JP2000228827A - Charger, battery judging device, charging method, battery judging method and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charger and the like in a simple constitution for judging the quality of charging a battery, and charging continuously, and a charger and the like for charging adequately, even when a capacity of a secondary battery is not known beforehand. SOLUTION: An AC signal is applied from an AC generating unit 4 to a battery (B), and a voltage across both ends of the battery (B) is detected by a potential difference detecting unit 6. The maximum value thereof is notified to a control unit 1 by a peak detecting unit 5. The control unit 1 judges whether or not the battery (B) is a secondary battery, on the basis of the maximum value informed from the peak detecting unit 5. If it is a secondary battery, the control unit 1 instructs a charging power supply 2 to feed a charging current to the battery (B). While the charging battery supply 2 controls a pulse width modulation unit 3, the charging battery supply 2 feeds the battery (B) with a charging current. A voltage between the potential difference is detected continuously by the potential difference detecting unit 6, and the result is notified to the control unit 1. The control unit 1 judges repeatedly whether or not the voltage informed by the potential difference detecting unit 6 stops to increase, and if the control unit 1 judges that it is stopped, the unit makes the charging power supply 2 to end charging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a charging apparatus and a charging method for charging a battery, and more particularly, to a charging apparatus and a charging method for identifying a rechargeable battery and performing charging.

[0002]

2. Description of the Related Art To charge a secondary battery, generally,
A method of flowing a current (charging current) for charging the secondary battery to the secondary battery is used. However, the appearance of a secondary battery such as a nickel-cadmium battery is often almost the same as the appearance of a primary battery such as a manganese dry battery, and therefore, it cannot be determined from the appearance alone that the battery is a secondary battery. Many. For this reason, there is a danger that a charging current may flow to the primary battery by mistake and cause an accident such as damage or overheating of the primary battery. Further, even if a charging current flows through the primary battery, the electromotive force of the primary battery does not sufficiently recover.

In order to avoid this problem, a method has been adopted in which whether or not the battery to be charged is a secondary battery is determined regardless of the appearance. Specifically, a determination method utilizing the fact that the AC impedance of the secondary battery when an AC voltage is applied to the secondary battery is smaller than the AC impedance of the primary battery when the AC voltage is applied to the primary battery Was taken.

[0004] Further, even in the case of a secondary battery, if a charging current is excessively supplied, the secondary battery is deteriorated, and further, there is a risk of causing an accident such as breakage or overheating. In order to avoid this problem, a method has been adopted in which the capacity of the secondary battery is grasped in advance, and an appropriate amount of charging current is determined in advance based on the capacity.

[0005]

However, in the case where it is determined whether or not a battery is a secondary battery by using the above-described method focusing on a difference in AC impedance when an AC voltage is applied to the battery, conventionally, , The AC impedance of the battery,
Measurement was performed using an AC bridge.

However, an apparatus for determining the type of battery using an AC bridge has a complicated structure and is difficult to operate. Therefore, it is not practical to incorporate a device for determining the type of battery using an AC bridge into a consumer charger.

In an apparatus for determining the type of battery using an AC bridge, the determination result is given as an impedance value of each side of the bridge when the AC bridge is in a balanced state. Therefore, it is difficult for an apparatus that determines the type of battery using an AC bridge to obtain the determination result as data in a format suitable for digital signal processing. For this reason, it is difficult to configure a charging device that automatically shifts to the charging operation immediately upon receiving the determination result of the battery type.

In addition, the technique of determining an appropriate amount of charging current in order to prevent the charging current from flowing excessively through the secondary battery cannot be applied when the type of the secondary battery cannot be known in advance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a charging apparatus and a charging method that automatically and continuously determine whether or not to charge a battery and automatically charge the battery with a simple configuration. With the goal. It is another object of the present invention to provide a charging device and a charging method for appropriately charging a secondary battery without knowing the capacity of the secondary battery in advance.

[0010]

In order to achieve the above object, a charging apparatus according to a first aspect of the present invention comprises: an AC applying means for applying an AC voltage between both poles of a battery for a certain period; Voltage detecting means for detecting a voltage between the battery and the voltage detected by the voltage detecting means within the certain period, to determine whether the battery is a secondary battery, and a control signal representing the determination result. Battery determining means for outputting, and the control signal output by the battery determining means, and when the control signal indicates that the battery is determined to be a secondary battery, charging for charging the battery A charging current source for supplying a current to the battery,
It is determined whether or not the increase in the magnitude of the voltage detected by the voltage detection means has substantially stopped during the period when the charging current is being supplied to the battery, and when it is determined that the increase has substantially stopped, the control signal And a full-charge determining means for stopping the output of.

[0011] According to such a charging device, whether or not the battery is a secondary battery is determined based on the voltage between both electrodes of the battery, regardless of the AC bridge, so that the configuration is simplified. In addition, since charging can be stopped by detecting that the battery has reached a fully charged state based on the voltage between both electrodes of the battery, charging can be performed properly without knowing the capacity of the secondary battery in advance. Since the voltage between the two electrodes of the battery can be easily converted into a digital signal, the determination of whether or not the battery can be charged and the charging of the battery are automatically and continuously performed with a simple configuration.

The battery discriminating means includes a peak detecting means for outputting a signal representing the maximum value of the voltage detected by the voltage detecting means within the predetermined period, and acquiring the signal outputted by the peak detecting means. And a means for determining whether or not the battery is a secondary battery based on the signal and outputting a control signal indicating a result of the determination. As a result, a signal representing the maximum value of the voltage between both ends of the battery is created. Based on this signal, the type of the battery can be easily determined by digital signal processing.

[0013] The voltage detecting means may include, for example, means for outputting a signal indicating a value of a voltage value between the two electrodes of the battery detected by the voltage detecting means. In this case, the full charge determination unit periodically acquires a value represented by the signal output by the voltage detection unit during a period in which the charging current is supplied to the battery, and the acquired latest value is: When the value is equal to or less than the most recently obtained value, the end of the proper charging is detected by providing a means for determining that the increase in the voltage between both electrodes of the battery has substantially stopped.

[0014] The charging current source may supply the charging current pulse periodically. In this case, the charging current source controls the amount of the charging current by providing a unit that adjusts the time width of the pulse of the charging current so that the average amount of the magnitude of the charging current matches a predetermined condition. May be.

A charging device according to a second aspect of the present invention detects voltage between both electrodes of a battery, and outputs a signal representing a value of the detected voltage, and a self-controlling device. While the signal is being supplied, a charging current source for supplying a charging current for charging the battery to the battery, and a voltage output by the voltage detection means during a period when the charging current is being supplied to the battery. Periodically acquire the value represented by the signal,
By determining whether or not the acquired latest value is equal to or less than the most recently acquired value, it is determined whether or not the increase in the magnitude of the voltage across the battery has substantially stopped,
And charging control means for supplying the control signal to the charging current source when it is determined that the control signal has not stopped, and stopping the supply of the control signal when determining that the control signal has stopped.

According to such a charging device, charging can be stopped by detecting that the battery has reached a fully charged state, based on the voltage between the two electrodes of the battery, so that the capacity of the secondary battery is known in advance. Charging can be performed properly without the need.

Further, the battery discriminating apparatus according to a third aspect of the present invention comprises: an AC applying means for applying an AC voltage between both electrodes of the battery for a certain period; and a voltage detecting means for detecting a voltage between both electrodes of the battery. A peak detection unit that outputs a signal representing a maximum value of the magnitude of the voltage detected by the voltage detection unit within the fixed period, and the signal output by the peak detection unit is obtained, based on the signal. Means for determining whether or not the battery is a secondary battery and outputting a signal indicating the result of the determination.

According to such a battery discriminating apparatus, it is determined whether or not the battery is a secondary battery based on the voltage between both electrodes of the battery, regardless of the AC bridge. The device is realized. In addition, since the voltage between both electrodes of the battery can be easily converted into a digital signal, such a battery determination device can automatically determine whether or not the battery can be charged and automatically charge the battery with a simple configuration. , A charging device that is performed continuously.

Further, the charging method according to a fourth aspect of the present invention includes: an AC application step of applying an AC voltage between both electrodes of the battery for a certain period; a voltage detection step of detecting a voltage between both electrodes of the battery; A battery discriminating step of discriminating whether or not the battery is a secondary battery based on the voltage detected by the voltage detecting step within the fixed period, and outputting a control signal indicating a discrimination result; and the battery discriminating step. When the control signal is output, and the control signal indicates that the battery is determined to be a secondary battery, a charging current source that supplies a charging current for charging the battery to the battery. The battery determining step includes determining whether or not the increase in the magnitude of the voltage detected by the voltage detecting step has substantially stopped during a period in which the charging current is being supplied to the battery. When it is determined that a mere manner, comprises a full charge determination step of stopping the output of the control signal, characterized in that.

According to such a charging method, whether or not the battery is a secondary battery is determined based on the voltage between both electrodes of the battery, regardless of the AC bridge, so that the configuration is simplified. In addition, since charging can be stopped by detecting that the battery has reached a fully charged state based on the voltage between both electrodes of the battery, charging can be performed properly without knowing the capacity of the secondary battery in advance. Since the voltage between the two electrodes of the battery can be easily converted into a digital signal, the determination of whether or not the battery can be charged and the charging of the battery are automatically and continuously performed with a simple configuration.

A charging method according to a fifth aspect of the present invention includes: a voltage detecting step of detecting a voltage between both electrodes of a battery and outputting a signal representing a value of the detected voltage; While the signal is being supplied, a charging current source for supplying the battery with a charging current for charging the battery, and the voltage detection step outputs during the period when the charging current is being supplied to the battery. By periodically acquiring the value represented by the signal and determining whether or not the acquired latest value is equal to or less than the most recently acquired value, the increase in the magnitude of the voltage across the battery is reduced. Determine whether or not substantially stopped, when determined not stopped, supplying the control signal to the charging current source, when determined that stopped,
A charge control step of stopping supply of the control signal.

According to such a charging method, charging can be stopped by detecting that the battery has reached a fully charged state, based on the voltage between the two electrodes of the battery, so that the capacity of the secondary battery is known in advance. Charging can be performed properly without the need.

Also, the battery discriminating method according to a sixth aspect of the present invention includes an AC applying step of applying an AC voltage between both electrodes of the battery for a certain period, and a voltage detecting step of detecting a voltage between both electrodes of the battery. A peak detection step of outputting a signal representing a maximum value of the magnitude of the voltage detected by the voltage detection step within the fixed period, and acquiring the signal output by the peak detection step, based on the signal, Determining whether the battery is a secondary battery and outputting a signal indicating the determination result.

According to such a battery determination method, it is determined whether or not a battery is a secondary battery based on the voltage between both electrodes of the battery, regardless of the AC bridge. A method is implemented. In addition, since the voltage between both electrodes of the battery can be easily converted into a digital signal, such a battery determination method automatically determines whether or not the battery can be charged and automatically charges the battery with a simple configuration. , A charging method performed continuously is realized.

Further, a computer-readable recording medium according to a seventh aspect of the present invention includes an AC applying means for applying an AC voltage between both poles of a battery for a certain period, and detecting a voltage between both poles of the battery, A voltage detection unit that outputs a signal representing a value of the detected voltage, and a charging current source that supplies a charging current for charging the battery to the battery while the control signal is supplied to the voltage detection unit. The computer connected to the, signal acquisition means for acquiring the signal output by the voltage detection means, the signal acquired by the signal acquisition means represents, the voltage detected by the voltage detection means within the certain period, Based on the value of the size, determine whether the battery is a secondary battery, when it is determined that the secondary battery,
A battery determination unit that supplies the control signal to the charging current source, and a voltage of the voltage detected by the voltage detection unit during a period in which the charging current is supplied to the battery, represented by the signal acquired by the signal acquisition unit. The magnitude is determined whether or not the increase has been substantially stopped, and when it is determined that the increase has been stopped, a full charge determination means for stopping the supply of the control signal, and a program for causing the program to function as control means including: It is recorded.

According to the computer for executing the program recorded on such a recording medium, the AC applying means, the voltage detecting means, and the charging current source, the voltage between the two poles of the battery is independent of the AC bridge. , It is determined whether or not the battery is a secondary battery, so that the configuration is simplified. In addition, since charging can be stopped by detecting that the battery has reached a fully charged state based on the voltage between both electrodes of the battery, charging can be performed properly without knowing the capacity of the secondary battery in advance.
Since the voltage between the two electrodes of the battery can be easily converted into a digital signal, the determination of whether or not the battery can be charged and the charging of the battery are automatically and continuously performed with a simple configuration.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
A charger will be described as an example with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a charger according to an embodiment of the present invention. As shown
This charger includes a control unit 1, a charging power supply 2, a pulse width modulation unit 3, an AC generation unit 4, a peak detection unit 5, a potential difference detection unit 6, and a resistor R.

The control unit 1 has a CPU (Central Processing).
Unit 11 and A / D (Analog-to-Digital) converters 12 and 13, and includes a power supply control terminal, an AC control terminal, a peak voltage input terminal, and a battery voltage input terminal. A power control terminal of the control unit 1 is connected to a control input terminal of the charging power supply 2 described later. The AC control terminal is connected to a later-described control input terminal of the AC generator 4. The peak voltage input terminal is connected to an output terminal of the peak detection unit 5 described later. The battery voltage input terminal is connected to an output terminal of the potential difference detection unit 6, which will be described later.

The CPU 11 supplies an AC generation control signal for instructing the generation of an AC signal to the AC generation unit 4 via the AC control terminal of the control unit 1. The A / D converter 12 A / D converts a signal supplied to the peak voltage input terminal of the control unit 1 and supplies the signal to the CPU 11. CPU 11 is an A / D
Based on the signal supplied from converter 12, it is determined whether or not to charge battery B to be charged in charging power supply 2. Then, a control signal representing the determination result is supplied from its own power control terminal to a control input terminal of the charging power supply 2 described later. The control signal may be, for example, a digital signal that has a high level when charging is to be performed and has a low level when charging is to be stopped.

The A / D converter 13 A / D converts a signal supplied to the battery voltage input terminal of the control unit 1 and
11 The CPU 11 includes an A / D converter 13
It is determined whether or not to end charging of the battery B based on the signal supplied from the charging power source.
Is switched so as to indicate that the execution of the charging current is stopped.

The charging power supply 2 is composed of a switching power supply or the like, and has a control input terminal, an output terminal, and a control output terminal. A control input terminal of the charging power supply 2 is connected to a power supply control terminal of the control unit 1. The output terminal is composed of a positive electrode and a negative electrode. The positive electrode of the output terminal is connected to the input terminal of the pulse width modulation unit 3, and the negative electrode is connected to the negative electrode of the battery B. The control output terminal is connected to the control terminal of the pulse width modulator 3.

The charging power supply 2 determines whether or not the control signal supplied to its own control input terminal instructs execution of charging of the battery B. Then, when it is determined that the command instructs execution of charging, a voltage for supplying a current (charging current) for charging the battery B is generated between both electrodes of its own output terminal. When it is determined that the stop of the execution of the charging is instructed, the generation of the voltage for supplying the charging current is stopped.

The charging power supply 2 generates a voltage for supplying a charging current to the battery B so that the average amount of the current flowing through its output terminal for a predetermined time becomes a predetermined value. Next, the pulse width of a pulse described later generated by the pulse width modulation unit 3 is determined. Then, a pulse width control signal representing the determined pulse width is supplied from its own control output terminal to a later-described control terminal of the pulse width modulator 3.

The pulse width modulator 3 has an input terminal, an output terminal, and a control terminal. The input terminal of the pulse width modulator 3 is connected to the output terminal of the charging power supply 2, the output terminal is connected to the positive electrode of the battery B, and the control terminal is connected to the control output terminal of the charging power supply 2. The pulse width modulation unit 3 has a constant period, a pulse width indicated by a pulse width control signal supplied to its own control terminal, and a peak voltage substantially proportional to a voltage supplied to its own input terminal. A square wave is generated at its output.

The AC generator 4 has a control input terminal and an output terminal. The control input terminal of the AC generator 4 is connected to the AC control terminal of the controller 1, and the output terminal is connected to the negative electrode of the battery B. The AC generator 4 generates an AC voltage having a predetermined waveform at its output terminal while the AC control signal is being supplied to its own control input terminal. The AC voltage generated by the AC generator 4 may be, for example, a triangular wave obtained by integrating the AC control signal when the AC control signal is a rectangular wave. In this case, the AC generator 4 includes an integrating circuit. What is necessary is just to consist of.

The peak detector 5 has a detection terminal and an output terminal. The detection terminal of the peak detection unit 5 is connected to one pole of the battery B, the reference voltage input terminal is connected to the output terminal of the potential difference detection unit 6, and the output terminal is connected to the battery determination input terminal of the control unit 1. I have. The peak detection unit 5 determines at any time
A signal representing the maximum value of the amplitude of the signal supplied to its own detection terminal during a recent certain period is supplied from its own output terminal.

The peak detector 5 has, for example, a configuration shown in FIG. 2, for example. As shown, the peak detection unit 5 includes an operational amplifier OPA1 having an inverting input terminal, a non-inverting input terminal, and an output terminal, a diode D having an anode and a cathode, resistors R1, R2 and RT, a capacitor CT, , A buffer BUF having an input terminal and an output terminal.

One end of the resistor R1 forms the detection end of the peak detection section 5, and the other end is connected to the inverting input end of the operational amplifier OPA1. The resistor R2 is connected between the inverting input terminal and the output terminal of the operational amplifier OPA1. The voltage at the non-inverting input terminal of the operational amplifier OPA1 is maintained at a predetermined voltage _Vref by a voltage source (not shown). Diode D
Is connected to the output terminal of the operational amplifier OPA1, and the cathode is connected to the input terminal of the buffer BUF.

One end of the resistor RT is connected to the cathode of the diode D, and the voltage at the other end is maintained at the voltage _Vref by a voltage source (not shown). One end of the capacitor CT is connected to the cathode of the diode D, and the voltage at the other end is kept at the voltage _Vref by a voltage source (not shown).

The operational amplifier OPA1 and the resistors R1 and R
2 constitutes an inverting amplifier. Specifically, the one end to the voltage V _in of the resistor R1 which forms the detection end of the peak detector 5 is applied to the output terminal of the operational amplifier OPA 1, the voltage V _{ou t} represented by Formula 1 generated I do.

[0042]

V _out = (− r ₂ / r ₁ ) · V _in + ｛1+
(R ₂ / r ₁ )｝ · V _ref (where r ₁ is the resistance value of the resistor R ₁ and r ₂ is the resistor R
2)

The voltage at the output terminal of the operational amplifier OPA1 is applied to the anode of the diode D. When the diode D itself is forward-biased, the operational amplifier OPA1
Of the capacitor CT and the capacitor CT.

Therefore, when the voltage at the output terminal of the operational amplifier OPA1 is higher than the voltage at the connection point between the capacitor CT and the diode D, the operational amplifier OPA1
When T is charged, the voltage at the connection point between the capacitor CT and the diode D becomes substantially equal to the voltage at the output terminal of the operational amplifier OPA1.

On the other hand, when the voltage at the output terminal of the operational amplifier OPA1 is lower than the voltage at the connection point between the capacitor CT and the diode D, the diode D is not forward-biased and the output terminal of the operational amplifier OPA1 and the capacitor CT Is substantially shut off. In this case, the charge stored in the capacitor CT is discharged to the resistor RT, and the voltage across the capacitor CT decreases. The speed at which the voltage between both ends of the capacitor CT decreases increases as the product of the capacitance of the capacitor CT and the resistance value of the resistor RT (time constant between the capacitor CT and the resistor RT) decreases.

Therefore, the voltage at the connection point between the capacitor CT and the diode D represents the maximum value of the voltage at the output terminal of the operational amplifier OPA1 within a predetermined time determined by the time constant between the capacitor CT and the resistor RT. Become like The voltage at the connection point between the capacitor CT and the diode D is supplied to the input terminal of the buffer BUF. At the output terminal of the buffer BUF serving as the output terminal of the peak detection unit 5, a voltage substantially equal to the voltage of its own input terminal is generated.

By the above-described operation, the output terminal of the peak detecting unit 5 of FIG. 2 is substantially at a predetermined time determined by the time constant of the capacitor CT and the resistor RT. 5, a voltage representing the lowest value of the voltage applied to the detection terminals is generated. The detection end of the peak detection unit 5 is battery B
Assuming that the potential of the positive electrode of the battery B connected to the positive electrode of the output terminal of the charging power source 2 is kept constant, the voltage applied to the detection terminal of the peak detection unit 5 The minimum value of the voltage indicates the maximum value of the voltage between both electrodes of the battery B.

The potential difference detecting section 6 has an inverting input terminal, a non-inverting input terminal, and an output terminal. The inverting input terminal of the potential difference detecting section 6 is connected to the negative electrode of the battery B, and the non-inverting input terminal is
Is connected to the positive electrode. The output terminal of the potential difference detector 6
It is connected to the battery voltage input terminal of the control unit 1.

The potential difference detector 6 supplies a signal representing a value substantially proportional to the potential difference between its inverting input terminal and the non-inverting input terminal from its output terminal. Therefore, for example, even if the voltage supplied to the battery B from each pole of the output terminal of the charging power supply 2 includes in-phase noise, the noise is represented by the signal supplied from the output terminal of the potential difference detection unit 6. Does not substantially contribute to the value. That is, in-phase noise included in the voltage of each pole at the output terminal of the charging power supply 2 is removed by the potential difference detection unit 6.

The potential difference detecting section 6 has, for example, the configuration shown in FIG. As shown in the figure, the potential difference detecting section 6 includes operational amplifiers OPA2 and OPA3 and a resistor R3.
To R10. Operational amplifiers OPA2 and O
PA3 is, for example, substantially the same as the operational amplifier OPA1 in FIG.

The resistance values of the resistors R3 and R4 are substantially equal, one end of the resistor R3 forms a non-inverting input terminal of the potential difference detecting section 6, and the other end is connected to one end of the resistor R4.
The other end of the resistor R4 is grounded. Resistors R3 and R
The connection point 4 is connected to the non-inverting input terminal of the operational amplifier OPA3.

The resistances of the resistors R5 and R6 are substantially equal. One end of the resistor R5 forms an inverting input terminal of the potential difference detecting section 6, and the other end is connected to one end of the resistor R6. The other end of the resistor R6 is grounded. Resistors R5 and R6
Is connected to the non-inverting input terminal of the operational amplifier OPA3.

The resistance values of the resistors R7 and R8 are substantially equal. One end of the resistor R7 is connected to the output terminal of the operational amplifier OPA2, and the other end is connected to one end of the resistor R8. The voltage at the other end of the resistor R8 is maintained at a predetermined voltage _Vref by a voltage source (not shown). The connection point between the resistors R7 and R8 is connected to the inverting input terminal of the operational amplifier OPA2.

The resistance values of the resistors R9 and R10 are substantially equal. One end of the resistor R9 is connected to the output terminal of the operational amplifier OPA3, and the other end is connected to one end of the resistor R10. The other end of the resistor R10 is connected to the output terminal of the operational amplifier OPA2. The connection point between the resistors R9 and R10 is connected to the inverting input terminal of the operational amplifier OPA3. The output terminal of the operational amplifier OPA3 forms the output terminal of the potential difference detector 6.

In the potential difference detecting section 6 of FIG. 3, the voltage applied to the non-inverting input terminal of the potential difference detecting section 6 is V +, and the voltage applied to the inverting input terminal of the potential difference detecting section 6 is V-. In this case, its own output terminal (that is, the operational amplifier OPA3
At the output end of the circuit, a voltage V _diff represented by Expression 2 is generated. This voltage V _diff has a value representing the difference between the voltages V ₊ and V ₋ .

[0056]

V _diff = (V ₊ ) − (V ₋ ) − (V _ref )

The resistor R is for securing a current path between the output terminal of the AC generator 4 and the ground. One end of the resistor R is connected to the positive electrode of the battery B, and the other end is grounded. However, when the potential difference detector 6 is as shown in FIG. 3, the resistors R3 and R4 of FIG. 3 perform the function of the resistor R of FIG. There is no.

(Operation) Next, the operation of this charger will be described. (Determination of Battery Type) When the charger starts the operation of determining the type of the battery in a state where the battery B is connected to the charger as described above, first, the control unit 1 performs a predetermined period ( An AC generation control signal is sent to the AC generation unit 4 for about 5 seconds, for example.

The AC generator 4 generates an AC signal while the AC generation control signal is being supplied, and supplies the AC signal to the negative electrode of the battery B. As a result, an AC current flowing through the battery B and the resistor R is generated between the output terminal of the AC generator 4 and the ground. Due to this AC current, a voltage is generated across the battery B that is substantially proportional to the product of the impedance of the battery B and the magnitude of the AC current.

On the other hand, the negative and positive voltages of the battery B are applied to the inverting input terminal and the non-inverting input terminal of the potential difference detecting section 6. The voltage of each pole of the battery B includes a voltage component that changes substantially in phase due to, for example, a voltage drop generated across the resistor R. However, since this voltage component that changes in phase is removed by the potential difference detection unit 6, a voltage substantially proportional to the voltage between the two electrodes of the battery B is generated at the output terminal of the potential difference detection unit 6.

The voltage at the output terminal of the potential difference detecting unit 6 is supplied to the detecting terminal of the peak detecting unit 5 and the battery voltage input terminal of the control unit 1. As a result, the signal supplied from the output terminal of the peak detection unit 5 to the battery identification input terminal of the control unit 1 is the voltage of the voltage between both ends of the battery B after the AC generation unit 4 starts generating the AC signal. It represents the maximum value.

When the above-mentioned predetermined period has elapsed, the control unit 1
Stops supplying the AC generation control signal. As a result, the AC generator 4 stops generating the AC signal. When the AC generation unit 4 stops generating the AC signal, the signal supplied from the output terminal of the peak detection unit 5 corresponds to both ends of the battery B during the above-described period during which the AC generation unit 4 supplies the AC signal. Represents the maximum value of the voltage between them.

The control unit 1 is based on a signal supplied from the output terminal of the peak detection unit 5 to its own battery identification input terminal.
It is determined whether the battery B is a secondary battery. Specifically, the control unit 1 determines whether or not the maximum value of the voltage between both ends of the battery B exceeds 0.8 volts, for example, based on a signal supplied to the input terminal for battery determination. . When it is determined that the battery B is exceeded, it is determined that the battery B is a secondary battery, and when it is determined that the battery B is not exceeded, it is determined that the battery B is not a secondary battery or is not mounted.

When the controller 1 determines that the battery B is not a secondary battery or is not mounted, the charger ends the operation. In this case, the battery B is not charged.

(Charging) On the other hand, if it is determined that the battery B is a secondary battery, this charger monitors the voltage between both ends of the battery B while supplying a charging current to the battery B as described below. It is repeatedly determined whether or not a phenomenon (a so-called “−ΔV phenomenon”) in which the voltage between both ends of the fully charged secondary battery starts to decrease has occurred in the battery B, and this phenomenon has occurred. Until the determination, the charging current is continuously supplied to the battery B.

That is, when it is determined that the battery B is a secondary battery, the control unit 1 sends a control signal for instructing the charging power supply 2 to execute charging. In response to the control signal, the charging power supply 2 generates a voltage for causing a charging current to flow between both poles of its own output terminal. As a result, a charging current starts flowing from the positive terminal at the output terminal of the charging power source 2 to the negative terminal at the output terminal of the charging power source 2 through the input terminal and the output terminal of the pulse width modulation unit 3 and the battery B in this order. Thus, charging of the battery B starts.

When the charging of the battery B is started, the charging power supply 2 starts monitoring the magnitude of the charging current flowing to its own output terminal. Then, the pulse of the pulse supplied from the output terminal of the pulse width modulation unit 3 is set so that the time average of the charging current is substantially equal to a predetermined value (for example, the value of the charging current determined as the rating of the battery B). The width is determined, and a pulse width control signal representing the determined pulse width is supplied to the control terminal of the pulse width modulator 3. Thus, a substantially constant amount of charging current is supplied to the battery B.

On the other hand, the voltages of the negative electrode and the positive electrode of the battery B are continuously applied to the inverting input terminal and the non-inverting input terminal of the potential difference detecting section 6. Therefore, a signal representing a value substantially proportional to the voltage between both electrodes of the battery B is continuously supplied from the output terminal of the potential difference detection unit 6 to the battery voltage input terminal of the control unit 1.

The A / D converter 13 of the control section 1 continuously A / D converts a signal supplied to its own battery voltage input terminal and supplies it to the CPU 11. The CPU 11 periodically samples and stores the value represented by the signal supplied from the A / D converter 13 after charging of the battery B is started.

Then, the CPU 11 determines whether or not the voltage between both ends of the battery B has started to decrease based on the value sampled and stored most recently by the CPU 11 and the most recent value sampled and stored. I do.

When it is determined that the voltage drop between both ends of the battery B has not started, the control section 1 continuously supplies the charging power supply 2 with a control signal instructing execution of charging. On the other hand, when determining that the voltage drop between both ends of the battery B has started, the control unit 1 determines that the battery B has reached a fully charged state, and instructs the charging power supply 2 to stop the execution of charging. Supply signal.

Upon receiving a control signal from the control unit 1 instructing the stop of the execution of charging, the charging power supply 2 stops generating a voltage for supplying a charging current in response to the control signal. As a result, the charging current does not substantially flow through the battery B. That is, the charging of the battery B ends.

The configuration of this charger is not limited to the above. For example, the output terminal of the AC generator 4 is a battery B
May be connected to the positive electrode. Further, the control unit 1 may be composed of a plurality of integrated circuits, may be composed of individual semiconductors, or may be composed of a microcomputer.

The adjustment of the charging current does not need to be performed by the pulse width modulation method using the pulse width modulation unit 3.
For example, the charging current may be adjusted by adjusting the magnitude of the voltage generated by the charging power supply 2 to flow the charging current.

While determining whether or not the battery B is a secondary battery, the control unit 1 uses a charging power supply 2 and a power supply (not shown) for driving the pulse width modulation unit 3 to charge the battery B. The power supply, the charging power supply 2, and the pulse width modulation section 3 may be controlled so that the supply of power to the power supply 2 and the pulse width modulation section 3 is substantially stopped.

Although the embodiment of the present invention has been described above, the charging device of the present invention does not rely on a dedicated system.
This can be realized using a normal computer system.
For example, the charging power supply 2, the pulse width modulation unit 3, the AC generation unit 4, the peak detection unit 5, the potential difference detection unit 6, and the A / D
By installing the program from a medium (floppy (registered trademark) disk, CD-ROM, or the like) storing a program for executing the above-described operation in a personal computer having a converter, the charging for executing the above-described processing is performed. The device can be configured.

The medium for supplying the program to the computer may be a communication medium (medium for temporarily and fluidly storing the program, such as a communication line, a communication network, or a communication system). For example, the program may be posted on a bulletin board (BBS) of a communication network and distributed via the network. Distribution via a network may be performed by transmitting a modulated wave obtained by modulating a carrier wave by the program. Then, by starting this program and executing it in the same manner as other application programs under the control of the OS, the above-described processing can be executed.

When the OS shares part of the processing,
Alternatively, when the OS constitutes a part of one component of the present invention, the recording medium may store a program excluding the part. Also in this case, in the present invention, it is assumed that the recording medium stores a program for executing each function or step executed by the computer.

[0079]

As described above, according to the present invention, it is possible to realize a charging apparatus and a charging method that automatically and continuously determine whether or not to charge a battery and charge the battery with a simple configuration. You. Further, according to the present invention, a charging device and a charging method for appropriately charging without knowing the capacity of the secondary battery in advance are realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a charger according to an embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating a configuration of a peak detection unit.

FIG. 3 is a circuit diagram illustrating a configuration of a potential difference detection unit.

[Explanation of symbols]

 Reference Signs List 1 control unit 11 CPU 12, 13 A / D converter 2 charging power supply 3 pulse width modulation unit 4 AC generation unit 5 peak detection unit 6 potential difference detection unit BUF buffer CT capacitor D diode OPA1 to OPA3 Operational amplifiers R, RT, R1 R10 resistor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G016 CA00 CB31 CB33 CC01 CC04 CC16 CC20 CC23 CC27 CD01 CD09 CD10 CD14 5G003 AA01 BA01 CA01 CA11 CC02 GB03 GC05 5H030 AA03 AS20 BB04 BB51 FF43 FF51

Claims (10)

[Claims] 1. An AC applying means for applying an AC voltage between both electrodes of a battery for a certain period of time, a voltage detecting means for detecting a voltage between both electrodes of the battery, and a voltage detected by the voltage detecting means within the certain period of time. A battery discriminating means for discriminating whether or not the battery is a secondary battery, and outputting a control signal representing a discrimination result; and obtaining the control signal output by the battery discriminating means, Includes a charging current source that supplies a charging current for charging the battery to the battery when it indicates that the battery is a secondary battery. It is determined whether or not the increase in the magnitude of the voltage detected by the voltage detection means during the period when the battery is being supplied is substantially stopped, and when it is determined that the increase has been substantially stopped, the output of the control signal is determined. Full charge judgment hand to stop A charging device comprising a step. 2. The battery detecting means according to claim 1, wherein said battery detecting means outputs a signal representing a maximum value of the magnitude of the voltage detected by said voltage detecting means within said predetermined period, and said signal output by said peak detecting means. And a means for determining whether the battery is a secondary battery based on the signal, and outputting a control signal indicating a result of the determination. Charging device. 3. The voltage detecting means includes means for outputting a signal representing a value of a voltage between both electrodes of the battery detected by the battery detecting means. During the period in which the voltage is supplied to the battery, the value represented by the signal output by the voltage detection means is periodically acquired, and when the acquired latest value is equal to or less than the most recently acquired value, the bipolar electrode of the battery is obtained. The charging device according to claim 1, further comprising: a unit configured to determine that the increase in the voltage between the two has substantially stopped. 4. The charging current source according to claim 1, wherein the charging current source periodically supplies the charging current pulse, and the charging current pulse is supplied so that an average amount of the charging current meets a predetermined condition. The charging device according to claim 1, further comprising a unit for adjusting a time width of the charging device. 5. A voltage detecting means for detecting a voltage between both electrodes of a battery and outputting a signal representing a value of the detected voltage, and charging the battery while a control signal is supplied to the battery. A charging current source for supplying a charging current to the battery, and a period in which the charging current is being supplied to the battery, periodically acquiring and acquiring a value represented by the signal output by the voltage detection unit. By determining whether or not the latest value is equal to or less than the most recently obtained value, it is determined whether or not the increase in the magnitude of the voltage between both ends of the battery has substantially stopped. A charging control unit that supplies the control signal to the charging current source when it is determined that the charging current is not present, and stops the supply of the control signal when it is determined that the charging current source is stopped. 6. An AC applying means for applying an AC voltage between both electrodes of the battery for a certain period, a voltage detecting means for detecting a voltage between both electrodes of the battery, and a voltage detected by the voltage detecting means within the certain period. Peak detection means for outputting a signal representing the maximum value of the magnitude, and acquiring the signal output by the peak detection means, based on the signal, to determine whether the battery is a secondary battery And a means for outputting a signal representing a determination result. 7. An AC application step of applying an AC voltage between both electrodes of the battery for a certain period; a voltage detection step of detecting a voltage between both electrodes of the battery; and a voltage detected by the voltage detection step within the certain period. A battery determination step of determining whether or not the battery is a secondary battery, and outputting a control signal representing the determination result; and obtaining the control signal output by the battery determination step, Comprises a charging current source for supplying a charging current for charging the battery to the battery when indicating that the battery is determined to be a secondary battery, wherein the battery determining step includes: It is determined whether or not the increase in the magnitude of the voltage detected by the voltage detection step during the period in which the battery is supplied is substantially stopped,
A charging method, comprising: a full charge determination step of stopping output of the control signal when it is determined that the charging has been substantially stopped. 8. A voltage detecting step of detecting a voltage between both electrodes of the battery and outputting a signal representing a value of the detected voltage, and charging the battery while a control signal is supplied to the battery. And a charging current source that supplies a charging current to the battery for a period during which the charging current is being supplied to the battery, periodically acquires and acquires a value represented by the signal output by the voltage detection step. By determining whether or not the latest value is equal to or less than the most recently obtained value, it is determined whether or not the increase in the magnitude of the voltage between both ends of the battery has substantially stopped. A charging control step of supplying the control signal to the charging current source when it is determined that there is no charge, and stopping the supply of the control signal when it is determined that the charging current source has stopped. 9. An AC application step of applying an AC voltage between both electrodes of the battery for a certain period of time, a voltage detection step of detecting a voltage between both electrodes of the battery, and a voltage detected by the voltage detection step within the certain period of time. A peak detection step of outputting a signal representing the maximum value of the magnitude of, and acquiring the signal output by the peak detection step,
Determining whether the battery is a secondary battery based on the signal, and outputting a signal indicating the determination result. 10. An AC applying means for applying an AC voltage between both poles of a battery for a certain period of time, and a voltage detecting means for detecting a voltage between both poles of the battery and outputting a signal representing a value of the detected voltage. And a charging current source for supplying a charging current for charging the battery to the battery while the control signal is being supplied to the computer. A signal acquisition unit to acquire, and whether the battery is a secondary battery based on a value of the magnitude of the voltage detected by the voltage detection unit within the certain period, represented by the signal acquired by the signal acquisition unit. Determining whether the battery is a secondary battery, when determining that the battery is a secondary battery, a battery determining unit that supplies the control signal to the charging current source; and the charging current represented by the signal acquired by the signal acquiring unit is the battery. Is supplied to Full charge determination means for stopping the supply of the control signal, when the magnitude of the voltage detected by the voltage detection means during the period is substantially determined to have stopped increasing, and when it is determined that the increase has been stopped, A computer-readable recording medium on which a program for causing a computer to function as a control unit is recorded.