JP2000134816A - Electronic apparatus and ac adaptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To consistently supply stable power for operation to a plurality of types of electronic apparatuses with different power supply input specifications, without preparation of AC adaptors peculiar to respective apparatuses and, further, realize an automatic apparatus specification recognition function and an output power supply matching function, i.e., an AC adaptor generates and outputs an operation power supply matched with the specifications of the apparatus main part without requiring an exclusive control signal line, and furthermore, without affecting noise upon the apparatus operation. SOLUTION: When an AC adaptor 11 is connected to an electronic apparatus main part 12, the electronic apparatus main part 12 varies the impedance on a power supply output line PL for a certain time period, to inform the AC adaptor 11 of the power supply input specifications of itself. The AC adaptor 11 recognizes the power supply input specifications of the power supply object apparatus based on the information given by the impedance variation from the apparatus main part 12 and generates and outputs operation power by the output specifications which follows the recognized input specifications.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electronic device operable by an AC adapter power supply and an AC adapter for supplying an operation power supply to the electronic device. Further, the present invention relates to an electronic device and an AC adapter having a function of switching a power output specification of an AC adapter according to a power input specification of a device main body.

[0002]

2. Description of the Related Art Conventionally, in an electronic device such as a portable personal computer, which can be operated by an AC adapter power supply, a dedicated device having a specific standard depending on a model and furthermore, a type of a built-in secondary battery and the like. AC adapter was required.

Therefore, conventionally, there has been a problem that a dedicated AC adapter must be prepared each time the type of the electronic device and the type of the secondary battery change. On the other hand, as a conventional technology for identifying an AC adapter in this type of device, a configuration in which a dedicated signal line for identifying the AC adapter is provided (Japanese Patent Laid-Open No. 2-261888 (software notification type battery charging system), 168185 (battery charger)) and a device that combines a specific signal voltage with the DC output of an AC adapter and separates them on the device side (JP-A-7-143949 (AC adapter and device using AC adapter)), etc. Exists.

[0004] Among these technologies, in a configuration in which a dedicated signal line for identifying the AC adapter is provided to identify the AC adapter, an AC power supply line is separately provided between the AC adapter and the device in addition to the DC power supply line. A dedicated signal line for identifying the adapter and a connector terminal for connecting the signal line are required, which results in a large diameter adapter cable, which imposes restrictions on the connector connection means, which is inconvenient and complicated in structure. There was a problem of inviting. Further, since the number of parts on the exterior structure increases, sufficient consideration is required for handling, and poor contact of the connector, disconnection of the signal line, and the like are likely to occur, and there is also a problem in reliability.

In a configuration in which a specific signal voltage is combined with a DC output voltage of an AC adapter and separated on a device side,
Since a signal synthesis circuit is required on the AC adapter side and a signal separation circuit is required on the device side, there has been a problem that the circuit configuration is complicated. Further, D, which is a power supply for operation,
Since the specific signal voltage is superimposed on the C voltage, for example, when this configuration is applied to a sophisticated electronic device that is easily affected by noise such as a personal computer, the signal voltage becomes a noise source and causes a malfunction. Therefore, there is a problem that it cannot be used for electronic devices such as personal computers which are easily affected by noise.

[0006]

As described above, conventionally, in an electronic device such as a portable personal computer, which can be operated by an AC adapter power supply, conventionally, depending on the model, the type of a built-in secondary battery, and the like. Therefore, a dedicated AC adapter having a specific standard is required, so every time the type of device or the type of secondary battery changes,
There is a problem that a dedicated AC adapter must be prepared for each.

In the conventional AC adapter identification technology, in a configuration in which a dedicated signal line for identifying the AC adapter is provided, an AC adapter identification line is separately provided between the AC adapter and the device in addition to the DC power supply line. A dedicated signal line and a connector terminal for connecting the signal line are required, and the adapter cable is increased in diameter and the connector connecting means is restricted, which results in poor usability and complicated structure. There was a problem. Further, since the number of parts on the exterior structure increases, sufficient consideration is required for handling, and poor contact of the connector, disconnection of the signal line, and the like are likely to occur, and there is also a problem in reliability. Furthermore, in the conventional AC adapter identification technology, in a configuration in which a specific signal voltage is combined with the DC output voltage of the AC adapter and separated on the device side, a signal combining circuit is required on the AC adapter side, and the device side is required. Since a signal separation circuit is required, there is a problem that the circuit configuration is complicated, and a specific signal voltage is superimposed on a DC voltage serving as a power supply for operation. When applied to sensitive electronic devices that are easily affected, the signal voltage is liable to cause a malfunction due to a noise source, and therefore cannot be applied to electronic devices such as personal computers that are easily affected by noise.

[0008] The present invention has been made in view of the above circumstances,
In an electronic device operable with an AC adapter power supply,
Provided are an electronic device and an AC adapter that can always supply and control a stable operation power supply in accordance with the device specifications for a plurality of types of devices having different power input specifications without preparing an AC adapter unique to each device. The purpose is to:

Further, according to the present invention, in an electronic device operable by an AC adapter power supply, an AC adapter is connected to the device main body so that the AC adapter generates and outputs an operation power supply conforming to the specification of the device main body. An object of the present invention is to provide an electronic device and an AC adapter which can realize a function of automatically recognizing device specifications and a function of matching output power without requiring a dedicated control signal line and without affecting the operation of the device with noise. And

[0010]

SUMMARY OF THE INVENTION The present invention relates to an electronic device which can be operated by an AC adapter power supply.
When the C adapter is connected, the impedance of the power line of the AC adapter is changed for a certain period of time to notify the AC adapter of the power input specification of the own device.
Further, according to the present invention, the AC adapter recognizes a power supply input specification of a power supply target device based on information notification from the device main body due to impedance fluctuation, and generates an operation power supply based on the output specification according to the recognized input specification. Output.

By having the function of automatically recognizing device specifications and the function of matching output power, it is possible to prepare a plurality of types of devices having different power input specifications without preparing an AC adapter unique to each device. It is possible to always supply a stable operation power supply according to the device specifications, and to supply a stable operation power supply according to the device specifications without requiring a dedicated control signal line and without affecting the operation of the device with noise.

That is, the present invention relates to an AC adapter having an output specification switching function and an electronic apparatus having an external power input function of receiving an operation power from the AC adapter.
By changing the input impedance of the electronic device for a certain period of time, the output specification of the AC adapter is switched without requiring a control signal line.

At this time, the power supply input impedance switching means of the electronic device first changes the output voltage or output current of the AC adapter on the device side, and changes the voltage or current on the AC adapter side to “1”. "(H) or" 0 "(L) is detected. The AC adapter is “1”,
Identification information (digital data) by combination of "0" or frequency (period) of "1" and "0" respectively
The input specification of the device is recognized based on the identification information (period data) having different values, or the identification information (duty data) in which the duty is changed between "1" and "0", and the output specification is switched.

Thus, on the device side, a signal is output to the power supply line only during a partial period before receiving the normal operation power from the AC adapter, and the operation power received from the AC adapter includes other signals. Is not superimposed, there is no possibility that the noise accompanying the signal synthesis will affect the operation of the main circuit via the power supply line, and is therefore susceptible to the noise. For example, portable terminal equipment of personal computers, etc. And stable operation with high reliability can be expected.

If the output specifications of the AC adapter do not match the input specifications of the electronic device, or if there is no change in the input impedance of the electronic device for identifying the AC adapter, the AC adapter stops the output, or By reducing the output voltage, current, etc. below a predetermined value,
Inconvenience due to mismatch between the AC adapter and the device can be eliminated.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an AC according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a main part of the entire electronic device including an adapter.

In FIG. 1, reference numeral 11 denotes an AC adapter, and reference numeral 12 denotes a main body of an electronic device. 13 to 16 are AC adapters 1
Reference numeral 13 denotes an AC → DC converter for converting external commercial AC power (AC) into DC power (DC), and 14 denotes an AC connected to an output terminal of the AC → DC converter 13. An output voltage / output current detecting unit 15 for detecting a change in impedance on the output line (PL) of the adapter 11 as a voltage value or a current value, and 15 based on the detection output of the output voltage / output current detecting unit 14 Power output line (P
L) An output fluctuation analysis unit for analyzing the identification information type (digital data / periodic data / duty data) and its data content (specification number) from the output impedance fluctuation content above, and 16 is the analysis result of the output fluctuation analysis unit 15 ( An output voltage / output current set value control unit that switches the set values of the output voltage and output current of the AC adapter 11 according to the power input specification of the connected electronic device body 12 according to the specification number).

Reference numerals 17 to 19 denote electronic device main bodies 12 respectively.
17 is an input impedance switching unit for switching and controlling the input impedance of the power output line (PL) of the AC adapter 11, and 18 is the AC adapter 1
Electronic equipment body 12 using DC output power of 1 as an operation power supply
When the AC adapter 11 is connected and the power supply for normal operation is not yet received (referred to as a device specification recognition mode), the main circuit unit (system) 19 has a constant power supply specification according to its own device. During this period, the input impedance control section 17 switches (turns on / off) the input impedance switching section 17.

The impedance variation on the power supply output line (PL) of the electronic device main body 12 at this time is represented by A
When the C adapter 11 is connected, means for performing a predetermined time, or switching of the output specification of the AC adapter 11 is completed, and the AC adapter 11 is switched from the low voltage specification recognition mode to the normal operation mode according to the device specification. Any means for performing the operation until the switching is performed may be used.

For example, the AC adapter 11 supplies the power output line (P) until the device specification of the electronic device main body 12 is recognized by the impedance fluctuation on the power output line (PL).
L), the power for information exchange at a low power and low voltage level (for example, a constant voltage of about 5 V to 6 V) is output as a device specification recognition mode, and the electronic device main body 12 outputs the low power and low voltage level for information exchange. While receiving the power of
Implements impedance conversion to notify device specifications. Thereafter, the AC adapter 11 recognizes and sets the device specifications by the impedance conversion, and outputs power (for example, a constant voltage of 15 V to 18 V) according to the set device specifications to the power output line (PL). Alternatively, while receiving power for information exchange at a low power and low voltage level from the AC adapter 11, impedance conversion for notifying the device specifications is performed in the device specification recognition mode, and power according to the device specifications (for example, 15 V to 18 V) is used. After confirming that a constant voltage has been received, the operation of changing the impedance is stopped.

In the configuration shown in FIG. 1, when AC power is supplied to the AC adapter 11, the AC power is changed from AC to AC.
The power is converted into DC power by the DC converter 13 and supplied to the electronic device main body 12 via the power output line (PL).
At this time, since the AC adapter 11 has not yet received the information for recognizing the power supply specification of the device due to the impedance change from the connected device, the predetermined small power low in the device specification recognition mode has not been received. A power having a voltage value (a voltage significantly lower than the operating voltage of the system 19) is output on a power supply output line (PL) as a power supply for information exchange.

When the main body 12 of the electronic device receives a power source for information exchange of a predetermined low power and low voltage value from the AC adapter 11,
In order to notify the C adapter 11 of the power input specification of the own device, the impedance on the predetermined power output line (PL) is changed in accordance with the power specification of the own device for a certain period.

That is, in the electronic equipment main body 12, when the input impedance control section 19 recognizes that a predetermined low-voltage information exchange power supply is supplied on the power supply output line (PL), the input impedance control section 19 determines in advance for a predetermined period. According to the identification information type (digital data / period data / duty data), the input impedance switching unit 17 is switched (on / off) in accordance with the power input specification of the own device to control the impedance of the power output line (PL). Fluctuate. Due to the change in the input impedance, the output impedance of the AC adapter 11 changes.

In the AC adapter 11, the output voltage / output current detector 14 detects the fluctuation of the output impedance, and the output fluctuation analyzer 15 analyzes the output impedance fluctuation. The output voltage / output current setting value control unit 16 switches the output voltage and output current set values of the AC adapter 11 in accordance with the power input specification of the connected electronic device main body 12 based on the analysis result of the fluctuation contents.

After the change of the set value of the AC adapter 11, the input impedance control unit 19 stops the switching of the input impedance by the input impedance switching unit 17, and the system 18 is supplied with the power according to the device specifications as the operation power. You.

FIG. 6 to FIG. 12 show examples of impedance fluctuations due to specific identification information types (digital data / periodic data / duty data), setting of device specifications associated therewith, and examples of power output in accordance with the device specifications. And will be described later.

Next, a specific example of the configuration of the AC adapter 11 is shown in FIGS. FIG. 2 shows a first embodiment of the AC adapter 11 having the above-described functions. In the first embodiment shown in FIG. 2 shows an example of a configuration realized by.

When AC power is input to the AC adapter 11, the AC power is applied to the AC → DC converter 1 shown in FIG.
3 is rectified and smoothed by a bridge diode and a capacitor of the pre-stage rectifier circuit 101 included in
DC conversion is performed.

The D output from the pre-stage rectifier circuit 101
The C power is also attenuated (voltage / current conversion) by the switching circuit 105 and the transformer (transformer) 102 included in the AC → DC converter 13, and the diode of the post-stage rectifier circuit 103 also included in the AC → DC converter 13. ,
And rectified and smoothed by a capacitor and output on a power supply output line (PL).

At this time, the output voltage and the output current are supplied to the voltage dividing resistors 107 and 108, the current detecting resistor 106 and the current detecting resistor included in the output voltage / output current detecting section 14 shown in FIG.
Error amplifier 115 for voltage, error amplifier 112 for current
And the like, and the value of the detection result is the PWM control unit 1
04 (feedback).

The PWM controller 104 controls the switching circuit 105 based on the values of the detection results of the output voltage and the output current.
(Pulse width modulation) control. The output power stabilization control is performed by the PWM control.

Here, the detection of the output voltage is performed by inputting the voltage data (ed) obtained by dividing the output voltage by the voltage dividing resistors 107 and 108 to the voltage error amplifier 115.

The output current is detected by amplifying the voltage between both ends of the current detecting resistor 106 by an amplifier (amplifier) 111, and changing the current value (id) of the current error to the current error amplifier 112.
This is performed by inputting to the comparator 117 and the timer 110.

The current error amplifier 112 compares the current data (id) with the reference voltage (e2), and inputs the value of the comparison result to the voltage error amplifier 115 as current comparison data (ic).

The voltage error amplifier 115 performs the following operations (a) and (b) according to the magnitude of the current comparison data (ic) and the voltage data (ed). Operation (a) When the output current value (id) detected from both ends of the current detection resistor 106 is equal to or less than the output current set value set by the reference voltage (e2), the current comparison data (ic) indicates a voltage error. It is not sent to the amplifier 115.

In this case, the voltage error amplifier 115
The voltage data (ed) is compared with the reference voltage (e1) of the reference voltage setting unit 116. Therefore, the voltage error amplifier 1
The voltage comparison data (ec), which is output from No. 15, is a comparison result with the voltage set value set by the reference voltage (e1) of the reference voltage setting unit 116.

The voltage comparison data (ec) output from the voltage error amplifier 115 is output to the output voltage / output current set value control unit 109, which constitutes the output voltage / output current set value control unit 16 shown in FIG. It is sent to the PWM control unit 104.

The PWM control unit 104 recognizes the current output based on the voltage comparison data (ec) and performs PWM (pulse width modulation) control on the switch 105 to perform stabilized output control. That is, when the output current value is equal to or less than the current set value,
The output voltage becomes the output voltage set value.

Operation (b) The output current value is equal to the reference voltage (e
If the output current set value set in 2) is exceeded, current comparison data (ic) is output to the voltage error amplifier 115.

In this case, the voltage error amplifier 115
[Voltage data (ed) + current comparison data (ic)] is compared with the reference voltage (e1) of the reference voltage setting unit 116. Therefore, the voltage comparison data (ec) output from the voltage error amplifier 115 is smaller than the voltage set value (reference voltage (e1)) set by the reference voltage setting unit 116 by the current comparison data (ic). The result is a comparison by value.

The voltage comparison data (ec) output from the voltage error amplifier 115 is sent to the output voltage / output current set value control unit 109 and the PWM control unit 104. The PWM control unit 104 calculates the voltage comparison data (ec)
To recognize the current output and switch 105 to PWM
(Pulse width modulation) control to perform stabilized output control.

As a result, the output voltage decreases by the amount of the current comparison data (ic). That is, when the output current value exceeds the current set value, the current is limited and the output voltage changes.

Incidentally, the diode 114 stores the voltage data (e
d) prevents unnecessary current input to the current error amplifier 112 from sneaking. In this embodiment, FIG.
As shown in FIG. One is a current limit value (1) for preventing an overcurrent, and the other is when the electronic device body 12 has a secondary battery.
Current limit value for constant current charging of the secondary battery (2)
It is. The switching between the current limit value (1) and the current limit value (2) is realized by switching the set value of the reference voltage setting unit 113, that is, the reference voltage value (e2) by the timer 110.

The switching between the current limit value (1) and the current limit value (2) is as follows: (a) When the output current is equal to or less than the current limit value (2), the reference voltage (e2) of the reference voltage setting unit 113 is changed. Is switched to the reference voltage value which becomes the output current set value of the current limit value (1).

(B) When the output current exceeds the current limit value (2) After a lapse of a predetermined time, for example, six seconds after the current limit value (2) is exceeded, the reference voltage (e2) of the reference voltage setting unit 113 is changed. ,
The reference voltage value is switched to the output current set value of the current limit value (2).

Next, the switching control of the output specification of the AC adapter 11 will be described. The comparator 117 compares the reference voltage (e3) of the reference voltage setting unit 118 with the current data (id). When the reference voltage (e3) of the reference voltage setting unit 118 satisfies the current data (id), the comparator 117 outputs the output voltage. Send “1” to the output current set value control unit 109. When the reference voltage (e3) of the reference voltage setting unit 118 is larger than the current data (id), “0” is sent to the output voltage / output current setting value control unit 109.

Output voltage / output current set value control section 109
Detects a change in impedance on the power supply output line (PL) due to the electronic device main body 12 from the “1” and “0”, and, based on the content of the change, a reference voltage value (e1) of the reference voltage setting unit 116, and Reference voltage value and current limit value (2) of current limit value (1) switched by timer 110
Switch the reference voltage value.

In addition to the above-described embodiment, the PWM control unit 104 stores the voltage comparison data and the current comparison data respectively.
When controlling by inputting to the control unit, control without using the timer 110, limiting the output voltage with a constant current output, controlling only the output voltage, controlling only the output current, and the like can be considered. When the control of the output voltage / output current set value control unit 109 is implemented by a microcomputer, the microcomputer for controlling the output voltage / output current set value is used to control the PW of the switch 105.
The case where M control is performed is considered.

Next, a second embodiment of the AC adapter 11 will be described with reference to FIG. In the second embodiment shown in FIG. 2, a configuration example is shown in which the recognition of the specification due to the change in the impedance is realized by detecting the change in the voltage.

The AC adapter 11 according to the second embodiment
Is significantly different from the AC adapter 11 according to the first embodiment described above in the following two points. (1). The data input to the comparator 117 is voltage data (ed) instead of current data (id).

(2). A diode 119 is added to prevent an unnecessary current from entering the current comparison data (ic) to the comparator 117. This (1),
With the change in (2), (a) the current data (id) is the current error amplifier 112,
And to the timer 110 (not to the comparator 117 here).

(B) The voltage data (ed) is input to the voltage error amplifier 115 and the comparator 117. (C) The comparator 117 compares the reference voltage (e3) of the reference voltage setting unit 118 with the voltage data (ed), and when the reference voltage (e3) of the reference voltage setting unit 118 ≦ the voltage data (ed), “1” is sent to the output voltage / output current setting value control unit 109. When the reference voltage (e3) of the reference voltage setting unit 118 is larger than the voltage data (ed), the output voltage
“0” is sent to the output current set value control unit 109.

Output voltage / output current set value control section 109
Detects a change in the output impedance due to the electronic device main body 12 from the “1” and “0”, and determines the reference voltage value (e1) of the reference voltage setting unit 116 and the current limit switched by the timer 110 according to the content of the change. The reference voltage value of the value (1) and the reference voltage value of the current limit value (2) are switched.

The other operations are the same as the operations of the AC adapter 11 in the first embodiment described with reference to FIG. Next, a configuration of a main part of the electronic device main body 12 according to the embodiment of the present invention will be described with reference to FIG.

When the AC adapter 11 is connected to the electronic device main unit 12, the input impedance control unit 19 turns on the switch S11 of the impedance switching unit 17 in accordance with impedance variation means predetermined by the input specifications of the electronic device main unit 12. The impedance on the power output line (PL) of the AC adapter 11 is changed by controlling the switching between the power supply and the power supply off. After this output impedance change,
Power according to the specifications of the device is supplied from the AC adapter 11 to the system 18 as an operation power source.

At this time, the resistor R11 of the impedance switching unit 17 is provided for protecting the switch S11 and determining the fluctuation range of the input impedance. Next, an embodiment of the present invention in which the electronic device main body 12 includes a secondary battery will be described with reference to FIG.

When the AC adapter 11 is connected to the electronic device main body 12, the input impedance control unit 18 switches the switch of the impedance switching unit 17 by impedance variation means determined in advance according to the power supply input specification of the system 19, and 11 power output lines (PL)
Vary the impedance above.

When the secondary battery 21 is charged at a constant current when the system 19 is powered off or in the sleep state, the charging control unit 22 stores the maximum charging current and the maximum charging voltage from the storage unit of the secondary battery 21. Read each data,
The signal is sent to the input impedance control unit 18.

The input impedance control unit 18 determines the power input specification of the electronic device main body 12 based on the data of the maximum charging current and the maximum charging voltage, and performs impedance switching by a predetermined variation means according to the power input specification. The impedance of the power supply output line (PL) of the AC adapter 11 is changed by controlling the switching of the switch of the unit 17.

Due to the variation of the output impedance, 2
A constant current value for charging the secondary battery 21 with a constant current is determined.
When the secondary battery 21 is connected, the diode D11 is connected to the impedance switching unit 17 from the secondary battery 21.
This is provided in order to prevent unnecessary current from flowing into the switch and to change the output impedance by the switch of the impedance switching unit 17. Various switches such as switching transistors and FETs can be applied to the switches of the input impedance switching unit 17.

As a modified example of the above-described charging control of the secondary battery, when charging the secondary battery 21 at a constant current when the system 19 is turned off, first, the charging control unit 22 controls the charging of the secondary battery 21. The current battery capacity, maximum charging current, and maximum charging voltage are read from the battery capacity data stored in the storage unit, and the values are sent to the input impedance control unit 18. When the charging is started, the charging capacity is recognized based on the charging current, and the battery capacity data stored in the storage unit of the secondary battery 21 is rewritten according to the recognized value.

At the time of charging the secondary battery 21, the input impedance control unit 18 uses an impedance variation means determined in advance by a power supply input specification determined from the maximum charging current and the maximum charging voltage input from the charging control unit 22. The switch of the impedance switching unit 17 is controlled to be turned on / off, and the power supply output line (P
L) Vary the impedance above. The fluctuation of the output impedance determines a constant current value for charging the secondary battery 21 with a constant current.

Next, a specific example in which the power supply input specification of the device is notified to the AC adapter 11 due to the fluctuation of the impedance on the power supply output line (PL), and the AC adapter 11
A specific example of processing for recognizing the power supply input specification of the device based on the above-described impedance fluctuation and switching the output specification will be described with reference to FIGS.

Here, the power supply input specification notifying means of the device due to the fluctuation of impedance and the AC adapter 11
There are three examples of the power input specification recognition means of the device on the side, which are based on digital data, periodic data, and duty data due to the impedance change due to the switch operation.
-Specification 4 will be described as a recognition and switching target.

When the input impedance control section 19 of the electronic device main body 12 recognizes that the power supply for information exchange of a predetermined low voltage is supplied on the power supply output line (PL), predetermined identification information is provided for a predetermined period. According to the type (digital data / cycle data / duty data), the input impedance switching unit 17 is switched (on / off) in accordance with the power supply input specification of the own device to change the impedance of the power supply output line (PL). Here, data (specification number data) indicating a device input specification in a digital data format as shown in FIG. 10, a cycle data format as shown in FIG. 11, or a duty data format as shown in FIG.
Is notified to the AC adapter 11 via the power supply output line (PL).

The output voltage / output current detecting section 14 of the AC adapter 11 detects the above-mentioned fluctuation of the output impedance and sends it to the output fluctuation analyzing section 15. The output fluctuation analysis unit 15 analyzes the details of the fluctuation of the output impedance as shown in FIG. 10, FIG. 11, or FIG. The output voltage / output current setting value control unit 16 switches the output voltage and output current set values of the AC adapter 11 in accordance with the power input specification of the connected electronic device main body 12 based on the analysis result of the fluctuation contents.

Here, when the output voltage / output current setting value control unit 16 receives data indicating the device input specification in a digital data format as shown in FIG. 10, the output specification setting processing as shown in FIG. 6 is performed. When the data indicating the device input specification is received in the cycle data format as shown in FIG. 11, the output specification setting process as shown in FIG. 7 is executed, and the device is set in the duty data format as shown in FIG. When the data indicating the input specification is received, the output specification setting processing as shown in FIG. 8 is executed.

In the output specification setting process shown in FIG. 6, when the output voltage / output current set value control unit 16 receives the device input specification data in the digital data format as shown in FIG. 10 (steps S11 and S12 in FIG. 6). Then, the data content is determined (steps S13, S15, S17, S19 in FIG. 6). If the data content is "1h", the output specification of "specification 1" shown in FIG. Output line (PL)
(Step S14 in FIG. 6) and the data content is "2".
If it is "h", the output specification of "Specification 2" shown in FIG. 9 is set, and the power according to the specification is output to the power supply output line (PL) (Step S16 in FIG. 6), and the data content is "3h". For example, the output specification of "Specification 3" shown in FIG. 9 is set, and the power according to the specification is output to the power supply output line (PL) (Step S18 in FIG. 6), and if the data content is "4h", FIG.
The output specification of "Specification 4" shown in (1) is set, and the power according to the specification is output to the power supply output line (PL) (step S20 in FIG. 6).

In the output specification setting process shown in FIG. 7, when the output voltage / output current set value control unit 16 receives the device input specification data in the periodic data format as shown in FIG.
Steps S21 and S22) and determine the data contents (FIG. 7).
Steps S23, S25, S27, S29), when the data content is "2
In the case of “0 ms cycle”, the output specification of “Specification 1” shown in FIG. 9 is set and the power according to the specification is supplied to the power supply output line (PL).
(Step S24 in FIG. 7), and the data content is "10".
If it is "ms cycle", the output specification of "Specification 2" shown in FIG. 9 is set, and the power according to the specification is output to the power supply output line (PL) (step S26 in FIG. 7), and the data content is "5 ms cycle". If so, the output specification of "Specification 3" shown in FIG. 9 is set and the power according to the specification is output on the power supply output line (PL) (Step S28 in FIG. 7), and the data content is "2.5 ms cycle". If there is, the output specification of "Specification 4" shown in FIG. 9 is set, and the power according to the specification is output to the power supply output line (PL) (Step S30 in FIG. 7).

In the output specification setting process shown in FIG. 8, when the output voltage / output current set value control unit 16 receives the device input specification data in the duty data format as shown in FIG. 12 (steps S31 and S32 in FIG. 8). Then, the data content is determined (steps S33, S35, S37, S39 in FIG. 8), and if the data content is "duty 20%", "Specification 1" shown in FIG.
The output specification is set and the power according to the specification is output on the power supply output line (PL) (step S34 in FIG. 8). If the data content is “duty 40%”, the output of “specification 2” shown in FIG. The specification is set and the power according to the specification is output to the power supply output line (PL) (step S36 in FIG. 8). If the data content is “duty 60%”, the output specification of “specification 3” shown in FIG. The power set and output according to the specification is output on the power supply output line (PL) (FIG. 8, step S3).
8) If the data content is “duty 80%”, FIG.
The output specification of "Specification 4" shown in (1) is set, and the power according to the specification is output to the power supply output line (PL) (step S40 in FIG. 8).

As described above, the impedance control unit 19 of the electronic device main body 12 performs switching control of the impedance switching unit 17 in accordance with the power supply input specifications of the electronic device itself, so that the four types of specifications shown in FIG. )
The specification identification information in accordance with the specification of the own device is provided on the power output line (PL) in a digital data format as shown in FIG. 10, a periodic data format as shown in FIG. 11, or a duty data format as shown in FIG. The AC adapter 11 is notified by the impedance fluctuation,
The output voltage / output current set value control unit 16 recognizes the power input specification of the electronic device main body 12 received from the output fluctuation analysis unit 15 in a processing procedure as shown in FIG. 6, FIG. 7, or FIG.
An output specification is set and power according to the specification is output on a power supply output line (PL).

If the output specifications of the AC adapter 11 do not match the input specifications of the electronic device body 12, the AC adapter 11 maintains a constant low-power low-voltage output state, or supplies power at the time of connection. It is possible to avoid a disadvantage that the operation power supply which is not normally output to the electronic device main body 12 due to a stop or the like is supplied. Also, in the case where there is no impedance fluctuation for notifying the device specifications or for identifying the AC adapter 11, the low-power low-voltage output state is maintained as described above, or the power supply at the time of connection is maintained. Equipment protection such as stopping

As described above, according to the embodiment of the present invention, in an electronic device receiving power according to specifications from an AC adapter and in an AC adapter having an output specification switching function, the impedance of an adapter power input line of the electronic device is Means for supplying power that conforms to the specifications of the electronic device in a two-wire system using only a power output line (PL) without using any extra signal line.

Further, according to the power input specification of the electronic device,
Since the output specifications of the adapter can be changed, it is not necessary to prepare a dedicated AC adapter for each electronic device, and the same AC adapter can be used for electronic devices having different power input specifications.

Further, since the impedance fluctuation time of the external power supply input line of the electronic device is limited, and since the operation power is not supplied to the device until the device specification is recognized and set, the influence of noise on the device is reliably prevented. it can.

Further, when the output specification of the AC adapter does not match the power input specification of the electronic apparatus, or the impedance fluctuation on the electronic apparatus side performed to identify the AC adapter (or to notify the AC adapter of the specification of the apparatus). When there is no device, it is possible to easily take equipment protection measures such as stopping the output, lowering the voltage, or preventing a large current from flowing.

In the above-described embodiment, there are four types of power supply input specifications of the device, and identification information (digital data) by a combination of "1" and "0", or "1" and "0". The input specification of the device is recognized by the identification information (period data) having different frequencies (periods), or the identification information (duty data) having different duties between "1" and "0". However, the present invention is not limited to this. For example, in the device specification recognition mode, the device side maintains the impedance on the power output line (PL) in an impedance state specific to the specification of the device. A pulls down to a potential state of 3V,
The device B of the specification 2 can use impedance variation means such as pulling down to a potential state of 1.5 V.

The configuration of the AC adapter 11 is not limited to the circuit configuration shown in FIGS.
The present invention can be applied to a configuration in which only one of the current detections is provided or a configuration in which a battery other than a secondary battery is charged by constant current and constant voltage charging.

[0079]

As described above in detail, according to the present invention, A
In an electronic device that can be operated by the C adapter power supply, without preparing an AC adapter unique to each device,
It is possible to provide an electronic device and an AC adapter that can always supply and control a stable operation power supply according to device specifications for a plurality of types of devices having different power input specifications.

Further, according to the present invention, in an electronic device operable by an AC adapter power supply, an AC adapter is connected to the device main body, so that the AC adapter generates an operation power supply conforming to the specification of the device main body. It is possible to provide an electronic device and an AC adapter capable of realizing an automatic recognition function of device specifications and a matching function of output power to be output without requiring a dedicated control signal line and without affecting the operation of the device with noise.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a main part of an entire electronic device including an AC adapter according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of the AC adapter according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a circuit configuration of an AC adapter according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of an impedance switching control circuit of the electronic device main body according to the embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of an impedance switching control circuit including a charge control circuit of a secondary battery of the electronic device main body according to the embodiment of the present invention.

FIG. 6 is a flowchart showing a setting procedure of an output specification when the AC adapter receives data indicating a device input specification in a digital data format in the embodiment of the present invention.

FIG. 7 is a flowchart showing a setting procedure of an output specification when the AC adapter receives data indicating a device input specification in a frequency (period) data format in the embodiment of the present invention.

FIG. 8 is a flowchart showing a setting procedure of an output specification when the AC adapter receives data indicating a device input specification in a duty data format in the embodiment of the present invention.

FIG. 9 is a view showing a specification example of a device for explaining the operation in the embodiment.

FIG. 10 is a time chart in the case of performing impedance fluctuation using data in accordance with the specifications of the device shown in FIG. 9 in the embodiment.

FIG. 11 is a time chart in the case where the impedance is changed at a frequency (period) according to the specifications of the device shown in FIG. 9 in the embodiment.

FIG. 12 is a time chart in the case where the impedance is changed at a duty according to the specifications of the device shown in FIG. 9 in the embodiment.

[Explanation of symbols]

 11: AC adapter, 12: Electronic equipment body, 13: AC → DC converter, 14: Output voltage / output current detector, 15: Output fluctuation analyzer, 16: Output voltage / output current set value controller, 17 ... Input impedance switching section, 18: main circuit section (system), 19: input impedance control section, 21: secondary battery, 22: charging control section, 101: front-stage rectifier circuit, 102: transformer (transformer), 103: rear stage Rectifier circuit, 104: PWM control unit, 105: Switching circuit, 106: Current detection resistor, 107: Voltage division resistor, 108: Voltage division resistor, 109: Output voltage / output current set value control unit, 110: Timer Reference numeral 111: Amplifier (amplifier) 112: Current error amplifier 113: Reference voltage setting unit 114: Diode 115: Voltage error amplifier Reference numeral 116: Reference voltage setting unit, 117: Comparator, 118: Reference voltage setting unit, 119: Diode, PL: Power output line of the AC adapter 11.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 5B011 DA02 DA13 DB01 DB02 GG03 GG06 HH01 5G003 AA01 BA01 CA03 DA04 FA08 GC05 5G065 DA06 GA04 HA17 JA02 LA04 NA05

Claims (8)

[Claims] 1. An electronic device operable with an AC adapter power supply, comprising means for notifying the AC adapter of a device power supply specification by temporarily varying impedance of a power output line of the AC adapter. Electronic equipment characterized by the following. 2. When an initial power is supplied from an AC adapter to a device main body, the impedance on a power supply line to which the power is supplied is varied on the device main body side in accordance with a predetermined condition, and the power supply is performed on the AC adapter side. 2. The electronic device according to claim 1, wherein the power supply input specification of the device main body is recognized by analyzing the impedance fluctuation content on the line, and the power according to the specification is output on the power supply line. 3. The electronic device according to claim 2, wherein the impedance on the power supply line is varied for a predetermined time on the device main body side in accordance with a frequency, a duty, or a digital value defined by an external power supply input specification. 4. An electronic device comprising a device body and an AC adapter for supplying operating power to the device body, wherein a power input terminal for inputting power output from the AC adapter to the device body; A secondary battery whose charge is controlled at least by constant current control or constant voltage control by the adapter power supplied to the power input terminal; and the adapter power supplied to the power input terminal or the secondary battery.
A main circuit that operates using a secondary battery as an operating power source, and when the AC adapter is connected to the power input terminal,
Impedance control means for changing the impedance of the power input terminal for a certain period of time to notify the AC adapter of the power input specification of the device main body, wherein the AC adapter has a stabilized power circuit, and a power output of the power circuit. Means for detecting a current or voltage change accompanying an impedance change at the end, and recognizing a power input specification of the device main body from the detected value; and controlling the stabilized power supply circuit in accordance with the recognized power input specification to obtain the power input. An electronic apparatus, comprising: a power supply control circuit that generates a power supply according to specifications and controls output from the power supply output terminal. 5. An AC adapter is connected to the power supply output terminal until the power supply output specification recognizes the power supply input specification of the device main body due to the impedance fluctuation of the power supply output terminal or for a predetermined period. Output of power for information exchange at low power level, and while receiving power for information exchange at low power and low voltage level, the impedance fluctuation operation for the device itself to notify the power input specification of the device The electronic device according to claim 4, wherein: 6. An apparatus main body includes a secondary battery having storage means for holding power management information, and an adapter power supply input based on the power management information of the storage means built in the secondary battery. 6. The electronic device according to claim 5, wherein the impedance of the terminal is changed for a certain period of time to inform the AC adapter of the adapter power input specification of the device body. 7. An AC adapter for supplying operating power to an electronic device, a means for recognizing a power input specification of an electronic device to be supplied with power from an impedance variation on a power supply line, and the recognition result. Means for generating a power supply conforming to the above specifications and outputting the power supply on a power supply line. 8. A means for recognizing a power supply input specification of a device main body based on an impedance change on a power supply line, and until a power supply input specification of the device main body is recognized based on an impedance change on the power supply line or a predetermined value. Means for outputting power for information exchange at a low power and low voltage level that does not reach the operating power supply voltage of the main circuit of the device main body on the power supply line for a predetermined period, and impedance variation on the power supply line And means for outputting, on the power supply line, power according to the specification of the recognition result when the power supply specification of the electronic device to be supplied with power is recognized. The described AC adapter.