JP2006121797A - Charger - Google Patents

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JP2006121797A
JP2006121797A JP2004305506A JP2004305506A JP2006121797A JP 2006121797 A JP2006121797 A JP 2006121797A JP 2004305506 A JP2004305506 A JP 2004305506A JP 2004305506 A JP2004305506 A JP 2004305506A JP 2006121797 A JP2006121797 A JP 2006121797A
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charging
voltage
current
circuit
charge
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Koichi Mikami
孝一 三上
Takuya Ishii
卓也 石井
Hiroshi Saito
浩 齊藤
Akira Watabe
亮 渡部
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Panasonic Holdings Corp
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Matsushita Electric Industrial Co Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

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Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit which detects an accurate charge finish current by a boosting charge method for a charger to a lithium ion secondary cell. <P>SOLUTION: This charger is provided with a circuit, where the impedance varies according to the charge current flowing to a secondary cell, as an accurate current detecting circuit. When the charger operates in constant current charge, it varies impedance into low one thereby operating it in high effeiciency. When it operates, with the voltage generated across a detection resistor constant in a voltage detecting circuit, and a charge current drops gradually, the impedance of the accurate current detecting circuit is increased, whereby the voltage drop of a charge current detecting circuit is enlarged more than the voltage drop with only the charge current detecting resistor. The relative error by the voltage of error such as the dispersion of parts to the voltage drop of the charge current detecting circuit is smaller than the relative error by the voltage of error such as the dispersion, etc. of parts to the voltage drop with only the charge current detecting resistor, so this can detect an accurate charge finish current resistant to the dispersion, etc. of parts. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、リチウムイオン電池等の２次電池の充電に好適な充電方法に関するものである。   The present invention relates to a charging method suitable for charging a secondary battery such as a lithium ion battery.

近年、リチウムイオン電池等の２次電池を急速充電する場合に、スイッチング電源を用いた降圧コンバータが、アダプタなどからの入力電源電圧を所望の電圧に変換する手段として多用されている。図６に示す充電器は、従来の充電器（例えば特許文献１）を示すものである。従来の充電器は充電終了の検出が容易で検出精度が高いことが特徴である。   In recent years, when a secondary battery such as a lithium ion battery is rapidly charged, a step-down converter using a switching power supply is frequently used as a means for converting an input power supply voltage from an adapter or the like into a desired voltage. The charger shown in FIG. 6 is a conventional charger (for example, Patent Document 1). Conventional chargers are characterized by easy detection of charging completion and high detection accuracy.

以下に図６を用いて従来の充電器の動作を説明する。   The operation of the conventional charger will be described below with reference to FIG.

図６において、１はAC電源でありそのAC入力は入力フィルタ2を介して整流・平滑回路3に供給される。3で整流、平滑された後、トランス4の１次側に供給され、パワーMOSFET5によってスイッチングされる。パワーMOSFET5はそのゲートにPWM(Pulse Wi-dth Modulation)制御回路6から印加されて駆動し、スイッチング動作を行う。これにより、トランス4の2次側出力が制御される。トランス4は、1次側をパワーMOSFET5によってスイッチングされることにより、2次側の所定の出力電圧を発生し、その2次側出力は整流・平滑回路7に供給され、直流に整流、平滑された後、スイッチ部8を介して2次電池9に供給される。2次電池9の負極側には充電電流検出抵抗10が介挿されており、この点の電位は出力電流信号として出力制御回路11に入力される。また、スイッチ部8の出力側（すなわち、図中のA）の電圧(以下、A電圧)は出力電圧信号として出力制御回路11および電池電圧検出回路12に入力される。電池電圧検出回路12は2次電池9の正極側の電位を検出して充電終了の判断を行い、充電制御回路13を制御する。充電制御回路13による充電状態の制御は表示部14に表示される。出力制御回路11は主にエラーアンプなどによって構成され、整流、平滑された2次側出力電圧および出力電流を基準値と比較し、そのエラー出力はフォトカプラ回路15を経由してPWM制御回路6に出力される。これにより、整流、平滑された2次側出力情報がトランス4の1次側にフィードバックされてPWM制御され、充電器が定電流充電で動作するシステムと充電電流検出抵抗10の両端で発生する電圧が一定で動作するシステムが得られる。
特許第３４３０２６４号公報 In FIG. 6, reference numeral 1 denotes an AC power source, and the AC input is supplied to the rectifying / smoothing circuit 3 through the input filter 2. After being rectified and smoothed by 3, it is supplied to the primary side of the transformer 4 and switched by the power MOSFET 5. The power MOSFET 5 is driven by being applied to its gate from a PWM (Pulse Wi-dth Modulation) control circuit 6 to perform a switching operation. Thereby, the secondary side output of the transformer 4 is controlled. The transformer 4 generates a predetermined output voltage on the secondary side by switching the primary side by the power MOSFET 5, and the secondary side output is supplied to the rectification / smoothing circuit 7, and is rectified and smoothed to direct current. After that, it is supplied to the secondary battery 9 via the switch unit 8. A charging current detection resistor 10 is inserted on the negative electrode side of the secondary battery 9, and the potential at this point is input to the output control circuit 11 as an output current signal. Further, the voltage (hereinafter referred to as A voltage) on the output side (that is, A in the figure) of the switch unit 8 is input to the output control circuit 11 and the battery voltage detection circuit 12 as an output voltage signal. The battery voltage detection circuit 12 detects the potential on the positive electrode side of the secondary battery 9, determines the end of charging, and controls the charging control circuit 13. The control of the state of charge by the charge control circuit 13 is displayed on the display unit 14. The output control circuit 11 is mainly composed of an error amplifier or the like, compares the rectified and smoothed secondary output voltage and output current with a reference value, and outputs the error output via the photocoupler circuit 15 to the PWM control circuit 6 Is output. As a result, the rectified and smoothed secondary output information is fed back to the primary side of the transformer 4 and PWM controlled, and the voltage generated across the charging current detection resistor 10 and the system in which the charger operates with constant current charging. A system that operates with a constant is obtained.
Japanese Patent No. 3430264

しかしながら、充電器は充電状態を検出する際、2次電池9の負極側に介挿された充電電流検出抵抗10は、充電器が定電流充電で動作しているときの効率を良くするために低抵抗の抵抗を用いて充電電流を検出する場合が多かった。この場合、充電電流検出抵抗10の両端で発生する電圧が一定で動作するとき、充電電流検出抵抗10に流れる電流が小さくなり、検出される電圧は部品のバラツキ等の影響を受け、高精度に電流を検出することが困難となる。   However, when the charger detects the state of charge, the charging current detection resistor 10 inserted on the negative electrode side of the secondary battery 9 is for improving the efficiency when the charger is operating at constant current charging. In many cases, the charging current is detected using a low-resistance resistor. In this case, when the voltage generated at both ends of the charging current detection resistor 10 operates at a constant voltage, the current flowing through the charging current detection resistor 10 becomes small, and the detected voltage is affected by component variations and the like, and the accuracy is high. It becomes difficult to detect the current.

本発明は、上記問題点を解決するためになされたものであり、簡単な検出回路で充電終了電流を精度よく検出し、好適な２次電池の充電器の提供を目的とする。   The present invention has been made to solve the above problems, and an object of the present invention is to provide a suitable secondary battery charger by accurately detecting the charge end current with a simple detection circuit.

AC電源からのAC入力は入力フィルタを介して整流・平滑回路に供給される。整流、平滑された後、トランスの１次側に供給され、パワーMOSFETによってスイッチングされる。パワーMOSFETはそのゲートにPWM(Pulse Wi-dth Modulation)制御回路から印加されて駆動し、スイッチング動作を行う。これにより、トランス4の2次側出力が制御される。トランスは、1次側をパワーMOSFETによってスイッチングされることにより、2次側の所定の出力電圧を発生し、その2次側出力は整流・平滑回路に供給され、直流に整流、平滑された後、スイッチ部を介して2次電池に供給される。2次電池の負極側には高精度充電電流検出回路が介挿されており、この点の電位は出力電流信号として出力制御回路に入力される。また、スイッチ部の出力側の電圧は出力電圧信号として出力制御回路および電池電圧検出回路に入力される。電池電圧検出回路は2次電池の正極側の電位を検出して充電終了の判断を行い、充電制御回路を制御する。充電制御回路による充電状態の制御は表示部に表示される。出力制御回路は主にエラーアンプなどによって構成され、整流、平滑された2次側出力電圧および出力電流を基準値と比較し、そのエラー出力はフォトカプラ回路を経由してPWM制御回路に出力される。これにより、整流、平滑された2次側出力情報がトランス4の1次側にフィードバックされてPWM制御され、2次電池を充電する際、充電器が定電流充電で動作するシステムと定電圧充電で動作するシステムが得られる。高精度充電電流検出回路として2次電池に流れる充電電流に応じてインピーダンスが可変する回路を設け、充電器が定電流充電で動作する時は低インピーダンスに可変し、高精度充電電流検出回路の両端で発生する電圧が一定で動作し、かつ充電電流が徐々に低下する時は、高精度充電電流検出回路のインピーダンスを増加させることで、充電電流検出回路の電圧降下を充電電流検出抵抗のみの電圧降下に対して大きくする。   The AC input from the AC power supply is supplied to the rectification / smoothing circuit via the input filter. After being rectified and smoothed, it is supplied to the primary side of the transformer and switched by the power MOSFET. The power MOSFET is driven by being applied to its gate from a PWM (Pulse Wi-dth Modulation) control circuit to perform a switching operation. Thereby, the secondary side output of the transformer 4 is controlled. The transformer generates a predetermined output voltage on the secondary side by switching the primary side with the power MOSFET, and the secondary side output is supplied to the rectification / smoothing circuit, rectified and smoothed to DC The secondary battery is supplied via the switch unit. A high-accuracy charging current detection circuit is inserted on the negative electrode side of the secondary battery, and the potential at this point is input to the output control circuit as an output current signal. The voltage on the output side of the switch unit is input to the output control circuit and the battery voltage detection circuit as an output voltage signal. The battery voltage detection circuit detects the potential on the positive electrode side of the secondary battery, determines the end of charging, and controls the charge control circuit. The control of the state of charge by the charge control circuit is displayed on the display unit. The output control circuit mainly consists of an error amplifier, etc., compares the rectified and smoothed secondary output voltage and output current with the reference value, and the error output is output to the PWM control circuit via the photocoupler circuit. The As a result, the rectified and smoothed secondary side output information is fed back to the primary side of the transformer 4 and PWM controlled, and when charging the secondary battery, the charger operates with constant current charging and constant voltage charging. A system that works with As a high-accuracy charging current detection circuit, a circuit whose impedance varies according to the charging current flowing in the secondary battery is provided, and when the charger operates with constant current charging, it is variable to low impedance, and both ends of the high-accuracy charging current detection circuit When the operating voltage is constant and the charging current gradually decreases, increasing the impedance of the high-accuracy charging current detection circuit reduces the voltage drop of the charging current detection circuit to the voltage of only the charging current detection resistor. Increase against descent.

この構成によれば、充電器が定電流充電で動作しているときは、充電電流検出回路のインピーダンスは小さいので、充電電流検出抵抗と同等の効率が得られる。電圧検出回路で検出抵抗の両端で発生する電圧が一定で動作するとき、充電電流検出回路のインピーダンスを増加させることにより充電電圧検出回路の電圧降下に対する部品のバラツキ等による誤差電圧による相対誤差は、充電電流検出抵抗のみにおける電圧降下に対する部品のバラツキ等による誤差電圧による相対誤差に比べて小さく、部品のバラツキ等に強い高精度の充電終了電流が検出できる。   According to this configuration, when the charger is operating with constant current charging, the impedance of the charging current detection circuit is small, so that the same efficiency as the charging current detection resistor can be obtained. When the voltage generated at both ends of the detection resistor in the voltage detection circuit operates at a constant voltage, the relative error due to the error voltage due to variations in the parts with respect to the voltage drop of the charge voltage detection circuit by increasing the impedance of the charge current detection circuit is A high-accuracy charging end current that is small compared to the relative error due to the error voltage due to the component variation or the like with respect to the voltage drop only at the charging current detection resistor and strong against the component variation or the like can be detected.

以下、本発明を実施するための形態について、図面を参照しながら説明する。   Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

（実施の形態１）
図１において、１はAC電源でありそのAC入力は入力フィルタ2を介して整流・平滑回路3に供給される。3で整流、平滑された後、トランス4の１次側に供給され、パワーMOSFET5によってスイッチングされる。パワーMOSFET5はそのゲートにPWM(Pulse Wi-dth Modulation)制御回路6から印加されて駆動し、スイッチング動作を行う。これにより、トランス4の2次側出力が制御される。トランス4は、1次側をパワーMOSFET5によってスイッチングされることにより、2次側の所定の出力電圧を発生し、その2次側出力は整流・平滑回路7に供給され、直流に整流、平滑された後、スイッチ部8を介して2次電池9に供給される。2次電池9の負極側には高精度充電電流検出回路16が介挿されており、この点の電位は出力電流信号として出力制御回路11に入力される。また、スイッチ部8の出力側の電圧は出力電圧信号として出力制御回路11および電池電圧検出回路12に入力される。電池電圧検出回路12は2次電池9の正極側の電位を検出して充電終了の判断を行い、充電制御回路13を制御する。充電制御回路13による充電状態の制御は表示部14に表示される。出力制御回路11は主にエラーアンプなどによって構成され、整流、平滑された2次側出力電圧および出力電流を基準値と比較し、そのエラー出力をフォトカプラ回路15を経由してPWM制御回路6に出力される。これにより、整流、平滑された2次側出力情報がトランス4の1次側にフィードバックされてPWM制御され、2次電池を充電する際、充電器が定電流充電で動作するシステムと高精度充電電流検出回路16の両端で発生する電圧が一定で動作するシステムが得られる。 (Embodiment 1)
In FIG. 1, reference numeral 1 denotes an AC power source, and the AC input is supplied to a rectifying / smoothing circuit 3 via an input filter 2. After being rectified and smoothed by 3, it is supplied to the primary side of the transformer 4 and switched by the power MOSFET 5. The power MOSFET 5 is driven by being applied to its gate from a PWM (Pulse Wi-dth Modulation) control circuit 6 to perform a switching operation. Thereby, the secondary side output of the transformer 4 is controlled. The transformer 4 generates a predetermined output voltage on the secondary side by switching the primary side by the power MOSFET 5, and the secondary side output is supplied to the rectification / smoothing circuit 7, and is rectified and smoothed to direct current. After that, it is supplied to the secondary battery 9 via the switch unit 8. A high-accuracy charging current detection circuit 16 is inserted on the negative electrode side of the secondary battery 9, and the potential at this point is input to the output control circuit 11 as an output current signal. The voltage on the output side of the switch unit 8 is input to the output control circuit 11 and the battery voltage detection circuit 12 as an output voltage signal. The battery voltage detection circuit 12 detects the potential on the positive electrode side of the secondary battery 9, determines the end of charging, and controls the charging control circuit 13. The control of the state of charge by the charge control circuit 13 is displayed on the display unit 14. The output control circuit 11 is mainly composed of an error amplifier or the like, compares the rectified and smoothed secondary output voltage and output current with a reference value, and outputs the error output via the photocoupler circuit 15 to the PWM control circuit 6 Is output. As a result, rectified and smoothed secondary side output information is fed back to the primary side of the transformer 4 and PWM controlled, and when charging the secondary battery, the charger operates with constant current charging and high precision charging A system that operates with a constant voltage generated across the current detection circuit 16 can be obtained.

2次側出力電圧および出力電流を基準値と比較する際、充電器が定電流充電で動作しているとき、高精度電流検出回路16は低インピーダンスに制御され、高効率に電流を検出する。電圧検出回路で検出抵抗の両端で発生する電圧が一定で動作するとき、2次電池の充電電流の減少に伴い、高精度電流検出回路16のインピーダンスは増加する。高精度電流検出回路16に流れる充電電流による電圧降下は、充電電流検出抵抗10に流れる充電電流による電圧降下に比べて大きくなり、2次電池の充電電流が小さい場合において、出力制御電圧11に入力される信号は大きい出力電流信号が入力される。   When comparing the secondary output voltage and output current with the reference values, when the charger is operating at constant current charging, the high-accuracy current detection circuit 16 is controlled to low impedance and detects current with high efficiency. When the voltage generated at both ends of the detection resistor operates at a constant voltage detection circuit, the impedance of the high-precision current detection circuit 16 increases as the charging current of the secondary battery decreases. The voltage drop due to the charging current flowing through the high-accuracy current detection circuit 16 is larger than the voltage drop due to the charging current flowing through the charging current detection resistor 10, and is input to the output control voltage 11 when the charging current of the secondary battery is small. The output signal is a large output current signal.

図２は、本実施の形態の特徴部分である、高精度電流検出回路である。2次側出力電圧および出力電流を基準値と比較する際、充電器が定電流充電で動作しているとき、抵抗値の小さい充電電流検出抵抗10により、高効率に電流を検出される。充電器が定電圧充電で動作しているとき、電圧検出回路17は充電器が定電圧充電で動作していると判断し、その情報が抵抗選択回路18に入力される。抵抗選択回路18により、スイッチ部19をオフに制御し、充電電流検出抵抗10を通って、充電電流検出抵抗10と直列に接続された充電電流検出抵抗10の抵抗値の10倍程度の抵抗値を有する充電電流検出抵抗20にも充電電流が流れる。充電電圧電流検出抵抗10のみの電圧降下に比べて、充電電圧電流検出抵抗10と充電電圧電流検出抵抗20の電圧降下は大きいので、2次電池の充電電流が小さい場合、充電器が定電圧充電で動作しているときにおいても、出力制御電圧11に入力される信号は充電電流検出抵抗10のみの出力電流信号に比べて大きい出力電流信号が出力制御電圧11に入力される。   FIG. 2 shows a high-accuracy current detection circuit that is a characteristic part of the present embodiment. When the secondary output voltage and output current are compared with reference values, when the charger is operating at constant current charging, the current is detected with high efficiency by the charging current detection resistor 10 having a small resistance value. When the charger is operating at constant voltage charging, the voltage detection circuit 17 determines that the charger is operating at constant voltage charging, and the information is input to the resistance selection circuit 18. The resistance selection circuit 18 controls the switch unit 19 to be turned off, and the resistance value of the charging current detection resistor 10 connected in series with the charging current detection resistor 10 through the charging current detection resistor 10 is about 10 times the resistance value. The charging current also flows through the charging current detection resistor 20 having Compared to the voltage drop of only the charging voltage / current detection resistor 10, the voltage drop of the charging voltage / current detection resistor 10 and the charging voltage / current detection resistor 20 is large, so if the charging current of the secondary battery is small, the charger is charged at a constant voltage. Even during the operation, an output current signal that is larger than the output current signal of only the charging current detection resistor 10 is input to the output control voltage 11.

充電電流検出抵抗10のみを用いた検出特性と図２の高精度電流検出回路を用いた検出特性を比較すると、充電器が定電圧充電で動作しているときの充電電流をI、充電電流検出抵抗10の抵抗値をR、バラツキ等による誤差電圧をΔV、充電電流検出抵抗20の抵抗値を9Rとする。充電電流検出抵抗10のみを用いて充電電流を検出した場合の相対誤差は
ΔV/(I・R)
となる。高精度電流検出回路を用いて充電電流を検出した場合、充電電流が流れる抵抗の抵抗値はR+9R=10Rとなる。その場合の相対誤差は
ΔV/(I・10R)
となる。これは、充電電流検出抵抗10のみを用いて充電電流を検出した場合に比べて相対誤差が1/10になり、したがって充電電流の検出精度が10倍となる。図２の充電電流検出回路を用いることで、例えば図４のような充電器が定電圧充電で動作している領域で、充電電流が徐々に低下した場合においても高精度の充電電流が検出可能となる。また、図１のような充電装置に図２の充電電流検出回路を用いることで、高精度の充電終了電流を検出可能となる。 Comparing the detection characteristics using only the charging current detection resistor 10 and the detection characteristics using the high-accuracy current detection circuit in FIG. 2, the charging current when the charger is operating at constant voltage charging is I, and the charging current detection The resistance value of the resistor 10 is R, the error voltage due to variation is ΔV, and the resistance value of the charging current detection resistor 20 is 9R. The relative error when detecting the charging current using only the charging current detection resistor 10 is ΔV / (I ・ R)
It becomes. When the charging current is detected using the high-accuracy current detection circuit, the resistance value of the resistor through which the charging current flows is R + 9R = 10R. In that case, the relative error is ΔV / (I ・ 10R)
It becomes. In this case, the relative error becomes 1/10 as compared with the case where the charging current is detected using only the charging current detection resistor 10, and therefore the detection accuracy of the charging current is 10 times. By using the charging current detection circuit of FIG. 2, for example, in a region where the charger as shown in FIG. 4 is operating at constant voltage charging, even when the charging current gradually decreases, a highly accurate charging current can be detected. It becomes. Further, by using the charging current detection circuit shown in FIG. 2 in the charging apparatus as shown in FIG. 1, it is possible to detect the charging end current with high accuracy.

また、図２は図３のように抵抗を並列に接続することでも同様の効果が得られる。この場合、2次側出力電圧および出力電流を基準値と比較する際、充電器が定電流充電で動作しているとき、抵抗値の小さい充電電流検出抵抗10により、高効率に電流を検出される。充電器が定電圧充電で動作しているとき、電圧検出回路17は充電器が定電圧充電で動作していると判断し、その情報が抵抗選択回路18に入力される。抵抗選択回路18により、スイッチ部19をオフに制御し、充電電流検出抵抗10を通って、充電電流検出抵抗10と並列に接続された充電電流検出抵抗10の抵抗値の10倍程度の抵抗値を有する充電電流検出抵抗20にも充電電流が流れる。充電電圧電流検出抵抗10のみの電圧降下に比べて、充電電圧電流検出抵抗10と充電電圧電流検出抵抗20の電圧降下は大きいので、2次電池の充電電流が小さい場合、充電器が定電圧充電で動作しているときにおいても、出力制御電圧11に入力される信号は充電電流検出抵抗10のみの出力電流信号に比べて大きい出力電流信号が出力制御電圧11に入力される。   In FIG. 2, the same effect can be obtained by connecting resistors in parallel as shown in FIG. In this case, when comparing the secondary output voltage and output current with the reference values, when the charger is operating at constant current charging, the current is detected with high efficiency by the charging current detection resistor 10 having a small resistance value. The When the charger is operating at constant voltage charging, the voltage detection circuit 17 determines that the charger is operating at constant voltage charging, and the information is input to the resistance selection circuit 18. The resistance selection circuit 18 controls the switch unit 19 to be turned off, and the resistance value of the charging current detection resistor 10 connected in parallel with the charging current detection resistor 10 through the charging current detection resistor 10 is about 10 times the resistance value. The charging current also flows through the charging current detection resistor 20 having Compared to the voltage drop of only the charging voltage / current detection resistor 10, the voltage drop of the charging voltage / current detection resistor 10 and the charging voltage / current detection resistor 20 is large, so if the charging current of the secondary battery is small, the charger is charged at a constant voltage. Even during the operation, an output current signal that is larger than the output current signal of only the charging current detection resistor 10 is input to the output control voltage 11.

（実施の形態２）
図５のようなAC電源1と2次電池9が非絶縁された充電装置においても、高精度充電電流検出回路16を用いることで、高精度の充電終了電流が検出可能となる。 (Embodiment 2)
Even in a charging device in which the AC power source 1 and the secondary battery 9 are not insulated as shown in FIG. 5, the high-accuracy charging end current can be detected by using the high-accuracy charging current detection circuit 16.

本発明は、リチウムイオン電池等の２次電池の充電に有用である。   The present invention is useful for charging a secondary battery such as a lithium ion battery.

本発明の実施の形態１における電流検出回路を用いた充電回路ブロック構成図Charging circuit block configuration diagram using the current detection circuit according to the first embodiment of the present invention 本発明の実施の形態１における電流検出回路の構成例1を示す図The figure which shows the structural example 1 of the current detection circuit in Embodiment 1 of this invention. 本発明の実施の形態１における電流検出回路の構成例2を示す図The figure which shows the structural example 2 of the current detection circuit in Embodiment 1 of this invention. 本発明の実施の形態１における充電状態の過渡特性図Transient characteristic diagram of charge state in Embodiment 1 of the present invention 本発明の実施の形態２における電流検出回路を用いた充電回路ブロック構成図Charging circuit block configuration diagram using the current detection circuit in Embodiment 2 of the present invention 従来の電流検出回路を用いた充電回路ブロック構成図Charge circuit block configuration diagram using a conventional current detection circuit

符号の説明Explanation of symbols

１ AC電源
２ 入力フィルタ
３ 整流・平滑回路
４ トランス
５ パワーMOSFET
６ PWM制御回路
７ 整流・平滑回路
８ スイッチ部
９ 2次電池
１０ 充電電流検出抵抗
１１ 出力制御回路
１２ 電圧検出回路
１３ 充電制御回路
１４ 表示部
１５ フォトカプラ回路
１６ 高精度充電電流検出回路
１７ 電圧検出回路
１８ 抵抗選択回路
１９ スイッチ部
２０ 充電電流検出抵抗 1 AC power supply 2 Input filter 3 Rectifier / smoothing circuit 4 Transformer 5 Power MOSFET
6 PWM control circuit 7 Rectification / smoothing circuit 8 Switch unit 9 Secondary battery 10 Charging current detection resistor 11 Output control circuit 12 Voltage detection circuit 13 Charge control circuit 14 Display unit 15 Photocoupler circuit 16 High-accuracy charging current detection circuit 17 Voltage detection Circuit 18 Resistance selection circuit 19 Switch unit 20 Charging current detection resistor

Claims (1)

2次電池を装着し、出力制御手段によって所定電圧以下の充電を定電流で行い、前記所定電圧を超える充電を定電圧で行うように制御し、
スイッチング手段により2次電池への充電電流を所定周期で遮断するとともに、
充電制御手段により前記スイッチング手段の作動を制御して充電の制御を行う充電制御手段を有する充電装置において、
2次側電池の電流を検出する検出回路を設け、
前記充電制御手段は、
前記電流検出手段の出力として検出された、電流よりも小さくなるように設定した基準値と比較する手段を有し、
前記比較手段の比較結果によって、感度を変える機能を持つ検出回路を持つことを特徴とする充電装置。 A secondary battery is mounted, and the output control means performs charging at a predetermined voltage or lower with a constant current, and controls charging to exceed the predetermined voltage with a constant voltage,
While cutting off the charging current to the secondary battery at a predetermined cycle by the switching means,
In the charging apparatus having the charging control means for controlling the charging by controlling the operation of the switching means by the charging control means,
Provide a detection circuit to detect the current of the secondary battery,
The charge control means includes
Means for comparing with a reference value set to be smaller than the current detected as the output of the current detection means;
A charging device comprising a detection circuit having a function of changing sensitivity according to a comparison result of the comparison means.
JP2004305506A 2004-10-20 2004-10-20 Charger Pending JP2006121797A (en)

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Cited By (9)

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JP2007020299A (en) * 2005-07-07 2007-01-25 Matsushita Electric Ind Co Ltd Charger
JP2008283743A (en) * 2007-05-08 2008-11-20 Fuji Electric Device Technology Co Ltd Secondary battery protective device and semiconductor integrated circuit device
US8035347B2 (en) 2007-07-25 2011-10-11 Sony Corporation Battery charger
JP2013051819A (en) * 2011-08-31 2013-03-14 Panasonic Corp Charger
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JP2007020299A (en) * 2005-07-07 2007-01-25 Matsushita Electric Ind Co Ltd Charger
JP4526453B2 (en) * 2005-07-07 2010-08-18 パナソニック株式会社 Charger
JP2008283743A (en) * 2007-05-08 2008-11-20 Fuji Electric Device Technology Co Ltd Secondary battery protective device and semiconductor integrated circuit device
US8035347B2 (en) 2007-07-25 2011-10-11 Sony Corporation Battery charger
TWI392194B (en) * 2007-07-25 2013-04-01 Sony Corp Battery charger
TWI392193B (en) * 2007-07-25 2013-04-01 Sony Corp Battery charger and charging method
JP2013051819A (en) * 2011-08-31 2013-03-14 Panasonic Corp Charger
KR20180111759A (en) * 2016-02-05 2018-10-11 광동 오포 모바일 텔레커뮤니케이션즈 코포레이션 리미티드 Charging system for terminal, charging method and power adapter
CN107912076A (en) * 2016-02-05 2018-04-13 广东欧珀移动通信有限公司 For the charging system of terminal, charging method and power supply adaptor
KR20180098608A (en) * 2016-02-05 2018-09-04 광동 오포 모바일 텔레커뮤니케이션즈 코포레이션 리미티드 Charging system for terminal, charging method and power adapter
JP2018525961A (en) * 2016-02-05 2018-09-06 広東欧珀移動通信有限公司 Terminal charging system, charging method and power adapter
US10320225B2 (en) 2016-02-05 2019-06-11 Guangdong Oppo Mobile Telecommunications Corp., Ltd. Charging system and charging method for increasing service life of battery of terminal and power adapter thereof
US10491030B2 (en) 2016-02-05 2019-11-26 Guangdong Oppo Mobile Telecommunications Corp., Ltd. Charging system and charging method for terminal and terminal
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CN106487073A (en) * 2016-12-13 2017-03-08 合肥中感微电子有限公司 A kind of power supply circuits and electronic equipment
CN106487073B (en) * 2016-12-13 2021-01-12 合肥中感微电子有限公司 Power supply circuit and electronic equipment
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