inserted and the rechargeable battery requires initial charging, the rechargeable battery is reversibly reacted after supplying the control signal to the power driving means to charge the first charging voltage capable of initial charging. The charging device of the rechargeable battery, characterized in that for supplying the control signal to the power supply driving means to charge at the second charging voltage capable of fast charging or standard charging in order to switch to fast charging or standard charging when the charging is started. . 2. The apparatus according to claim 1, wherein said charging method selecting means comprises an open collector type RS flip-flop; And the residual voltage detecting means detects the residual voltage of the rechargeable battery and applies the residual voltage signal to the RS flip-flop of the open collector type of the charging method selecting means. The charging device for a rechargeable battery according to claim 1, wherein the charging current is changed according to the power supply voltage of the charging method selected by the charging method selecting means while using the current limiting element as it is.