JPH05111182A - Charger circuit for radio telephone - Google Patents
Charger circuit for radio telephoneInfo
- Publication number
- JPH05111182A JPH05111182A JP26439091A JP26439091A JPH05111182A JP H05111182 A JPH05111182 A JP H05111182A JP 26439091 A JP26439091 A JP 26439091A JP 26439091 A JP26439091 A JP 26439091A JP H05111182 A JPH05111182 A JP H05111182A
- Authority
- JP
- Japan
- Prior art keywords
- charging current
- transistor
- resistor
- voltage
- wireless telephone
- 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.)
- Pending
Links
Landscapes
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は無線電話機の充電器回路
に関する。FIELD OF THE INVENTION This invention relates to wireless telephone charger circuits.
【０００２】[0002]
【従来の技術】一般に無線電話機の充電可能な二次電池
に電源アダプタから直流電圧を供給して充電する際に、
充電電流を検出することにより充電中である旨を発光ダ
イオード等を利用して表示する無線電話機の充電器が知
られている。従来、この種の無線電話機の充電器回路は
図２に示すように、電源アダプタ１から直流電圧を供給
するが、正極性出力端子３は抵抗器Ｒ１を介して無線電
話機２の正極性入力端子５に接続されている。また、負
極性出力端子４は無線電話機２の負極性入力端子６に接
続されている。この無線電話機２への充電電流は抵抗器
Ｒ１流れ、この充電電流による抵抗器Ｒ１の両端の電圧
降下はトランジスタＴＲ１のエミッタおよび抵抗器Ｒ２
を介してトランジスタＴＲ１のベースに印加され、トラ
ンジスタＴＲ１のエミッタ・コレクタ間を導通状態とし
ている。トランジスタＴＲ１のコレクタは電流制限用抵
抗値Ｒ３と発光ダイオードＬＥＤの直列回路を介して負
極性出力端子４に接続されている。したがって発光ダイ
オードＬＥＤに電流が流れて発光し、充電中である旨を
表示していた。2. Description of the Related Art Generally, when charging a rechargeable secondary battery of a wireless telephone by supplying a DC voltage from a power adapter,
2. Description of the Related Art There is known a charger for a wireless telephone which displays a fact that it is being charged by detecting a charging current by using a light emitting diode or the like. Conventionally, the charger circuit of this type of wireless telephone supplies a DC voltage from the power adapter 1 as shown in FIG. 2, but the positive output terminal 3 has a positive input terminal of the wireless telephone 2 via a resistor R1. Connected to 5. The negative output terminal 4 is connected to the negative input terminal 6 of the wireless telephone 2. The charging current to this radio telephone 2 flows through the resistor R1, and the voltage drop across the resistor R1 due to this charging current is caused by the emitter of the transistor TR1 and the resistor R2.
Is applied to the base of the transistor TR1 via the transistor TR1 to bring the emitter and collector of the transistor TR1 into conduction. The collector of the transistor TR1 is connected to the negative output terminal 4 via the series circuit of the current limiting resistance value R3 and the light emitting diode LED. Therefore, a current flows through the light emitting diode LED to emit light, indicating that charging is in progress.
【０００３】[0003]
【発明が解決しようとする課題】この従来の無線電話機
の充電器回路では、充電電流のほぼすべてが抵抗器Ｒ１
を流れるため抵抗器Ｒ１の両端の電圧降下は充電電流に
ほぼ正比例する。このため特に充電電流が大きな時に
は、抵抗器Ｒ１の両端の電圧降下も増大し、充分な充電
電流をととるために出力電圧を増大せねばならなくな
る。また抵抗器Ｒ１としても定格電力の大きなものを使
用せねばならないという欠点があった。In the conventional charger circuit of the wireless telephone, almost all of the charging current is the resistor R1.
Voltage drop across resistor R1 is approximately directly proportional to the charging current. Therefore, especially when the charging current is large, the voltage drop across the resistor R1 also increases, and the output voltage must be increased in order to obtain a sufficient charging current. Further, there is a drawback that the resistor R1 having a large rated power must be used.
【０００４】[0004]
【課題を解決するための手段】本発明の無線電話機の充
電器回路は、直流充電電圧を供給する電源アダプタと、
この電源アダプタから無線電話機に充電電流を供給する
際の充電電流検出用抵抗とを有する無線電話機の充電器
回路において、前記充電電流検出用抵抗と並列にエミッ
タコレクタ間を接続し、さらに前記充電電流検出用抵抗
の両端電圧の分圧電圧をベースに供給しているトランジ
スタを備えている。SUMMARY OF THE INVENTION A charger circuit for a wireless telephone according to the present invention comprises a power supply adapter for supplying a DC charging voltage,
In a charger circuit of a wireless telephone having a charging current detecting resistor when supplying a charging current from the power adapter to the wireless telephone, an emitter collector is connected in parallel with the charging current detecting resistor, and the charging current is further increased. It is provided with a transistor that supplies the divided voltage of the voltage across the detection resistor to the base.
【０００５】[0005]
【実施例】次に本発明について図面を参照して説明す
る。図１は本発明の一実施例を示す回路図である。図１
において図２の従来例と同一の符号は同一の構成と機能
を有する。すなわち、本実施例ではトランジスタＴＲ２
のエミッタとコレクタが抵抗器Ｒ１と並列に接続され、
さらにトランジスタＴＲ２のバイアス用として抵抗器Ｒ
４，Ｒ５が接続されている。図１において、充電電流に
よる抵抗器Ｒ１の電圧降下は抵抗器Ｒ４，Ｒ５により分
圧されてトランジスタＴＲ２のベース・エミッタ間にバ
イアス電圧を供給している。今、充電電流が増大しトラ
ンジスタＴＲ２のベース・エミッタ間のバイアス電圧が
トランジスタＴＲ２のベース・エミッタ間カットオフ電
圧（シリコントランジスタの場合約０．６Ｖ）を超える
と、トランジスタＴＲ２のコレクタ・エミッタ間は導通
し、充電電流の一部がトランジスタＴＲ２を流れはじめ
る。トランジスタＴＲ２が導通を開始する充電電流（こ
の時の電流をＩｓと記す）は抵抗器Ｒ１の値によって設
定ができる。充電電流が電流値Ｉｓを超えると、トラン
ジスタＴＲ２が導通し、その後すべてトランジスタＴＲ
２を流れる。従って抵抗器Ｒ１を流れる電流は、充電電
流によらないので抵抗器Ｒ１の定格電力を小さいものに
設定できる。したがって電源アダプタ１の出力電圧は無
線電話機２の二次電池が必要とする電圧よりも０．６〜
１Ｖ程度のごくわずか高いだけでよい。The present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment of the present invention. Figure 1
2, the same reference numerals as those in the conventional example in FIG. 2 have the same configurations and functions. That is, in this embodiment, the transistor TR2
The emitter and collector of are connected in parallel with the resistor R1,
Further, a resistor R is used for biasing the transistor TR2.
4, R5 are connected. In FIG. 1, the voltage drop of the resistor R1 due to the charging current is divided by the resistors R4 and R5 to supply a bias voltage between the base and emitter of the transistor TR2. Now, when the charging current increases and the bias voltage between the base and emitter of the transistor TR2 exceeds the base-emitter cutoff voltage of the transistor TR2 (about 0.6 V in the case of a silicon transistor), the collector-emitter of the transistor TR2 becomes It becomes conductive, and a part of the charging current starts flowing through the transistor TR2. The charging current at which the transistor TR2 starts to conduct (the current at this time is referred to as Is) can be set by the value of the resistor R1. When the charging current exceeds the current value Is, the transistor TR2 becomes conductive, and then the transistor TR2 is turned on.
Flowing through 2. Therefore, since the current flowing through the resistor R1 does not depend on the charging current, the rated power of the resistor R1 can be set to a small value. Therefore, the output voltage of the power adapter 1 is about 0.6 to more than the voltage required by the secondary battery of the wireless telephone 2.
Only a very high voltage of about 1V is required.
【０００６】[0006]
【発明の効果】以上説明したように本発明による無線電
話機の充電器回路では充電電流検出用の抵抗器として定
格電力の小さなものを使用できるので、充電器として低
消費電力にできる。また、電源アダプタの充電電圧も小
さくてすむという効果がある。As described above, in the charger circuit of the wireless telephone according to the present invention, a resistor having a small rated power can be used as the resistor for detecting the charging current, so that the power consumption of the charger can be reduced. Further, there is an effect that the charging voltage of the power adapter can be small.
【図１】本発明の一実施例を示す回路図である。FIG. 1 is a circuit diagram showing an embodiment of the present invention.
【図２】従来の無線電話機の充電器回路の回路図であ
る。FIG. 2 is a circuit diagram of a charger circuit of a conventional wireless telephone.
１ 電源アダプタ ２ 無線電話機 ３ 正極性出力端子 ４ 負極性出力端子 ５ 正極性入力端子 ６ 負極性入力端子 ＴＲ１ トランジスタ ＴＲ２ トランジスタ ＬＥＤ 発光ダイオード Ｒ１，Ｒ２，Ｒ３，Ｒ４，Ｒ５ 抵抗器 1 Power Adapter 2 Wireless Telephone 3 Positive Output Terminal 4 Negative Output Terminal 5 Positive Input Terminal 6 Positive Input Terminal TR1 Transistor TR2 Transistor LED Light Emitting Diode R1, R2, R3, R4, R5 Resistor
Claims (1)
と、この電源アダプタから無線電話機に充電電流を供給
する際の充電電流検出用抵抗とを有する無線電話機の充
電器回路において、前記充電電流検出用抵抗と並列にエ
ミッタコレクタ間を接続し、さらに前記充電電流検出用
抵抗の両端電圧の分圧電圧をベースに供給しているトラ
ンジスタを備えていることを特徴とする無線電話機の充
電器回路。1. A charger circuit for a wireless telephone having a power supply adapter for supplying a DC charging voltage and a charging current detection resistor for supplying a charging current from the power supply adapter to the wireless telephone. A charger circuit for a wireless telephone, comprising: a transistor having an emitter and a collector connected in parallel with a resistor and further having a transistor for supplying a divided voltage of a voltage across the charging current detecting resistor to a base.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26439091A JPH05111182A (en) | 1991-10-14 | 1991-10-14 | Charger circuit for radio telephone |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26439091A JPH05111182A (en) | 1991-10-14 | 1991-10-14 | Charger circuit for radio telephone |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05111182A true JPH05111182A (en) | 1993-04-30 |
Family
ID=17402494
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26439091A Pending JPH05111182A (en) | 1991-10-14 | 1991-10-14 | Charger circuit for radio telephone |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05111182A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53128514A (en) * | 1977-04-15 | 1978-11-09 | Daido Steel Co Ltd | Heating method in flame impact type heating furnace |
| JPS62107641A (en) * | 1985-11-01 | 1987-05-19 | 松下電器産業株式会社 | Charge control circuit |
-
1991
- 1991-10-14 JP JP26439091A patent/JPH05111182A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53128514A (en) * | 1977-04-15 | 1978-11-09 | Daido Steel Co Ltd | Heating method in flame impact type heating furnace |
| JPS62107641A (en) * | 1985-11-01 | 1987-05-19 | 松下電器産業株式会社 | Charge control circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 19971202 |