Power connection authentication system, power adapter, electronic device, and power connection authentication method

Abstract

To provide a power supply connection authentication system which reduces possibility of causing a fault as much as possible even if a power supply adapter and an electronic apparatus are erroneously connected and to provide the power supply adapter, the electronic apparatus and a power supply connection authentication method.SOLUTION: A power supply connection authentication system 100 includes: a power supply adapter 1 connected to a commercial AC power supply 3; and an electronic apparatus 2 to which power is supplied through the power supply adapter. The power supply adapter includes an output part 1B which outputs preliminary voltage lower than rated output voltage in an output start state and a no-load state in an initial stage, outputs the rated output voltage when a prescribed authentication request signal is received from the electronic apparatus on the basis of the preliminary voltage and continues output of the preliminary voltage when the authentication request signal is not received. The electronic apparatus includes a power supply relay part 22 provided between a power supply input terminal 2in and an original inner circuit of the electronic apparatus.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a power connection authentication system, a power adapter, an electronic device powered by the power adapter, and a power connection authentication method.

Background Art

[0002] In many electronic devices, a power adapter (AC adapter) is externally connected in order to miniaturize the device body. The input side of the power adapter is connected directly to an outlet to which a commercial AC voltage is supplied or by means of a cord with a plug. The DC side of the power adapter is a single plug and is inserted into the inlet of one electronic device and connected to each other in a one-to-one relationship. Since the power adapter requires a DC voltage corresponding to the electronic device, its quality, and current capacity, it is usually dedicated to each individual electronic device.

[0003] On the other hand, since the DC side plug of the power adapter and the inlet of the electronic device are designed based on industry standards, basically, their shapes are common. Therefore, when a plurality of electronic devices are arranged close to each other and their respective power adapters are connected to the electronic devices, there may be a mistake. If an incompatible power adapter is mistakenly connected to an electronic device, it may cause a failure or malfunction in both the power adapter and the electronic device.

[0004] Therefore, it has been proposed to detect a misconnection based on the signal level or the frequency of the signal observable from the non-genuine product when either the power adapter or the electronic device connected to each other is a genuine product and the other is a non-genuine product (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, even if it is a wrong connection, once it is connected, the output of the power adapter is supplied to the electronic device. Even if the user notices the error and disconnects the connection in a short time, it may cause a failure or malfunction of the electronic device. The present disclosure aims to minimize the possibility of causing a failure even if the power adapter and the electronic device are misconnected.

Means for Solving the Problems

[0007] The present disclosure includes the following inventions. However, the present invention is defined by the scope of the claims.

[0008] (Power Connection Authentication System) Disclosed is a power connection authentication system including a power adapter connected to a commercial AC power supply and an electronic device powered through the power adapter, wherein the power adapter outputs a preliminary voltage lower than the rated output voltage in an initial output start state and a no-load state, and outputs the rated output voltage when a predetermined authentication request signal is received from the electronic device based on the preliminary voltage, and continues to output the preliminary voltage when the authentication request signal is not received, and includes an output unit; the electronic device includes a power relay unit provided between a power input terminal and an original internal circuit of the electronic device, and the power relay unit includes an authentication request unit that transmits the authentication request signal to the power adapter when it detects that the preliminary voltage has been input, and an operation permission unit that operates the internal circuit when it detects the rated output voltage after detecting the preliminary voltage, and is a power connection authentication system.

[0009] (Power Adapter) From the perspective of a power adapter, it is a power adapter interposed between a commercial AC power supply and an electronic device that requires a DC power input, an AC / DC conversion unit that converts an AC voltage into a DC voltage, a current detection circuit that detects a current flowing through a DC output circuit of the AC / DC conversion unit, and a control unit that controls the AC / DC conversion unit based on a detection output of the current detection circuit. The control unit causes the AC / DC conversion unit to output a preliminary voltage lower than the rated output voltage in an initial output start state and a no-load state, and when a predetermined authentication request signal is received from the electronic device based on the preliminary voltage, output the rated output voltage, and continue to output the preliminary voltage when the authentication request signal is not received. It is a power adapter.

[0010] (Electronic device) From the perspective of an electronic device, it is an electronic device that receives a supply of DC power input by being connected to a power adapter, a power input terminal, the original internal circuit of the electronic device, and a power relay unit provided between the power input terminal and the internal circuit. The power relay unit when detecting that a preliminary voltage lower than the rated output voltage of the power adapter is input, an authentication request unit that transmits an authentication request signal to the power adapter, and an operation permission unit that operates the internal circuit when the event that the rated output voltage is detected after detecting the preliminary voltage is established. It is an electronic device provided with

[0011] (Power connection authentication method in a power connection authentication system) From the perspective of the method, it is a power connection authentication method for determining whether a commercial AC power supply and an electronic device powered through the power adapter are properly connected to each other, In the initial output start state and the no-load state, a preliminary voltage lower than the rated output voltage is output from the power adapter, when the electronic device detects that the preliminary voltage has been input, it transmits an authentication request signal to the power adapter, when the power adapter receives a predetermined authentication request signal from the electronic device, it outputs the rated output voltage, and when it does not receive the authentication request signal, it continues to output the preliminary voltage, after the electronic device detects the preliminary voltage, when the event that the rated output voltage has been detected is established, it operates the internal circuit, This is a power connection authentication method.

[0012] (Power connection authentication method in a power adapter) A power connection authentication method for determining whether a power adapter connected to a commercial AC power supply and supplying power to an electronic device is connected to a proper electronic device, the power adapter, in the initial output start state and the no-load state, outputs a preliminary voltage lower than the rated output voltage, when it receives a predetermined authentication request signal from the electronic device, it outputs the rated output voltage, and when it does not receive the authentication request signal, it continues to output the preliminary voltage, This is a power connection authentication method.

[0013] (Power connection authentication method in an electronic device) A power connection authentication method for determining whether an electronic device powered from a commercial AC power supply via a power adapter is connected to a proper power adapter, the electronic device, when it detects a preliminary voltage lower than the rated output voltage that should be input when not authenticated from a proper power adapter, it transmits an authentication request signal to the power adapter, after detecting the preliminary voltage, when the event that the rated output voltage has been detected is established, it operates the internal circuit, This is a power connection authentication method.

Advantages of the Invention

[0014] According to the present disclosure, even if the power adapter and the electronic device are misconnected, it is possible to minimize the possibility of causing a failure.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0016] [Description of Embodiments of the Present Disclosure] The embodiments of the present disclosure mainly include at least the following.

[0017] (1) This is a power connection authentication system including a power adapter connected to a commercial AC power supply and an electronic device powered through the power adapter, The power adapter outputs a preliminary voltage lower than the rated output voltage in the initial output start state and the no-load state, and outputs the rated output voltage when a predetermined authentication request signal is received from the electronic device based on the preliminary voltage, and continues to output the preliminary voltage when the authentication request signal is not received, and is provided with an output unit. The electronic device includes a power relay unit provided between a power input terminal and an original internal circuit of the electronic device. When the power relay unit detects that the preliminary voltage has been input, it includes an authentication request unit that transmits the authentication request signal to the power adapter, and after detecting the preliminary voltage, based on the establishment of the event that the rated output voltage has been detected, it includes an operation permission unit that operates the internal circuit.

[0018] In the power connection authentication system configured as described above, between the power adapter and the electronic device connected thereto, the preliminary voltage is boosted to the rated output voltage through the reception of the authentication request signal. If the authentication request signal cannot be received, since the power adapter outputs only the preliminary voltage, the internal circuit of the electronic device does not operate. Thereby, even if the power adapter and the electronic device are misconnected, the possibility of causing a failure can be reduced as much as possible. In addition, the user can recognize that it is a wrong connection because the electronic device does not operate normally.

[0019] (2) In the power connection authentication system of (1) above, the DC side plug of the power adapter to be attached to the power input terminal is, for example, a two-pole pin. In this case, the connection of the DC side plug to the electronic device is easy to attach and detach even if it is the wrong counterpart, and misconnection is likely to occur. In such a case, full-power supply in the wrong connection state can be suppressed.

[0020] (3) In the power connection authentication system of (1) or (2) above, the authentication request signal is, for example, a pulse current. In this case, the authentication request signal can be identified and detected by a pulse or a pulse train current that does not flow as a normal load current.

[0021] (4) From the perspective of a power adapter, a power adapter interposed between a commercial AC power supply and an electronic device that requires a DC power input, the power adapter includes an AC / DC conversion unit that converts an AC voltage into a DC voltage, a current detection circuit that detects a current flowing through a DC output circuit of the AC / DC conversion unit, and a control unit that controls the AC / DC conversion unit based on a detection output of the current detection circuit. The control unit causes the AC / DC conversion unit to output a preliminary voltage lower than the rated output voltage in an initial output start state and a no-load state, and when a predetermined authentication request signal is received from the electronic device based on the preliminary voltage, outputs the rated output voltage, and when the authentication request signal is not received, continues to output the preliminary voltage.

[0022] In the power adapter configured in this way, if an authentication request signal is not received from the electronic device connected to the power adapter, the output remains at the preliminary voltage, so the internal circuit of the electronic device does not operate. If an authentication request signal is received, the power adapter boosts the preliminary voltage to the rated output voltage. The power adapter supplies the rated output voltage only when an appropriate electronic device is connected, and does not provide the rated output voltage to an inappropriate electronic device. Thereby, even if the power adapter and the electronic device are misconnected, the possibility of causing a failure can be reduced as much as possible. In addition, the user can recognize that the connection is incorrect because the electronic device does not operate normally.

[0023] (5) From the perspective of an electronic device, an electronic device that receives a supply of DC power input by being connected to a power adapter, the electronic device includes a power input terminal, an original internal circuit of the electronic device, and a power relay unit provided between the power input terminal and the internal circuit. The power relay unit includes an authentication request unit that transmits an authentication request signal to the power adapter when it detects that a preliminary voltage lower than the rated output voltage of the power adapter is input, and an operation permission unit that operates the internal circuit when the event that the rated output voltage is detected after the preliminary voltage is detected is established.

[0024] In the electronic device configured as described above, unless an authentication request signal is sent to the power adapter, the voltage supplied from the power adapter remains at the standby voltage, so the internal circuit of the electronic device does not operate. If an authentication request signal is sent, the power adapter boosts the standby voltage to the rated output voltage. The electronic device can receive the supply of the rated output voltage only when an appropriate power adapter is connected. This can minimize the possibility of causing a failure even if the power adapter and the electronic device are misconnected. Also, the user can recognize that the connection is incorrect because the electronic device does not operate normally.

[0025] (6) From the perspective of a method in a power connection authentication system, a power connection authentication method for determining whether a power adapter connected to a commercial AC power supply and an electronic device powered through the power adapter are properly connected to each other, comprising: (a) outputting a standby voltage lower than the rated output voltage from the power adapter in an initial output start state and a no-load state; (b) when the electronic device detects that the standby voltage has been input, transmitting an authentication request signal to the power adapter; (c) the power adapter outputs the rated output voltage when a predetermined authentication request signal is received from the electronic device, and continues to output the standby voltage when the authentication request signal is not received; (d) after detecting the standby voltage, the electronic device operates the internal circuit when the event that the rated output voltage has been detected is established.

[0026] According to such a power connection authentication method, unless the electronic device sends an authentication request signal to the power adapter, the voltage supplied from the power adapter remains at the standby voltage, so the internal circuit of the electronic device does not operate. If the electronic device sends an authentication request signal, the power adapter boosts the standby voltage to the rated output voltage. The electronic device can receive the supply of the rated output voltage only when an appropriate power adapter is connected. This can minimize the possibility of causing a failure even if the power adapter and the electronic device are misconnected. Also, the user can recognize that the connection is incorrect because the electronic device does not operate normally.

[0027] (7) From the perspective of the method in a power adapter, a power connection authentication method for determining whether a power adapter connected to a commercial AC power supply and supplying power to an electronic device is connected to an appropriate electronic device, wherein the power adapter: (a) outputs a preliminary voltage lower than the rated output voltage in an initial output start state and a no-load state; (b) outputs the rated output voltage when receiving a predetermined authentication request signal from the electronic device, and continues to output the preliminary voltage when the authentication request signal is not received.

[0028] According to such a power connection authentication method, if the power adapter does not receive the authentication request signal, the voltage supplied from the power adapter remains at the preliminary voltage, so the internal circuit of the electronic device does not operate. If the authentication request signal is received, the power adapter boosts the preliminary voltage to the rated output voltage. As a result, the electronic device can receive the supply of the rated output voltage only when an appropriate power adapter is connected. Thereby, even if the power adapter and the electronic device are misconnected, the possibility of causing a failure can be reduced as much as possible. Also, the user can recognize that it is a wrong connection because the electronic device does not operate normally.

[0029] (8) From the perspective of the method in an electronic device, a power connection authentication method for determining whether an electronic device powered from a commercial AC power supply via a power adapter is connected to an appropriate power adapter, wherein the electronic device: (a) transmits an authentication request signal to the power adapter when detecting a preliminary voltage lower than the rated output voltage that should be input from the appropriate power adapter when not authenticated; (b) operates the internal circuit when the event that the rated output voltage is detected after detecting the preliminary voltage is established.

[0030] According to such a power supply connection authentication method, by detecting that a predetermined preliminary voltage has been input, the electronic device transmits an authentication request signal to the power adapter, and as a result, can receive the supply of the rated output voltage from the power adapter. When the voltage detected by the electronic device is not the predetermined preliminary voltage, the electronic device does not transmit an authentication request signal to the power adapter, and as a result, cannot receive the supply of the rated output voltage. If the voltage supplied from the power adapter remains at the preliminary voltage, the internal circuit of the electronic device does not operate. In this way, the electronic device can receive the supply of the rated output voltage only when an appropriate power adapter is connected. Thereby, even if the power adapter and the electronic device are misconnected, the possibility of causing a failure can be reduced as much as possible. In addition, the user can recognize that the connection is incorrect because the electronic device does not operate normally.

[0031] [Details of Embodiments of the Present Disclosure] Hereinafter, a specific example of the power supply connection authentication system of the present disclosure will be described with reference to the drawings. FIG. 1 is a diagram showing a circuit configuration of a power supply connection authentication system 100 including a power adapter 1 and an electronic device 2 connected thereto. The electronic device 2 is a device that requires a DC voltage and is not particularly limited. As an example, it is a home-side device (ONU: Optical Network Unit) for optical communication.

[0032] 《Power Adapter》 In FIG. 1, the power adapter 1 is connected to an outlet 4 of a commercial AC power supply 3. In the illustrated example, the AC-side plug (blade) 1 ac is directly attached to the power adapter 1, but the AC-side plug may be inserted into the outlet via a covered wire from the power adapter 1. On the DC side of the power adapter 1, two DC circuits (apparently one cable) 1p and 1n are drawn out, and a DC-side plug 1 dc is connected to the tip. The DC-side plug 1 dc is a coaxial two-pole pin.

[0033] The power adapter 1 includes, inside thereof, a rectifier circuit 11, a smoothing capacitor 12, a high-frequency transformer 13, a switching element 14, a rectifier circuit 15, a smoothing capacitor 16, a control unit 17, and a current detection circuit 18, which are connected as shown in the figure. When viewed separately as a main circuit part and a control circuit part, it includes an AC / DC conversion unit 1A as the main circuit part, and the current detection circuit 18 and the control unit 17 as the control circuit part. Further, the high-frequency transformer 13, the switching element 14, the rectifier circuit 15, the smoothing capacitor 16, the control unit 17, and the current detection circuit 18 constitute an output part 1B (DC / DC converter) that can provide a plurality of output voltages.

[0034] Next, the operation of the power adapter 1 will be described. Note that the voltage values described below are merely examples for explanation and are not limited to these numerical values.

[0035] The rectifier circuit 11 is ac connected to the AC-side plug 1 and outputs a pulsating DC voltage obtained by full-wave rectifying an AC voltage (100V). The pulsating DC voltage is smoothed by the smoothing capacitor 12 to become a DC voltage (about 141V). The DC voltage is applied to the series combination of the primary-side winding 13p of the high-frequency transformer 13 and the switching element 14. The switching element 14 is, for example, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), but may be other semiconductor elements such as an IGBT (Insulated Gate Bipolar Transistor).

[0036] The switching element 14 is switched and controlled by the control unit 17. By switching the switching element 14 at a high frequency, a stepped-down pulse-shaped voltage is induced in the secondary winding 13s of the high-frequency transformer 13. This voltage is rectified by the rectifier circuit 15 and smoothed by the smoothing capacitor 16. A DC low voltage is generated across the smoothing capacitor 16. This low voltage becomes the output voltage between the DC circuits 1p and 1n. The current flowing through the DC circuit 1n is detected by the current sensor 18s and the current detection circuit 18. The current sensor 18s is, for example, a Hall element or a shunt resistor with a low resistance value. The detection output of the current detection circuit 18 is supplied to the control unit 17.

[0037] The control unit 17 is, for example, a PWM controller that performs PWM (Pulse Width Modulation) control on the switching element 14. There are two types of PWM control duty (high level, low level). When the duty is at a high level, the rated output voltage (e.g., 12V) is output between the DC circuits 1p and 1n. When the duty is at a low level, a standby voltage (e.g., 3.3V) lower than the rated output voltage is output between the DC circuits 1p and 1n. The control unit 17 monitors the potential of the DC circuit 1p, performs feedback control based on the output voltage, and finely adjusts the duty so that the output voltage becomes the target rated output voltage or standby voltage. Note that the control unit 17 may be a microcomputer. In that case, the microcomputer executes software (computer program) to realize the necessary control functions as a PWM controller.

[0038] The control unit 17 and the current detection circuit 18 require a control power supply voltage. When an AC voltage is applied to the AC side plug 1 ac , the smoothing capacitor 12 is charged, so it can be used as a power supply. For example, the control power supply voltage can be supplied to the control unit 17 and the current detection circuit 18 from the positive side of the smoothing capacitor 12 via a high resistance (e.g., several hundred kΩ).

[0039] 《Electronic device》 The electronic device 2 receives a supply of DC voltage by attaching the DC-side plug 1 of the power adapter 1 dc to the inlet 2 in (power input terminal). The electronic device 2 includes an internal circuit 21 that realizes the original internal functions of the device body, and a power relay unit 22 provided in front of the internal circuit 21. The power relay unit 22 is interposed between the inlet 2 in and the internal circuit 21, and controls whether to supply a predetermined DC voltage to the internal circuit 21 based on the input DC voltage.

[0040] The power relay unit 22 includes a switch 23, a resistor 24, a control unit 25, and an internal power supply unit 26. The DC circuits 2p and 2n are respectively connected to the DC circuits 1p and 1n of the power adapter 1. The switch 23 is a semiconductor element such as a MOSFET, and is connected between the DC circuits 2p and 2n via the resistor 24 in series. The control unit 25 supplies a drive signal to the gate of the switch 23. The control unit 25 has a function of detecting the voltage between the DC circuits 2p and 2n, a function of turning on / off the switch 23 to output a pulse, and a function of giving a command to turn on (permit) or turn off (prohibit) the power output to the internal circuit 21 to the internal power supply unit 26. The control unit 25 may be an IC configured in hardware to have the function, or may be a microcomputer that realizes the function by software (computer program).

[0041] Functionally, the power relay unit 22 includes (i) an authentication request unit 22A that transmits a predetermined authentication request signal to the power adapter 1 when it detects that a preliminary voltage has been input from the power adapter 1, and (ii) an operation permission unit 22B that operates the internal circuit 21 when the event that the rated output voltage has been detected after detecting the preliminary voltage is established.

[0042] 《Operation of Power Connection Authentication》 Next, the operation of power connection authentication when the power adapter 1 and the electronic device 2 configured as described above are connected will be described. FIG. 2 is a graph showing the change in the output voltage of the power adapter 1 from the state where the power adapter 1 and the electronic device 2 are connected. The horizontal axis represents time, and the vertical axis represents voltage [V].

[0043] At time t1, the AC side plug 1 of the power adapter 1 ac is connected to the commercial AC power supply. Also, the DC side plug 1 dc is connected to the electronic device 2. Thereby, the power adapter 1 starts to output a standby voltage (3.3V). In the initial state (default), the power adapter 1 always outputs a standby voltage, and the standby voltage is supplied to the electronic device 2. At this stage, due to the presence of the power relay unit 22, a predetermined DC voltage is not yet supplied to the internal circuit 21. That is, the internal circuit 21 is not operating.

[0044] Due to the supply of the standby voltage, the control unit 25 of the electronic device 2 starts operating, gives a gate signal to turn on the switch 23 for a certain period of time, and then turns it off, thereby generating a specified pulse (pulse current). The predetermined pulse is a pulse having a predetermined pulse width. This pulse is detected by the current detection circuit 18 of the power adapter 1 and becomes an authentication request signal for the power adapter 1. When the control unit 17 confirms that the current detection circuit 18 has detected a specified pulse, authentication is OK, and the control unit 17 changes the duty to a high level at time t2. Thereby, the power adapter 1 outputs a rated output voltage (12V). The control unit 25 of the electronic device 2 catches the event that the voltage input from the power adapter 1 changes from the standby voltage to the rated output voltage, and outputs a power-on command signal to the internal power supply unit 26. Thereby, the internal power supply unit 26 supplies a predetermined DC voltage to the internal circuit 21, and the internal circuit 21 starts operating.

[0045] The above authentication requirement is that a pulse with a predetermined pulse width has been detected. However, various other authentication requirements are possible. For example, in order to ensure the certainty of authentication, if the output voltage of the power adapter 1 is not boosted to the rated output voltage despite transmitting a pulse, the pulse may be transmitted again to perform multiple authentication attempts. Also, it may be used as an authentication requirement to transmit as a pulse train at a certain period and that the period or the number of pulses of the pulse is a predefined value.

[0046] After time t3, the rated output voltage continues to be supplied and the internal circuit 21 of the electronic device 2 operates. At time t4, (a) if the electronic device 2 has a power-on switch and this is turned off, (b) if the AC side plug 1 of the power adapter 1 ac is unplugged from the outlet 4, or (c) if the DC side plug 1 of the power adapter 1 dc is removed from the electronic device 2, the load current flowing through the electronic device 2 rapidly decreases and it becomes a no-load state. This no-load state is the following state.

[0047] In the case of (a), a minute standby current may flow, but the current value is close to 0. In the case of (b), the current value becomes 0 when the smoothing capacitor 16 has completely discharged. In the case of (c), the current value becomes 0 immediately after removing the DC side plug 1 dc . When the current detection circuit 18 and the control unit 17 detect this change in the load current, they return the duty to the default low level. As a result, in the case of the above (a), the output voltage of the power adapter 1 becomes the standby voltage. In the case of the above (b) or (c), the output voltage of the power adapter 1 becomes 0 (dotted line in FIG. 2).

[0048] Next, the operation of power connection authentication in various cases will be described with reference to FIGS. 3 to 7 as flowcharts showing the processing procedures. The main part of the operation is the power adapter 1 and the power relay unit 22 of the electronic device 2.

[0049] (At startup) Figure 3 is a flowchart when starting up the electronic device 2. First, the AC side plug 1 of the power adapter 1 ac is connected to the outlet 4, and the DC side plug 1 dc is connected to the electronic device 2 (step S31). Thereby, the power adapter 1 outputs a preliminary voltage (step S32), and the preliminary voltage is input to the power relay unit 22 (step S33). The control unit 25 of the electronic device 2 starts operating with the preliminary voltage and outputs a pulse (or a pulse train, the same hereinafter).

[0050] When the current detection circuit 18 of the power adapter 1 detects a pulse, the control unit 17 determines whether the pulse is a specified one (step S36). If "YES", it outputs the rated output voltage (step S37). After detecting the preliminary voltage, the control unit 25 of the electronic device 2 to which the rated output voltage is input determines that the event that the rated output voltage has been detected has occurred, gives an on signal to the internal power supply unit 26, and operates the internal circuit 21 (step S38).

[0051] If "NO" in step S36, the output of the power adapter 1 maintains the preliminary voltage, and the internal circuit 21 does not operate. Thereby, even if the power adapter 1 and the electronic device 2 are connected in a wrong pair, only the preliminary voltage which is a low voltage is supplied, so that the possibility of causing a failure can be reduced as much as possible. Also, the user can recognize that it is a wrong connection because the electronic device 2 does not operate normally.

[0052] (When the AC side plug is unplugged) Figure 4 is a flowchart when the user unplugs the AC side plug 1 of the power adapter 1 from the outlet 4 from the state where the preliminary voltage or the rated output voltage is supplied from the power adapter 1 to the electronic device 2 (step S40). When the user unplugs the AC side plug 1 ac from the outlet 4, acWhen it is unplugged (step S41), the output voltage of the power adapter 1 drops, and when the smoothing capacitor 16 finishes discharging, it becomes 0V (step S42). As a result, the input voltage to the power relay unit 22 also becomes 0V, and the electronic device 2 is turned off (step S43).

[0053] If the internal circuit 21 was in an operating state, it will be turned off. If it was originally turned off, it remains turned off as it is.

[0054] (When the DC side plug is unplugged) FIG. 5 is a flowchart from the state where the standby voltage or the rated output voltage is supplied from the power adapter 1 to the electronic device 2 (step S50) until the user unplugs the DC side plug 1 dc of the power adapter 1 from the inlet 2 in of the electronic device 2. When the user unplugs the DC side plug 1 dc (step S51), the power relay unit 22 loses the input voltage and is turned off (step S54).

[0055] If the internal circuit 21 was in an operating state, it will be turned off. If it was originally turned off, it remains turned off as it is.

[0056] The current detection circuit 18 detects that the load current has become 0 (step S52). In response to this, the control unit 17 changes the output voltage to the standby voltage (step S53). Also, the current detection state is initialized, and it enters a state of waiting for a pulse.

[0057] (Genuine power adapter + non - genuine electronic device) FIG. 6 is a flowchart when a non - genuine electronic device is accidentally connected to a genuine power adapter 1. In step S61, the AC side plug 1 ac is plugged into the outlet 4, and the DC side plug 1 dcThey are respectively connected to the electronic device. The power adapter 1 first outputs a preliminary voltage (step S62). The preliminary voltage is input to the electronic device (step S65). However, since the preliminary voltage is a low voltage, the electronic device does not operate (step S66). Also, since it does not have a function of transmitting a pulse, no pulse is transmitted. As a result, on the power adapter 1 side, no pulse is detected (step S63), and the output of the preliminary voltage continues (step S64).

[0058] (Non-genuine power adapter + genuine electronic device) FIG. 7 is a flowchart when a genuine electronic device 2 is erroneously connected to a non-genuine power adapter. In step S71, the AC side plug 1 ac is connected to the outlet 4, and the DC side plug 1 dc is connected to the electronic device respectively. The power adapter 1 first outputs a voltage (the voltage value is unknown) (step S72). The voltage is input to the electronic device (step S73). The control unit 25 of the electronic device 2 detects the voltage (step S74) and determines whether it is a preliminary voltage (step S75). Here, whether it is lower or higher than the preliminary voltage (including the allowable error range), it is not a preliminary voltage. In the case of a non-genuine power adapter, in many cases, a voltage higher than the preliminary voltage is suddenly input.

[0059] If it is not a preliminary voltage, regardless of the determination, the power adapter continues the same output (step S76). If it is a preliminary voltage, the control unit 25 causes a pulse to be output (step S77). However, since the non-genuine power adapter does not have a function of reacting to the pulse, it continues the same output voltage (step S78). The internal circuit 21 is always in a power-off state and does not operate.

[0060] Summary of the Disclosure The above disclosure can be generally expressed as follows.

[0061] First, the power connection authentication system 100 includes a power adapter 1 connected to a commercial AC power supply and an electronic device 2 powered through the power adapter 1. The power adapter 1 outputs a preliminary voltage lower than the rated output voltage in the initial output start state and no-load state, and outputs the rated output voltage when a predetermined authentication request signal (pulse) is received from the electronic device 2 based on the preliminary voltage, and continues to output the preliminary voltage when the authentication request signal is not received. It is provided with an output unit 1B.

[0062] On the other hand, the electronic device 2 is provided with a power relay unit 22 provided between a power input terminal (inlet 2 in ) and the original internal circuit 21 of the electronic device. When the power relay unit 22 detects that the preliminary voltage has been input, it includes an authentication request unit 22A that transmits an authentication request signal to the power adapter 1, and after detecting the preliminary voltage, a startup permission unit 22B that operates the internal circuit when the event of detecting the rated output voltage is established.

[0063] In the power connection authentication system 100 configured in this way, between the power adapter 1 and the electronic device 2 connected thereto, the preliminary voltage is boosted to the rated output voltage through the reception of the authentication request signal. If the authentication request signal cannot be received, since the power adapter 1 outputs only the preliminary voltage, the internal circuit 21 of the electronic device 2 does not operate. Thereby, even if the power adapter 1 and the electronic device 2 are misconnected, the possibility of causing a failure can be reduced as much as possible. In addition, the user can recognize that the connection is incorrect because the electronic device 2 does not operate normally.

[0064] The DC-side plug 1 of the power adapter 1 attached to the power input terminal (inlet 2 in ) is, for example, a two-pole pin. dc In this case, the connection of the DC-side plug 1 to the electronic device 2 is easy to attach and detach even if it is the wrong counterpart, and misconnection is likely to occur. In such a case, full-power supply in the misconnected state can be suppressed. In this case, the connection of the DC-side plug 1 to the electronic device 2 dc is easy to attach and detach even if it is the wrong counterpart, and misconnection is likely to occur. In such a case, full-power supply in the misconnected state can be suppressed.

[0065] The authentication request signal is, for example, a pulsed current. In this case, the authentication request signal can be identified and detected by a pulse or a pulse train current that does not flow as a normal load current.

[0066] From the perspective of the power adapter 1, this is a power adapter 1 interposed between the commercial AC power supply 3 and the electronic device 2 that requires a DC power input. This power adapter 1 includes an AC / DC conversion unit 1A that converts an AC voltage into a DC voltage, a current detection circuit 18 that detects the current flowing through the DC output circuit of the AC / DC conversion unit 1A, and a control unit 17 that controls the AC / DC conversion unit 1A based on the detection output of the current detection circuit 18. The control unit 17 causes the AC / DC conversion unit 1A to output a preliminary voltage lower than the rated output voltage in (i) the initial output start state and the no-load state, and (ii) when a predetermined authentication request signal is received from the electronic device 2 based on the preliminary voltage, it outputs the rated output voltage, and when the authentication request signal is not received, it continues to output the preliminary voltage.

[0067] In the power adapter 1 configured in this way, if the authentication request signal is not received from the electronic device 2 connected to the power adapter 1, the output remains at the preliminary voltage, so the internal circuit 21 of the electronic device 2 does not operate. If the authentication request signal is received, the power adapter 1 boosts the preliminary voltage to the rated output voltage. The power adapter 1 supplies the rated output voltage only when an appropriate electronic device 2 is connected, and does not provide the rated output voltage to an inappropriate electronic device. Thereby, even if the power adapter 1 and the electronic device 2 are misconnected, the possibility of causing a failure can be reduced as much as possible. Also, the user can recognize that the connection is incorrect because the electronic device 2 does not operate normally.

[0068] From the perspective of the electronic device 2, this is an electronic device 2 that receives the supply of a DC power input by being connected to the power adapter 1. The electronic device 2 has a power input terminal (inlet 2 in) and the original internal circuit 21 of the electronic device, a power input terminal, and a power relay unit 22 provided between the internal circuit 21. The power relay unit 22 includes an authentication request unit 22A that transmits an authentication request signal to the power adapter 1 when it detects that a preliminary voltage has been input, and an operation permission unit 22B that operates the internal circuit 21 when the event that the rated output voltage has been detected after detecting the preliminary voltage is established.

[0069] In the electronic device 2 configured as described above, if an authentication request signal is not transmitted to the power adapter 1, the voltage supplied from the power adapter 1 remains at the preliminary voltage, so the internal circuit 21 of the electronic device 2 does not operate. If an authentication request signal is transmitted, the power adapter 1 boosts the preliminary voltage to the rated output voltage. The electronic device 2 can receive the supply of the rated output voltage only when an appropriate power adapter 1 is connected. As a result, even if the power adapter 1 and the electronic device 2 are misconnected, the possibility of causing a failure can be reduced as much as possible. Also, the user can recognize that the connection is incorrect because the electronic device 2 does not operate normally.

[0070] When the power adapter 1 is a genuine product and the electronic device is a non-genuine product, the power adapter 1 continues to output the preliminary voltage, so the non-genuine electronic device is provided with only the preliminary voltage and consequently does not operate. Conversely, when the power adapter is a non-genuine product and the electronic device 2 is a genuine product, the operation permission unit 22B does not operate. This is because even for a genuine electronic device 2, the requirements for the necessary event are not satisfied, so the operation permission unit 22B does not operate. As a result, power supply to the internal circuit 21 is blocked and the internal circuit 21 does not operate.

[0071] <Supplementary Note> It should be considered that all aspects of the embodiments disclosed this time are illustrative and not restrictive. The scope of the present invention is indicated by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0072] 1 Power adapter 1A AC / DC conversion unit 1B Output section 1 ac AC side plug 1 dc DC side plug 1p DC circuit 1n DC circuit 2 Electronic device 2 in Inlet 2p DC circuit 2n DC circuit 3 Commercial AC power supply 4 Socket 11 Rectifier circuit 12 Smoothing capacitor 13 High-frequency transformer 13p Primary winding 13s Secondary winding 14 Switching element 15 Rectifier circuit 16 Smoothing capacitor 17 Control section 18 Current detection circuit 18s Current sensor 21 Internal circuit 22 Power relay section 22A Authentication request section 22B Operation permission section 23 Switch 24 Resistor 25 Control section 26 Internal power supply section 100 Power connection authentication system

Claims

1. A power connection authentication system including a power adapter connected to a commercial AC power supply and an electronic device powered through the power adapter, wherein the power adapter, outputs a preliminary voltage lower than the rated output voltage in an initial output start state and a no-load state, and outputs the rated output voltage when a predetermined authentication request signal is received from the electronic device based on the preliminary voltage, and continues to output the preliminary voltage when the authentication request signal is not received, and includes an output unit; the electronic device includes a power relay unit provided between a power input terminal and an original internal circuit of the electronic device, and the power relay unit, when detecting that the preliminary voltage is input, includes an authentication request unit that transmits the authentication request signal to the power adapter; and an operation permission unit that operates the internal circuit when an event that the rated output voltage is detected after the preliminary voltage is detected is established; and the power adapter further includes a control unit that switches the output voltage from the output unit between the preliminary voltage and the rated output voltage by switching the duty of a PWM signal output to the output unit between a low level and a high level; when the output unit is outputting the rated output voltage, the control unit switches the duty of the PWM signal output to the output unit from the high level to the low level when detecting the no-load state; a power connection authentication system.

2. The power connection authentication system according to claim 1, wherein a DC side plug of the power adapter attached to the power input terminal is a two-pole pin.

3. The power connection authentication system according to claim 1 or claim 2, wherein the authentication request signal is a pulse current.

4. A power adapter interposed between a commercial AC power supply and an electronic device that requires a DC power input, including an AC / DC conversion unit that converts an AC voltage into a DC voltage, a current detection circuit that detects a current flowing through a DC output circuit of the AC / DC conversion unit, and a control unit that controls the AC / DC conversion unit based on a detection output of the current detection circuit, wherein the control unit, in an initial output start state and a no-load state, outputs a PWM signal having a low-level duty to the AC / DC conversion unit to output a preliminary voltage lower than the rated output voltage. When a predetermined authentication request signal is received from the electronic device based on the preliminary voltage, the rated output voltage is output by outputting a PWM signal having a high-level duty to the AC / DC conversion unit, and when the authentication request signal is not received, the output of the preliminary voltage is continued by continuing to output a PWM signal having a low-level duty to the AC / DC conversion unit. When the AC / DC conversion unit is outputting the rated output voltage and the no-load state is detected, the duty of the PWM signal output to the AC / DC conversion unit is switched from the high level to the low level. Power adapter.

5. A power connection authentication method for determining whether a power adapter connected to a commercial AC power supply and an electronic device powered through the power adapter are properly connected to each other, In an initial output start state and a no-load state, a preliminary voltage lower than the rated output voltage is output from the power adapter by outputting a PWM signal having a low-level duty to an AC / DC conversion unit that converts AC from the commercial AC power supply to DC. When the electronic device detects that the preliminary voltage has been input, the electronic device transmits an authentication request signal to the power adapter. When the power adapter receives a predetermined authentication request signal from the electronic device, the rated output voltage is output by outputting a PWM signal having a high-level duty to the AC / DC conversion unit, and when the authentication request signal is not received, the output of the preliminary voltage is continued by continuing to output a PWM signal having a low-level duty to the AC / DC conversion unit. After detecting the preliminary voltage, the electronic device operates the internal circuit when the event that the rated output voltage has been detected is established. When the power adapter is outputting the rated output voltage and the no-load state is detected, the duty of the PWM signal output to the AC / DC conversion unit is switched from the high level to the low level. Power connection authentication method.

6. A power connection authentication method for determining whether a power adapter connected to a commercial AC power supply and supplying power to an electronic device is properly connected to the appropriate electronic device, The power adapter is In the initial output start state and no-load state, a PWM signal having a low level duty is output to an AC / DC conversion unit that converts AC from the commercial AC power supply to DC, thereby outputting a preliminary voltage lower than the rated output voltage. When a predetermined authentication request signal is received from the electronic device, a PWM signal having a high level duty is output to the AC / DC conversion unit to output the rated output voltage. When the authentication request signal is not received, the output of the PWM signal having the low level duty to the AC / DC conversion unit is continued to continue the output of the preliminary voltage. When the rated output voltage is being output, when the no-load state is detected, the duty of the PWM signal output to the AC / DC conversion unit is switched from the high level to the low level. Power connection authentication method.

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