JP2003204676A - Ac-dc adaptor, and apparatus connected to the adaptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an AC-DC adaptor which can save energy and power cost through power saving by putting it in a power saving mode at no load, thereby reducing wasteful power consumption, and to provide an apparatus connected to the adaptor, and a control method for them. <P>SOLUTION: This AC-DC adaptor (100) can be connected with an apparatus for supplying DC power by means of a power (VCC) line (14) and a ground (GND) line (16) and includes a controller (34), first means (32 and 38) which are connected to the GND line and the controller and detect a short-circuit current between VCC line and the GND line and generate a power saving mode signals (overcurrent signal) which is sent to the controller, and second means (42, 44, and 46), which are connected to the VCC line and the controller and detect the trigger voltage supplied to the VCC line and generate reset signals to be sent to the controller. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention generally relates to AC
With regard to the DC-DC adapter, in more detail, when it is not necessary to supply the DC power (when there is no load), the power-saving mode can be used to save unnecessary power consumption. Regarding The “power saving mode” of the AC-DC adapter referred to in this specification means a state of minimum power consumption, that is, a so-called standby state. More specifically, the AC-DC adapter is connected to an AC power source. In the state, it means a state in which only the internal controller is operating, in other words, a state in which the switching operation as the power supply is stopped.

[0002]

2. Description of the Related Art An AC-DC adapter is a device for converting AC power (voltage) into DC power (voltage) and supplying the DC power to equipment. The AC-DC adapter is
It is used in many devices such as a notebook personal computer (PC). In general, as shown in FIG.
The C-DC adapter 1 is used by connecting one AC plug 2 to the AC power outlet 3 and connecting the other DC plug 4 to the DC power input jack 6 of the device 5.

Normally, even after the use of the device 5 is finished and the power switch of the device is turned off, the AC plug 2 of the AC-DC adapter 1 is connected to the outlet 3 and the DC plug 4 is the jack 6 of the device 5. Often remains connected to. Further, even when the DC plug 4 is removed from the jack 6 of the device 5, the AC plug 2 is often still connected to the outlet 3. Therefore, even after the use of the device 5 is finished, the AC power is often kept supplied to the AC-DC adapter 1.

In the conventional AC-DC adapter, when the AC power is supplied, the adapter repeats the switching operation inside as an electric power source, and even if there is no load, the power of several watts (W) is used. Is wasted. Therefore, set the AC-DC adapter to the power saving mode.
If the useless power consumption at the time of no load can be reduced by setting the (standby mode), it contributes to energy saving by saving power and electricity bill.

On the other hand, even if the useless power consumption can be reduced by putting the AC-DC adapter into the power saving mode, no load condition occurs, for example, when the use of the device is resumed. If the AC-DC adapter does not return to the normal operating state, that is, the state where it can supply the DC power to the connected equipment, automatically and instantly when the load state changes from the Will be damaged. Therefore, the AC-DC adapter in the power saving mode is immediately put into the normal operation mode (a state in which DC power can be supplied to the connected device).
Need to return to.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce unnecessary power consumption by setting a power saving mode when there is no load, and to save energy by saving power and save electricity bills. A DC adapter, a device connected to the adapter, and a control method thereof.

An object of the present invention is to cancel the power saving mode,
An object of the present invention is to provide an AC-DC adapter capable of immediately returning to a normal operation mode (a state in which DC power can be supplied to a device to be connected), a device connected to the adapter, and a control method thereof.

[0008]

According to the present invention, there is provided an AC-DC adapter (100) which can be connected to a device supplying DC power by a power supply (VCC) line and a ground (GND) line. Line and above GN
The first means (64, 32, 3) for putting the adapter in the power saving mode by shorting the D line.
4, 38) and second means (66, 70, 72, 74, 76, 34, 4) for canceling the power saving mode by applying a trigger pulse to the VCC line.
2, 44, 46), and an AC-DC adapter is provided.

According to the present invention, there is provided an AC-DC adapter (100) which can be connected to a device supplying DC power with a power supply (VCC) line and a ground (GND) line. First means (38, 34, 32) for putting the adapter into a power saving mode by a short circuit current between them, and a first means for canceling the power saving mode with a trigger voltage supplied to the VCC line. 2 means (42, 44, 46, 34)
An AC-DC adapter including the following is provided.

According to the present invention, there is provided a method of controlling an AC-DC adapter which can be connected to a device for supplying DC power by a power supply (VCC) line and a ground (GND) line. A control method is provided that includes a step of detecting a short-circuit current between the GND lines, and (b) putting the adapter into a power saving mode when the short-circuit current is detected. Furthermore, according to the present invention, in addition to the steps (a) and (b) above,
A method of controlling an AC-DC adapter, comprising: (c) detecting a trigger voltage supplied to the VCC line; and (d) canceling the power saving mode when the trigger voltage is detected. Provided.

According to the present invention, there is provided an AC-DC adapter (100) connectable to a device for supplying a DC power source by a power supply (VCC) line and a ground (GND) line, the controller (34) and the GND. Line and the controller, connect the VCC line and the G
First means (32, 38) for detecting a short circuit current between the ND lines and generating a power saving mode signal (overcurrent signal) to be sent to the controller;
Connect to the C line and the above controller, and connect to the above VC
A second means (42, 44, 46) for detecting the trigger voltage supplied to the C line and generating a reset signal to be sent to the controller is provided.

According to the present invention, there is provided a method of controlling a device connected to an AC-DC adapter by a power supply (VCC) line and a ground (GND) line, the method comprising: (a) shorting the VCC line and the GND line. And (b) detecting a short-circuit current between the shorted VCC line and the GND line, and (c) putting the adapter in a power saving mode when the short-circuit current is detected. A control method is provided. Furthermore, according to the present invention, in addition to the steps (a) to (c), (d) a step of supplying a trigger voltage to the VCC line, and (e) detecting a trigger voltage on the VCC line. And (f) releasing the power saving mode when the trigger voltage is detected, a method of controlling a device connected to an AC-DC adapter through a power supply (VCC) line and a ground (GND) line. Will be provided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments (examples) of the present invention will be described with reference to the drawings. FIG. 2 is a diagram showing an embodiment of the configuration of the AC-DC adapter 100 according to the present invention. The AC-DC adapter 100 includes an AC plug 12 connected to an AC power source, a power supply (VCC) line 14 and a ground (GND) line 1 output from the AC plug 12.
6 of diode bridge circuit 18, capacitor 20, isolation transformer 22, and transformer 2
Rectifying diode 24 on the secondary VCC line, diode 2 for preventing the inflow of trigger pulse to the capacitor 20
6, capacitor 28, resistors 30, 32, control IC (controller) 34 on the primary side of the transformer, control IC
A photocoupler 38 connected to the overcurrent protection terminal 36 of 34 and the GND line 16, a capacitor 42, a resistor 44, a photocoupler 46, and a control IC 34 connected in series between the reset terminal 40 of the control IC 34 and the VCC line 14.
Output terminal 48, a switching transistor 50 connected to the GND line 16 on the primary side of the transformer, and a DC plug 52.

FIG. 3 shows an embodiment of the configuration of a device 200 connected to the AC-DC adapter 100 according to the present invention. FIG. 3 shows the VCC of the AC-DC adapter 100 of FIG.
VC connectable to line 14 and GND line 16 respectively
C switch 60 and GND line 62, off switch 64 between VCC line 60 and GND line 62, on switch 66 connected to VCC line 60, trigger pulse connected to one terminal 68 of on switch 66 ( Voltage) source 70, 72, 74, 76, on
It is composed of a main circuit 80 of a device connected to one terminal 78 of the switch 66. In FIG. 3, as the trigger pulse (voltage) generation source, a battery 70, a CMOS backup battery 72, a power supply from an equipment interface, a voltage 74 generated from a signal, and a solar cell 76 are illustrated. However, the present invention is not limited to the above, other voltage sources may be used, and at least one of these may be used. Further, the OFF switch 64 and the ON switch 66 may be any switch such as a mechanical switch or an electronic switch such as a transistor.

The operation of the AC-DC adapter 10 of FIG. 2 will be described. First, an operation (normal operation mode) of supplying DC power to a device to be connected, which is a normal operation, will be described. When the AC plug 12 is connected to an AC power source (not shown), electric power is supplied to the control IC 34. Control IC
34 outputs a control signal of a predetermined frequency from the output terminal 48 to the switching transistor 50. The switching transistor 50 repeats ON and OFF operations according to the control signal. This switching transistor 5
By the switching operation of 0, the AC voltage on the primary side of the isolation transformer 22 is converted into the DC voltage on the secondary side. The converted DC voltage is supplied to the rectifying diode 24.
Is smoothed to a voltage having a predetermined amplitude. The smoothed DC voltage is supplied to the device via the DC plug 52. Even if the DC plug is not connected to the device and there is no load, the AC plug 12 performs the above series of operations.
As long as it is connected to the AC power supply.

In FIG. 2, a resistor 30 is provided between the VCC line 14 and the GND line 16 on the secondary side of the transformer in order to eliminate the overshoot voltage generated by the leakage inductance of the isolation transformer 22. There is. In the normal operating mode described above,
Even in the unloaded state where the DC plug is not connected to the device, the VCC line 14 is connected through the resistor 30.
Idle current flows between the GND line 16 and the GND line 16. Therefore, even with no load, the current is consumed by the idle current. In addition, switching
Also in the switching operation of the transistor 50 and the voltage conversion operation of the isolation transformer 22, extra power (current) consumption such as heat generation due to transistor switching operation, heat generation due to transformer winding or core, and heat generation due to diode switching operation. Occurs. Therefore, extra power consumption occurs in addition to the power consumption due to the above-described idle current, and the power amount becomes about 2 to 4 W.

Next, the operation of the adapter in the power saving mode (standby mode), which is a feature of the present invention, will be described.
In the present invention, by executing this power saving mode and returning (cancelling) from the power saving mode, unnecessary power consumption under no load can be reduced quickly and effectively.

While operating in the normal operating mode,
When switching to the standby mode, V on the secondary side of the transformer shown in FIG.
The CC line 14 and the GND line 16 are short-circuited to be in the overcurrent state. In addition, the VCC line 14
The method of short-circuiting the GND line 16 will be described later. At this time, the photocoupler 38 is turned on by the voltage generated in the resistor 32. The ON output of the photocoupler 38 is input to the overcurrent protection terminal 36 of the control IC 34.
The control IC 34 stops the oscillation, that is, stops the switching operation of the switching transistor 50. As a result of the switching operation of the switching transistor 50 being stopped, the output of the secondary side of the transformer 22 is 0V.
become. The potential of the VCC line 14 becomes 0V. In addition,
At this time, even if the photo coupler 38 is turned off, the control I
A trigger signal is input to the reset terminal 40 of the control IC 34 or a control I
The oscillation of the control IC 34 (PWM control of the transistor 50) will not restart again unless the power supply VCC of the C34 drops.

Now, a method of short-circuiting the VCC line 14 and the GND line 16 in FIG. 2 in order to enter the standby mode will be described. The method of short-circuiting is
Not limited to the method described below, the VCC line 14 and G
Any method or means for shorting the ND line 16 can be applied. In FIG. 3, it is assumed that the adapter 100 is switched to the standby mode when the power switch of the device is turned off. The off switch 64 is turned on in conjunction with turning off the power switch to short-circuit the VCC line 60 to the GND line. In this case, since the VCC line is a transition from the active state (high potential), it can be short-circuited by using an electric switch such as FET.

In this standby mode, since the oscillation of the control IC 34 is stopped, the functions of the switching transistor 50 and the transformer 22 are stopped, and the potential of the output VCC line 14 is 0V. Therefore, as described above, the VCC line 14 and the G
Idle current between ND lines 16, switching action of switching transistor 50 and transformer 22
The extra power consumption in the voltage conversion operation in the is drastically reduced.
As a result, the power consumption, which was about 2 to 4 W, is reduced to about one tenth to 200 to 300 mW, which is reduced by about one digit.

Next, the cancellation of the standby mode and the return to the normal operation mode will be described. When the adapter 100 is in the standby state, the power supply VCC is supplied only to the control IC 34, the control IC 34 is operating in the standby state, and the output of the secondary side of the transformer 22 is 0V. In this state, a voltage (trigger voltage pulse) of about 1 V at the minimum is applied to the VCC line 14. The method of applying the trigger voltage pulse will be described later. This voltage pulse is a voltage that can turn on the photocoupler 46 for a moment, and may be about 1V. Further, the diode 26 prevents the capacitor 28 from being charged with a current due to the trigger voltage pulse. Further, the capacitor 42 cuts off the DC component of the trigger voltage pulse, and the resistor 44 adjusts the amount of current so that the photocoupler 46 can be turned on with a minimum amount of electric energy (electric power).

The photocoupler 46 which is turned on inputs the on output as a reset signal to the reset terminal 40 of the control IC 34. The control IC 34 is released from the standby state by the reset signal and restarts the switching operation. The switching transistor 50 also
The switching operation of ON and OFF is restarted, and the AC voltage on the primary side of the isolation transformer 22 is DC on the secondary side.
Converted to voltage. As a result, the adapter 100 returns to the normal operation mode. At this time, the photocoupler 46 may be turned on again depending on the rising waveform of VCC. In that case, if a signal protection circuit such as a one-short-multi circuit is inserted between the control IC 34 and the photocoupler 46 and the resetting is not accepted for a certain period of time after the control IC 34 is reset,
It is possible to prevent the photo coupler 46 from turning on again. By the above operation, this adapter 100
Can exit standby mode and return to normal operating mode without adding a special control signal line. As a result, it is possible to quickly transition between the standby mode and the normal operation mode.

Now, a method of applying a trigger voltage pulse to the VCC line for canceling the standby mode will be described. Note that the method is not limited to the method described below, and any method or means capable of supplying a trigger voltage pulse to the VCC line can be applied. In FIG. 3, the on-switch 78 connected to the main circuit 80 side in the device is momentarily switched to the trigger voltage generation sources 70 to 76 side, and the trigger voltage is supplied to the VCC line 60. After that, the ON switch 78 is returned to the main circuit 80 side. The switching of the on-switch 78 to the trigger voltage generation source side may be performed, for example, in conjunction with the on-operation of the power switch of the device.

Various types of trigger voltage generation sources can be considered depending on the device. As mentioned above, at a voltage of 1 V or higher,
It suffices if there is electric energy that can momentarily turn on the photocoupler 42 (FIG. 2). Notebook type P
In portable equipment such as C, a battery is considered. In addition, a lithium battery for CMOS backup can be used. Moreover, in stationary type peripheral devices, a minute power supply may be taken from the interface with the host PC. Taking the LCD display as an example, since the DDC 5V for plug & play comes to the display side via the video connector, it can be used. Also, in the case of a self-powered USB device, a voltage of 5V is applied to the USB line, which can be used. In these examples, the power source is directly received, but it may be possible to receive only the signal. For example, in the case of a device in which the clock is constantly coming from the host PC side, if the clock signal is integrated and the capacitor is charged, it can be sufficiently used as a trigger voltage pulse. Furthermore, the solar cells used in calculators can also be used. These trigger voltage sources are shown in FIG.
If it is connected in parallel (OR) with a diode like
Operates if any one of the voltage sources is active.

One of the important points of the present invention described above is that the standby mode is realized only by the same GND line and VCC line as the conventional one without providing a new signal line between the adapter and the equipment. In point. In this respect, the adapter of the present invention can be applied not only to a certain device but also to all the devices on the market, which is extremely effective.

Next, as a more specific embodiment of the present invention, a case where the adapter of the present invention is connected to a notebook PC will be described. Generally, the AC-DC adapter is always connected to an AC power outlet, and its DC plug is connected to a notebook PC so that DC power is supplied to the PC. However, when carrying a PC or when it is stored in a desk at night, it is necessary to shift to a standby mode to save power. In the case of a notebook PC, even to charge the battery inside it,
Since the AC-DC adapter is used, it is appropriate that the transition to the standby mode and the return from the standby mode transition when the DC plug of the AC-DC adapter is inserted and removed.

FIG. 4 shows the DC of the AC-DC adapter of the present invention.
A cross-sectional view of an embodiment of a plug 84 and a DC jack 86 of a notebook PC is shown. When the DC plug 84 is pulled out from the jack 86, the VCC line 88 and the GND line 90 are short-circuited at the contact 92. Therefore, when the notebook PC is not connected, the AC-DC adapter is always in the standby mode.

Next, the DC plug 84 is inserted into the DC jack 86 of the PC. The a portion 96 of the jack 86 is made of an insulating material, and this a portion 96 is the VCC of the DC plug 84 first.
The contact 91 of the line 90 is touched. As a result of the contact 91 being pushed up, the short circuit between the VCC line 90 and the GND line 88 of the DC plug 84 is released. Next, the b portion 98 to which the trigger voltage for restoration is supplied contacts the contact 91 of the VCC line. At this time, VC on the plug side
The trigger voltage is applied to the C line 90, and the adapter returns from the standby mode to the normal operation mode. Further, when the plug 84 is inserted, the PC side VCC line connected to the jack side c portion 99 is connected to the plug (adapter) side VCC line 90, and a DC voltage is supplied to the PC side. On the contrary, when pulling out the plug 84 from the jack 86, pull out the a portion 96 at the tip of the jack until the V
The CC line 88 and GND line 90 are shorted and the adapter is in standby mode. If the trigger battery voltage cannot be supplied for some reason, such as when the battery of the PC is broken, plug the plug 84 into the jack 86 and then disconnect the AC plug 12 (FIG. 2) of the adapter from the outlet. The control IC 34 (FIG. 2) of the adapter is reset and the adapter 100 enters the normal operation mode.

Lastly, the standby mode is not supported, that is, the operation of applying a trigger voltage to the VCC line to release the standby mode and the operation of short-circuiting the VCC line and the GND line for shifting to the standby mode are supported. No, the AC of the present invention is applied to a notebook PC.
The case of applying a DC adapter will be described. Needless to say, the present invention can be applied not only to notebook PCs but also to devices that require any DC power source.

FIG. 5 is a diagram showing a configuration 120 of the AC-DC adapter having the novel option box 102 of the present invention. The option box 102 in FIG. 5 is a small box for releasing the standby mode, which incorporates a small battery 104 such as a dry cell or a solar cell as a trigger voltage source, and is connected to the DC plug 108 which is the output of the adapter section 106. To do. Box output plug 110
Is plugged into the DC jack 112 of the notebook PC for connection. This option box 102 and A
A set of C-DC adapters 106 constitutes one AC-DC adapter (120 in FIG. 5). This adapter 12
By using 0, the notebook PC (device) is a normal notebook PC without a trigger voltage source.
(Equipment) can also obtain the above-mentioned power saving effect.

Next, the option box 102 shown in FIG.
The operation of the AC-DC adapter 120 including the above will be described. When connecting the plug 110 of the option box 102 to a notebook PC (device), (A)-> in FIG.
(B)-> (C)
The shape of is defined. That is, in the (A) unconnected state, the VCC line 114 and the GND line 116 of the plug 110 are short-circuited, and the adapter 106 is in the standby mode. In the connection process of (B), the VCC line 114 of the plug 110 is connected to the output 118 of the trigger voltage source 104, and the trigger voltage is applied to the VCC line 114. As a result, the standby mode of the adapter 106 is released, the normal operation mode is restored, and the DC voltage is output to the VCC line 114. In addition, box tag 11
When 0 is inserted into the jack 112, the device is in the (C) device connection state, and DC power (voltage) from the adapter 106 is supplied to the notebook PC (device).

When the notebook type PC (apparatus) has been used and the plug 110 is to be unplugged, the reverse operation of FIG.
When the operation of (B)-> (A) is followed and the removal is completed, the VCC line 114 and the GND line 116 of the plug 110 are short-circuited, and the adapter 106 enters the standby mode. As described above, the AC-DC adapter of the present invention can be used even in a normal device that does not support the standby mode by only inserting / removing the plug 110 (attaching / detaching the device). If the device side supports the standby mode of the adapter, the option box 102 in FIG.
It is possible to secure the operation of the AC-DC adapter described above by removing.

Further, when the sequence of (A)->(B)-> (C) of FIG. 5 cannot be realized due to the limitation of the jack standard on the device side, etc., the on-switch 6 shown in FIG.
By providing the option box 102 with a switch having the same function as the switch 6 and the off switch 64, the same operation as in the case of FIG.

The notebook PC according to the present invention has been described above.
However, it is needless to say that the present invention can be applied to other devices. And according to this invention, the following effects can be acquired. (1) By setting the power saving mode when there is no load, it is possible to reduce wasteful power consumption, save energy, and save electricity bills. (2) It is possible to cancel the power saving mode and immediately return to the normal operation mode (a state in which DC power can be supplied to the connected device). (3) Regardless of whether or not the power saving mode is supported, power saving in the power saving mode can be achieved in all devices.

[Brief description of drawings]

FIG. 1 is a diagram showing a general configuration of an AC-DC adapter and a device connected to the adapter.

FIG. 2 is a diagram showing an example of a configuration of an AC-DC adapter of the present invention.

FIG. 3 is a diagram showing an example of a configuration on the device side connected to the AC-DC adapter of the present invention. .

FIG. 4 is a cross-sectional view of the DC plug of the AC-DC adapter of the present invention and the DC jack of the notebook PC.

FIG. 5 AC with option box of the invention
It is a figure which shows the structure of a DC adapter.

[Explanation of symbols]

1, 100, 106: AC-DC adapter 2, 12: AC plug 3: AC power outlet 4, 52, 84, 108, 110: DC plug 5,200 ,: Equipment 6,86: DC jack 14, 60, 90, 114: VCC line 16, 62, 88, 94, 116: GND line 18: Diode bridge circuit 20, 28, 42: Capacitor 22: Isolation transformer 24, 26: Diode 30, 32, 44: Resistance 34: Control IC (controller) 38, 46: Photo coupler 50: Switching transistor 64, 66: Switch 80: Main circuit in equipment 70, 72, 74, 76: trigger voltage source 102: Option box

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Seiichi Idei             1623 1423 Shimotsuruma, Yamato-shi, Kanagawa Japan             BM Co., Ltd. Daiwa Office F-term (reference) 5H006 AA00 CA01 CA07 CB01 CC08                       DA04 DB01 DC02 DC05 HA06                       HA08

Claims (13)

[Claims] 1. A device for supplying a DC power source and a power source (VC)
An AC-DC adapter connectable by a C) line and a ground (GND) line, which is a first means for putting the adapter in a power saving mode by short-circuiting the VCC line and the GND line. Second means for releasing the power saving mode by applying a trigger pulse to the VCC line;
AC-DC adapter including. 2. The AC-DC adapter according to claim 1, wherein the first means includes a switch for short-circuiting the VCC line and the GND line, and the second means includes a source for generating the trigger pulse. . 3. A device for supplying a DC power source and a power source (VC)
An AC-DC adapter connectable by a C) line and a ground (GND) line, the first means for putting the adapter into a power saving mode by a short-circuit current between the VCC line and the GND line. A second means for canceling the power saving mode by a trigger voltage supplied to the VCC line. 4. The first means includes means for detecting a short circuit current between the VCC line and the GND line,
The AC-DC adapter of claim 3, wherein the second means includes means for detecting a trigger voltage applied to the VCC line. 5. A device for supplying a DC power source and a power source (VC)
C) A method for controlling an AC-DC adapter that can be connected with a line and a ground (GND) line, comprising: (a) detecting a short circuit current between the VCC line and the GND line; and (b) the short circuit. Placing the adapter in a power saving mode when a current is detected. 6. The method further includes: (c) detecting a trigger voltage supplied to the VCC line; and (d) canceling the power saving mode when the trigger voltage is detected. Item 5. Control method according to item 5. 7. A device for supplying a DC power source and a power source (VC)
An AC-DC adapter which can be connected by a C) line and a ground (GND) line, which is connected to a controller, the GND line and the controller, and detects a short-circuit current between the VCC line and the GND line. A first means for generating a power-saving mode signal (overcurrent signal) to be sent to the controller, connected to the VCC line and the controller,
Second means for detecting a trigger voltage supplied to the VCC line and generating a reset signal to be sent to the controller. 8. The controller generates a signal for stopping the supply of DC power to the device when receiving the overcurrent signal, and a DC power supply to the device when receiving the reset signal. The AC-DC adapter according to claim 7, wherein the AC-DC adapter generates a signal for starting the supply of. 9. A device connected to an AC-DC adapter by a power supply (VCC) line and a ground (GND) line, the device including a short-circuit means for short-circuiting the VCC line and the GND line. Trigger voltage generation means for supplying a trigger voltage to the VCC line, the adapter for detecting a short-circuit current generated by the short circuit of the VCC line and the GND line, to put the adapter in a power saving mode. The first means of
And a second means for canceling the power saving mode by detecting the trigger voltage of the VCC line. 10. The short-circuit means short-circuits the VCC line and the GND line when the power switch of the device is turned off or when the connection between the device and the adapter is released. A device to be connected to the AC-DC adapter according to claim 9. 11. The AC-DC adapter of claim 10, wherein the trigger voltage generating means supplies a trigger voltage to the VCC line when the device and the adapter are connected. machine. 12. The power supply (VCC) for the AC-DC adapter
A method of controlling a device connected by a line and a ground (GND) line, comprising: (a) a step of short-circuiting the VCC line and the GND line; and (b) a short-circuit current between the shorted VCC line and the GND line. And (c) putting the adapter in a power saving mode when the short-circuit current is detected. 13. A method comprising: (d) supplying a trigger voltage to the VCC line; (e) detecting a trigger voltage on the VCC line; and (f) detecting the trigger voltage. The control method according to claim 12, further comprising the step of canceling the power saving mode.