JP2002374675A - Power source adapter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To integrate power source adapters which are separately necessary for a plurality of electronic units together into one adapter. SOLUTION: A power source unit 2 and an output cords 3 of the power source adapter are separated, and the cords 3 are constituted to be replaceable. Each cord 3 has a plug 6 adapted to the electronic device 25 to be used, and a voltage-setting circuit for outputting a power source voltage adapted to the unit 25 or voltage set information; thus since the power source voltage adapted to the unit 25 is output automatically, when the cord 3 adapted at each time is connected to the unit 2 at connecting of the unit 25 to be used, the one power source unit can be used for various electronic device 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power adapter for supplying DC power to various electronic devices, and an output cord and a battery constituting the power adapter.

[0002]

2. Description of the Related Art Various types of electronic equipment using a DC power supply are supplied from a power adapter which connects the power supply to an AC outlet and converts the AC voltage from an AC voltage to a DC voltage suitable for the equipment to be used. Or using battery means.

[0003]

When carrying a plurality of electronic devices, such as a personal computer, a video camera, and a mobile phone, to a bag on a business trip or the like, it is necessary to carry a power adapter dedicated to each electronic device together. This is because the shape, polarity, operating voltage, and the like of plugs connected to each electronic device are different from each other. For that purpose, or intertwined each of line with the amount of power adapter is bulky, or difficult to understand how is any because it is very similar, and you forget the power adapter required.

Also, for example, when the user is in a place where AC power is not supplied, electronic equipment without a battery cannot be used at all. Similarly, battery-owned devices, such as a cell phone's dead battery, could not be reused, even if the battery of an unused video camera was fully charged.

[0005] If a battery of another electronic device owned here can be used, it can be used.

[0006]

SUMMARY OF THE INVENTION In order to solve these problems, the present invention combines a power adapter, which is required for each of a plurality of electronic devices, into one, and performs operations such as output voltage setting. Is unnecessary.

As a means for integrating the power adapters, first, a power supply unit of the power supply adapter and an output cord for supplying an output voltage from the power supply unit to the outside are separated, so that the output cord can be exchanged. . A special output code is prepared for each electronic device used.

The output code can be provided with an identification tag for identifying the target electronic device of the output code or a tag which can be written and identified by the user.

A plug for connecting the output cord to each electronic device has a shape and polarity suitable for each target electronic device.

[0010] The output cord incorporates a voltage setting element or a voltage setting circuit for determining a voltage value of an output voltage supplied from the power supply unit to the equipment to be used.

The connection between the power cord and the output cord of the power supply unit is provided in addition to a conventional voltage output terminal for supplying the output voltage from the power supply unit to the outside.
Add connection means (terminals) to the built-in voltage setting element / circuit.

As the voltage setting element means of the output cord, there are electronic parts such as a zener diode and a shunt regulator. The electronic component is connected as a part of an output voltage setting circuit of a voltage converter in the power supply unit. In addition, it is possible to use a voltage dividing circuit using a resistor or a voltage setting circuit combining a plurality of these elements.

Alternatively, the output code may have voltage setting information for determining the voltage value of the output voltage of the equipment to be used, instead of or in addition to the above-mentioned element / circuit, and reading means for reading the voltage setting information into the power supply unit. An additional method is also possible.

As voltage setting information means to be provided in the output code, there are means for storing information in an electronic storage element, and means for storing digital or analog value information using an electronic circuit.

The power supply unit electrically reads out the information using a reading means, and sets an output voltage value of the voltage converter based on the information. In this case, it is also possible to limit the maximum current value for the target electronic device and to set and read information such as the charging characteristics of the battery in the target electronic device.

As a substitute for the electric means, it is also possible to use optical means or magnetic means. Record the set voltage or current in the output code using a bar code or a magnetic means such as a magnetic memory or optical means equivalent to the bar code,
Means for reading using an optical reading means or a magnetic reading means and setting an output voltage is also effective.

By using the above means, the output voltage is automatically set only by selecting an output code suitable for the target device.

If the battery adapter and the battery charging circuit means / power supply circuit means are added to the power adapter,
Even when an unexpected power failure or an AC outlet cannot be found, it is possible to supply a voltage value suitable for the equipment used.

Further, by making the battery means detachable, for example, when a charged battery of the electronic device A is attached, the electric power charged to the battery can be used to supply power to a different electronic device B.

[0020]

The power adapter according to the present invention has a power supply unit and an output cord suitable for the electronic device to be used (a plug suitable for the target electronic device and a setting element / circuit or setting information of a suitable voltage value are held). Prepare
By connecting, the output voltage value of the voltage converter in the power supply unit can be automatically adjusted based on the voltage set value in the output code. One power supply unit can support various electronic devices.

Further, if a battery is added to the power adapter, it can be used when an unexpected power failure or AC power is not found, and by making the battery detachable, the electronic device A that is not to be used can be used. It can be configured to supply power to different electronic devices B using a battery.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below.

FIG. 1 is a perspective view showing an overall view of a conventional power adapter. Reference numeral 1 denotes an outlet plug and a power cord for connecting to an AC outlet, 2 denotes a power supply unit having a voltage converter therein, and 3 denotes an output cord.
This power adapter connects the outlet plug 1 to a commercial AC power outlet and inputs AC power.

FIG. 2 is a perspective view of an embodiment in which the output cord 3 is exchanged according to various electronic devices. Reference numeral 4 denotes a connection portion of the power supply unit 2 to the output cord 3, reference numeral 5 denotes a connection portion of the output cord 3 to the power supply unit 2, and reference numeral 6 denotes plugs which are connected to each electronic device and have different shapes and polarities.

Reference numeral 25 denotes an example of each electronic device, and reference numeral 26 denotes an identification tag for clarifying which electronic device is used. Identification tag 26
Alternatively, tags that can be written and identified by the user themselves can be added to the output code 3 as necessary.

As described above, the power supply unit 2 and the output cord 3
And the output cords 3 having the plugs 6 respectively adapted to the various electronic devices 25 to be used are connected to the connection units 4.5.
By connecting to the power supply unit each time, various electronic devices can be mechanically supported.

Next, an electric means for creating a power supply voltage suitable for the electronic equipment to be used by exchanging the output cord 3 will be described.

FIG. 3 is an internal configuration diagram of the embodiment. 3a
3b is an example of an output code, and for explanation, the output code 3a is for an output voltage of 5V and 3b is for an output voltage of 8V.

Reference numerals 7a and 7b denote power supply output terminals for supplying power to the electronic equipment located at the connection portion 4 of the power supply unit 2, and 7
c · 7d is a voltage setting circuit connection terminal also located at the connection part 4, 8a · 8b is a power supply output connection terminal located at the connection part 5 of the output cord 3, and 8c · 8d is a voltage also located at the connection part 5. Indicates a setting circuit output terminal.

Reference numeral 9 denotes an AC /
DC voltage converter, 10 denotes a voltage setting element (Zener diode), and the voltage setting value of 10a is 5V, 10b
Is 8V.

FIG. 4 is a schematic circuit diagram in which the embodiment of FIG. 3 is developed by a switching AC / DC converter using a flyback method. 11 is a bridge for full-wave rectification, 12
Denotes an insulating transformer, 13 denotes a switching element, 14 denotes a switching control circuit, 15 denotes a photocoupler, and 16 denotes a secondary voltage smoothing circuit.

The circuit operation will be described in brief. First, power is transmitted from the primary side smoothed by the bridge 11 for full-wave rectification of the AC input from the AC power supply 1 to the secondary side via the insulating transformer 12. are doing. Thereafter, the following operation is repeated.

(A) When the switching element 13 is turned on, power is supplied to the secondary side, and the output voltage on the secondary side increases. As a result, when the voltage value across the Zener diode 10a exceeds the breakdown voltage of the Zener diode, a current flows through the Zener diode and the output of the photocoupler 15 becomes O
N, the signal is received by the switching control circuit 14 and the switching element 13 is turned off.

(B) When the switching element 13 is turned off, the power to the secondary side stops, and the output voltage on the secondary side decreases. As a result, when the voltage value across the Zener diode 10a becomes less than the breakdown voltage of the Zener diode, no current flows through the Zener diode, the output of the photocoupler 15 is turned off, and the signal is transmitted to the switching control circuit 1
4 turns on the switching element 13.

The switching type AC / DC converter comprises:
By repeating (a) and (b) (switching) the output voltage on the secondary side is generated and stabilized by the smoothing circuit 16.
The switching of (a) and (b) is controlled by a small fluctuation of the secondary voltage such that the secondary voltage exceeds / does not exceed the breakdown voltage of the Zener diode 10a. As a result, AC / D
The C converter can generate a stable output voltage value.

Therefore, the output voltage value on the secondary side is determined by the breakdown voltage value of the Zener diode 10. Zener diode 10a for output voltage set value 5V shown in FIGS.
Can be dealt with by using a breakdown voltage value of about 4 V obtained by subtracting the input voltage drop (tentatively 1 V) of the photocoupler 15 connected in series from the voltage setting value of 5 V. Zener diode 10b for output voltage setting value 8V
(The breakdown voltage value is 7V), the output voltage value changes from 5V to 8V.

In the present invention, the Zener diode 10
Are attached separately to the output cord 3 side. With this configuration, it is possible to change the output voltage only by changing the output code 3 having the built-in Zener diodes 10 having different breakdown voltage values. For example, if the output code 3a in FIGS.
The output voltage automatically changes from 5V to 8V.

As an embodiment, the present invention can be applied to a converter using a system other than the flyback system.

The voltage setting element is not limited to a Zener diode, but may be a shunt regulator, a voltage setting circuit formed by combining elements, a voltage dividing circuit using a resistor, or the like in accordance with various types of converters and the accuracy of output voltage. Can be used.

Also, a DC / DC power supply input source is DC.
A converter is also possible, and various considerations can be made in addition to the description of the number and arrangement of terminals of the connection portion.

FIG. 5 is an internal configuration diagram of another embodiment. 1
7 indicates voltage setting information, and the voltage setting value of 17a is 10
V and 17b are 3V. Reference numeral 18 denotes a voltage setting information reading device.

In this embodiment, unlike the embodiment of FIGS. 3 and 4, the voltage setting information 17 in the output code 3 is not directly used as a part of the output voltage adjustment circuit, but the information is read out as digital or analog information and output. A means for adjusting the voltage is used. In this case, it is conceivable to set not only the voltage value but also various kinds of control information of the voltage converter 9 such as the maximum current value and the stop of power supply according to the charging characteristics of the battery in the target electronic device.

As one embodiment of the voltage setting information 17,
An implementation in which necessary data is stored in an electronic storage component such as a ROM can be considered. A device for reading data from the ROM or the like
In step S8, control signals such as an output voltage value and a maximum current value are supplied to the voltage converter 9 to control the output.

In addition, a resistance value, a constant voltage circuit, a constant current circuit,
It is conceivable to use a frequency generating circuit or the like as the voltage setting information 17, or to adjust the set value of the output voltage of the output code 3 by attaching a variable resistor, a DIP switch, or the like.

It is also conceivable to use optical means and magnetic means. A set voltage value or the like is recorded in the connection portion 5 of the output code 3 by bar code printing or an optical means equivalent thereto, and is read out by using the optical reading device 18 to set an output voltage. It is also effective to use a magnetic reading device 18 to record the set voltage value or the like by magnetic printing or a magnetic means equivalent to the magnetic recording device, read the data using the magnetic reader 18, and set the output voltage.

The voltage setting information 17 and the reading device 18 described above can be mounted in place of or in addition to the voltage setting element / circuit 10 described with reference to FIGS.

In each embodiment, the voltage setting element / circuit 1
By providing 0 or the voltage setting information 17 on the output code 3 side, even if an electronic device of a new use voltage that has not been planned appears, a new output code 3 is prepared each time without replacing the power supply unit 2. If you can do it.

FIG. 6 is an internal configuration diagram of an embodiment to which an output protection circuit is added. Reference numeral 19 denotes a voltage absorber (including a zener diode for short-circuit protection). The voltage set value of 19a is a value obtained by adding a margin to 5V of 10a.
b is a value obtained by adding a margin to 8 V of 10b.

When a voltage higher than the set voltage is output due to some abnormality of the power adapter according to the present invention, external devices may be damaged. When a voltage higher than the set voltage is output, or when a current higher than the maximum current value flows,
By adding a circuit for protecting the external device, it is possible to prevent external devices from being damaged.

Means for directly short-circuiting the excessive voltage or means for indirectly detecting and stopping the output of the power supply unit 2 can be considered. By incorporating the short-circuiting means or the detecting means in the output cord 3, Thus, an output protection circuit suitable for each output voltage can be realized.

As an example of the short-circuit means, a voltage absorber 19 is provided between the power supply outputs 8a and 8b in the output cord 3 of FIG.
When a voltage higher than the maximum voltage is applied, a short-circuit current flows between both ends, thereby preventing an excessive voltage from being applied to the external device.

As an example of the detecting means, a means for adding a detecting circuit including a Zener diode for detecting an overvoltage is similarly effective between the power supply outputs 8a and 8b in the output cord 3. When a voltage higher than the breakdown voltage is applied to both ends of the overvoltage detecting Zener diode, a short-circuit current flows. Therefore, it is possible to configure a circuit that detects the short-circuit current and cuts off the output on the power supply unit 2 side.

The voltage set value at which the zener diode for short-circuit protection and the voltage absorber 19 operate may be set to a value slightly exceeding the normal output voltage value. For example, if the output voltage set value is 5V, the voltage absorber 19a can be mounted on each output code 3 such as 7V, if the output voltage set value is 8V, the voltage absorber 19b can be mounted on 10V.

Further, in the power supply adapter according to the present invention, it is not known how much the output should be, until the output cord 3 is connected to the power supply unit 2. Therefore, if the power supply is connected as it is, an indefinite voltage can be output first. There is. Therefore, if the voltage setting circuit is connected before the wiring section of the power supply to be supplied to the outside is connected by devising the connectors and terminals of the connection sections 4 and 5, the setting is normally performed. Voltage can be supplied from the beginning.

FIG. 7 shows an embodiment in which a device for delaying the connection to the output terminal is added.

As shown in FIG. 7, the power supply output terminals 8a and 8b of the connection portion 5 of the output cord 3 are shortened and arranged inside, and the output voltage setting element connection terminals 8c and 8 are provided.
Make d longer and place it outside. With such a configuration, the power output terminal 7 of the connection portion 4 of the power supply unit 2 is provided.
Before the output voltage is externally supplied by being connected to
The Zener diode 10 of the output cord 3 is first connected to the AC / DC converter via the terminals 7c and 7d of the connection part 4 of the power supply unit 2, so that a margin for setting the output voltage correctly can be obtained. It is also conceivable to provide a time delay by providing a delay mechanism such as a two-stage insertion or the like after turning or turning back after insertion.

As another means for delaying the power supply output, before and immediately after the output cord 3 is connected to the power supply unit 2, the power supply output circuit is shut off and the power supply is not output. It is also conceivable that the voltage comparison means determines that the output voltage has reached the optimum value or the output voltage value has reached the optimum value and starts power supply output.

FIG. 11 is an internal configuration diagram showing an example of a means for generating a delay time until output. 29 is a relay coil, 30 is a relay contact, and 31 is a short-circuit terminal by the output code 3. The relay coil 29 is energized to drive the relay through the short-circuiting terminal 31 newly provided in the connection portions 4 and 5, and as a result, the power supply output circuit that has been cut off by the relay contact 30 is connected, so that the power supply output is performed. Can be supplied externally. At this time, due to the time delay that occurs until the relay is driven, power can be output to an external device when the output voltage value is stable, and further time delay can be added by adding a time delay circuit such as a timer relay. It is possible.

In addition, the fact that the output voltage value has reached the optimum value is detected by using a voltage comparison circuit such as a comparator, and if the output voltage value is the same as the set voltage, the power supply output circuit, which has been cut off, is connected and externally supplied. A way to start is also conceivable.

Further, a manual switch can be separately provided, and after the power supply unit 2 and the output cord 3 are connected, the switch can be pressed to output the power supply output to the external device for the first time.

FIG. 8 is a perspective view of an embodiment in which a battery is added to the present invention, and FIG. 9 is an internal configuration diagram thereof. FIG. 8A is a perspective view when the battery is separated, and FIG. 8B is a perspective view when the battery is connected.

FIG. 9A shows the operation when the AC power supply is valid, and the broken thin line indicates the operation invalidation part. FIG. 9B shows a state in which the AC power supply is invalid and the operation is performed using the power from the battery.

Reference numeral 20 denotes a battery, 21 denotes a connection portion between the power supply unit and the battery, 22 denotes a battery charging circuit,
Is the power supply circuit from the battery (DC / DC converter)
Is shown.

The detachable battery 2 is connected to the power adapter.
0, the battery charging circuit 22 and the power supply circuit 23
The electronic device can be used even when there is no power supply such as an AC power supply.

FIG. 9A shows a state in which ordinary AC power is turned on, power is output from the AC / DC converter 9 and at the same time power is supplied to the charging circuit 22 to charge the connected battery 20. .

FIG. 9B shows a state in which no AC power is obtained and power is supplied from the battery 20 to the power supply circuit (DC / DC converter). Since the output voltage of the DC / DC converter is set by a DC / DC converter voltage setting element (such as a Zener diode) 24 connected to the voltage setting element connection terminals 8e and 8f located at the connection portion 5 of the output cord 3, By changing the output code 3 so as to set the output voltage value of the AC / DC converter 9, the output voltage value from the battery can be changed.

With the configuration shown in FIG. 9, when the AC power supply is valid, the output voltage value of the voltage setting
When the battery is driven, the output voltage of the voltage setting element 24 can be changed according to the power supply condition, such as 4 V. As a result, for example, when the battery is driven, a device that extends the battery life instead of reducing the operation speed of the electronic device can be realized.

Of course, the voltage setting information 17 shown in FIG.
It is also possible to finely set and store the output voltage value or the like in a (ROM or the like) and read and set it.

A power supply circuit (DC /
The DC converter 23 can use either a step-up or step-down converter, and can raise or lower the voltage of the battery. It is also conceivable to add the switching terminal or the like to the connection section 5 of the output cord 3.

Further, if only the connection portion 5 of the output cord 3 is prepared as a single unit so that the user can perform the wiring work, it is possible to process the existing power adapter owned by the user and use it. .

FIG. 10 is an explanatory view of processing and diverting a conventional power adapter. 27 is a conventional power adapter, 28
Denotes a screw for fixing the wiring from the power supply adapter 27.

FIG. 10 (a) is a perspective view of a conventional power adapter, and FIG. 10 (b) is a diagram showing a method of fixing the wiring of the cut power adapter. A connection portion 5 having an output voltage value compatible with the existing AC adapter 27 is prepared, and the wiring from the AC adapter 27 is cut off while leaving the plug side.
The power output wiring is pulled out from the cut cord and connected to the terminals 8a and 8b of the connection portion 5.

In this manner, a conventional power adapter can be remodeled and used as the output cord 3 of the power adapter of the present invention. Further, the terminal 8 of the connection section 5
It is also conceivable to make the voltage setting element 10 connected to c · 8d replaceable. It is possible to have the voltage setting information 17 instead of the voltage setting element 10, and if the variable resistor or the like described above is mounted as the voltage setting information 17, the user can adjust the output voltage value of the output code 3.・
It is also possible to change it.

Although various embodiments have been described above, various modifications can be considered for the configuration of each part. Various signal terminals can be added to the connection parts 4 and 5 as necessary.
Also, the number of terminals can be reduced. For example, in FIG. 3, the connection terminals are described as having four configurations from 8a to 8d, but if implemented in the circuit example of FIG. 4, 8b and 8d can be combined because they are the same circuit net. The number of terminals will be three.

It is of course possible to prepare a plurality of AC / DC converters 9 and connection portions 4 in the power supply unit 2 to increase the number of voltage output portions to two or more, and to provide a secondary circuit of the AC / DC converter 9. Can be easily realized by preparing two or more and separately preparing a dedicated voltage output unit having a fixed voltage value.

[0076]

As described above, the present invention makes it possible to use a common power supply unit among power supply adapters required for various electronic devices, and to carry several types of electronic devices in a bag on a business trip or the like. Realizing space saving.

Further, even if a device using a voltage which is not expected in the future appears, if the range of the used voltage and the used current falls within the maximum specifications of the power supply unit, there is no need to replace the power supply unit. If the method of changing the output cord side from the multiple output voltage values prepared by the power supply unit is adopted, the voltage value can be selected only within the limited set number. If the output code side has the information of the voltage setting value as in the present invention, it is possible to flexibly cope with it only by preparing an output code containing elements or circuits for setting a newly required output voltage value.

Further, when it is necessary to supply power to a plurality of electronic devices at the same time, by providing the required number of power supply units according to the present invention, the configuration with the least waste can be realized. For example, laptops, digital cameras, camcorders,
When carrying six types of electronic devices such as an external DVD-ROM device, a printer, and a mobile phone, three power supply units of the present invention may be prepared if the maximum number of simultaneous use is three. The number can be further reduced if the electronic device to be used uses a battery drive. Of course, it is possible to increase the number of DC voltage output units of the power supply unit to two or more.

In addition, by adding a battery and a battery charging / feeding circuit to the power adapter of the present invention, power can be supplied to the equipment in use even when an unexpected power failure or AC power source is not found. Further, it is possible to make the battery detachable so that the battery of the electronic device A can supply power to a different electronic device B. For example, if the detachable battery is shared with the one used for the video camera, the battery of the video camera can be charged by the power adapter, and the charged battery is attached to the power adapter in an environment without AC power. Thus, power can be supplied to another electronic device.

The input power of the power adapter according to the present invention is not limited to the AC power, but the AC power adapter for other electronic equipment is used to receive the DC power output from the power adapter and output the DC power from the DC / DC converter. A configuration for creating a voltage is also possible. For example, in a case where a personal computer and its power adapter are always carried around, it is possible to reduce the size and cost by using the output from the power adapter as the input power of the power adapter according to the present invention.

Further, by preparing only the connection portion of the output cord as a single unit so that the user can easily perform the wiring work, the AC adapter manufactured in the past can be used. If you prepare connection parts corresponding to various output voltage values, obtain a connection part with an output voltage value compatible with the AC adapter you own, cut the wiring of the AC adapter and connect it to the connection part For example, past products can be used in the power adapter according to the present invention.

[Brief description of the drawings]

FIG. 1 is a perspective view of a conventional power supply unit.

FIG. 2 is a perspective view of the embodiment.

FIG. 3 is an internal configuration diagram of the embodiment.

FIG. 4 is a schematic circuit diagram of an embodiment.

FIG. 5 is an internal configuration diagram of a second embodiment.

FIG. 6 is an internal configuration diagram of an embodiment to which an output protection circuit is added.

FIG. 7 is an explanatory diagram of an embodiment to which an output delay mechanism is added.

FIG. 8 is a perspective view of an embodiment in which a battery is added to the present invention.

FIG. 9 is an internal configuration diagram of an embodiment in which a battery is added to the present invention.

FIG. 10 is an explanatory view of diverting a conventional power adapter.

FIG. 11 is an internal configuration diagram to which a means for generating a delay time is added.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Outlet plug 2 Power supply unit 3 Output cord 3a Output cord (for 5V) 3b Output cord (for 8V) 4 Connection part of power supply unit 5 Connection part of output cord 6 Plug 7a-7f terminal 8a-8f terminal 9 Voltage converter (AC / DC converter) 10 Voltage setting element 10a Voltage setting element (for 5V) 10b Voltage setting element (for 8V) 11 Full-wave rectification bridge 12 Insulation transformer 13 Switching element 14 Switching control circuit 15 Photocoupler 16 Smoothing circuit 17 Voltage setting information 17a Voltage Setting information (for 10 V) 17 b Voltage setting information (for 3 V) 18 Voltage setting information reader 19 Voltage absorber 20 Battery 21 Battery connection terminal 22 Battery charging circuit 23 Battery power supply circuit (DC / DC converter) 24 C / DC converter voltage setting device 25 various kinds of electronic devices 26 identification tag 27 power adapter 28 wiring fixing screw 29 the relay coil 30 the relay contact 31 shorting terminal

Claims (6)

[Claims] A power input means; an output cord means for supplying an exchangeable output voltage to an external device;
Voltage converter means for generating one or a plurality of output voltages from the input voltage input from the power supply input means and supplying each output voltage to the outside through output code means; and A power adapter characterized in that an electronic circuit comprising an element for determining a set value of an output voltage or a plurality of elements is provided as a part. 2. An output code means for converting information such as an output voltage value into a digital or analog signal to an electric means, an optical means, or a magnetic means in place of or in addition to an element or an electronic circuit for determining the set value of the output voltage. 2. The power supply adapter according to claim 1, further comprising a voltage setting means for holding the power supply means and reading the voltage and setting an output voltage value on the power supply unit main body side. 3. The power adapter according to claim 1, wherein a protection element or a circuit for clamping an excessive voltage generated between the power supply output terminals from the output cord means is added to the output cord means. 4. A power adapter according to claim 1, wherein a junction of the output cord is connected to a terminal of the voltage setting circuit before a terminal of a power output supplied to the outside through the output cord means. . 5. The power supply is not output immediately after the output cord means is connected to the power supply unit, and the voltage comparison means determines that the power supply has been reached manually or after a predetermined time has elapsed by using the time delay means, or that the optimum voltage has been reached. 2. The power adapter according to claim 1, wherein the power adapter starts outputting power. 6. The power adapter according to claim 1, further comprising detachable battery means, charging means for the battery, and power feeding means from the battery.