JP6219893B2 - Power adapter and voltage adjustment method for power adapter - Google Patents

Description

  The present invention relates to a power adapter that converts a power input from the outside into a power having a different specification and outputs the power, and particularly relates to a power adapter that can supply power to an external device via a power supply cable that can be separated from the power adapter.

  In recent years, devices having a USB (Universal Serial Bus) interface have been widely used. An AC (Alternating Current) adapter (power adapter) is generally used as a device that can supply power to these devices. This AC adapter converts, for example, an AC 100 V (volt) power source into a DC (Direct Current) power source, and then supplies the DC power source to a device (external device) via a USB cable.

  FIG. 15 illustrates an appearance of a configuration in which power is supplied to the device 300 via the general AC adapter 5 and the USB cable 200. As illustrated in FIG. 15, the AC adapter 5 includes an output connector 10 to which a USB cable 200 can be connected. In the state where the input plug 100 is connected to an AC 100V outlet, the AC adapter 5 converts the AC 100V into a DC power source, and then outputs the converted DC power source from the output connector 10. The AC adapter 5 charges the lithium ion secondary battery 302 built in the device 300 while being connected to the device 300 via the USB cable 200.

  In the configuration shown in FIG. 15, the user can also use a commercially available USB cable as the USB cable 200 in addition to the USB cable that comes standard with the device 300. USB cables generally have different impedance characteristics depending on the cable length or the thickness of the wire. In FIG. 15, the voltage output from the output connector 10 drops by an amount determined by the impedance characteristic of the USB cable 200 and then is input to the input connector 301 in the device 300. Therefore, depending on the impedance characteristics of the USB cable 200, the amount of voltage drop increases, and as a result, the value of the voltage input to the input connector 301 may be lower than the voltage value at which the lithium ion secondary battery 302 can be charged. . In this case, the AC adapter 5 cannot charge the lithium ion secondary battery 302. Therefore, an AC adapter that can output a voltage value that can charge or operate the device is required in consideration of a voltage drop amount due to a USB cable connected to the device.

  As an example of a technique related to such an AC adapter, Patent Document 1 discloses a secondary that is configured by an AC adapter and a power supply cable, and is built in the mobile terminal by connecting the power supply cable to the mobile terminal. A charging system for charging a battery is disclosed. The AC adapter in this charging system includes an input stage circuit, a measurement circuit, and correction means. The input stage circuit converts an AC voltage supplied from the outside into a DC charging voltage. The measurement circuit measures a voltage drop caused by the power supply cable. The correction means corrects the voltage value of the charging voltage so as to increase and supply a voltage value corresponding to the measured voltage drop.

  Patent Document 2 discloses a control device that controls communication between an in-vehicle device and a device connected to the in-vehicle device via a cable. The control device detects the length of the cable and, based on the detected length of the cable, changes the power supply voltage supplied to the power supply line of the cable, thereby providing a power supply voltage at the connector connected to the device. To control.

  Further, in Patent Document 3, when power is supplied to a USB, the USB cable is connected to the device after a predetermined time from when the switch is switched so that the USB cable is connected to a resistor having a known resistance value. A circuit for switching the switch is disclosed. This circuit detects the resistance value of the USB cable during a predetermined time when the USB cable is connected to the resistor, and after the USB cable is connected to the device after the predetermined time, the voltage is determined based on the detected resistance value. An operation to compensate for the descent is performed.

  Patent Document 4 discloses a USB power booster that is inserted into an arbitrary portion of a USB cable when supplying a power supply voltage from a USB host to the USB device via the USB cable. This USB power booster monitors the voltage of the power supply bus in the USB cable, and when the voltage drops below the voltage threshold, boosts the voltage to the voltage threshold and passes it to the USB device side via the USB cable. Output.

JP 2012-223077 International Publication No. 2010-137114 JP 2014-117077 JP 2008-305148 A

  The above-described charging system according to Patent Document 1 and the control device according to Patent Document 2 measure the voltage in the USB cable by using the signal line in the USB cable. That is, in the techniques disclosed in Patent Documents 1 and 2, the USB cable needs to have a configuration that realizes measuring a voltage by using a signal line. In the circuit according to Patent Document 3 and the USB power booster according to Patent Document 4 described above, a USB jack provided with a plurality of switches or a USB power booster is provided in the middle of a USB cable that supplies power to the device. Need to be placed.

  As described above, the technologies disclosed in Patent Documents 1 to 4 consider that the amount of voltage drop due to a power supply cable such as a USB cable connected to a device is taken into account, and output a voltage value at which the device can be charged or operated. It cannot be said that it has high versatility and can be realized with a simple configuration. The main object of the present invention is to provide a power adapter or the like that solves this problem.

  The power adapter according to an aspect of the present invention can be connected to the first connection portion that can be energized to one end of the power supply cable and to the other end of the power supply cable. In the case where the second connecting portion, the second connecting portion are connected to be energized, the load portion having an electrical load, and the feeding cable are connected to the first and second connecting portions, A measuring means for measuring a voltage at the second connecting portion when a current flows to the load portion by power supply from the outside, and the first connecting portion according to the voltage measured by the measuring means And adjusting means for adjusting the voltage output to the power supply cable and maintaining the adjusted voltage after the power supply cable is disconnected from the second connection portion.

  In another aspect of achieving the above object, a voltage adjustment method for a power adapter according to an aspect of the present invention includes a first connection portion that can be connected to one end of a power supply cable so as to be energized, and the power supply cable. A power adapter comprising: a second connection portion capable of being connected to the other end of the power supply so as to be capable of being energized; and a load portion connected to the second connection portion so as to be capable of being energized and having an electrical load. The power supply cable is connected to the first and second connection portions, and the voltage at the second connection portion is changed according to the current flowing to the load portion by power supply from the outside. After adjusting the voltage output from the first connection portion to the power supply cable according to the measured voltage, the power supply cable is not connected to the second connection portion. Even maintain the regulated voltage .

  The invention of the present application can realize the output of a voltage that can charge or operate the device in consideration of the amount of voltage drop due to the power supply cable connected to the device with a highly versatile and simple configuration. And

1 is a block diagram illustrating a configuration of an AC adapter 1 according to a first embodiment of the present invention. It is the figure (top view and side view) which illustrates the external appearance of the AC adapter 1 which concerns on 1st Embodiment of this invention. It is a figure (perspective view) which illustrates the appearance of AC adapter 1 concerning a 1st embodiment of the present invention. It is a figure (top view) which illustrates the appearance of the composition which connects USB cable 200 to output connector 10 and input connector 11 in AC adapter 1 concerning a 1st embodiment of the present invention. It is a characteristic view (graph) which illustrates change of voltage value in measurement points X and Y before and after AC adapter 1 concerning a 1st embodiment of the invention in this application adjusts an output voltage value. It is a figure (top view) which illustrates the appearance of composition which supplies electric power to apparatus 300 via AC adapter 1 and USB cable 200 concerning a 1st embodiment of the invention in this application. It is a flowchart which shows the flow of a series of operation using the AC adapter 1 which concerns on 1st Embodiment of this invention. It is a block diagram which shows the structure of the AC adapter 2 which concerns on the 2nd Embodiment of this invention. It is a characteristic view (graph) which illustrates the change of the voltage value in the measurement points X and Y before and after the AC adapter 2 which concerns on 2nd Embodiment of this invention adjusts an output voltage value. It is a flowchart which shows the flow of a series of operation using the AC adapter 2 which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the AC adapter 3 which concerns on the 3rd Embodiment of this invention. It is a figure (top view) which illustrates the external appearance of the AC adapter 3 which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the flow of a series of operation using the AC adapter 3 which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows the structure of the AC adapter 4 which concerns on 4th Embodiment of this invention. FIG. 3 is a diagram (top view) illustrating an appearance of a configuration in which power is supplied to a device 300 via a general AC adapter 5 and a USB cable 200.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
FIG. 1 is a block diagram conceptually showing an AC adapter 1 according to the first embodiment of the present invention. The AC adapter 1 according to the present embodiment is a device that can be connected to a device having a USB interface by a USB cable, and converts the AC 100 V into a DC voltage and then inputs the DC voltage to the device.

  The AC adapter 1 according to the embodiment includes an output connector 10, an input connector 11, a load unit 12, a measurement unit 13, an adjustment unit 14, a storage unit 15, an input plug 100, a rectification / smoothing unit 101, a high-frequency transformer 102, and a rectification. / The smoothing part 103 is provided. The measurement unit 13 and the adjustment unit 14 are configured by an electronic circuit. The storage unit 15 is a storage device such as an electronic memory. The storage unit 15 has a storage control function realized by an electronic circuit or a computer program and a processor that operates according to the computer program.

  The input plug 100 is a plug that can be connected to an AC 100 V outlet, and inputs the input AC 100 V to the rectifying / smoothing unit 101. The rectification / smoothing unit 101 aligns the polarity of the alternating current (AC 100 V) in one direction, smoothes the AC 100 with a built-in electrolytic capacitor (not shown), and inputs the smoothed AC 100 V to the adjustment unit 14. The adjustment unit 14 repeatedly performs electrical on / off (switching adjustment) using a built-in switching element (not shown), thereby converting AC 100 V into high frequency alternating current, and inputting the high frequency alternating current to the high frequency transformer 102. To do. The high frequency transformer 102 transmits the input high frequency alternating current from the primary side to the secondary side, and inputs the high frequency alternating current transmitted to the secondary side to the rectifying / smoothing unit 103. The rectifying / smoothing unit 103 generates a DC voltage obtained by rectifying and smoothing the input high-frequency alternating current using a built-in diode and an electrolytic capacitor (not shown), and inputs the generated DC voltage to the output connector 10. To do. The DC voltage generated by the rectifying / smoothing unit 103 is fed back to the adjusting unit 14 via the measuring unit 13, and the adjusting unit 14 repeatedly performs switching adjustment to stabilize the DC voltage input to the output connector 10. To do. Such a technique for converting AC100V into a DC voltage is a technique provided in a general AC adapter, and thus detailed description thereof is omitted.

  FIG. 2A is a top view showing the appearance of the AC adapter 1 according to this embodiment, FIG. 2B is a side view thereof, and FIG. 3 is a perspective view thereof. The output connector 10 shown in FIGS. 1 to 3 is a connector (socket) that can be connected to, for example, a USB cable having a USB type A plug. The input connector 11 is a connector (socket) that can be connected to, for example, a USB cable having a micro USB type B plug.

  FIG. 4 illustrates a top view illustrating an appearance of a configuration in which the USB cable 200 is connected to the output connector 10 and the input connector 11 in the AC adapter 1 according to the present embodiment. The connector 201 included in the USB cable 200 is, for example, a USB type A plug, and the connector 202 is, for example, a micro USB type B plug. Therefore, the connector 201 can be connected to the connector 10, and the connector 202 can be connected to the connector 11. Note that the shapes (types) of the output connector 10, the input connector 11, and the connectors 201 and 202 described above are examples, and the shapes of these connectors may be different from those described above.

  The load unit 12 is an element having an electrical load such as an electrical resistance, and is connected to the input connector 11. Therefore, when the input plug 100 is connected to an AC 100V outlet and the USB cable 200 is connected to the output connector 10 and the input connector 11, a current that flows from the input plug 100 to the load unit 12 is generated. The magnitude of the electrical load related to the load unit 12 is set to be equivalent to the maximum value that can be possessed by the device connectable to the AC adapter 1 by the USB cable 200, for example.

  The measurement unit 13 measures voltage values at measurement points X and Y illustrated in FIG. 1 in a state where the input plug 100 is connected to an AC 100V outlet and the USB cable 200 is connected to the output connector 10 and the input connector 11. Although the measurement point X is provided at the input portion to the output connector 10 in FIG. 1, the measurement point X may be provided inside the output connector 10, for example. The measurement point Y is provided at the output portion from the input connector 11 in FIG. 1, but may be provided inside the input connector 11, for example. The measurement unit 13 inputs the measurement result to the adjustment unit 14. Since a general configuration can be adopted for the configuration in which the measurement unit 13 can measure the DC voltage, the description in the present embodiment is omitted.

  The adjustment unit 14 adjusts the voltage value (output voltage value) output to the high-frequency transformer 102 based on the measurement result by the measurement unit 13. As for the configuration in which the adjustment unit 14 can adjust the output voltage value, for example, a switch element, a comparator, and the like can be adopted among the configurations described in FIG. Omitted. Such a configuration capable of adjusting the output voltage value can be realized by an integrated circuit in recent years. FIG. 5 is a characteristic diagram (graph) illustrating a change in voltage value at the measurement points X and Y before and after the adjustment unit 14 adjusts the output voltage value. As illustrated in FIG. 5, the voltage value at the measurement point X measured by the measurement unit 13 is 5.0 V before the adjustment unit 14 adjusts the output voltage value. At this time, a voltage drop (0.4 V in the example shown in FIG. 5) determined by the impedance characteristic occurs in the USB cable 200, so the voltage value at the measurement point Y is 4.6V. In the example shown in FIG. 5, since the minimum voltage value that can charge the device connected to the AC adapter 1 by the USB cable 200 is 4.75 V, the voltage value at the measurement point Y is lower than the minimum voltage value that can be charged. ing. For this reason, before the adjustment part 14 adjusts an output voltage value, there exists a possibility that the AC adapter 1 may become unable to charge the apparatus connected.

  The adjustment unit 14 increases the output voltage value until the voltage value at the measurement point Y reaches 5.0 V, which is the voltage value at the measurement point X before adjusting the output voltage value. At that time, the adjustment unit 14 adjusts the output voltage value while referring to the voltage values at the measurement points X and Y input from the measurement unit 13. The adjustment unit 14 stops the adjustment operation to increase the output voltage value when the voltage values at the measurement points X and Y sequentially reach 5.4V and 5.0V.

  The adjustment unit 14 stores in the storage unit 15 adjustment information representing an internal state when the output voltage value is adjusted so that the voltage at the measurement points X and Y increases by 0.4 V. Thereafter, when the USB cable 200 is connected to the output connector 10, the adjustment unit 14 reads out this adjustment information from the storage unit 15 so that the voltage at the measurement points X and Y is increased by 0.4V. The voltage value can be adjusted.

  After the adjustment by the adjustment unit 14 is completed, the user removes the connector 202 in the USB cable 200 from the input connector 11 and connects it to the connector 301 included in the device 300 as shown in FIG. . Similar to the input connector 11, the connector 301 is a connector (socket) that can be connected to a micro USB type B plug. In the state shown in FIG. 6, the voltage value output from the output connector 10 by the AC adapter 1 is 5.4V. At this time, the voltage value at the connector 301 is 5.0V. As a result, the AC connector 1 starts charging the lithium ion secondary battery 302 built in the device 300.

  Next, a flow of a series of operations using the AC adapter 1 according to the present embodiment will be described in detail with reference to the flowchart of FIG.

  The user connects the output connector 10 to the connector 201 of the USB cable 200 and the input connector 11 to the connector 202 (step S101). The input plug 100 is connected to an AC 100 outlet by the user (step S102).

  The measurement unit 13 measures the voltage value at the measurement points X and Y, for example, triggered by the current flowing, and inputs the measurement result to the adjustment unit 14 (step S103). The adjustment unit 14 adjusts the output voltage value so that the voltage value at the measurement points X and Y is increased by the value of the voltage difference between the measurement points X and Y from the voltage value at the start of adjustment (step S104). If the voltage values at the measurement points X and Y do not reach the target value (No in step S105), the operation returns to step S103. When the voltage values at the measurement points X and Y reach the target values (Yes in step S105), the adjustment unit 14 stores adjustment information regarding the adjusted voltage values in the storage unit 15 (step S106).

  The measurement unit 13 detects from the measurement result of the voltage value that the connector 202 of the USB cable 200 is connected to the connector 301 of the device 300 (step S107). The adjustment unit 14 maintains and outputs the adjusted output voltage value (step S108), and the entire operation ends.

The power adapter 1 according to the present embodiment is highly versatile and has a simple configuration in consideration of the amount of voltage drop due to the power supply cable connected to the device and outputting a voltage that can charge or operate the device. The reason is that the power adapter 1 operates as follows. That is,
The power adapter 1 includes the load unit 12 so that when the output connectors 10 and 11 are connected to the USB cable 200 (power supply cable) and AC 100 V is supplied from the outside, the device is connected via the USB cable 200. In the same manner as when power is supplied to 300, the current flows through the USB cable 200.
The measurement unit 13 measures the voltage values at the output connector 10 and the input connector 11 when AC 100 V is supplied from the outside with the output connectors 10 and 11 connected to the USB cable 200.
The adjustment unit 14 adjusts the output voltage value so that the voltage value at the output connector 10 and the input connector 11 is increased by the value of the voltage difference at the output connector 10 and the input connector 11 from the voltage value at the start of adjustment ( Calibrate). Then, after the connector 202 of the USB cable 200 is connected to the connector 301 of the device 300, the adjustment unit 14 maintains and outputs the adjusted output voltage value.

  Below, the effect implement | achieved by AC adapter 1 which concerns on this embodiment is demonstrated in detail.

  When a device is charged or operated from a power supply cable such as a USB cable from the AC adapter, the AC adapter needs to output a voltage value in consideration of a voltage drop amount due to the USB cable. In a general system corresponding to such a function, it is necessary to add a function to the USB cable, or to arrange a dedicated device in the middle of the USB cable. Therefore, considering the amount of voltage drop due to a power supply cable such as a USB cable connected to the device, it is possible to output a voltage value at which the device can be charged or operated with a highly versatile and simple configuration. This is a problem.

  In response to such a problem, in the AC adapter 1 according to the present embodiment, the load unit 12 is provided so that power is supplied from the outside while the output connector 10 and the input connector 11 are connected to the USB cable 200. Sometimes, the current flows through the USB cable 200 in the same manner as when power is supplied to the device 300 via the USB cable 200. The measurement unit 13 measures voltage values at the output connector 10 and the input connector 11 when power is supplied from the outside while the output connectors 10 and 11 are connected to the USB cable 200. The adjustment unit 14 adjusts the output voltage value so that the voltage value at the output connector 10 and the input connector 11 is increased by the value of the voltage difference at the output connector 10 and the input connector 11 from the voltage value at the start of adjustment. Then, after the connector 202 of the USB cable 200 is connected to the connector 301 of the device 300, the adjustment unit 14 maintains and outputs the adjusted output voltage value. Thereby, the AC adapter 1 according to the present embodiment outputs a voltage value that can charge or operate the device in consideration of a voltage drop amount due to a power supply cable such as a USB cable connected to the device. And can be realized with a simple configuration.

  Further, the adjustment unit 14 according to the present embodiment stores the adjustment information when adjusting the output voltage value in the storage unit 15. When the AC adapter 1 supplies power to the device 300 via the same USB cable 200, the adjustment unit 14 can quickly adjust the output voltage value by reading the adjustment information from the storage unit. That is, for the USB cable 200 that has been adjusted once for the output voltage value, the user omits the work of connecting the both ends of the USB cable 200 to the AC adapter 1 and adjusting the output voltage value from the AC adapter 1. be able to. Therefore, the AC adapter 1 according to the present embodiment can improve the convenience for the user regarding the work of adjusting the output voltage value.

  Note that the power supply cable connected to the AC adapter 1 of the present embodiment is not limited to a USB cable. The output connector 10 and the input connector 11 according to the present embodiment may be connectors that can be connected to a power feeding cable corresponding to a standard other than USB.

<Second Embodiment>
FIG. 8 is a block diagram conceptually showing the structure of the AC adapter 2 according to the second embodiment of the present invention. In the following description, configurations that operate in the same manner as in the first embodiment are given the same numbers as in the first embodiment, and description thereof is omitted.

  The AC adapter 2 according to the embodiment includes an output connector 10, an input connector 11, a load unit 12, a measurement unit 23, an adjustment unit 24, a storage unit 15, an input plug 100, a rectification / smoothing unit 101, a high-frequency transformer 102, and a rectification. / The smoothing part 103 is provided.

  The measurement unit 23 is configured such that the voltage at the measurement point Y illustrated in FIG. 8 (voltage with reference to the ground) in a state where the input plug 100 is connected to an AC 100V outlet and the USB cable 200 is connected to the output connector 10 and the input connector 11. ). As for the configuration in which the measurement unit 23 can measure the DC voltage, a general configuration can be adopted as in the measurement unit 13 according to the first embodiment. The measurement unit 23 inputs the measurement result to the adjustment unit 24.

  The adjustment unit 24 adjusts the voltage value output to the high-frequency transformer 102 based on the measurement result by the measurement unit 23. FIG. 9 is a characteristic diagram (graph) illustrating the change in the voltage value at the measurement point X (not measured by the measurement unit 23 in the present embodiment) and Y before and after the adjustment unit 24 adjusts the output voltage value. As illustrated in FIG. 9, before the adjustment unit 24 adjusts the output voltage value, the voltage values at the measurement points X and Y are 5.0 V and 4 in order as in the example shown in FIG. .6V. In the example shown in FIG. 9 as well, as in the example shown in FIG. 5, the minimum voltage value that can charge the device connected to the AC adapter 2 by the USB cable 200 is 4.75 V. There is a possibility that the AC adapter 2 cannot charge the connected device before adjusting.

  As illustrated in FIG. 8, the adjustment unit 24 stores the reference voltage information 240 in, for example, a memory in an integrated circuit. The reference voltage information 240 is information indicating a minimum voltage value (reference voltage value) that can charge a device connected to the AC adapter 2 by the USB cable 200. In the present embodiment, the reference voltage information 240 is information indicating 4.75V. This reference voltage value is set by a user, for example. The adjustment unit 24 increases the output voltage value until the voltage value at the measurement point Y reaches 4.75 V, which is the reference voltage value. The adjusting unit 24 stops the operation of increasing the output voltage value when the voltage value at the measurement point Y reaches 4.75V. At this time, the voltage value at the measurement point X becomes 5.15 V, which is increased by 0.15 V from 5.0 V.

  Next, a flow of a series of operations using the AC adapter 2 according to the present embodiment will be described in detail with reference to the flowchart of FIG.

  First, the same operation as in steps S101 and S102 is performed (step S201). The measurement unit 23 measures a voltage value at the measurement point Y, for example, triggered by the current flowing, and inputs the measurement result to the adjustment unit 24 (step S202). The adjustment unit 24 compares the voltage value at the measurement point Y with the reference voltage value indicated by the reference voltage information 240 (step S203).

  When the voltage value at the measurement point Y is smaller than the reference voltage value (Yes in Step S204), the adjustment unit 24 adjusts the output voltage value so that the voltage value at the measurement point Y rises to the reference voltage value (Step S204). S205). If the voltage value at the measurement point Y is greater than or equal to the reference voltage value (No in step S204), the operation proceeds to step S206. Processing similar to that in steps S106 to S108 is performed (step S206), and the entire operation ends.

The power adapter 2 according to the present embodiment has a high versatility and a simple configuration to output a voltage that can charge or operate the device in consideration of a voltage drop amount due to a power supply cable connected to the device. The reason is that the power adapter 2 operates as follows. That is,
The power adapter 2 includes the load unit 12 so that when the output connectors 10 and 11 are connected to the USB cable 200 (power supply cable) and AC 100 V is supplied from the outside, the device is connected via the USB cable 200. In the same manner as when power is supplied to 300, the current flows through the USB cable 200.
The measurement unit 23 measures the voltage value at the input connector 11 when AC 100 V is supplied from the outside with the output connectors 10 and 11 connected to the USB cable 200.
The adjustment unit 24 adjusts the output voltage value so that the voltage value at the input connector 11 rises to the reference voltage value when the voltage value at the input connector 11 is smaller than the reference voltage value. The adjustment unit 24 maintains and outputs the adjusted output voltage value after the connector 202 of the USB cable 200 is connected to the connector 301 of the device 300.

  Unlike the measurement unit 22 according to the first embodiment, the measurement unit 23 according to the present embodiment measures the voltage value at the measurement point Y. The adjustment unit 24 adjusts the output voltage value so that the voltage value at the measurement point Y increases to the reference voltage indicated by the reference voltage information 240. Thereby, the AC adapter 2 according to the present embodiment can flexibly cope with various devices having different reference voltage values.

<Third Embodiment>
FIG. 11 is a block diagram conceptually showing the structure of the AC adapter 3 according to the third embodiment of the present invention. In the following description, configurations that operate in the same manner as in the first or second embodiment are given the same numbers as in the first or second embodiment, and description thereof is omitted.

  The AC adapter 3 according to the embodiment includes an output connector 10, an input connector 11, a load unit 12, a measurement unit 13, an adjustment unit 34, a storage unit 35, an input switch 36, a display unit 37, an input plug 100, and a rectification / smoothing unit 101. A high-frequency transformer 102 and a rectifying / smoothing unit 103.

  The storage unit 35 includes a plurality of (for example, three) entries that can store adjustment information when the adjustment unit 34 adjusts the output voltage value. The storage unit 35 stores the adjustment information input from the adjustment unit 34 in one of the three entries based on an instruction from the adjustment unit 34.

  FIG. 12 is a diagram (top view) illustrating the appearance of the AC adapter 3 according to this embodiment. As shown in FIG. 12, the AC adapter 3 includes an input switch 36 that can be pressed by the user, and a display unit 37 that can be visually recognized by the user.

  Each time the input switch 36 is pressed by the user, the input switch 36 notifies the adjustment unit 34 that the input switch 36 has been pressed.

  The display unit 37 includes three light emitting elements (for example, LEDs (Light Emitting Diode)) as illustrated in FIG. The number of LEDs provided in the display unit 37 is not limited to three. The display unit 37 lights or blinks at least one of the three LEDs based on an instruction from the adjustment unit 34. The display unit 37 changes the emission color of these LEDs to red or yellow based on an instruction from the adjustment unit 34.

  Similar to the adjustment unit 14 according to the first embodiment, the adjustment unit 34 has a function of adjusting the voltage value output to the high-frequency transformer 102 based on the measurement result by the measurement unit 13. The adjustment unit 34 determines whether or not the voltage value at the observation point Y satisfies a predetermined standard in a state where the USB cable 200 is connected to the output connector 10 and the input connector 11. An example of the predetermined standard is “being a predetermined threshold value or more”. The adjustment unit 34 controls the display unit 37 so that at least one of the LEDs included in the display unit 37 blinks red when the voltage value of the observation point Y does not satisfy a predetermined standard. In this case, the USB cable 200 is replaced with another cable by the user as a cable unsuitable for use.

  Whenever the adjustment unit 34 is notified that the input switch 36 has been pressed, the adjustment unit 34 sequentially changes the LED that lights or blinks on the display unit 37 according to, for example, a round robin method. In the present embodiment, the three LEDs included in the display unit 37 are associated with the three entries included in the storage unit 35 on a one-to-one basis.

  The adjustment unit 34 controls the LED included in the display unit 37 to blink yellow when the voltage values at the measurement points X and Y reach the target values. The adjustment unit 34 stores the adjustment information regarding the adjusted voltage value in the entry of the storage unit 35 indicated by the blinking LED in the display unit 37. Thereafter, when the USB cable 200 is connected to the output connector 10, the adjustment unit 34 reads this adjustment information from the entry in the storage unit 35 selected by the user's pressing operation on the input switch 36. The output voltage value can be adjusted so that the voltage value output from the output connector 10 becomes the target value.

  Next, a flow of a series of operations using the AC adapter 3 according to the present embodiment will be described in detail with reference to the flowchart of FIG.

  First, operations similar to those in steps S101 and S102 are performed (step S301). The measurement unit 13 measures the voltage value at the measurement points X and Y, for example, triggered by the current flowing (step S302). When the voltage value at the measurement point Y does not satisfy the standard (No in Step S303), the adjustment unit 34 controls the LED included in the display unit 37 to blink in red (Step S304). The USB cable 200 is replaced with another cable by the user (step S305), and the process returns to step S301.

  When the voltage value at the measurement point Y satisfies the standard (Yes in step S303), the adjustment unit 34 determines that the voltage value at the measurement points X and Y is the voltage difference at the measurement points X and Y from the voltage value at the start of adjustment. The output voltage is adjusted so as to increase by the value (step S306). If the voltage values at the measurement points X and Y do not reach the target value, the operation returns to step S302.

  When the voltage values at the measurement points X and Y reach the target values, the adjustment unit 34 performs control so that the LED included in the display unit 37 blinks in yellow (step S308). The adjustment unit 34 sequentially changes the blinking LEDs on the display unit 37 every time the input switch 36 is pressed (step S309). The adjustment unit 34 stores the adjustment information regarding the adjusted voltage value in the entry of the storage unit 15 indicated by the blinking LED in the display unit 37 (step S310). The same operation as S107 and S108 is performed (step S311), and the entire operation ends.

The power adapter 3 according to the present embodiment is highly versatile and has a simple configuration in consideration of the amount of voltage drop due to a power supply cable connected to the device and outputting a voltage that can charge or operate the device. The reason is that the power adapter 3 operates as follows. That is,
The power adapter 3 includes the load unit 12 so that when the output connectors 10 and 11 are connected to the USB cable 200 (power supply cable) and AC100V is supplied from the outside, the device is connected via the USB cable 200. In the same manner as when power is supplied to 300, the current flows through the USB cable 200.
The measurement unit 13 measures the voltage values at the output connector 10 and the input connector 11 when AC 100 V is supplied from the outside with the output connectors 10 and 11 connected to the USB cable 200.
The adjustment unit 34 adjusts the output voltage value so that the voltage value at the output connector 10 and the input connector 11 is increased by the value of the voltage difference at the output connector 10 and the input connector 11 from the voltage value at the start of adjustment. . The adjustment unit 34 maintains and outputs the adjusted output voltage value after the connector 202 of the USB cable 200 is connected to the connector 301 of the device 300.

  The storage unit 35 according to the present embodiment includes a plurality of entries for storing adjustment information by the adjustment unit 34. The adjustment unit 34 stores the adjustment information in an entry designated by the user via the user interface (input switch 36 and display unit 37). Thereby, the AC adapter 3 distinguishes and manages the adjustment information regarding the plurality of USB cables 200. Therefore, the AC adapter 3 according to the present embodiment connects the both ends of the USB cable 200 to the AC adapter 1 and outputs from the AC adapter 1 with respect to the plurality of USB cables 200 that have been adjusted once for the output voltage value. An optimal voltage value can be output without performing a process of adjusting the voltage value. Therefore, the AC adapter 3 according to the present embodiment can further improve the convenience for the user regarding the operation of adjusting the output voltage value.

  In addition, the adjustment unit 34 according to the present embodiment determines whether or not the voltage value at the observation point Y satisfies a predetermined reference in a state where the USB cable 200 is connected to the output connector 10 and the input connector 11, and The determination result is displayed via the display unit 37. Thereby, the AC adapter 3 according to the present embodiment can notify the user of a USB cable that has a large voltage drop amount and is not suitable for use.

  The display unit 37 according to the present embodiment may include a device other than the LED. The display unit 37 may include, for example, an LCD (Liquid Crystal Display) and display information using characters. In this case, the display unit 37 may display the content of the adjustment information including the voltage value output from the adjustment unit 34, for example.

  Further, the AC adapter 3 according to the present embodiment may include the measurement unit 23 according to the second embodiment instead of the measurement unit 13. In this case, the adjustment unit 34 performs the same processing as the adjustment unit 24 according to the second embodiment for adjustment related to the output voltage value.

<Fourth Embodiment>
FIG. 14 is a block diagram conceptually showing the structure of the power adapter 4 according to the fourth embodiment of the present invention.

  The power adapter 4 according to this embodiment includes a first connection unit 40, a second connection unit 41, a load unit 42, a measurement unit 43, and an adjustment unit 44.

  The 1st connection part 40 can be connected with the end of the electric power feeding cable 400 so that electricity supply is possible.

  The second connection portion 41 can be connected to the other end of the power supply cable 400 so as to be energized.

  The load part 42 is connected to the second connection part 41 so as to be energized, and has an electrical load.

  When the power feeding cable 400 is connected to the first connection unit 40 and the second connection unit 41, the measurement unit 43 is configured so that the current flows to the load unit 42 by power supply from the outside. The voltage at the connection part 41 is measured.

  The adjustment unit 44 adjusts the voltage output from the first connection unit 40 to the power supply cable 400 according to the voltage measured by the measurement unit 43. The adjustment unit 44 maintains the adjusted voltage after the power feeding cable 400 is disconnected from the second connection unit 41.

The power adapter 4 according to the present embodiment is highly versatile and has a simple configuration in consideration of the amount of voltage drop due to the power supply cable connected to the device and outputting a voltage that can charge or operate the device. The reason is that the power adapter 4 operates as follows. That is,
The power adapter 4 includes the load unit 42, so that when the first connection unit 40 and the second connection unit 41 are connected to the power supply cable 400 and supplied with power from the outside, the power supply adapter 4 is connected via the power supply cable 400. In the same manner as when power is supplied to the device, current is caused to flow through the power supply cable 400.
The measurement unit 43 measures the voltage at the second connection unit 41 when the first connection unit 40 and the second connection unit 41 are supplied with power from the outside while being connected to the power supply cable 400.
The adjustment unit 44 adjusts the voltage output from the first connection unit 40 to the power feeding cable 400 according to the voltage measured by the measurement unit 43. And the adjustment part 44 maintains and outputs the adjusted output voltage, after the electric power feeding cable 400 becomes unconnected with the second connection part 41.

  The present invention has been described above using the above-described embodiment as an exemplary example. However, the present invention is not limited to the above-described embodiment. That is, the present invention can apply various modes that can be understood by those skilled in the art within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 AC adapter 10 Output connector 11 Input connector 12 Load part 13 Measurement part 14 Adjustment part 15 Memory | storage part 100 Input plug 101 Rectification / smoothing part 102 High frequency transformer 103 Rectification / smoothing part 200 USB cable 201 Connector 202 Connector 300 Equipment 301 Connector 302 Lithium Ion secondary battery 2 AC adapter 23 Measurement unit 24 Adjustment unit 240 Reference voltage information 3 AC adapter 34 Adjustment unit 35 Storage unit 36 Input switch 37 Display unit 4 Power adapter 40 First connection unit 41 Second connection unit 43 Measurement unit 44 Adjustment unit 400 Power supply cable

Claims (10)

A first connection portion capable of being connected to one end of the power supply cable so as to be energized;
A second connection portion capable of being connected to the other end of the power supply cable so that energization is possible;
A load portion connected to the second connection portion so as to be energized and having an electrical load;
Measurement in which the voltage at the second connection portion is measured when a current flows to the load portion by power supply from the outside when the power supply cable is connected to the first and second connection portions. Means,
After adjusting the voltage output from the first connection to the power supply cable according to the voltage measured by the measuring means, the power supply cable is not connected to the second connection. Adjusting means for maintaining the adjusted voltage;
With power adapter. The measuring means measures the voltage at the first connection;
The adjusting means adjusts the voltage output from the first connection portion to the power supply cable to a magnitude obtained by adding a value indicated by a voltage difference in the first and second connection portions,
The power adapter according to claim 1. The adjusting means adjusts the voltage output from the first connection portion to the power supply cable to a magnitude obtained by adding a value indicated by a difference between a predetermined reference voltage and a voltage at the second connection portion,
The power adapter according to claim 1. Storage means capable of storing adjustment information relating to the adjusted voltage;
The adjustment unit adjusts the voltage output from the first connection unit to the power supply cable, and then stores the adjustment information in the storage unit, so that the power supply cable is not connected to the second connection unit. After that, based on the adjustment information stored in the storage means, to maintain the adjusted voltage,
The power adapter according to any one of claims 1 to 3. The adjusting means determines whether or not the voltage at the second connection measured by the measuring means satisfies a reference;
The power adapter according to any one of claims 1 to 4. Further comprising display means for displaying information input from the adjusting means;
The adjustment means inputs at least one of the adjustment information and a determination result regarding whether or not the voltage at the second connection portion satisfies a reference to the display means.
The power adapter according to claim 5. The display means displays the information input from the adjustment means by changing the state of light emission or by characters.
The power adapter according to claim 6. An input unit that receives an input operation and inputs the content of the input operation to the adjustment unit;
The storage means includes a plurality of entries capable of storing the adjustment information,
The adjusting means accesses any one of the plurality of entries based on the content of the input operation input from the input means.
The power adapter according to any one of claims 4 to 7. The magnitude of the electrical load of the load section is the same or substantially the same magnitude as the electrical load of an external device that is supposed to supply power from the first connection section via the power supply cable.
The power adapter according to any one of claims 1 to 8. A first connection portion capable of being connected to one end of the power supply cable so as to be energized;
A second connection portion capable of being connected to the other end of the power supply cable so that energization is possible;
A load part that is electrically connected to the second connection part and has an electrical load;
Using a power adapter with
The power supply cable is connected to the first and second connection portions, and in response to a current flowing to the load portion by power supply from the outside, the voltage at the second connection portion is measured,
According to the measured voltage, the voltage output from the first connection portion to the power supply cable is adjusted, and the power supply cable is adjusted after being disconnected from the second connection portion. Maintain voltage,
How to adjust the voltage of the power adapter.

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