JPH0865907A - Current detecting circuit and overcharge preventive device - Google Patents
Current detecting circuit and overcharge preventive deviceInfo
- Publication number
- JPH0865907A JPH0865907A JP6196543A JP19654394A JPH0865907A JP H0865907 A JPH0865907 A JP H0865907A JP 6196543 A JP6196543 A JP 6196543A JP 19654394 A JP19654394 A JP 19654394A JP H0865907 A JPH0865907 A JP H0865907A
- Authority
- JP
- Japan
- Prior art keywords
- current
- battery
- switch circuit
- circuit
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- 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
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は電流方向を検出する電流
検出回路と、この電流検出回路を適用した充電防止装置
に関し、特に電池の放電効率の向上に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current detection circuit for detecting a current direction and a charge prevention device to which the current detection circuit is applied, and more particularly to improvement of discharge efficiency of a battery.
【０００２】[0002]
【従来の技術】従来より電池充電時の過充電防止装置
は、図６に示すように内部にボディダイオードＤを有す
るスイッチ素子（例えばＭＯＳ−ＦＥＴ）Ｑ8 をこのボ
ディダイオードＤの順方向が上記電池１の放電方向（矢
印Ａ）となるように電池１と直列に接続し、電圧監視Ｉ
C Ｍ1 により電池電圧を常時監視しながら充電を行い、
充電電圧が規定値を越えた場合、この電圧監視ＩC Ｍ1
の出力ＯＶでスイッチ素子Ｑ8 をオフして充電電流を遮
断し、過充電による電池１の劣化や破壊等を防止すると
いうものであった。2. Description of the Related Art Conventionally, as shown in FIG. 6, an overcharge preventing device for charging a battery has a switch element (for example, a MOS-FET) Q8 having a body diode D therein, and the forward direction of the body diode D is the above battery. The battery 1 is connected in series so that the discharge direction is 1 (arrow A), and the voltage monitoring I
Charging while constantly monitoring the battery voltage with C M1,
If the charging voltage exceeds the specified value, this voltage monitoring IC M1
The switch element Q8 is turned off by the output OV to shut off the charging current to prevent the deterioration and destruction of the battery 1 due to overcharging.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、このよ
うな過充電防止装置付き電池の場合、通常放電は上記ス
イッチ素子Ｑ8 を介して行われるが、過充電防止機能が
作動中はスイッチ素子Ｑ8 がオフ状態であるため放電は
スイッチ素子Ｑ8 のボディダイオードＤを介して行われ
るが、この放電電流でボディダイオードＤによる電圧降
下が生じて回路損失が大きくなり、効率の良い放電がで
きなくなるという欠点がある。However, in the case of such a battery with an overcharge prevention device, the normal discharge is performed through the switch element Q8, but the switch element Q8 is turned off while the overcharge prevention function is operating. Since this is the state, the discharge is performed through the body diode D of the switch element Q8, but this discharge current causes a voltage drop due to the body diode D, which causes a large circuit loss, which makes it impossible to perform efficient discharge. .
【０００４】本発明の目的は、上記欠点を解消するため
に上記過充電防止装置に電流検出回路を搭載し、過充電
防止機能が作動している電池でも効率良く放電できる安
定した過充電防止装置を提供することである。An object of the present invention is to mount a current detection circuit on the overcharge prevention device in order to eliminate the above-mentioned drawbacks, and to stably discharge even a battery having an overcharge prevention function operating, which is a stable overcharge prevention device. Is to provide.
【０００５】[0005]
【課題を解決するための手段】即ち、本発明では、スイ
ッチ回路（３）を設けた方向自在の電流経路に接続され
た電流検出回路（４）であって、上記スイッチ回路
（３）と直列に接続した電流検出用の素子（Ｒi ）と、
該電流検出用の素子（Ｒi ）の電流方向を検出するトラ
ンジスタ（Ｑ6 ）及び（Ｑ7 ）と、上記スイッチ回路
（３）を駆動する駆動回路とで構成され、上記トランジ
スタ（Ｑ6 ）及び（Ｑ7 ）が所定方向の電流を検出する
と、その出力（Ｓ）に基づいて上記スイッチ回路（３）
をオンするように構成した。That is, according to the present invention, there is provided a current detection circuit (4) connected to a directional current path provided with a switch circuit (3), which is in series with the switch circuit (3). An element (Ri) for current detection connected to
The transistors (Q6) and (Q7) for detecting the current direction of the current detecting element (Ri) and the drive circuit for driving the switch circuit (3), and the transistors (Q6) and (Q7). Detects a current in a predetermined direction, the switch circuit (3) is based on its output (S).
Configured to turn on.
【０００６】又、本発明では、充電可能な電池（１）
と、上記電池（１）の電圧を検出する電圧検出器（２）
と、上記電池（１）に直列に設けられたスイッチ回路
（３）を備え、充電時に上記電池（１）の電圧が規定値
を越えた時、上記電圧検出器（２）の出力（ＯＶ）に基
づいて上記スイッチ回路（３）がオフし、充電電流を遮
断するようにした過充電防止装置（７）において、上記
スイッチ回路（３）に電流検出用の素子（Ｒi ）或いは
（Ｑ8 ）を有する電流検出回路（４）を接続し、上記電
池（１）の放電時に、上記電流検出回路（４）の出力
（Ｓ）に基づいて上記スイッチ回路（３）がオンするよ
うに構成した。Further, in the present invention, a rechargeable battery (1)
And a voltage detector (2) for detecting the voltage of the battery (1)
And a switch circuit (3) provided in series with the battery (1), and when the voltage of the battery (1) exceeds a specified value during charging, the output (OV) of the voltage detector (2). In the overcharge prevention device (7) in which the switch circuit (3) is turned off based on the above, and the charging current is cut off, an element (Ri) or (Q8) for current detection is added to the switch circuit (3). The current detection circuit (4) which it has was connected, and when the battery (1) was discharged, the switch circuit (3) was turned on based on the output (S) of the current detection circuit (4).
【０００７】[0007]
【作 用】上記構成により、本発明では、電流検出用の
素子に所定の方向に電流が流れるとその電流が電流検出
回路によって検出され、電流検出回路の出力に基づいて
スイッチ回路がオンする。[Advantages] With the above configuration, in the present invention, when a current flows through the current detection element in the predetermined direction, the current is detected by the current detection circuit, and the switch circuit is turned on based on the output of the current detection circuit.
【０００８】又、本発明では、充電時に電池の電圧が所
定の電圧を越えると電圧検出器によって過充電が検出さ
れ、上記電圧検出器の出力に基づいてスイッチ回路がオ
フし、充電電流が遮断される。放電が開始されると放電
電流が電流検出回路によって検出され、電流検出回路の
出力に基づいて上記スイッチ回路が再びオンして電圧降
下の無い効率的な放電が行われる。Further, according to the present invention, when the voltage of the battery exceeds a predetermined voltage during charging, overcharge is detected by the voltage detector, the switch circuit is turned off based on the output of the voltage detector, and the charging current is cut off. To be done. When the discharge is started, the discharge current is detected by the current detection circuit, and the switch circuit is turned on again based on the output of the current detection circuit to perform the efficient discharge without a voltage drop.
【０００９】[0009]
【実施例】図１は本発明に係る電流検出回路４を組み込
んだ過充電防止装置７の基本構成を示すブロック図であ
る。1 is a block diagram showing the basic construction of an overcharge prevention device 7 incorporating a current detection circuit 4 according to the present invention.
【００１０】図中、１は充電可能な電池（２次電池）
で、その正極端子側は＋端子５に接続され、負極端子側
は電流検出用の素子Ｒi を有する電流検出回路４、ボデ
ィダイオードＤを有するスイッチ素子内蔵のスイッチ回
路３を介して−端子６に接続されている。上記電流検出
回路４は放電時の放電電流を検出するためのもので、そ
の出力Ｓがスイッチ回路３に接続されている。更に、上
記電池１の端子間には電池電圧を監視するための電圧検
出器２が接続されており、その出力ＯＶがスイッチ回路
３に接続されている。In the figure, 1 is a rechargeable battery (secondary battery)
The positive terminal side is connected to the + terminal 5, and the negative terminal side is connected to the-terminal 6 via the current detection circuit 4 having the current detection element Ri and the switch circuit 3 having the body diode D with a built-in switching element. It is connected. The current detection circuit 4 is for detecting the discharge current at the time of discharge, and its output S is connected to the switch circuit 3. Further, a voltage detector 2 for monitoring the battery voltage is connected between the terminals of the battery 1, and its output OV is connected to the switch circuit 3.
【００１１】上述の構成において電池１を充電する時に
は、＋端子５及び−端子６に充電器（図示せず）を接続
する。この時、スイッチ回路３はオン状態とされ、充電
は充電器〜＋端子５〜電池１〜電流検出回路４〜スイッ
チ回路３のスイッチ素子〜−端子６の電流経路となり、
電圧検出器２により電池電圧が監視されながら電池１の
充電が行われる。充電が進み電池電圧が所定の電圧を越
えた場合電圧検出器２が作動し、その出力ＯＶに基づい
てスイッチ回路３がオフ状態となって充電電流が遮断さ
れ、過充電が防止される。When charging the battery 1 in the above-mentioned structure, a charger (not shown) is connected to the + terminal 5 and the-terminal 6. At this time, the switch circuit 3 is turned on, and charging is performed from the charger to the + terminal 5 to the battery 1 to the current detection circuit 4 to the switch element of the switch circuit 3 to the current path of the terminal 6.
The battery 1 is charged while the battery voltage is monitored by the voltage detector 2. When the charging progresses and the battery voltage exceeds a predetermined voltage, the voltage detector 2 operates, the switch circuit 3 is turned off based on the output OV, the charging current is interrupted, and overcharging is prevented.
【００１２】次に、＋端子５及び−端子６に負荷（図示
せず）を接続して電池１を放電する時、スイッチ回路３
はオン状態とされ、放電は電池１〜＋端子５〜負荷〜−
端子６〜スイッチ回路３のスイッチ素子〜電流検出回路
４の電流経路で行われるが、上述の過充電防止機能が作
動中に放電が開始されるとスイッチ回路３はオフ状態で
あるため放電電流はスイッチ回路３のボディダイオード
Ｄを介して流れ、このボディダイオードＤによる電圧降
下のため放電効率が低下してしまう。かかる不都合を解
消するために搭載したものが本発明の特徴とするところ
の電流検出回路４である。Next, when a load (not shown) is connected to the + terminal 5 and the-terminal 6 to discharge the battery 1, the switch circuit 3
Is turned on, and discharge is from battery 1 + terminal 5 load ~-
It is performed in the current path from the terminal 6 to the switch element of the switch circuit 3 to the current detection circuit 4. However, if discharge is started during the operation of the above-mentioned overcharge prevention function, the switch circuit 3 is in the OFF state, and therefore the discharge current is The current flows through the body diode D of the switch circuit 3, and the voltage drop by the body diode D lowers the discharge efficiency. The current detection circuit 4, which is a feature of the present invention, is mounted to eliminate such inconvenience.
【００１３】即ち、電流検出回路４の電流検出用の素子
Ｒi に放電方向（矢印Ａ）に電流が流れると電流検出回
路４が作動し、その出力Ｓによって今までオフ状態であ
ったスイッチ回路３が強制的にオン状態とされるため、
放電電流はスイッチ回路３のスイッチ素子を介して流
れ、ボディダイオードＤによる電圧降下が防止されるの
である。That is, when a current flows in the discharge direction (arrow A) in the current detecting element Ri of the current detecting circuit 4, the current detecting circuit 4 operates, and the output S thereof causes the switch circuit 3 which has been in the off state until now. Is forcibly turned on,
The discharge current flows through the switch element of the switch circuit 3, and the voltage drop due to the body diode D is prevented.
【００１４】図２は、図１に過放電防止機構を付加した
過充電防止装置７の基本構成を示すブロック図である。
回路構成は図１の電圧検出器２の他に過放電電圧監視用
に電圧検出器２a を設けると共にスイッチ回路３と直列
に放電電流遮断用のスイッチ回路３a を接続したもので
ある。このスイッチ回路３a はスイッチ回路３と同様に
ボディダイオードＤa を有するスイッチ素子を内蔵し、
上記電圧検出器２a の出力ＵＶが接続されている。FIG. 2 is a block diagram showing the basic construction of an overcharge prevention device 7 in which an overdischarge prevention mechanism is added to FIG.
In addition to the voltage detector 2 of FIG. 1, the circuit configuration is such that a voltage detector 2a is provided for monitoring the overdischarge voltage, and a switch circuit 3a for interrupting the discharge current is connected in series with the switch circuit 3. This switch circuit 3a has a built-in switch element having a body diode Da, like the switch circuit 3.
The output UV of the voltage detector 2a is connected.
【００１５】上述の構成において、電池１を充電する時
には＋端子５及び−端子６に充電器を接続する。この
時、スイッチ回路３及びスイッチ回路３a はオン状態と
され、充電は充電器〜＋端子５〜電池１電流検出回路４
〜スイッチ回路３a のスイッチ素子〜スイッチ回路３の
スイッチ素子〜−端子６の電流経路となり、電圧検出器
２によって電池電圧が監視されながら充電が行われる。
充電が進み電池電圧が所定の電圧を越えると電圧検出器
２が作動し、その出力ＯＶに基づいてスイッチ回路３が
オフ状態となって充電電流が遮断される。In the above structure, when charging the battery 1, a charger is connected to the + terminal 5 and the-terminal 6. At this time, the switch circuit 3 and the switch circuit 3a are turned on, and charging is performed from the charger to the + terminal 5 to the battery 1 current detection circuit 4
~ Switch element of switch circuit 3a ~ Switch element of switch circuit 3 ~ -Current path of terminal 6 becomes, and charging is performed while the battery voltage is monitored by the voltage detector 2.
When charging progresses and the battery voltage exceeds a predetermined voltage, the voltage detector 2 operates, and the switch circuit 3 is turned off based on the output OV to cut off the charging current.
【００１６】上述の過充電防止機能が作動中に放電が開
始されるとスイッチ回路３はオフ状態であるため放電は
電池１〜＋端子５〜負荷〜−端子６〜スイッチ回路３の
ボディダイオードＤ〜スイッチ回路３a 〜電流検出回路
４の電流経路で行われ、電流検出回路４の電流検出用の
素子Ｒi に放電方向（矢印Ａ）に電流が流れる。この電
流検出用の素子Ｒi による電圧降下で電流検出回路４が
作動し、その出力Ｓがオフ状態であったスイッチ回路３
をオン状態に変え、効率的な電池１の放電が行われる。When discharging is started during the operation of the above-mentioned overcharge preventing function, the switch circuit 3 is in an off state, so that the discharging is performed by the battery 1 to the + terminal 5 to the load to the −terminal 6 to the body diode D of the switch circuit 3. ~ Switch circuit 3a ~ This is performed in the current path of the current detection circuit 4, and a current flows in the current detection element Ri of the current detection circuit 4 in the discharge direction (arrow A). The current detection circuit 4 operates due to the voltage drop due to the current detection element Ri, and the switch circuit 3 whose output S is in the off state
Is turned on, and the battery 1 is efficiently discharged.
【００１７】放電が進み、電池電圧が所定の電圧以下に
なると電圧検出器２a が作動し、その出力ＵＶに基づい
てスイッチ回路３a がオフ状態となって放電電流が遮断
され、過放電が防止される。尚、過放電防止機能作動中
の充電（再充電）は、充電器〜＋端子５〜電池１〜電流
検出回路４〜スイッチ回路３a のボディダイオードＤa
〜スイッチ回路３のスイッチ素子〜−端子６の電流経路
となる。When the discharge progresses and the battery voltage becomes lower than a predetermined voltage, the voltage detector 2a operates, the switch circuit 3a is turned off based on the output UV, the discharge current is interrupted, and the overdischarge is prevented. It The charging (recharging) during the operation of the over-discharge prevention function is performed by the charger, the + terminal 5, the battery 1, the current detection circuit 4, the body diode Da of the switch circuit 3a.
-Switch element of switch circuit 3--It becomes a current path of terminal 6.
【００１８】図３は、図１の基本構成に対応した具体的
な電子回路の一実施例である。FIG. 3 shows an embodiment of a specific electronic circuit corresponding to the basic configuration of FIG.
【００１９】図３において、電池１の正極端子側が＋端
子５に接続され、負極端子側は抵抗Ｒi 、ＭＯＳ−ＦＥ
ＴＴＱ4 を介して−端子６に接続されている。このＭＯ
Ｓ−ＦＥＴＴＱ4 は内部にボディダイオードＤを有する
もので、このボディダイオードＤが放電に対して順方向
になるようにＭＯＳ−ＦＥＴＴＱ4 が接続され、そのゲ
ート、ソース間にＭＯＳ−ＦＥＴＴＱ4 ドライブ用のト
ランジスタＱ3 と抵抗Ｒ5 を接続してスイッチ回路３が
構成されている。In FIG. 3, the positive electrode terminal side of the battery 1 is connected to the + terminal 5, and the negative electrode terminal side is a resistor Ri and a MOS-FE.
It is connected to the-terminal 6 via TTQ4. This MO
The S-FET TQ4 has a body diode D therein. The MOS-FET TQ4 is connected so that the body diode D is in the forward direction with respect to discharge, and a MOS-FET TQ4 driving transistor Q3 is provided between its gate and source. And a resistor R5 are connected to form a switch circuit 3.
【００２０】又、上記ＭＯＳ−ＦＥＴＴＱ4 のドレイン
と直列に接続された抵抗Ｒi は放電電流検出用の素子
で、この電流検出用の抵抗Ｒi と放電電流検出用のトラ
ンジスタＱ6 及びＱ7 と、上記スイッチ回路３を駆動す
るための駆動回路（トランジスタＱ5 、Ｑ1 、Ｑ2 及び
抵抗Ｒ1 〜Ｒ3 、抵抗Ｒ6 〜Ｒ9 ）とで電流検出回路４
が構成されている。一方、上記電池１の端子間には電池
電圧を検出するための電圧監視ＩC Ｍ1 （或いは、コン
パレータを使用しても良い）を用いた電圧検出器２が接
続され、その出力ＯＶが抵抗Ｒ10を介してトランジスタ
Ｑ3 のベースに接続されている。尚、この電圧監視ＩC
Ｍ1 は設計上決められた過充電電圧値（例えば３Ｖ）に
設定されたものが使用されている。A resistor Ri connected in series with the drain of the MOS-FET TQ4 is an element for detecting a discharge current. The resistor Ri for detecting the current, the transistors Q6 and Q7 for detecting the discharge current, and the switch circuit described above. Drive circuit (transistors Q5, Q1, Q2 and resistors R1 to R3, resistors R6 to R9) for driving the current detection circuit 4
Is configured. On the other hand, a voltage detector 2 using a voltage monitor IC M1 (or a comparator may be used) for detecting the battery voltage is connected between the terminals of the battery 1, and its output OV is connected to a resistor R10. It is connected to the base of the transistor Q3 via. This voltage monitoring IC
The M1 is set to an overcharge voltage value (for example, 3V) determined by design.
【００２１】本発明に係る過充電防止装置７の回路構成
は以上の通りで、以下にその動作を説明する。The circuit configuration of the overcharge prevention device 7 according to the present invention is as described above, and its operation will be described below.
【００２２】充電する場合は、上述したように＋端子５
及び−端子６に充電器を接続し、電池１に電流を流し込
む。充電によって電池電圧は上昇するが、充電電圧は電
圧監視ＩC Ｍ1 の設定値より低いため電圧検出器２は作
動せず、その出力はＯＶは“Ｌ”でトランジスタＱ3 は
オフとなり、ＭＯＳ−ＦＥＴＴＱ4 はゲートが“Ｈ”と
なってオン状態とされている。この時、電流検出用の抵
抗Ｒi には充電方向に電流が流れるためトランジスタＱ
6 はオン状態となり、後述する電流検出回路４は作動し
ない。When charging, as described above, the positive terminal 5
And-a battery charger is connected to the terminal 6 and a current is supplied to the battery 1. Although the battery voltage rises due to charging, the voltage detector 2 does not operate because the charging voltage is lower than the set value of the voltage monitoring IC M1, the output is OV "L", the transistor Q3 is off, and the MOS-FET TQ4 is The gate is "H" and is in the ON state. At this time, since a current flows through the resistor Ri for current detection in the charging direction, the transistor Q
6 is turned on, and the current detection circuit 4 described later does not operate.
【００２３】充電が進み、電池電圧が電圧監視ＩC Ｍ1
の設定電圧値以上になると出力ＯＶは“Ｈ”に変化し、
トランジスタＱ3 がオンしてＭＯＳ−ＦＥＴＴＱ4 はゲ
ートが“Ｌ”に固定されてオフ状態となり、充電電流は
遮断される。As the charging progresses, the battery voltage is monitored by the voltage IC M1
When the voltage exceeds the set voltage value of, the output OV changes to "H",
The transistor Q3 is turned on, the gate of the MOS-FET TQ4 is fixed to "L", and the MOS-FET TQ4 is turned off, so that the charging current is cut off.
【００２４】放電する場合（電池を使用する）は＋端子
５及び−端子６に使用目的に応じた負荷が接続される。
この時、ＭＯＳ−ＦＥＴＴＱ4 オフ状態が維持されてい
るため、負荷の接続によって発生する放電電流は−端子
６からＭＯＳ−ＦＥＴＴＱ4のボディダイオードＤを介
して電流検出用の抵抗Ｒi に流れる。この放電電流によ
って抵抗Ｒi に電圧降下が生じ、今までオン状態であっ
たトランジスタＱ6 をオフにする。その結果、トランジ
スタＱ5 がオフ、次段のトランジスタＱ1 がオンとな
り、そのコレクタ電流で抵抗Ｒ2 に電圧降下が生じトラ
ンジスタＱ2 をオンとするため、今まで電圧監視ＩC Ｍ
1 の“Ｈ”出力によってオン状態が維持されていたトラ
ンジスタＱ3 がオフし、ＭＯＳ−ＦＥＴＴＱ4 を再びオ
ン状態に復帰させる。このため、ボディダイオードＤを
介して流れていた放電電流はＭＯＳ−ＦＥＴＴＱ4 を介
して流れるようになり、電圧降下の無い効率的な通常の
放電が行われるのである。When discharging (using a battery), a load according to the purpose of use is connected to the + terminal 5 and the-terminal 6.
At this time, since the off state of the MOS-FET TQ4 is maintained, the discharge current generated by the connection of the load flows from the-terminal 6 to the resistor Ri for current detection through the body diode D of the MOS-FET TQ4. This discharge current causes a voltage drop in the resistor Ri, turning off the transistor Q6 which has been on until now. As a result, the transistor Q5 is turned off and the transistor Q1 in the next stage is turned on, and the collector current causes a voltage drop in the resistor R2 to turn on the transistor Q2.
The "H" output of 1 turns off the transistor Q3, which was kept on, and returns the MOS-FET TQ4 to the on state again. Therefore, the discharge current flowing through the body diode D comes to flow through the MOS-FET TQ4, and efficient normal discharge without voltage drop is performed.
【００２５】図４は図２の基本構成に対応した具体的な
電子回路の一実施例で、図３の回路でスイッチ回路３と
直列にスイッチ回路３a を接続したものである。このス
イッチ回路３は内部にボディダイオードＤa を有するＭ
ＯＳ−ＦＥＴＴＱ8 をこのボディダイオードＤa が充電
に対して順方向になるように接続し、そのゲートとソー
スの間にＭＯＳ−ＦＥＴＴＱ8 ドライブ用のトランジス
タＱ9 を接続して構成されている。更に、電池１の端子
間には、この電池電圧を検出するための電圧監視ＩC Ｍ
2 （或いは、コンパレータを使用しても良い）を用いた
電圧検出器２aが接続され、その出力ＵＶが抵抗Ｒ13を
介してスイッチ回路３a のトランジスタＱ9 のベースに
接続されている。尚、この電圧監視ＩC Ｍ2 は、設計上
決められた過放電電圧値（例えば１Ｖ）に設定されたも
のが使用されている。FIG. 4 shows an embodiment of a specific electronic circuit corresponding to the basic configuration of FIG. 2, in which the switch circuit 3a is connected in series with the switch circuit 3 in the circuit of FIG. The switch circuit 3 has an internal body diode Da.
The OS-FET TQ8 is connected so that the body diode Da is in the forward direction with respect to charging, and the MOS-FET TQ8 drive transistor Q9 is connected between the gate and the source. Further, between the terminals of the battery 1, a voltage monitor IC M for detecting this battery voltage is provided.
The voltage detector 2a using 2 (or a comparator may be used) is connected, and its output UV is connected to the base of the transistor Q9 of the switch circuit 3a via the resistor R13. The voltage monitoring IC M2 used is set to an overdischarge voltage value (for example, 1 V) determined by design.
【００２６】次に、この回路の動作を説明する。その動
作は付加した過放電防止機構以外は上述の回路動作と同
じであるのでその部分の説明は省略し、過放電防止機能
についてのみ説明する。Next, the operation of this circuit will be described. The operation is the same as the above-described circuit operation except for the added over-discharge prevention mechanism, so that the description of that part will be omitted and only the over-discharge prevention function will be described.
【００２７】本回路実施例で、放電中の電池電圧は電圧
監視ＩC Ｍ2 の設定電圧値以上となっているため、その
出力ＵＶは“Ｌ”でありトランジスタＱ9 はオフし、Ｍ
ＯＳ−ＦＥＴＴＱ8 はオン状態となって放電電流はＭＯ
Ｓ−ＦＥＴＴＱ8 を介して流れる。In this embodiment of the circuit, since the battery voltage during discharging is equal to or higher than the voltage value set by the voltage monitor IC M2, its output UV is "L", the transistor Q9 is turned off, and M
The OS-FET TQ8 is turned on and the discharge current is MO.
It flows through S-FET TQ8.
【００２８】放電が進み、電池電圧が電圧監視ＩC Ｍ2
の設定電圧値以下になると出力ＵＶは“Ｈ”に変化し、
トランジスタＱ9 がオンしてＭＯＳ−ＦＥＴＴＱ8 はゲ
ートが“Ｌ”に固定されてオフ状態となり、放電電流は
遮断される。従って再充電の時、充電電流は充電器〜＋
端子５〜電池１〜電流検出用の抵抗Ｒi 〜ボディダイオ
ードＤa 〜ＭＯＳ−ＦＥＴＴＱ4 〜−端子６を介して流
れる。As the discharge progresses, the battery voltage is monitored by the voltage IC M2
When it becomes less than the set voltage value of, the output UV changes to "H",
The transistor Q9 is turned on, the gate of the MOS-FET TQ8 is fixed to "L" and turned off, and the discharge current is cut off. Therefore, when recharging, the charging current is +
The current flows through a terminal 5, a battery 1, a current detecting resistor Ri, a body diode Da, a MOS-FET TQ4, and a terminal 6.
【００２９】以上が図４に示す回路例の動作である。本
実施例では放電電流を検出するために電流経路と直列に
電流検出用の抵抗Ｒi を挿入しているが、このような過
放電防止機構付きの過充電防止装置７では電流検出用の
抵抗Ｒi を放電遮断用のＭＯＳ−ＦＥＴＴＱ8 のオン抵
抗で代用することも可能であり、その具体例を図５に示
す。このように電流検出用の抵抗Ｒi を放電遮断用のＭ
ＯＳ−ＦＥＴＴＱ8 のオン抵抗で代用することにより部
品点数を削減できるばかりでなく、抵抗Ｒi によって生
ずる回路損失をより少なくできるのである。The above is the operation of the circuit example shown in FIG. In the present embodiment, the current detection resistor Ri is inserted in series with the current path to detect the discharge current. However, in the overcharge prevention device 7 with such an overdischarge prevention mechanism, the current detection resistor Ri is inserted. It is also possible to substitute the ON resistance of the MOS-FET TQ8 for interrupting the discharge, and a specific example thereof is shown in FIG. In this way, the current detection resistor Ri is connected to the discharge interruption M
Not only can the number of parts be reduced by substituting the ON resistance of the OS-FET TQ8, but the circuit loss caused by the resistance Ri can be further reduced.
【００３０】[0030]
【発明の効果】以上説明したように、本発明による電流
検出回路は方向自在の電流経路に接続し、決められた方
向の電流だけを検出する場合に非常に有効な回路であ
り、更にその出力で電流経路上に設けたスイッチ回路を
自在にオン・オフできるので、その用途は広く、極めて
実用価値の高いものといえる。As described above, the current detection circuit according to the present invention is a circuit which is very effective when it is connected to a freely directional current path and only detects a current in a predetermined direction. Since the switch circuit provided on the current path can be turned on and off freely, it has a wide range of uses and is of extremely high practical value.
【００３１】又、本発明によれば、電池の過充電時にス
イッチ回路がオフして充電電流を遮断するようにした過
充電防止装置に、放電電流を検出するため上記電流検出
回路を適用し、電池放電時に上記電流検出回路の出力に
基づいて上記スイッチ回路がオンするようにしたので、
放電時にスイッチ回路のボディダイオードによる電圧降
下が無くなり、この電圧降下による回路損失が排除され
るため電池の容量を効率良く取り出すことが可能とな
る。Further, according to the present invention, the above-mentioned current detection circuit for detecting the discharge current is applied to the overcharge prevention device in which the switch circuit is turned off to cut off the charging current when the battery is overcharged, Since the switch circuit is turned on based on the output of the current detection circuit when the battery is discharged,
When discharging, the voltage drop due to the body diode of the switch circuit is eliminated, and the circuit loss due to this voltage drop is eliminated, so that the capacity of the battery can be efficiently taken out.
【図１】本発明に係る過充電防止装置の基本構成を示す
ブロック図であるFIG. 1 is a block diagram showing a basic configuration of an overcharge prevention device according to the present invention.
【図２】図１に過放電防止機構を付加した過充電防止装
置の基本構成を示すブロック図である。FIG. 2 is a block diagram showing a basic configuration of an overcharge prevention device in which an overdischarge prevention mechanism is added to FIG.
【図３】図１の基本構成に対応した電子回路の一実施例
である。FIG. 3 is an example of an electronic circuit corresponding to the basic configuration of FIG.
【図４】図２の基本構成に対応した電子回路の一実施例
である。FIG. 4 is an example of an electronic circuit corresponding to the basic configuration of FIG.
【図５】図４とは別の電子回路の一実施例である。FIG. 5 is an embodiment of an electronic circuit different from that of FIG.
【図６】従来の過充電防止装置の電子回路の一実施例で
ある。FIG. 6 is an example of an electronic circuit of a conventional overcharge prevention device.
１ 電池 ２ 電圧検出器 ３ スイッチ回路 ４ 電流検出回路 ７ 過充電防止装置 ＯＶ 電圧検出器の出力 Ｒi 電流検出用の素子 Ｓ 電流検出回路の出力 1 battery 2 voltage detector 3 switch circuit 4 current detection circuit 7 overcharge prevention device OV voltage detector output Ri current detection element S current detection circuit output
───────────────────────────────────────────────────── フロントページの続き (72)発明者 若尾 正一 東京都港区新橋５丁目36番11号 富士電気 化学株式会社内 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shoichi Wakao 5-36-11 Shimbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd.
Claims (2)
の電流経路に接続された電流検出回路（４）であって、 上記スイッチ回路（３）と直列に接続した電流検出用の
素子（Ｒi ）と、該電流検出用の素子（Ｒi ）の電流方
向を検出するトランジスタ（Ｑ6 ）及び（Ｑ7）と、上
記スイッチ回路（３）を駆動する駆動回路とで構成さ
れ、上記トランジスタ（Ｑ6 ）及び（Ｑ7 ）が所定方向
の電流を検出すると、その出力（Ｓ）に基づいて上記ス
イッチ回路（３）がオンするようにしたことを特徴とす
る電流検出回路。1. A current detection circuit (4) connected to a directional current path provided with a switch circuit (3), the element (Ri for current detection connected in series with the switch circuit (3). ), Transistors (Q6) and (Q7) for detecting the current direction of the current detecting element (Ri), and a drive circuit for driving the switch circuit (3), the transistor (Q6) and A current detection circuit characterized in that when (Q7) detects a current in a predetermined direction, the switch circuit (3) is turned on based on the output (S).
（１）の電圧を検出する電圧検出器（２）と、上記電池
（１）に直列に設けられたスイッチ回路（３）を備え、
充電時に上記電池（１）の電圧が規定値を越えた時、上
記電圧検出器（２）の出力（ＯＶ）に基づいて上記スイ
ッチ回路（３）がオフし、充電電流を遮断するようにし
た過充電防止装置（７）において、 上記スイッチ回路（３）に電流検出用の素子（Ｒi ）或
いは（Ｑ8 ）を有する電流検出回路（４）を接続し、上
記電池（１）の放電時に上記電流検出回路（４）の出力
（Ｓ）に基づいて上記スイッチ回路（３）がオンするよ
うにしたことを特徴とする過充電防止装置。2. A rechargeable battery (1), a voltage detector (2) for detecting the voltage of the battery (1), and a switch circuit (3) provided in series with the battery (1). ,
When the voltage of the battery (1) exceeds a specified value during charging, the switch circuit (3) is turned off based on the output (OV) of the voltage detector (2) to interrupt the charging current. In the overcharge prevention device (7), a current detection circuit (4) having a current detection element (Ri) or (Q8) is connected to the switch circuit (3) so that the current flows when the battery (1) is discharged. An overcharge prevention device characterized in that the switch circuit (3) is turned on based on an output (S) of a detection circuit (4).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6196543A JP2956483B2 (en) | 1994-08-22 | 1994-08-22 | Overcharge prevention device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6196543A JP2956483B2 (en) | 1994-08-22 | 1994-08-22 | Overcharge prevention device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0865907A true JPH0865907A (en) | 1996-03-08 |
| JP2956483B2 JP2956483B2 (en) | 1999-10-04 |
Family
ID=16359495
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6196543A Expired - Lifetime JP2956483B2 (en) | 1994-08-22 | 1994-08-22 | Overcharge prevention device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2956483B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20000063427A (en) * | 2000-07-10 | 2000-11-06 | 양현승 | Precast concrete well foundation |
| WO2000070702A1 (en) * | 1999-05-17 | 2000-11-23 | Matsushita Electric Industrial Co., Ltd. | Circuit and device for protecting secondary battery |
| KR20140102303A (en) * | 2011-12-13 | 2014-08-21 | 오스람 게엠베하 | Circuit assembly and method for operating an led chain on alternating voltage |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02250636A (en) * | 1989-03-20 | 1990-10-08 | Pfu Ltd | Battery circuit |
| JPH0475430A (en) * | 1990-07-18 | 1992-03-10 | Asahi Chem Ind Co Ltd | Rechargeable power unit |
-
1994
- 1994-08-22 JP JP6196543A patent/JP2956483B2/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02250636A (en) * | 1989-03-20 | 1990-10-08 | Pfu Ltd | Battery circuit |
| JPH0475430A (en) * | 1990-07-18 | 1992-03-10 | Asahi Chem Ind Co Ltd | Rechargeable power unit |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000070702A1 (en) * | 1999-05-17 | 2000-11-23 | Matsushita Electric Industrial Co., Ltd. | Circuit and device for protecting secondary battery |
| US6577105B1 (en) | 1999-05-17 | 2003-06-10 | Matsushita Electric Industrial Co., Ltd. | Circuit and device for protecting secondary battery |
| KR20000063427A (en) * | 2000-07-10 | 2000-11-06 | 양현승 | Precast concrete well foundation |
| KR20140102303A (en) * | 2011-12-13 | 2014-08-21 | 오스람 게엠베하 | Circuit assembly and method for operating an led chain on alternating voltage |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2956483B2 (en) | 1999-10-04 |
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