JP2012016139A - Power source device and electronic device system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of suppressing power consumption of a power source device with a simple structure depending on a state of an electronic device.SOLUTION: The power source device comprises: a power conversion unit for converting an AC power to a DC power and outputting the DC power; a DC power output line for outputting the DC power output by the power conversion unit to the electronic device; a consumption monitoring unit for monitoring consumption of the DC power which has been output to the electronic device in the electronic device by detecting changes in a current in the DC power output line; a switching unit capable of switching between an input allowable state which allows the AC power to be input to the power conversion unit and an input inhibition state which inhibits the AC power from being input to the power conversion unit; and a switching power supply unit for supplying power for switching from the input inhibition state to the input allowable state from a power source different from a power source for the AC power. The switching unit switches between the input allowable state and the input inhibition state depending on the consumption in the electronic device monitored by the consumption monitoring unit.

Description

  The present invention relates to a power supply device and an electronic device system.

  Electronic devices such as personal computers and their peripheral devices (printers, modems, routers, etc.), or electrical appliances such as televisions and DVD recorders, generally have a DC power supply (for example, 5 volts, It operates with power supplied from a 1 amp DC power source. For this reason, in order to use a commercial AC power supply (for example, 100 V) as a power source for the operation of an electronic device, a power supply device that is externally attached or built in the electronic device specifies a commercial AC power supply. It is converted into a DC power supply of specifications (for example, Patent Document 1).

  In this technology, in a power supply device that provides a DC power source for supplying electric power to an electronic device via two power supply lines (power supply potential line and ground line) connected to the electronic device, When shifting to the standby state and when returning from the standby state to the operation state, the electronic device transmits a control signal to the power supply device via the power supply potential line. The power supply device that has received the control signal can recognize whether or not the electronic device is in a standby state by the control signal, and disconnects the commercial AC power supply when the electronic device is in a standby state. Thus, when the electronic device is in a standby state, the power consumption in the power supply device is suppressed to an extremely low level.

JP 2004-104850 A JP 2000-308257 A Japanese Patent Laid-Open No. 11-341804

  However, in the prior art described above, the configuration of the electronic device and the power supply device may be complicated. For example, the electronic device needs a configuration for generating a control signal for shifting from the standby state to the operating state and a control signal for shifting from the operating state to the standby state. In addition, the power supply device needs a configuration for analyzing these two types of control signals.

  A main advantage of the present invention is to provide a technique capable of suppressing power consumption of a power supply device with a simple configuration in accordance with the state of an electronic device.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

Application Example 1 A power supply device for supplying DC power to an electronic device,
A power conversion unit that converts AC power input from an AC power source into DC power and outputs the power;
DC power output line for outputting to the electronic device the DC power output from the power conversion unit connected to the electronic device,
A consumption monitoring unit that monitors the consumption of the DC power output from the DC power output line to the electronic device by detecting a change in current or voltage in the DC power output line;
A switching unit capable of switching between an input permissible state allowing input of AC power from the AC power source to the power conversion unit and an input prohibiting state prohibiting input of AC power from the AC power source to the power conversion unit. A switching unit that switches between the input allowed state and the input prohibited state according to consumption in the electronic device monitored by the consumption monitoring unit;
A switching power supply unit that supplies power for the switching unit to switch from the input-prohibited state to the input-permitted state from a power source different from the AC power source;
A power supply apparatus comprising:

  According to the above configuration, the power supply apparatus monitors the change in the current or voltage in the DC power output line, and according to the monitoring result, allows an input of AC power from the AC power source to the power converter, Then, the input switching state for prohibiting the input of AC power from the AC power source to the power conversion unit is switched. In the input prohibited state, the power consumption in the power conversion unit by the AC power supply can be suppressed to zero. Then, it is possible to switch from the input-prohibited state to the input-permitted state using power supplied from a power source different from the AC power source. Therefore, for example, the power consumption in the power supply device can be reduced according to the power consumption in the electronic device with a simple configuration without providing a circuit for analyzing the control signal from the electronic device side. Note that the DC power output line includes, for example, a reference potential line and a power supply potential line, and the voltage on the DC power output line means a potential difference between the reference potential line and the power supply potential line.

[Application Example 2] The power supply device according to Application Example 1,
In the input allowable state, the power conversion unit outputs a first voltage to the DC power output line,
In the input prohibited state, the consumption monitoring unit outputs the first voltage to the DC power output line using a power source different from the AC power source.

  According to the above configuration, since the output voltage has the same value in both the input-permitted state and the input-prohibited state, it is not necessary to provide a special circuit on the electronic device side, and the versatility of the power supply device can be improved.

[Application Example 3] The power supply device according to Application Example 1,
In the input allowable state, the power conversion unit outputs a first voltage to the DC power output line,
In the input prohibited state, the consumption monitoring unit outputs a second voltage lower than the first value to the DC power output line using a power source different from the AC power source. .

  According to the above configuration, in the input prohibited state, in addition to being able to suppress power consumption in the power conversion unit by the AC power supply to zero, it is also possible to suppress power for monitoring power consumption in the electronic device. Therefore, the power consumption of the entire power supply device can be more effectively suppressed.

[Application Example 4] The power supply device according to any one of Application Examples 1 to 3,
When the consumption monitoring unit detects that the current in the DC power output line is equal to or less than a specified value in the input allowable state, the switching unit switches from the input allowable state to the input prohibited state. A power supply device.

  According to the above configuration, switching from the input permission state to the input prohibition state can be realized with a simple configuration.

[Application Example 5] The power supply device according to Application Example 2 or Application Example 3,
When the consumption monitoring unit detects that the voltage on the DC power output line has become a specified value or less in the input prohibited state, the switching unit switches from the input prohibited state to the input permitted state. A power supply device.

  According to the above configuration, in addition to being able to realize switching from the input prohibited state to the input permitted state with a simple configuration, when the voltage output to the DC power output line in the input prohibited state is reduced for some reason ( For example, when the power source is a battery, the switching unit switches to the input permissible state when the power source is a battery, so that the inconvenience that the power supply device does not function can be avoided.

Application Example 6 An electronic device system,
Electronic equipment,
A power supply;
First and second wirings connected to the electrical device for supplying direct current power to the electronic device;
With
The power supply device
A power converter that converts AC power input from an AC power source into DC power and generates a first voltage between the first wiring and the second wiring;
A switching unit capable of switching between an input permissible state allowing input of AC power from the AC power source to the power conversion unit and an input prohibiting state prohibiting input of AC power from the AC power source to the power conversion unit; ,
Have
The electronic device is
A switching control unit for controlling the switching unit;
A power supply unit that supplies power to the switching control unit from a power source different from the AC power source;
Have
The switching unit is in the input allowable state when the first voltage is generated between at least the first wiring and the second wiring, and a second voltage different from the first voltage is applied. The input is permitted to be switched from the input permission state to the input prohibition state when it occurs between the first wiring and the second wiring.
The switching control unit controls the switching unit by generating the second voltage between the first wiring and the second wiring using the power supplied from the power supply unit. An electronic device system characterized by

  According to the above configuration, the switching control unit controls the switching unit by generating the second voltage between the first wiring and the second wiring using the power supplied from the first power supply unit. That is, switching between the input-permitted state and the input-prohibited state is performed. As a result, when the electronic device is in a standby state, the power consumption in the power conversion unit by the AC power supply can be suppressed to zero with a simple configuration.

[Application Example 7] The electronic device system according to Application Example 6,
The second voltage is higher than the first voltage;
The switching unit is in the input-inhibited state when the second voltage is generated between the first wiring and the second wiring, and the switching section switches between the first wiring and the second wiring. The input is allowed when the voltage generated between them is smaller than the second voltage,
The switching control unit generates the second voltage between the first wiring and the second wiring using the power supplied from the power supply unit, thereby prohibiting the input of the switching unit. An electronic device system, wherein the switching unit is controlled to the input allowable state by controlling to a state and not generating the second voltage.

  According to the above configuration, the power conversion unit using the AC power supply can be simply controlled by generating the second voltage between the first wiring and the second wiring using the power supplied from the power supply unit. The power consumption in can be suppressed to zero. Further, the DC power can be supplied to the electronic device by operating the power converter only by simple control that the second voltage is not generated between the first wiring and the second wiring.

[Application Example 8] The electronic device system according to Application Example 6,
The second voltage is a voltage whose polarity is opposite to that of the first voltage.
The switching unit is
When in the input-inhibited state, the input voltage is switched to the input-permitted state when the first voltage is generated between the first wiring and the second wiring,
When in the input allowed state, the second voltage is configured to be switched to the input prohibited state when triggered by the first voltage and the second wire,
The switching control unit temporarily generates the second voltage between the first wiring and the second wiring using the power supplied from the power supply unit, thereby causing the switching unit to Control from the input permission state to the input prohibition state, and temporarily generate the first voltage between the first wiring and the second wiring by using the power supplied from the power supply unit Thus, the switching unit is controlled from the input prohibited state to the input permitted state.

  According to the above configuration, the power consumption in the power conversion unit by the AC power source is suppressed to zero only by temporarily generating the first voltage or the second voltage using the power supplied from the power supply unit. In addition, DC power can be supplied to the electronic device by operating the power conversion unit.

Application Example 9 An electronic device system,
Electronic equipment,
A power supply;
First and second wirings connected to the electrical device for supplying direct current power to the electronic device;
With
The power supply device
A power converter that converts AC power input from an AC power source into DC power and generates a first voltage between the first wiring and the second wiring;
A switching unit capable of switching between an input permissible state allowing input of AC power from the AC power source to the power conversion unit and an input prohibiting state prohibiting input of AC power from the AC power source to the power conversion unit; ,
A power supply side switching control unit for controlling the switching unit;
Have
The electronic device is
A power supply unit for supplying power from a power source different from the AC power source;
Device-side switching for generating a second voltage between the first wiring and the second wiring using the power supplied from the power supply unit when the switching unit is in the input prohibited state A control unit;
With
The power supply side switching control unit switches the switching unit when a second voltage is generated between the first wiring and the second wiring when the switching unit is in the input prohibited state. An electronic device system, wherein the input prohibition state is switched to the input permission state.

  According to the above configuration, the electronic device only generates the second voltage between the first wiring and the second wiring using a power supply different from the AC power supply when the switching unit is in the input prohibited state. Thus, the switching unit can be switched from the input prohibited state to the input permitted state. As a result, with a simple configuration, it is possible to shift from a state where the switching unit in the power supply device is in the input-prohibited state and the power consumption of the power conversion unit by the AC power supply is zero, to a state where DC power is supplied from the power supply device it can.

[Application Example 10]
An electronic device system according to Application Example 9,
The power supply side switching control unit sets the switching unit to the input-permitted when the current in the first wiring or the second wiring becomes a specified value or less when the switching unit is in the input-permitted state. An electronic device system characterized by switching from a state to the input prohibited state.

  According to the above configuration, when the current supplied to the electronic device becomes equal to or lower than the specified value, the power unit can suppress the power consumption in the power conversion unit by the AC power source by setting the switching unit to the input prohibited state. . And when supply of the electric power from a power supply device is required, as above-mentioned, an electronic device uses the power supply different from an alternating current power supply, when a switching part is in an input prohibition state, and uses the 1st wiring and the 2nd wiring It is possible to shift to a state in which DC power is supplied from the power supply device simply by generating the second voltage between the two. As a result, a circuit for analyzing a control signal from the electronic device side is not provided on the power supply device side, or a circuit for generating a control signal is not provided on the electronic device side. Power consumption can be reduced.

[Application Example 11]
An electronic device system according to Application Example 9,
The first wiring is a power supply potential line to which a power supply potential is applied,
The second wiring is a reference potential line to which a reference potential is applied,
The device-side switching control unit can transmit a control signal to the power supply device via the power supply potential line when the switching unit is in the input allowable state.
The power supply side switching control unit has a receiving unit that receives the control signal, and when the control signal is received, the switching unit is switched from the input allowed state to the input prohibited state, Electronic equipment system.

  According to the above configuration, the electronic device can actively control the switching unit.

  The present invention can be realized in various forms. For example, in addition to inventions of electronic devices, power supply devices, electronic devices, and the like, electronic devices, power supply devices, electronic device control methods, etc. It can be realized in the form.

It is explanatory drawing which shows schematic structure of the electronic device system as 1st Example. It is a figure which shows the electrical constitution of the electronic device system. FIG. 6 is a diagram for explaining state transition of an AC adapter 100. It is a figure explaining the electrical constitution of the electronic device system 1000a in 2nd Example. It is a figure explaining the transition of the state of AC adapter 100a. It is a figure explaining the electrical constitution of the electronic device system 1000b in 3rd Example. It is a figure explaining the electrical constitution of the electronic device system 1000c in 4th Example. It is a figure explaining the electrical constitution of the electronic device system 1000d in 5th Example. It is a figure explaining an input prohibition signal. It is a figure explaining the electrical constitution of the electronic device system 1000e in 6th Example. It is a figure explaining the transition of the state of AC adapter 100e. It is a figure explaining the electrical constitution of the electronic device system 1000f in 7th Example. It is a figure explaining the transition of the state of AC adapter 100f.

  Next, embodiments of the present invention will be described based on examples with reference to the drawings.

(1) First embodiment:
FIG. 1 is an explanatory diagram showing a schematic configuration of an electronic device system as a first embodiment of the present invention. The electronic device system 1000 includes an AC adapter 100 as a power supply device and a hard disk drive 200 as an electronic device. The AC adapter 100 includes a cord 10 and is connected to the hard disk drive 200 via the cord 10. The cord 10 includes a power supply potential line 11 and a reference potential line 12 which will be described later. The AC adapter 100 is used by being connected to a general commercial AC power supply (for example, AC 100 V (volt)). The hard disk drive 200 is provided with a power button 201, and the hard disk drive 200 can be switched between a function stop state and an operation state when pressed by the user.

  The hard disk drive 200 is connected to the personal computer 300 via an external connection bus 20, for example, a USB (Universal Serial Bus), and is used as an external storage device of the personal computer 300.

  FIG. 2 is a diagram showing an electrical configuration of the electronic device system 1000. In FIG. 2, illustration of the personal computer 300 and the external connection bus 20 is omitted for simplification of description. The same applies to FIGS. 4, 6 to 8, and 10.

  The AC adapter 100 converts AC power input from an AC power source into DC power and outputs it. Specifically, the AC adapter 100 has a constant voltage between two DC power output lines, that is, the power supply potential line 11 and the reference potential line 12 (in this embodiment, the potential of the power supply potential line 11 is a reference voltage). A constant voltage that is plus 5V with respect to the potential of the potential line 12) and a constant voltage type DC power source is provided to the hard disk drive 200. Hereinafter, in the case where the voltage is expressed by a numerical value, when the reference is not particularly described, the voltage is expressed using the potential of the reference potential line 12 as a reference (0 V).

  The AC adapter 100 includes a changeover switch 110, a change control unit 120, an internal power supply 130, and a power conversion unit 140. In this embodiment, the changeover switch 110 is a latching mechanical relay. The relay is turned on when a voltage of plus 5V is applied to the first input line 13 with reference to the second input line 14, and thereafter, the relay is kept on even when the voltage application is stopped. Further, the relay is turned off when a voltage of plus 5 V is applied to the second input line 14 with respect to the first input line 13, and thereafter the off state is maintained even when the voltage application is stopped. The

  When the changeover switch 110 is off, the AC adapter 100 is in a state where the input of AC power from the AC power supply to the power conversion unit 140 is blocked (prohibited) (input prohibited state). When the changeover switch 110 is on, the AC adapter 100 is in a state where the input of AC power from the AC power source to the power conversion unit 140 is allowed (input allowed state).

  The switching control unit 120 includes an input cutoff control circuit 121 and a consumption monitoring circuit 122. The input cutoff control circuit 121 controls on / off of the changeover switch 110 in accordance with an instruction (control signal) from the consumption monitoring circuit 122. Specifically, on / off of the changeover switch 110 is controlled by applying the voltage described above to the first input line 13 and the second input line 14 of the changeover switch 110. The consumption monitoring circuit 122 monitors the power consumption by the hard disk drive 200 by detecting a change in the current of the power supply potential line 11, and instructs the input cutoff control circuit 121 when to turn on / off the switch 110. To do. Specific control contents of the switching control unit 120 will be described later.

  As the internal power supply 130, for example, a secondary battery is used in the present embodiment.

  The power conversion unit 140 is a well-known switching power conversion circuit that generates a constant voltage having a desired magnitude by repeatedly turning on and off a so-called switching element (such as a bipolar transistor).

  The power converter 140 includes an input rectifier circuit 141, an input smoothing circuit 142, a switching circuit 143, a transformer 144, an output rectifier circuit 145, an output smoothing circuit 146, a feedback detection circuit 147, and a switching control circuit 148. It has.

  When the AC adapter 100 is in the input-permitted state, AC power input from the AC power supply is converted to DC by the input rectifier circuit 141 and the input smoothing circuit 142, and further switched by the switching circuit 143 to be converted into a pulse wave. . The switched power (pulse wave) is regulated through the transformer 144 and converted into a direct current by the output rectifier circuit 145 and the output smoothing circuit 146. The feedback detection circuit 147 and the switching control circuit 148 control on and off of the switching circuit 143 so as to keep the voltage of the power output from the output smoothing circuit 146 at a desired constant value (5 V in this embodiment).

  As a result, when the AC adapter 100 is in the input-permitted state, the power conversion unit 140 generates a constant voltage (in this embodiment, plus 5 V with the reference potential line 12 as the reference (0 V)) on the power supply potential line 11, and AC The adapter 100 provides direct current power to the hard disk drive 200.

  On the other hand, when AC adapter 100 is in the input prohibited state, AC power is not input to power conversion unit 140 from the AC power supply, and power conversion unit 140 stops operating.

  The hard disk drive 200 includes an electronic device circuit 210 for realizing a function as a hard disk drive, and a main switch 202. The electronic device circuit 210 includes all loads (all parts that consume power such as a control circuit and a motor for driving the disk) for realizing the function as a hard disk drive. The main switch 202 is a mechanical switch that can be switched on / off by pressing the power button 201 (FIG. 1).

  When the main switch 202 is off, the electrical connection between the electronic device circuit 210 and the power supply potential line 11 is disconnected, and the power consumption in the electronic device circuit 210 becomes zero. When the main switch 202 is on, the electronic device circuit 210 and the power supply potential line 11 are electrically connected, and the electronic device circuit 210 realizes a function as a hard disk drive. When the main switch 202 is on, the power consumption of the electronic device circuit 210 varies depending on the operating state of the hard disk drive, but never becomes zero.

  Next, referring to FIG. 3 in addition to FIGS. 1 and 2, the state control of the AC adapter 100 by the switching control unit 120 will be described. FIG. 3 is a diagram for explaining the state transition of the AC adapter 100. When the main switch 202 of the hard disk drive 200 is on, the changeover switch 110 of the AC adapter 100 is also on, and the AC adapter 100 is in an input-permitted state. Therefore, a constant voltage as a DC power supply is output from the power conversion unit 140 to the power supply potential line 11 and the reference potential line 12, and the electronic device circuit 210 operates with power supplied from the DC power supply.

  In the input allowable state, the consumption monitoring circuit 122 of the AC adapter 100 constantly monitors whether or not the current value In in the power supply potential line 11 is equal to or less than a specified value. The specified value is a value smaller than a current value corresponding to the minimum power consumption of the electronic device circuit 210 of the hard disk drive 200 in a state where the main switch 202 is on, and a value larger than zero. In the input permission state, the consumption monitoring circuit 122 operates using the power output from the power conversion unit 140 instead of the internal power supply 130. Further, in the input allowable state, charging of the internal power supply 130 that is a secondary battery is also performed by the power output from the power conversion unit 140.

  In this state, when the user presses the power button 201 of the hard disk drive 200 to turn off the main switch 202, the power consumption of the electronic device circuit 210 of the hard disk drive 200 becomes zero. Then, since the current value In in the power supply potential line 11 becomes zero, the consumption monitoring circuit 122 of the AC adapter 100 detects that the current value In in the power supply potential line 11 has become a specified value or less.

  When detecting that the current value In is equal to or less than the specified value, the consumption monitoring circuit 122 transmits a control signal instructing the input cutoff control circuit 121 to turn off the changeover switch 110. The input cutoff control circuit 121 that has received the control signal switches the changeover switch 110 from the on state to the off state. As a result, the AC adapter 100 is in an input prohibited state.

  When the input is prohibited, the constant voltage output from the power converter 140 to the power supply potential line 11 is lost. Here, in the input prohibited state, the consumption monitoring circuit 122 applies a constant voltage to the power supply potential line 11 using the internal power supply 130. Here, the applied voltage is, for example, the same voltage as the constant voltage output from the power conversion unit 140 in the input allowable state.

  In the input prohibited state, the consumption monitoring circuit 122 monitors whether or not the current value In in the power supply potential line 11 to which the constant voltage is applied by the internal power supply 130 is equal to or more than the specified value described above. In the input prohibited state, the consumption monitoring circuit 122 operates with the internal power supply.

  In this state, when the user presses the power button 201 of the hard disk drive 200 to turn on the main switch 202, the power consumption of the hard disk drive 200 becomes from zero to at least the above-described minimum power consumption. As a result, the current value In in the power supply potential line 11 becomes equal to or greater than the specified value. Then, the consumption monitoring circuit 122 of the AC adapter 100 detects that the current value In in the power supply potential line 11 is equal to or higher than a specified value.

  When detecting that the current value In is equal to or greater than the specified value, the consumption monitoring circuit 122 transmits a control signal instructing the input cutoff control circuit 121 to turn on the changeover switch 110. The input cutoff control circuit 121 that has received the control signal switches the changeover switch 110 from the off state to the on state. As a result, the AC adapter 100 is in an input allowable state.

  According to the first embodiment described above, when the main switch 202 of the hard disk drive 200 is turned off and it is no longer necessary to supply power from the AC adapter 100 to the hard disk drive 200, the power supply potential line 11 on the AC adapter 100 side. It is detected that the current value In is less than or equal to the specified value, and the state of the AC adapter 100 becomes an input prohibited state in which the changeover switch 110 is turned off. As a result, when the main switch 202 of the hard disk drive 200 is turned off, the power consumption of the power conversion unit 140 by the AC power supply of the AC adapter 100 can be suppressed to zero.

  Furthermore, when the AC adapter 100 is in the input prohibited state, the consumption monitoring circuit 122 applies the same voltage as when the input is permitted between the power supply potential line 11 and the reference potential line 12 by the internal power supply 130, The current value In in the power supply potential line 11 is monitored. When the current value In becomes equal to or higher than the specified value, the AC adapter 100 is set in an input-permitted state in which the changeover switch 110 is turned on. As a result, when the main switch 202 of the hard disk drive 200 is turned on from off, the AC adapter 100 can be returned to the input allowable state in which power can be supplied.

  Therefore, with only the configuration on the AC adapter 100 side, it is possible to realize the transition from the input permitted state to the input prohibited state and the transition from the input prohibited state to the input permitted state according to the state of the hard disk drive 200.

  Further, since the same voltage is applied to the power supply potential line 11 by the internal power supply 130 as in the input allowable state, a special configuration (for example, a circuit for transmitting a control signal to the AC adapter 100) is provided on the hard disk drive 200 side. This is unnecessary, and the versatility of the AC adapter 100 can be improved.

  Further, in the input prohibited state, the internal power supply 130 is used to apply a voltage to the power supply potential line 11, but is not used to pass a current except at the moment when the input prohibited state is switched to the input permitted state. There is almost no power consumption from the internal power supply 130. Therefore, in the input prohibited state, the power conversion unit 140 by the AC power supply becomes zero, and the power consumption can be suppressed as the entire AC adapter 100.

  Furthermore, since the internal power supply 130 uses a secondary battery and the internal power supply 130 is charged in an input-permitted state, the switching function of the changeover switch 110 in the AC adapter 100 is effective over a long period of time. can do.

(2) Second embodiment:
The schematic configuration of the electronic device system 1000a according to the second embodiment is the same as the schematic configuration of the electronic device system 1000 according to the first embodiment described with reference to FIG. Hereinafter, the same applies to the third to seventh embodiments.

  FIG. 4 is a diagram illustrating the electrical configuration of the electronic device system 1000a according to the second embodiment. The electronic device system 1000a includes an AC adapter 100a and a hard disk drive 200a.

  The AC adapter 100a in the second embodiment includes a power conversion unit 140 and a changeover switch 110a. Since the configuration of the power conversion unit 140 is the same as the configuration of the same name (power conversion unit 140) in the first embodiment, the same reference numerals are given in FIG. Hereinafter, the same applies to FIGS. 6 to 8, 10, and 12.

  As with the changeover switch 110 of the first embodiment, the changeover switch 110a has an input permissible state in which input of AC power from the AC power supply to the power conversion unit 140 is allowed and an input prohibited state in which the input is prohibited. It is a switch for switching. In this embodiment, a semiconductor relay is used as the changeover switch 110a. In this embodiment, the semiconductor relay is turned off while a voltage of about 1V is applied to the second input line 14a with the first input line 13a as a reference (0V), and the voltage is not applied. It is a normally-on (b contact) type relay that is turned on in between. As in the first embodiment, when the changeover switch 110a is on, the AC adapter 100a is in an input-permitted state, and when the changeover switch 110a is off, the AC adapter 100a is in an input prohibited state.

  When the AC adapter 100a is in the input-permitted state, the power conversion unit 140 generates a constant voltage (5 V in this embodiment) on the power supply potential line 11a and directs the hard disk drive 200a to DC as in the first embodiment. Provide power.

  The first input line 13a is electrically connected to the reference potential line 12a. The second input line 14a is electrically connected to the power supply potential line 11a via the protective resistor R1 and the Zener diode ZR1. The breakdown voltage of the Zener diode ZR1 is 5V in this embodiment. The protective resistance R1 is a resistance that is small enough to ignore a voltage drop in normal operation, and is a resistance for protecting a circuit by preventing an unexpected current from flowing due to a malfunction or the like.

  The hard disk drive 200a includes an electronic device circuit 210, a main switch 202, a control voltage application circuit 203a, and an internal power supply 130a.

  Since the configuration of the electronic device circuit 210 and the main switch 202 is the same as the configuration of the same name in the first embodiment (FIG. 2: the electronic device circuit 210 and the main switch 202), the same reference numerals are given in FIG. Description is omitted. The same applies to FIGS. 6 to 8 and FIG.

  The control voltage application circuit 203a is a circuit for controlling the state of the AC adapter 100a to either the input prohibited state or the input permission signal. The internal power supply 130a is a power supply that supplies power to the control voltage application circuit 203a in the input prohibited state. In the input allowable state, the control voltage application circuit 203a operates with power supplied from the AC adapter 100a. In the present embodiment, a secondary battery is used as the internal power supply 130a, and charging is performed using power supplied from the AC adapter 100a in an input-permitted state.

  Next, referring to FIG. 5 in addition to FIG. 4, the state control of the AC adapter 100a by the control voltage application circuit 203a will be described. FIG. 5 is a diagram for explaining the state transition of the AC adapter 100a. The control voltage application circuit 203a constantly monitors whether the main switch 202 is on or off. When the main switch 202 is on, the control voltage application circuit 203a does not apply a voltage between the power supply potential line 11a and the reference potential line 12b. As a result, since no voltage is applied between the first input line 13a and the second input line 14a of the changeover switch 110a, the changeover switch 110a is turned on and the AC adapter 100a is in an input-permitted state.

  Therefore, AC power is input to the power conversion unit 140, and a voltage of 5 V is generated between the power supply potential line 11a and the reference potential line 12a. At this time, the potential of the power supply potential line 11a is 5V, but due to the Zener diode ZR1, the potential of the second input line 14a is substantially 0V. Therefore, no voltage is generated between the first input line 13a and the second input line 14a, and the changeover switch 110a is maintained in the ON state.

  On the other hand, when the main switch 202 is off, the control voltage application circuit 203a applies a voltage of 6V to the power supply potential line 11a using the internal power supply 130a. As a result, the voltage of the second input line 14a is about 1V via the Zener diode ZR1. Therefore, a voltage of about 1V is applied to the second input line 14a with the first input line 13a as a reference (0V), and the changeover switch 110a is turned off. As a result, the changeover switch 110a is in the input prohibited state, and the power consumption in the power conversion unit 140 by the AC power supply becomes zero.

  According to the second embodiment described above, similarly to the first embodiment, when the main switch 202 of the hard disk drive 200a is turned off and it is no longer necessary to supply power from the AC adapter 100a to the hard disk drive 200a, the AC The state of the adapter 100a is an input prohibited state in which the changeover switch 110a is turned off. As a result, when the main switch 202 of the hard disk drive 200a is turned off, the power consumption of the power conversion unit 140 by the AC power supply of the AC adapter 100 can be suppressed to zero.

  When the AC adapter 100a is in the input prohibited state, the main switch 202 is monitored by the control voltage application circuit 203a that operates using the internal power supply 130a. When the main switch 202 is turned on, the changeover switch 110a is turned on, and the AC adapter 100a is switched from the input prohibited state to the input permitted state.

  Furthermore, on the hard disk drive 200a side, the constant voltage (6V) is applied to the power supply potential line 11a by using the internal power supply 130a, or only a simple control of not applying it is performed according to the state of the hard disk drive 200a. Thus, the transition from the input-permitted state to the input-prohibited state and the transition from the input-prohibited state to the input-permitted state can be realized.

  Further, since the internal power supply 130a uses a secondary battery and the internal power supply 130a is charged in an input-permitted state, the switching function of the changeover switch 110a in the AC adapter 100a is effective over a long period of time. can do.

(3) Third embodiment:
FIG. 6 is a diagram for explaining the electrical configuration of the electronic device system 1000b according to the third embodiment. The electronic device system 1000b includes an AC adapter 100b and a hard disk drive 200b.

  The AC adapter 100b in the third embodiment includes a power conversion unit 140 and a changeover switch 110b.

  As with the change-over switches 110 and 110a of the first and second embodiments, the change-over switch 110b is allowed to enter an AC power input from the AC power source to the power conversion unit 140, and the input is prohibited. This is a switch for switching the input prohibited state. In this embodiment, a normally-on (b contact) terminal of a mechanical relay is used as the changeover switch 110b. This relay is a relay that operates at a rated voltage of 12 V. When the voltage is about 10 V or more applied to the second input line 14 b with the first input line 13 b as a reference (0 V) when turned on, the relay is switched off. The specification is such that when the power of the second input line 14b is reduced to about 10 volts or less with the first input line 13b as a reference (0V) when the power is off, the power is switched on.

  As in the first and second embodiments, when the changeover switch 110b is on, the AC adapter 100b is in an input permitted state, and when the changeover switch 110b is off, the AC adapter 100b is in an input prohibited state. When the AC adapter 100b is in the input-permitted state, the power conversion unit 140 generates a constant voltage on the power supply potential line 11b and provides a DC power supply to the hard disk drive 200b, as in the first and third embodiments. .

  The first input line 13b is electrically connected to the reference potential line 12b. The second input line 14b is electrically connected to the power supply potential line 11b.

  The hard disk drive 200b includes an electronic device circuit 210, a main switch 202, a control voltage application circuit 203b, an internal power supply 130b, and a three-terminal regulator RG.

  Similar to the second embodiment, the control voltage application circuit 203b is a circuit for controlling the state of the AC adapter 100b to either the input prohibited state or the input permission signal. The internal power supply 130b is a power supply that supplies power to the control voltage application circuit 203b in the input prohibited state. In the input allowable state, the control voltage application circuit 203b operates with power supplied from the AC adapter 100b. In the present embodiment, a secondary battery is used as the internal power supply 130b, and charging is performed using the power supplied from the AC adapter 100b in the input-permitted state.

  The three-terminal regulator RG is a fixed output type (5 V), the input terminal is connected to the power supply potential line 11b, the output terminal is connected to the electronic device circuit 210, and the ground terminal is connected to the reference potential line 12b. The three-terminal regulator RG is preferably a low-loss three-terminal regulator having a maximum input voltage of 12 V or more and a small operable input / output minimum potential difference (0.5 V in this embodiment). The power converter 140 is configured to have a high output voltage in consideration of the voltage drop in the three-terminal regulator in order to provide the electronic device circuit 210 with a constant voltage DC power supply of 5 V (in this embodiment, 5.5 V). Output).

  Next, state control of the AC adapter 100b by the control voltage application circuit 203b will be described. The control voltage application circuit 203b always monitors whether the main switch 202 is on or off. First, the case where the changeover switch 110b is in the input allowable state and the main switch 202 is on will be described. At this time, the control voltage application circuit 203b does not apply a voltage to the power supply potential line 11b. As a result, the voltage between the first input line 13b and the second input line 14b of the changeover switch 110b is the voltage output between the reference potential line 12b and the power supply potential line 11b from the power converter 140. (5.5V). For this reason, the changeover switch 110b is kept on.

  Therefore, AC power is input to the power conversion unit 140, and the voltage of the power supply potential line 11a is maintained at 5.5V. Then, a 5.0V DC power supply is provided to the electronic device circuit 210 via the three-terminal regulator RG.

  When the main switch 202 is switched from on to off from this state, the control voltage application circuit 203b applies a voltage of 12V to the power supply potential line 11b using the power from the internal power supply 130b. Then, since a voltage of 12 V is applied to the second input line 14b with respect to the first input line 13b, the changeover switch 110b is switched from on to off. Therefore, the AC adapter 100b is in the input prohibited state, and the power consumption in the power conversion unit 140 by the AC power supply becomes zero.

  While the main switch 202 is off, the control voltage application circuit 203b maintains the potential of the power supply potential line 11b at 12V. Therefore, while the main switch 202 is off, the changeover switch 110b is maintained in the input prohibited state. The three-terminal regulator RG functions as a protection circuit that prevents the electronic device circuit 210 from being applied with a voltage of 12 V that greatly exceeds the rated 5 V. Note that, as such a protection circuit, not only the three-terminal regulator RG but also various step-down DC-DC converters such as a switching regulator can be used.

  When the main switch 202 is switched from OFF to ON from this state, the control voltage application circuit 203b drops the voltage of the power supply potential line 11b from 12V to 0V. Then, the potential difference between the second input line 14b and the first input line 13b becomes 0V, and the changeover switch 110b is switched from off to on. Therefore, the AC adapter 100b is in an input-permitted state, and a DC power source is provided from the power conversion unit 140 to the electronic device circuit 210 via the three-terminal regulator RG.

  According to the third embodiment described above, similarly to the first and second embodiments, the main switch 202 of the hard disk drive 200b is turned off, and it is no longer necessary to supply power to the hard disk drive 200 from the AC adapter 100b. At this time, the state of the AC adapter 100b becomes an input prohibited state in which the changeover switch 110b is turned off. As a result, when the main switch 202 of the hard disk drive 200b is turned off, the power consumption of the power conversion unit 140 by the AC power supply of the AC adapter 100b can be suppressed to zero.

  When the AC adapter 100b is in the input prohibited state, the main switch 202 is monitored by the control voltage application circuit 203b that operates using the internal power supply 130b. When the main switch 202 is turned on, the changeover switch 110b is turned on, and the AC adapter 100b is switched from the input prohibited state to the input permitted state.

  Furthermore, on the hard disk drive 200b side, the hard disk drive 200b is simply controlled by applying or not applying a constant voltage between the power supply potential line 11b and the reference potential line 12b using the internal power supply 130. According to the state of 200b, it is possible to realize a transition from the input permitted state to the input prohibited state and a transition from the input prohibited state to the input permitted state.

(4) Fourth embodiment:
FIG. 7 is a diagram illustrating the electrical configuration of the electronic device system 1000c according to the fourth embodiment. The electronic device system 1000c includes an AC adapter 100c and a hard disk drive 200c.

  The AC adapter 100c according to the fourth embodiment includes a power conversion unit 140 and a changeover switch 110c.

  Similarly to the change-over switches 110, 110a, and 110b of the first to third embodiments, the change-over switch 110c is allowed to input the AC power from the AC power source to the power conversion unit 140, and the input is prohibited. This is a switch for switching the input prohibited state. In this embodiment, a latching mechanical relay similar to that of the first embodiment is used as the changeover switch 110c. The relay is turned on when a voltage of plus 5V is applied to the second input line 14c with reference to the first input line 13c, and thereafter, the relay is kept on even when the voltage application is stopped. Further, this relay is turned off when a voltage of plus 5V is applied to the first input line 13c with reference to the second input line 14c, and then the off state is maintained even if the voltage application is stopped. The

  As in the first to third embodiments, when the changeover switch 110c is on, the AC adapter 100c is in an input-permitted state, and when the changeover switch 110c is off, the AC adapter 100c is in an input-inhibited state. When the AC adapter 100c is in the input-permitted state, the power conversion unit 140 applies a constant voltage to the power supply potential line 11c and provides a DC power supply to the hard disk drive 200c, as in the first to third embodiments.

  The first input line 13c is electrically connected to the reference potential line 12c. The second input line 14c is electrically connected to the power supply potential line 11c.

  The hard disk drive 200c includes an electronic device circuit 210, a main switch 202, a control voltage application circuit 203c, an internal power supply 130c, and a diode D1.

  Similar to the second and third embodiments, the control voltage application circuit 203c is a circuit for controlling the state of the AC adapter 100c to either the input prohibited state or the input permission signal. The internal power supply 130c is a power supply that supplies power to the control voltage application circuit 203c in the input prohibited state. In the input allowable state, the control voltage application circuit 203c operates with power supplied from the AC adapter 100c. In the present embodiment, a secondary battery is used as the internal power supply 130c, and charging is performed using the power supplied from the AC adapter 100c in the input-permitted state.

  The diode D1 is disposed between the power supply potential line 11c and the electronic device circuit 210, and functions as a protection circuit that suppresses a reverse current from flowing through the electronic device circuit 210.

  Next, state control of the AC adapter 100c by the control voltage application circuit 203c will be described. The control voltage application circuit 203c constantly monitors whether the main switch 202 is on or off. First, the case where the changeover switch 110c is in the input allowable state and the main switch 202 is on will be described. At this time, the control voltage application circuit 203c does not apply a voltage to the power supply potential line 11c. As a result, the voltage between the first input line 13c and the second input line 14c of the changeover switch 110c is the voltage output between the reference potential line 12c and the power supply potential line 11c from the power converter 140. (5V). That is, a voltage of plus 5V is applied to the second input line 14c with reference to the first input line 13c, and the changeover switch 110c is kept on.

  When the main switch 202 is switched from on to off from this state, the control voltage application circuit 203c uses the power from the internal power supply 130c to apply a voltage of minus 5V, that is, a voltage with the polarity reversed, to the power supply potential line 11c. The voltage is applied temporarily, that is, only for the time necessary for switching the changeover switch 110c, which is a latching relay. Then, a voltage of plus 5V is applied to the first input line 13c with reference to the second input line 14c, and the changeover switch 110c is switched from on to off. Therefore, the AC adapter 100c is in the input prohibited state, and the power consumption in the power conversion unit 140 is zero. The diode D1 functions as a protection circuit that prevents a current in the reverse direction from flowing through the electronic device circuit 210 when a voltage whose polarity is reversed is applied to the power supply potential line 11c.

  Note that it is preferable to appropriately arrange a protection circuit that protects the circuit that constitutes the power conversion unit 140 on the power conversion unit 140 side when a voltage whose polarity is reversed is applied to the power supply potential line 11c. . For example, an electrolytic capacitor is usually used for the output smoothing circuit 146 of the power conversion unit 140. For this reason, it is preferable to arrange a diode in series with the electrolytic capacitor so that a reverse voltage is not applied to the electrolytic capacitor.

  While the main switch 202 is off, the control voltage application circuit 203c does not apply a voltage between the power supply potential line 11c and the reference potential line 12c. Therefore, while the main switch 202 is off, the changeover switch 110c is maintained in the input prohibited state.

  When the main switch 202 is switched from OFF to ON from this state, the control voltage application circuit 203c applies a voltage of 5V to the power supply potential line 11c. Then, a voltage of plus 5V is applied to the second input line 14c with reference to the first input line 13c, and the changeover switch 110c is switched from OFF to ON. Therefore, the AC adapter 100c is in an input-permitted state, and a DC power source is provided from the power conversion unit 140 to the electronic device circuit 210 via the diode D1.

  According to the fourth embodiment described above, as in the first to third embodiments, the main switch 202 of the hard disk drive 200b is turned off, and it is no longer necessary to supply power from the AC adapter 100c to the hard disk drive 200c. At this time, the state of the AC adapter 100c becomes an input prohibited state in which the changeover switch 110c is turned off. As a result, when the main switch 202 of the hard disk drive 200c is turned off, the power consumption of the power conversion unit 140 by the AC power supply of the AC adapter 100c can be suppressed to zero.

  When the AC adapter 100c is in the input prohibited state, the main switch 202 is monitored by the control voltage applying circuit 203c that operates using the internal power supply 130c. When the main switch 202 is turned on, the changeover switch 110c is turned on, and the AC adapter 100c is switched from the input prohibited state to the input permitted state.

  Further, on the hard disk drive 200c side, the hard disk drive 200c is simply controlled by applying or not applying a constant voltage between the power supply potential line 11c and the reference potential line 12c using the internal power supply 130c. According to the state of 200c, the transition from the input permission state to the input prohibition state and the transition from the input prohibition state to the input permission state can be realized. Furthermore, since the constant voltage is applied using the internal power supply 130c only for the time required for switching the changeover switch 110c, which is a latching type relay, the power consumption of the internal power supply 130c can be suppressed.

(5) Fifth embodiment:
FIG. 8 is a diagram for explaining the electrical configuration of the electronic device system 1000d according to the fifth embodiment. The electronic device system 1000d includes an AC adapter 100d and a hard disk drive 200d.

  The AC adapter 100d in the fifth embodiment includes a power conversion unit 140, a changeover switch 110d, and a power supply side switching control circuit 150d.

  The change-over switch 110d, like the change-over switches 110, 110a-110c of the first to fourth embodiments, is allowed to input AC power from the AC power source to the power conversion unit 140, and the input is prohibited. This is a switch for switching the input prohibited state. In this embodiment, a latching mechanical relay similar to that in the first and fourth embodiments is used as the changeover switch 110d. The relay is turned on when a voltage of plus 5V is applied to the second input line 14d with reference to the first input line 13d, and thereafter, the relay is kept on even when the voltage application is stopped. On the other hand, this relay is turned off when a voltage of plus 5V is applied to the first input line 13d with reference to the second input line 14d, and then the off state is maintained even if the voltage application is stopped. The

  As in the first to fourth embodiments, when the changeover switch 110d is on, the AC adapter 100d is in an input-permitted state, and when the changeover switch 110d is off, the AC adapter 100d is in an input prohibited state. When the AC adapter 100d is in the input-permitted state, the power conversion unit 140 generates a constant voltage on the power supply potential line 11d and provides a DC power supply to the hard disk drive 200d, as in the first to fourth embodiments.

  The power supply side switching control circuit 150d applies a voltage to the first input line 13d and the second input line 14d in accordance with an instruction (control signal) from a device side switching control circuit 203d described later, and turns on the changeover switch 110d. Switch on / off. The power supply side switching control circuit 150d is electrically connected to the power supply potential line 11d and the reference potential line 12d in order to receive a control signal from the device side switching control circuit 203d.

  The hard disk drive 200d includes an electronic device circuit 210, a main switch 202, the device-side switching control circuit 203d described above, and an internal power supply 130d.

  The device side switching control circuit 203d is a circuit for transmitting an input prohibition signal and an input permission signal to the power supply side switching control circuit 150d. The internal power supply 130d is a power supply that supplies power to the device-side switching control circuit 203d in the input prohibited state. In the input allowable state, the device-side switching control circuit 203d operates with power supplied from the AC adapter 100d. In the present embodiment, a secondary battery is used as the internal power supply 130d, and charging is performed using power supplied from the AC adapter 100d in an input-permitted state.

  Next, referring to FIG. 9 in addition to FIG. 8, the state control of the AC adapter 100d by the device side switching control circuit 203d and the power source side switching control circuit 150d will be described. FIG. 9 is a diagram for explaining an input prohibition signal. The device-side switching control circuit 203d always monitors whether the main switch 202 is on or off. When the main switch 202 is on, the changeover switch 110d is controlled to be on.

  In this state, when the main switch 202 is switched from on to off, the device-side switching control circuit 203d outputs an input prohibition signal to the power supply potential line 11d. As shown in FIG. 9A, when the AC adapter 100d is in the input allowable state, a voltage of 5 V is applied to the power supply potential line 11d by the power conversion unit 140. The device-side switching control circuit 203d superimposes a voltage including a predetermined AC component on the power supply potential line 11d as an input prohibition signal. In FIG. 9B, two rectangular pulse signals having an amplitude of 1V are shown as an example of input prohibition signals. As a result, a voltage having the shape shown in FIG. 9C is generated in the power supply potential line 11d. The shape of the input prohibition signal is not limited to a rectangular pulse signal, and may be a predetermined signal such as an analog signal.

  The power supply side switching control circuit 150d always analyzes whether or not the input prohibition signal has been received by analyzing the voltage of the power supply potential line 11d. If the power supply side switching control circuit 150d determines that the input prohibition signal has not been received, it may continue to apply the voltage of the power supply potential line 11d to the second input line 14d (turns the changeover switch 110d on). The voltage does not need to be applied to the second input line 14d. When determining that the input prohibition signal has been received, the power supply side switching control circuit 150d switches the changeover switch 110d from on to off. As a result, the AC adapter 100d is in the input prohibited state, and the power consumption in the power conversion unit 140 by the AC power supply becomes zero.

  While the main switch 202 is off, the device-side switching control circuit 203d does not apply a voltage to the power supply potential line 11d. Then, no power is supplied to the power supply side switching control circuit 150d, and the power supply side switching control circuit 150d stops operating.

  When the main switch 202 is switched from OFF to ON from this state, the device-side switching control circuit 203d applies a voltage of 5V to the power supply potential line 11d as an input permission signal. When the potential of the power supply potential line 11d changes from 0V to 5V, that is, when an input permission signal is received, the power supply side switching control circuit 150d starts operation using the power of the input permission signal (voltage of 5V). The power supply side switching control circuit 150d applies a voltage for turning on the changeover switch 110d to the changeover switch 110d at least at the start of operation (applying a voltage of plus 5V to the first input line 13d). As a result, the changeover switch 110d is switched from OFF to ON, and the AC adapter 100d is changed from the input prohibited state to the input permitted state. Then, a DC power supply is provided from the power conversion unit 140 to the electronic device circuit 210. Thus, the change of the voltage of the power supply potential line 11d from 0V to 5V corresponds to a signal (input allowable signal) for switching the changeover switch 110d from OFF to ON.

  According to the fifth embodiment described above, as in the first to fourth embodiments, the main switch 202 of the hard disk drive 200d is turned off, and it is no longer necessary to supply power from the AC adapter 100d to the hard disk drive 200d. When the changeover switch 110d is turned off, the input is prohibited. As a result, when the main switch 202 of the hard disk drive 200d is turned off, the power consumption of the power conversion unit 140 by the AC power supply of the AC adapter 100d can be suppressed to zero.

  Further, when the AC adapter 100d is in the input prohibited state, the main switch 202 is monitored by the device side switching control circuit 203d that operates using the internal power supply 130d. When the main switch 202 is turned on, the changeover switch 110d is turned on, and the AC adapter 100d is switched from the input prohibited state to the input permitted state.

  Furthermore, since the input permission signal is simply applied with a constant potential of 5 V to the power supply potential line 11d, when the main switch 202 of the hard disk drive 200d is turned from off to on with simple control, the AC adapter 100d can be returned from the input-prohibited state to the input-permitted state. For example, when a complicated input allowable signal is used, a processing unit for analyzing the input allowable signal is necessary. However, in this embodiment, such a processing unit can be omitted.

(6) Sixth embodiment:
FIG. 10 is a diagram for explaining the electrical configuration of the electronic device system 1000e according to the sixth embodiment. The electronic device system 1000e includes an AC adapter 100e and a hard disk drive 200e.

  The AC adapter 100e in the sixth embodiment includes a power conversion unit 140, a changeover switch 110e, a switching control unit 120e, a power supply potential line 11e, a reference potential line 12e, a first input line 13e, 2 is basically the same as the configuration of the AC adapter 100 of the electronic device system 1000 in the first embodiment shown in FIG. 2 except that the internal power supply 130 is not provided.

  The hard disk drive 200e in the sixth embodiment includes an electronic device circuit 210, a main switch 202, a control voltage application circuit 203e, and an internal power supply 130e. Basically, the electronic device in the second embodiment shown in FIG. The configuration is the same as that of the hard disk drive 200a of the device system 1000a.

  The state control of the AC adapter 100e by the switching control unit 120e and the control voltage application circuit 203e in the electronic device system 1000e in the sixth embodiment will be described with reference to FIG. 11 in addition to FIG. FIG. 11 is a diagram for explaining the state transition of the AC adapter 100e. When the main switch 202 of the hard disk drive 200e is on, the changeover switch 110e of the AC adapter 100e is also on, and the AC adapter 100e is in an input-permitted state. Therefore, a constant voltage is output as a DC power source from the power conversion unit 140 to the power supply potential line 11e, and the electronic device circuit 210 operates with power supplied from the DC power source.

  In the input allowable state, the consumption monitoring circuit 122e of the AC adapter 100e constantly monitors whether or not the current value In in the power supply potential line 11e is equal to or less than a specified value, as in the first embodiment.

  In this state, when the user presses the power button 201 of the hard disk drive 200e to turn off the main switch 202, the power consumption of the electronic device circuit 210 of the hard disk drive 200e becomes zero. Then, since the current value In in the power supply potential line 11e becomes zero, the consumption monitoring circuit 122e of the AC adapter 100 detects that the current value In in the power supply potential line 11e has become a specified value or less.

  When detecting that the current value In is equal to or less than the specified value, the consumption monitoring circuit 122e transmits a control signal instructing the input cutoff control circuit 121e to turn off the changeover switch 110e. The input cutoff control circuit 121e that has received the control signal switches the changeover switch 110e from the on state to the off state. As a result, the AC adapter 100e is in an input prohibited state. The control so far is the same as the control in the first embodiment.

  When the input is prohibited, the constant voltage output from the power conversion unit 140 to the power supply potential line 11e and the reference potential line 12e is lost. Unlike the first embodiment, the AC adapter 100e does not include the internal power supply 130. For this reason, the consumption monitoring circuit 122e does not monitor (cannot perform) the input prohibited state.

  When the input is prohibited and power is not supplied from the power converter 140 to the electronic device circuit 210, the control voltage application circuit 203e in the hard disk drive 200e receives power from the internal power supply 130e and monitors the main switch 202. To do. Further, the voltage of the power supply potential line 11e is set to 0V. When the control voltage application circuit 203e detects that the main switch 202 is turned from OFF to ON, the control voltage application circuit 203e applies a voltage of 5V to the power supply potential line 11e as an input permission signal, as in the fifth embodiment. Apply. When the potential of the power supply potential line 11e changes from 0V to 5V, that is, when an input permission signal is received, the consumption monitoring circuit 122e uses the power of the input permission signal to turn off the changeover switch 110e to the input cutoff control circuit 121e. Turn it on. As a result, the AC adapter 100e is changed from the input prohibited state to the input permitted state, and a DC power source is provided from the power conversion unit 140 to the electronic device circuit 210.

  According to the sixth embodiment described above, when the main switch 202 of the hard disk drive 200e is turned off and it is no longer necessary to supply power from the AC adapter 100e to the hard disk drive 200e, the power supply potential line 11e on the AC adapter 100e side. It is detected that the current value In is less than or equal to the specified value, and the input switch is turned off when the changeover switch 110e is turned off. As a result, when the main switch 202 of the hard disk drive 200e is turned off, the power consumption of the power conversion unit 140 by the AC power supply of the AC adapter 100e can be suppressed to zero.

  When the AC adapter 100e is in the input prohibited state, the main switch 202 is monitored by the control voltage application circuit 203e that operates using the internal power supply 130e. When the main switch 202 is turned on, the changeover switch 110e is turned on, and the AC adapter 100e is switched from the input prohibited state to the input permitted state.

  Furthermore, since the input permission signal is simply applied with a constant potential of 5 V to the power supply potential line 11e, when the main switch 202 of the hard disk drive 200e is turned from off to on with simple control, the AC The adapter 100e can be returned from the input prohibited state to the input permitted state.

  Furthermore, since the transition from the input permitting state to the input prohibiting state is automatically performed on the AC adapter 100e side, it is not necessary to transmit an input prohibiting signal from the hard disk drive 200a side as in the fifth embodiment. For this reason, it is possible to realize a transition from the input-permitted state to the input-prohibited state without providing a circuit that generates an input-inhibited signal such as a pulse signal.

(7) Seventh embodiment:
FIG. 12 is a diagram for explaining the electrical configuration of the electronic device system 1000f according to the seventh embodiment. The electronic device system 1000f includes an AC adapter 100a and a hard disk drive 200f, and is connected to the personal computer 300 via the external connection bus 20. The external connection bus 20 is a bus (for example, USB) with a power supply terminal that can supply power from the personal computer 300 to the hard disk drive 200f.

  Since the AC adapter 100a of the electronic device system 1000f is the same as the AC adapter 100a (FIG. 4) in the second embodiment, the configuration of the AC adapter 100a is denoted by the same reference numerals in FIG. Is omitted.

  The hard disk drive 200f of the electronic device system 1000f includes a control voltage application circuit 203f, a transmission / reception circuit 212f, a read / write controller 214f, and a disk device 216f. The control voltage application circuit 203 f and the transmission / reception circuit 212 f operate with power supplied from the personal computer 300 via the external connection bus 20. On the other hand, the read / write controller 214f and the disk device 216f operate with electric power supplied from the AC adapter 100a via the power supply potential line 11a and the reference potential line 12a. The transmission / reception circuit 212f and the read / write controller 214f are connected via an internal bus 220f so that data communication is possible.

  The control voltage application circuit 203f operates the AC adapter 100a in either an input prohibited state or an input allowable state by the same operation as the control voltage application circuit 203a in the second embodiment according to an instruction (control signal) from the transmission / reception circuit 212f. To control.

  The transmission / reception circuit 212f is a circuit for exchanging data with the personal computer 300 via the external connection bus 20, and for exchanging data with the read / write controller 214f via the internal bus 220f. The transmission / reception circuit 212f of the present embodiment can further control the control voltage application circuit 203f by transmitting a control signal. This control will be described later.

  The read / write controller 214f is a controller that performs a read process of reading data stored in the disk device 216f and transmitting the data to the transmission / reception circuit 212f, and a write process of writing data received from the transmission / reception circuit 212f to the disk device 216f.

  In addition to FIG. 12, the state control of the AC adapter 100a by the transmission / reception circuit 212f and the control voltage application circuit 203f will be described with reference to FIG. FIG. 13 is a diagram illustrating the state transition of the AC adapter 100f.

  The hard disk drive 200f can transition to two operation states, a power saving state and a readable / writable state. The power saving state is a state in which the operation of the disk device 216f (such as idling operation) and the operation of the read / write controller 214f are stopped and only the transmission / reception circuit 212f and the control voltage application circuit 203f are activated. In the power saving state, access from the personal computer 300 can be accepted, but read processing or write processing cannot be performed in accordance with the access.

  The read / write enabled state is a state where all of the disk device 216f, the read / write controller 214f, the control voltage application circuit 203f, and the transmission / reception circuit 212f are activated. In the readable / writable state, read processing or write processing can be performed in response to an access from the personal computer 300.

  When the hard disk drive 200f is in a readable / writable state, if there is no access from the personal computer 300 for a predetermined period (for example, 10 minutes), the transmission / reception circuit 212f causes the control voltage application circuit 203f to enter a power saving state. A transition instruction signal is transmitted. The power saving state transition instruction signal is a control signal for instructing the control voltage application circuit 203f to switch the AC adapter 100a from the input permitted state to the input prohibited state.

  The control voltage application circuit 203f performs the same control as the control voltage application circuit 203a in the second embodiment, and switches the AC adapter 100a from the input permitted state to the input prohibited state. As a result, the read / write controller 214f and the disk device 216f stop operating, and the hard disk drive 200f shifts to the power saving state.

  On the other hand, when the hard disk drive 200f is in the power saving state, when the access from the personal computer 300 (either access for reading or access for writing) is accepted, the transmission / reception circuit 212f applies the control voltage. A read / write enable state transition instruction signal is transmitted to the circuit 203f. The readable / writable state transition instruction signal is a control signal that instructs the control voltage application circuit 203f to switch the AC adapter 100a from the input prohibited state to the input permitted state.

  The control voltage application circuit 203f performs the same control as the control voltage application circuit 203a in the second embodiment, and switches the AC adapter 100a from the input prohibited state to the input permitted state. As a result, the read / write controller 214f and the disk device 216f are activated, and the hard disk drive 200f shifts to a read / write enabled state.

  Thus, the timing for switching the AC adapter 100a from the input permitting state to the input prohibiting state is not limited to the on / off timing of the main switch 202 as in the first to sixth embodiments. For example, as in the seventh embodiment, in an electronic device that can take a first state with high power consumption and a second state with low power consumption, when shifting from the first state to the second state (even immediately before) It is also possible to switch from the input-permitted state to the input-prohibited state. In the electronic device, the input prohibited state may be switched to the input permitted state when the electronic device shifts from the second state to the first state (may be immediately before or after).

(8) Modification:
In addition, elements other than the elements claimed in the independent claims among the constituent elements in the above embodiments are additional elements and can be omitted as appropriate. The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

・ Modification 1
In the first embodiment, the internal power supply 130 applies the same voltage as the voltage (5 V in the first embodiment) output to the power supply potential line 11 in the input prohibited state and to the power supply potential line 11 in the input allowed state. Yes. Instead, a voltage different from the voltage output to the power supply potential line 11 in the input permitted state may be applied to the power supply potential line 11 in the input prohibited state. For example, a voltage (for example, 1 V) lower than the voltage output to the power supply potential line 11 in the input permitted state may be applied to the power supply potential line 11 in the input prohibited state. Depending on the internal resistance of the electronic device circuit 210 and the like, the electronic device circuit 210 may not operate normally at a voltage of 1 V when the main switch 202 is on, but a small amount of current may flow. At this time, the consumption monitoring circuit 122 of the AC adapter 100 may detect the small amount of current and switch the changeover switch 110 to the ON state. By so doing, it is possible to more effectively suppress the power consumption of the internal power supply 130 when shifting from the input-prohibited state to the input-permitted state.

・ Modification 2
In the first embodiment, in the input prohibited state, a voltage is applied to the power supply potential line 11 using the internal power supply 130 to monitor whether or not the current value in the power supply potential line 11 is equal to or higher than a specified value. Instead, the voltage drop of the power supply potential line 11 may be monitored, and when the voltage drop exceeds a specified value, the input prohibited state may be switched to the input allowed state. In this way, when the main switch 202 of the hard disk drive 200 is turned on, the input prohibition state can be switched to the input permission state, and the output of the internal power supply 130 becomes weak so that the main switch 202 of the hard disk drive 200 is switched. Even when the voltage is lowered, the internal power supply 130 can be charged by switching from the input-prohibited state to the input-permitted state even when the voltage drops. For this reason, a secondary battery with a small capacity can be applied to the internal power supply 130. Further, when the voltage of the power supply potential line 11 drops due to a malfunction of the internal power supply 130 in the input prohibited state, the input adapter is switched to the input allowable state, so that the problem that the AC adapter 100 does not function due to the malfunction of the internal power supply 130 is avoided. be able to.

・ Modification 3
In the first, fifth to seventh embodiments, the latching type relay is used as the changeover switch of the AC adapter. However, the present invention is not limited to such a contact switch. A semiconductor relay (non-contact switch) using a MOSFET or the like may be used as a switch for the AC adapter. Compared with a contact switch, a semiconductor relay has advantages such as a long life, excellent quietness, small size, and low power consumption. Specifically, for example, in the first embodiment, when a normally-off (a contact) type semiconductor relay is used and the input cutoff control circuit 121 is in the input prohibited state, the first input line 13 is used. When a voltage is not applied between the first input line 14 and the second input line 14 and the input is allowed, a predetermined voltage (for example, 1 V) is applied between the first input line 13 and the second input line 14. ) May be applied.

Modification 4
In the first to sixth embodiments, the internal power source is not limited to the secondary battery, and various power sources different from the AC power source that inputs AC power to the power conversion unit 140 of the AC adapter may be used. For example, a primary battery, a solar battery, a capacitor, etc. can be used. Also, in the second to sixth embodiments where the internal power supply is on the hard disk drive side, instead of the internal power supply, via the USB used to connect the personal computer and the hard disk drive as in the seventh embodiment. The supplied power may be used. Generally speaking, power supplied from any power source different from the AC power source input to the power conversion unit 140 may be used.

・ Modification 5
In the fifth embodiment, when the AC adapter 100d is switched from the input-prohibited state to the input-permitted state, the device-side switching control circuit 203d sends an input-prohibited signal containing an AC component to the power-side switching control via the power-supply potential line 11d. Although transmitting to the circuit 150d, it is not limited to this. For example, the device-side switching control circuit 203d may apply a constant voltage (for example, 6V) exceeding the rated voltage (5V in the fifth embodiment) of the AC adapter 100d to the power supply potential line 11d for a certain time. . In this way, the power supply side switching control circuit 150d may switch the changeover switch 110d from on to off when detecting an increase in the voltage in the power supply potential line 11d. In addition, the device-side switching control circuit 203d adjusts the internal resistance value of the electronic device circuit 210 to provide a load current (for example, 2.5A) exceeding the rated current (for example, 2A (ampere)) of the AC adapter 100d to the AC adapter. You may make it output to 100d. By doing so, the voltage of the power supply potential line 11d of the AC adapter 100d is lowered, so that the power supply side switching control circuit 150d may switch the changeover switch 110d from on to off when the voltage drop is detected. .

Modification 6
In the said 1st-7th Example, although the switching system is employ | adopted as the power converter 140, it is not restricted to this, All systems can be employ | adopted. For example, a so-called series method may be adopted.

・ Modification 7
In each of the embodiments described above, the change-over switches 110 and 100a to 100e are arranged between the AC power supply and the input rectifier circuit 141 that is a circuit on the most upstream side of the power converter 140 (see FIG. 2). It is not limited to this. For example, the changeover switches 110 and 100a to 100e may be disposed between the input rectifier circuit 141 and the input smoothing circuit 142, or may be disposed between the input smoothing circuit 142 and the switching circuit 143.

・ Modification 8
In each of the above embodiments, the hard disk drive is exemplified as an object to which the AC adapters 100, 100a to 100e supply the DC power, but any device that operates using the DC power as a power source is adopted as the DC power supply target. sell. For example, the supply target may be a personal computer, a Blu-ray recorder, a DVD recorder, a router, an SSD (Solid State Drive), a display, a copier, a TV, or the like.

Modification 9
In each of the above embodiments, the hard disk drive housing and the AC adapter housing are separate, but the power conversion unit 140 may be housed inside the hard disk drive housing.

Modification 10
As the internal configurations of the switching control units 120 and 120e, the control voltage application circuits 203a to 203c, 203e and 203f, and the device-side switching control circuit 203d, various configurations that operate as described above can be adopted.

11, 11a to 11e ... power supply potential line 10 ... code 12, 12a to 12e ... reference potential line 13, 13a to 13e ... first input line 14, 14a to 14e ... second 20 ... external connection bus 100, 100a to 100f ... AC adapter 110, 110a to 110e ... changeover switch 120, 121e ... switching control unit 121, 121e ... input cutoff control circuit 122, 122e ... consumption monitoring circuit 130, 130a to 130e ... internal power supply 140 ... power conversion unit 141 ... input rectifier circuit 142 ... input smoothing circuit 143 ... switching circuit 144 ... Transformer 145 ... Output rectifier circuit 146 ... Output smoothing circuit 147 ... Feedback detection circuit 148 ... Switching control circuit 150d ... Power supply side switching control circuit 200, 200a to 200f ... Hard disk drive 20 ... Power button 202 ... Main switches 203a to 203c, 203e, 203f ... Control voltage application circuit 203d ... Device side switching control circuit 210 ... Electronic device circuit 212f ... Transmission / reception circuit 216f .. Disk device 220f ... Internal bus 300 ... Personal computer 1000, 1000a to 1000f ... Electronic device system 214f ... Read / write controller

Claims (11)

A power supply device for supplying DC power to an electronic device,
A power conversion unit that converts AC power input from an AC power source into DC power and outputs the power;
DC power output line for outputting to the electronic device the DC power output from the power conversion unit connected to the electronic device,
A consumption monitoring unit that monitors the consumption of the DC power output from the DC power output line to the electronic device by detecting a change in current or voltage in the DC power output line;
A switching unit capable of switching between an input permissible state allowing input of AC power from the AC power source to the power conversion unit and an input prohibiting state prohibiting input of AC power from the AC power source to the power conversion unit. A switching unit that switches between the input allowed state and the input prohibited state according to consumption in the electronic device monitored by the consumption monitoring unit;
A switching power supply unit that supplies power for the switching unit to switch from the input-prohibited state to the input-permitted state from a power source different from the AC power source;
A power supply apparatus comprising: The power supply device according to claim 1,
In the input allowable state, the power conversion unit outputs a first voltage to the DC power output line,
In the input prohibited state, the consumption monitoring unit outputs the first voltage to the DC power output line using a power source different from the AC power source. The power supply device according to claim 1,
In the input allowable state, the power conversion unit outputs a first voltage to the DC power output line,
In the input prohibited state, the consumption monitoring unit outputs a second voltage lower than the first value to the DC power output line using a power source different from the AC power source. . The power supply device according to any one of claims 1 to 3,
When the consumption monitoring unit detects that the current in the DC power output line is equal to or less than a specified value in the input allowable state, the switching unit switches from the input allowable state to the input prohibited state. A power supply device. The power supply device according to claim 2 or 3, wherein
When the consumption monitoring unit detects that the voltage on the DC power output line has become a specified value or less in the input prohibited state, the switching unit switches from the input prohibited state to the input permitted state. A power supply device. An electronic device system,
Electronic equipment,
A power supply;
First and second wirings connected to the electrical device for supplying direct current power to the electronic device;
With
The power supply device
A power converter that converts AC power input from an AC power source into DC power and generates a first voltage between the first wiring and the second wiring;
A switching unit capable of switching between an input permissible state allowing input of AC power from the AC power source to the power conversion unit and an input prohibiting state prohibiting input of AC power from the AC power source to the power conversion unit; ,
Have
The electronic device is
A switching control unit for controlling the switching unit;
A power supply unit that supplies power to the switching control unit from a power source different from the AC power source;
Have
The switching unit is in the input allowable state when the first voltage is generated between at least the first wiring and the second wiring, and a second voltage different from the first voltage is applied. The input is permitted to be switched from the input permission state to the input prohibition state when it occurs between the first wiring and the second wiring.
The switching control unit controls the switching unit by generating the second voltage between the first wiring and the second wiring using the power supplied from the power supply unit. An electronic device system characterized by The electronic device system according to claim 6,
The second voltage is higher than the first voltage;
The switching unit is in the input-inhibited state when the second voltage is generated between the first wiring and the second wiring, and the switching section switches between the first wiring and the second wiring. The input is allowed when the voltage generated between them is smaller than the second voltage,
The switching control unit generates the second voltage between the first wiring and the second wiring using the power supplied from the power supply unit, thereby prohibiting the input of the switching unit. An electronic device system, wherein the switching unit is controlled to the input allowable state by controlling to a state and not generating the second voltage. The electronic device system according to claim 6,
The second voltage is a voltage whose polarity is opposite to that of the first voltage.
The switching unit is
When in the input-inhibited state, the input voltage is switched to the input-permitted state when the first voltage is generated between the first wiring and the second wiring,
When in the input allowed state, the second voltage is configured to be switched to the input prohibited state when triggered by the first voltage and the second wire,
The switching control unit temporarily generates the second voltage between the first wiring and the second wiring using the power supplied from the power supply unit, thereby causing the switching unit to Control from the input permission state to the input prohibition state, and temporarily generate the first voltage between the first wiring and the second wiring by using the power supplied from the power supply unit Thus, the switching unit is controlled from the input prohibited state to the input permitted state. An electronic device system,
Electronic equipment,
A power supply;
First and second wirings connected to the electrical device for supplying direct current power to the electronic device;
With
The power supply device
A power converter that converts AC power input from an AC power source into DC power and generates a first voltage between the first wiring and the second wiring;
A switching unit capable of switching between an input permissible state allowing input of AC power from the AC power source to the power conversion unit and an input prohibiting state prohibiting input of AC power from the AC power source to the power conversion unit; ,
A power supply side switching control unit for controlling the switching unit;
Have
The electronic device is
A power supply unit for supplying power from a power source different from the AC power source;
Device-side switching for generating a second voltage between the first wiring and the second wiring using the power supplied from the power supply unit when the switching unit is in the input prohibited state A control unit;
With
The power supply side switching control unit switches the switching unit when a second voltage is generated between the first wiring and the second wiring when the switching unit is in the input prohibited state. An electronic device system, wherein the input prohibition state is switched to the input permission state. The electronic device system according to claim 9,
The power supply side switching control unit sets the switching unit to the input-permitted when the current in the first wiring or the second wiring becomes a specified value or less when the switching unit is in the input-permitted state. An electronic device system characterized by switching from a state to the input prohibited state. The electronic device system according to claim 9,
The first wiring is a power supply potential line to which a power supply potential is applied,
The second wiring is a reference potential line to which a reference potential is applied,
The device-side switching control unit can transmit a control signal to the power supply device via the power supply potential line when the switching unit is in the input allowable state.
The power supply side switching control unit has a receiving unit that receives the control signal, and when the control signal is received, the switching unit is switched from the input allowed state to the input prohibited state, Electronic equipment system.

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