JP2675456B2 - Power supply switching device - Google Patents
Power supply switching deviceInfo
- Publication number
- JP2675456B2 JP2675456B2 JP3160417A JP16041791A JP2675456B2 JP 2675456 B2 JP2675456 B2 JP 2675456B2 JP 3160417 A JP3160417 A JP 3160417A JP 16041791 A JP16041791 A JP 16041791A JP 2675456 B2 JP2675456 B2 JP 2675456B2
- Authority
- JP
- Japan
- Prior art keywords
- power supply
- output side
- switching
- main
- sub
- 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.)
- Expired - Lifetime
Links
Landscapes
- Power Sources (AREA)
- Direct Current Feeding And Distribution (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、電子機器、特にパーソ
ナルコンピュータ等のバッテリ駆動の機器において、電
源用ＩＣを用いた場合に有効な電源供給切換装置に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply switching device which is effective when a power supply IC is used in electronic equipment, particularly battery driven equipment such as personal computers.
【０００２】[0002]
【従来の技術】一般に電子機器の電源回路は、ポータブ
ル型の場合、電池及びＡＣアダプタによって駆動できる
構成が多く採用されている。2. Description of the Related Art Generally, in the case of a portable type, a power supply circuit of an electronic device generally employs a structure which can be driven by a battery and an AC adapter.
【０００３】ここで東芝（株）製「ダイナブック３１０
０ＪＳＳ」の回路図に示されているようにメインロジッ
ク回路と呼ばれる主電子回路に対しては電源ラインと直
列に主電源スイッチを接続し、一方サブロジック回路へ
の電源供給は内蔵電池又はＡＣアダプタからの直流電源
電圧を３端子ＩＣを介して供給する構成である。Here, "Dynabook 310" manufactured by Toshiba Corporation
As shown in the circuit diagram of "0JSS", for the main electronic circuit called the main logic circuit, the main power switch is connected in series with the power line, while the power supply to the sub logic circuit is performed by the built-in battery or AC adapter. The DC power supply voltage is supplied via a 3-terminal IC.
【０００４】[0004]
【発明が解決しようとする課題】前述の従来例のように
主電源スイッチが電子スイッチ構成されている電子機器
において、上記電子スイッチのオン／オフ制御信号を発
生するサブロジック回路には常に電源が必要となり、内
蔵バッテリによるバッテリ駆動の場合には、その電力を
できるだけ小さくすることが臨ましい。In an electronic device in which the main power switch is constituted by an electronic switch as in the above-mentioned conventional example, the sub-logic circuit for generating the ON / OFF control signal for the electronic switch is always powered. It becomes necessary, and in the case of battery drive by the built-in battery, it is advisable to reduce the electric power as much as possible.
【０００５】そのために前記サブロジック回路への電源
供給は低消費電流タイプの３端子ＩＣが多用されている
が、このタイプの３端子ＩＣは、許容損失の大きいもの
がないために、大電流を連続して取出すことができな
い。For this reason, a low-current-consumption type three-terminal IC is often used for supplying power to the sub-logic circuit. However, since this type of three-terminal IC does not have a large allowable loss, it consumes a large current. It cannot be taken out continuously.
【０００６】[0006]
【課題を解決するための手段】本発明は、交流電源に接
続されるＡＣアダプタ及び内蔵電池を備えた電子機器に
おいて、前記ＡＣアダプタの出力と主電子回路との間に
主電源スイッチを接続し、前記ＡＣアダプタ及び内蔵電
池の出力側と前記主電源スイッチの制御信号を発生する
サブロジック回路との間にスイッチングダイオードを直
列接続すると共に該スイッチングダイオードの出力側及
び前記主電源スイッチをコンパレータの入力端子に接続
し、該コンパレータの出力端子を前記主電源スイッチと
サブロジック回路に接続し、前記スイッチングダイオー
ドの入力側の電力を起動時のみ所定値で供給し、低電力
構成となしてある。SUMMARY OF THE INVENTION The present invention relates to an electronic device having an AC adapter connected to an AC power source and a built-in battery, wherein a main power switch is connected between the output of the AC adapter and the main electronic circuit. Connecting a switching diode in series between the output side of the AC adapter and built-in battery and a sub-logic circuit that generates a control signal of the main power switch, and connecting the output side of the switching diode and the main power switch to the input of a comparator. It is connected to the terminal, the output terminal of the comparator is connected to the main power switch and the sub-logic circuit, and the power on the input side of the switching diode is supplied at a predetermined value only at the time of start-up, thereby forming a low power configuration.
【０００７】[0007]
【作用】本発明では、主電源スイッチに電子スイッチを
使用した電子機器において、上記主電源スイッチにオン
／オフ用の制御信号を発生するサブロジック回路の電源
は常時供給しておき、前記主電源スイッチがオフからオ
ンに前記制御信号によって切換えられると同時に主電子
回路用の主電源装置が立上がり、その後直ちに電源回路
を切換える構成である。According to the present invention, in an electronic device using an electronic switch as the main power switch, the main logic switch is always supplied with the power of the sub-logic circuit for generating the ON / OFF control signal. The main power supply device for the main electronic circuit is started at the same time when the switch is switched from off to on by the control signal, and the power supply circuit is switched immediately thereafter.
【０００８】[0008]
【実施例】図面に従って本発明を説明すると、図１は本
発明の電源供給切換装置の回路構成図、図２は同装置の
タイミングチャートを示す。図面において、（１）は主
電源端子、（２）はＡＣアダプタの出力端又はバッテリ
等に接続されたサブ電源端子、（３）は主電源回路、
（４）は主電源スイッチ、（５）は主電子回路、（６）
は平滑コンデンサ、（７）は３端子ＩＣ、（８）は直流
阻止ダイオード、（９）はＰチャンネルＭＯＳトランジ
スタより成るスイッチングトランジスタ、（１０）はサ
ブロジック回路、（１１）はコンパレータ、（１２）
（１３）（１４）（１５）は分圧抵抗を示す。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings. FIG. 1 is a circuit configuration diagram of a power supply switching device of the present invention, and FIG. 2 is a timing chart of the device. In the drawings, (1) is a main power supply terminal, (2) is a sub power supply terminal connected to an output end of an AC adapter or a battery, (3) is a main power supply circuit,
(4) is the main power switch, (5) is the main electronic circuit, (6)
Is a smoothing capacitor, (7) is a three-terminal IC, (8) is a DC blocking diode, (9) is a switching transistor composed of a P-channel MOS transistor, (10) is a sub-logic circuit, (11) is a comparator, and (12) is.
(13), (14), and (15) represent voltage dividing resistors.
【０００９】次に動作について説明すると、電源端子
（１）にはＡＣアダプタ又は内蔵バッテリからメインラ
インの直流電圧が供給され、主電源回路（３）から直流
安定電圧（例えば５Ｖ）が出力される。図示のように主
電源スイッチ（４）がオフの状態のときは、電源用の３
端子ＩＣ（７）には上記直流電圧（５Ｖ）がサブ電源と
して加わり、待機（スタンバイ）状態でダイオード
（８）のアノード側には５Ｖから順方向電圧ＶFを差引
いた電圧が加わっている。The operation will now be described. The power supply terminal (1) is supplied with the DC voltage of the main line from the AC adapter or the built-in battery, and the main power supply circuit (3) outputs the DC stable voltage (for example, 5V). . As shown in the figure, when the main power switch (4) is off,
The direct current voltage (5 V) is applied to the terminal IC (7) as a sub power supply, and a voltage obtained by subtracting the forward voltage V F from 5 V is applied to the anode side of the diode (8) in a standby state.
【００１０】前記ダイオード（８）はショットキーダイ
オードで構成した場合、ＶF＝０．３Ｖに設定できる。When the diode (8) is a Schottky diode, it can be set to V F = 0.3V.
【００１１】従ってこのときサブロジック回路（１０）
には３端子ＩＣ（７）を介して電源電圧（ＶCC）として
４．７Ｖが供給されており、コンパレータ（１１）のＨ
端子側は４．７Ｖ、Ｌ端子側は０Ｖとなるために、該コ
ンパレータ（１１）の出力はハイレベル「Ｈ」となり、
スイッチングトランジスタ（９）はオフになっている。Therefore, at this time, the sub logic circuit (10)
Is supplied with 4.7 V as a power supply voltage (V CC ) through a 3-terminal IC (7), and the H of the comparator (11) is
Since the terminal side becomes 4.7 V and the L terminal side becomes 0 V, the output of the comparator (11) becomes high level “H”,
The switching transistor (9) is off.
【００１２】一方サブロジック回路（１０）より、主電
源スイッチ（４）をオンにするための制御信号が出力さ
れ、図２（イ）に示すＶBがハイレベルになると、主電
源回路（３）からは図２に示す電圧ＶBが上昇し始め、
４．７Ｖに達する。On the other hand, when a control signal for turning on the main power supply switch (4) is output from the sub logic circuit (10) and V B shown in FIG. ), The voltage V B shown in FIG.
It reaches 4.7V.
【００１３】前記制御信号（ＶA）がハイレベル（Ｈ）
となると、サブロジック回路（１０）の消費電流が増大
し、電流ｉSは動作電流となった後に前記電圧ＶAが４．
７Ｖに達すると、スイッチングトランジスタ（９）はオ
ンとなって電力の供給は、３端子ＩＣ（７）からのサブ
電源（５Ｖ）から上記主電源回路（３）の出力ラインに
接続された主電源スイッチ（４）の出力側からの電圧に
切換わり、電流ｉMが動作電流となり、電流ｉSはほぼゼ
ロとなる。The control signal (V A ) is high level (H)
Then, the consumption current of the sub-logic circuit (10) increases, and the voltage V A becomes 4. after the current i S becomes the operating current.
When the voltage reaches 7V, the switching transistor (9) is turned on and the power is supplied from the sub power supply (5V) from the three-terminal IC (7) to the main power supply connected to the output line of the main power supply circuit (3). The voltage is switched from the output side of the switch (4), the current i M becomes the operating current, and the current i S becomes almost zero.
【００１４】次に制御信号がオンからオフレベル即ちＨ
からＬになると、主電源回路（３）からの電圧ＶBは降
下し始め、サブロジック回路（１０）側も待機状態とな
り、僅かな電流となり、主電源回路（３）側の５Ｖから
４．７Ｖ以下に下降するまで主電源回路（３）側から供
給され、その後は３端子ＩＣ（７）から５Ｖが供給され
て元の状態に戻る。Next, the control signal changes from ON to OFF level, that is, H.
When the voltage changes from L to L, the voltage V B from the main power supply circuit (3) begins to drop, the sub-logic circuit (10) side also enters a standby state, a slight current flows, and 5 V from 5 V on the main power supply circuit (3) side. The voltage is supplied from the main power supply circuit (3) side until the voltage drops to 7 V or less, and then 5 V is supplied from the three-terminal IC (7) to return to the original state.
【００１５】上記動作状態では、サブロジック回路（１
０）はスイッチングトランジスタ（９）の「オン抵抗×
負荷電流」の電圧を５Ｖから差引いた電圧が加わること
になり、仮にこの電圧を２Ω×０．１Ａ＝０．２Ｖとす
ると、ダイオード（８）の順方向電圧ＶFより低い値と
なるため、ほとんどの電流が主電源スイッチ（４）の出
力端から供給されることになり、３端子ＩＣ（７）の出
力側であるサブ電源側の５Ｖからは電流は流れない。In the above operating state, the sub logic circuit (1
0) is the “ON resistance of the switching transistor (9) ×
Will be the voltage of the voltage of the load current "was subtracted from 5V is applied, Assuming that this voltage and 2Ω × 0.1A = 0.2V, to become a value lower than the forward voltage V F of the diode (8), Most of the current is supplied from the output end of the main power switch (4), and no current flows from 5V on the sub power supply side which is the output side of the three-terminal IC (7).
【００１６】このことは３端子ＩＣ（７）の発熱として
〔（ＶS−５）×ｉS〕の電力損失を起動時のみ保証でき
ればよいことになる。This means that the power loss of [(V S −5) × i S ] as heat generation of the three-terminal IC (7) can be guaranteed only at the time of starting.
【００１７】[0017]
【発明の効果】本発明の電源供給切換装置によれば、従
来に比べて電源回路の容量が小さくて済み、特にサブ電
源側の３端子ＩＣが小型の電源用ＩＣで間に合い電源回
路の小型化が図れる。According to the power supply switching device of the present invention, the capacity of the power supply circuit can be made smaller than that of the conventional one, and in particular, the three-terminal IC on the sub-power supply side can be made small by the power supply IC, and the power supply circuit can be miniaturized. Can be achieved.
【図１】本発明装置の回路図を示す。FIG. 1 shows a circuit diagram of the device of the present invention.
【図２】本発明装置におけるタイミングチャートを示
す。FIG. 2 shows a timing chart in the device of the present invention.
１ 主電源端子 ２ サブ電源端子 ４ 主電源スイッチ ５ 主電子回路 ８ 直流阻止ダイオード ９ スイッチングトランジスタ １０ サブロジック回路 １１ コンパレータ 1 Main Power Supply Terminal 2 Sub Power Supply Terminal 4 Main Power Supply Switch 5 Main Electronic Circuit 8 DC Blocking Diode 9 Switching Transistor 10 Sub Logic Circuit 11 Comparator
Claims (1)
蔵電池を備えた電子機器において、前記ACアダプタの出
力側と主電子回路の入力側との間に主電源スイッチを接
続し、前記ACアダプタ又は内蔵電池の出力側とサブロジ
ック回路との間にスイッチングダイオードを直列接続す
ると共に該スイッチングダイオードの出力側及び前記主
電源スイッチの一端をコンパレータの入力端子に接続
し、前記主電源スイッチの一端と前記スイッチングダイ
オードの出力側にスイッチングトランジスタの出力側を
接続し、該スイッチングトランジスタの制御電極に前記
コンパレータの出力側を接続し、前記スイッチングダイ
オードの入力側の電力を起動時のみ所定値で供給し、低
電力化の構成となしたことを特徴とする電源供給切換装
置。1. A AC adapter is connected to an AC power source, and an electronic apparatus including a built-in battery, connect the main power switch between the input side of the output side and the main electronic circuit of the AC adapter, the AC the output side and one end of the main power switch of the switching diode is connected to the input terminal of the comparator as well as serially connected switching diodes between the output side and the sub-logic circuit of the adapter or built-in battery, one end of said main power supply switch And the switching die
Connect the output side of the switching transistor to the output side of the ode.
Connected to the control electrode of the switching transistor
A power supply switching device, characterized in that the output side of the comparator is connected and the power on the input side of the switching diode is supplied at a predetermined value only at the time of start-up, thereby reducing power consumption.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3160417A JP2675456B2 (en) | 1991-07-01 | 1991-07-01 | Power supply switching device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3160417A JP2675456B2 (en) | 1991-07-01 | 1991-07-01 | Power supply switching device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0515061A JPH0515061A (en) | 1993-01-22 |
| JP2675456B2 true JP2675456B2 (en) | 1997-11-12 |
Family
ID=15714480
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3160417A Expired - Lifetime JP2675456B2 (en) | 1991-07-01 | 1991-07-01 | Power supply switching device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2675456B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4783644B2 (en) | 2006-02-07 | 2011-09-28 | 富士通株式会社 | Power control apparatus, server apparatus, and power control method |
-
1991
- 1991-07-01 JP JP3160417A patent/JP2675456B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0515061A (en) | 1993-01-22 |
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