Misconnection prevention device and misconnection prevention method

Abstract

To provide a device and method that can simply prevent an erroneous connection even for a DC power source output terminal.SOLUTION: An erroneous connection prevention device of an electronic device comprises, for preventing an erroneous connection with respect to an external power source output circuit,: an external power source output interface to which a peripheral circuit is supposed to be connected, in which the peripheral circuit receives a power supply from the external power source output circuit connected to a power source line extending from the external power output circuit; an erroneous connection notification unit that, when an external power source is unintentionally connected to the external power source output interface connected to the power source line, gives notification indicative of the erroneous connection; a first opening / closing unit that is in an opening state when the power supply is not given to the electronic device provided in a route of the power source line, and is switched from the opening state to a closed state when the power supply is given thereto; and a second opening / closing unit that is in the closed state when the power supply is not given to the electronic device inserted and provided to / in the route linking between the power source line and the erroneous connection notification unit, gets switched to the opening state from the closed state when the power source is given thereto, and disengages the erroneous notification unit from the power source line.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an improper connection prevention device and an improper connection prevention method that reduce damage to equipment caused by improper connection during installation work of electronic equipment. [Background technology]

[0002] Generally, a monitoring device or the like that monitors an external device such as a sensor device has an interface to which the external device is connected (hereinafter referred to as an external device interface) and an interface to which an external power supply is connected (hereinafter referred to as an external power supply input interface). In such a monitoring device, if an external power supply is mistakenly connected to the external device interface to which the external device should be connected, a voltage may be applied to the internal circuit of the monitoring device, potentially damaging the internal circuit. Therefore, a technology has been proposed that can prevent damage to the internal circuit by detecting the incorrect connection.

[0003] Patent Document 1 discloses a technology for preventing damage to an external unit by turning on the external power switch of the external unit only when it is confirmed that the external unit is properly connected to a specified slot.

[0004] The technology described in Patent Document 1 prevents damage to external units by matching pre-registered identification numbers of external units with the identification numbers of external units connected to slots. However, the technology described in Patent Document 1 may not be able to prevent damage to external units when using external units that have not registered their identification numbers or that do not hold their identification numbers.

[0005] In contrast to such prior art, Patent Document 2 discloses an incorrect connection prevention device that has a function of effectively preventing damage to the internal circuitry of electronic equipment caused by incorrect connection.

[0006] The misconnection prevention device disclosed in Patent Document 2 includes an external device interface, an external power input interface, a misconnection notification unit connected to a signal line extending from the external device interface, and an open / close unit provided in the path that serves as the signal line connecting the external device interface and the internal circuit. The misconnection detection prevention unit outputs a signal indicating a misconnection when an external power supply is erroneously connected to the external device interface. The open / close unit is in an open state when an external power supply is not connected to the external device interface, and switches from the open state to a closed state when an external power supply is connected to the external power input interface. The misconnection detection prevention unit includes a misconnection notification unit that notifies the user of a misconnection.

[0007] Even in the misconnection prevention device disclosed in Patent Document 2, even if an external power supply is misconnected to an external device interface, the opening / closing part switches to the closed state when the external power supply is connected to the external power supply input interface in that state. In other words, there is a risk of damaging the internal circuitry of the electronic device by misconnecting the external power supply to the external device interface and then connecting the external power supply to the external power supply input interface while ignoring the misconnection state.

[0008] In response to this, Patent Document 3 discloses an incorrect connection prevention device that solves this problem. The incorrect connection prevention device disclosed in Patent Document 3 has a configuration similar to that of Patent Document 2, except for the difference in the operation of the opening and closing unit, as described below. In detail, the opening and closing unit is in an open state when an external power supply is not connected to the external power supply input interface, switches from the open state to a closed state when an external power supply is connected to the external power supply input interface, and maintains the open state when a signal indicating an incorrect connection is received, even if an external power supply is connected to the external power supply input interface. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 3-211630 [Patent Document 2] Patent No. 6021208 [Patent Document 3] Patent No. 6452174 Summary of the Invention [Problem to be solved by the invention]

[0010] The misconnection prevention device disclosed in Patent Document 2 outputs a signal indicating the misconnection when an external power supply is mistakenly connected to an external device interface, and switches the opening / closing part from an open state to a closed state when the external power supply is correctly connected to the external power input interface. The misconnection prevention device that operates in this way can prevent damage to the internal circuitry of an electronic device even if an external power supply is mistakenly connected to an external device interface.

[0011] Furthermore, the misconnection prevention device disclosed in Patent Document 3 cuts off the connection between the external device interface and the signal line connected to the internal circuit of the electronic device while the external power supply is connected to the external device interface, even if the external power supply is correctly connected to the external power input interface and power is supplied to the internal circuit of the electronic device via the power line. The misconnection prevention device that operates in this way can prevent damage to the internal circuit of the electronic device even if the external power supply is incorrectly connected to the external device interface and the external power supply is properly connected.

[0012] The misconnection prevention devices disclosed in Patent Documents 2 and 3 are protection circuits against the possibility of an external power supply being erroneously connected to an input / output signal terminal, which is an interface for an external device, when installing or reinstalling an electronic device (i.e., a "work error"). However, a connection abnormality related to a misconnection that can occur during this type of work can occur when the external power supply system of an electronic device (including an external power supply device) that has an external power output is mistakenly connected to a power output terminal (e.g., +5V or +24V), which is an interface for external power output of the electronic device.

[0013] If such an incorrect connection occurs, there is a possibility that the internal circuitry of the electronic device or the electronic device that outputs the incorrectly connected external power supply may be damaged.

[0014] For example, electronic devices such as security devices are frequently replaced due to location changes, circuit changes, or replacements. There are many types of electronic devices, some with terminals that output 24V or the like to power external peripheral devices, and some without. Some devices have similar appearances but have different output voltages, and some do not have silk printing. In addition, some electronic devices can change the voltage output externally depending on the settings.

[0015] If the DC power output terminal of an external device is mistakenly connected to the 24V output terminal of an electronic device, such as during replacement, current will flow from the higher potential to the lower potential, which may damage the device through which the current flows.

[0016] To prevent damage to the device itself, there is a protection circuit that incorporates a diode in series with the output line (power supply line) of the device to prevent reverse current flow. However, the diode has a forward voltage characteristic that V F (forward voltage) × I F This involves power loss (forward current), and the heat generation and power consumption of the diode are disadvantages for electronic devices.

[0017] There are various ways to connect the terminals of this type of electronic device, such as connecting various sensors with wired cables, connecting to the terminals of other electronic devices, or stringing together the terminals of the same type of electronic device. Electronic devices often use one or a combination of the following methods to prevent incorrect connections to terminals. However, there are also cases where incorrect connection prevention is not implemented, and is only specified in the circuit design diagram.

[0018] -Connection names are indicated on labels and silkscreen printed circuit boards ·The terminal block is physically separated into the power supply section and the sensor section. -Notation in the installation manual

[0019] However, despite these warnings and warnings, improper wiring during installation can cause damage to electronic equipment. Often, when replacing an electronic device, the output power of another device is connected to the external power supply of the electronic device, which can easily cause breakdowns or malfunctions.

[0020] Therefore, it is conceivable to connect the misconnection detection prevention unit (misconnection notification unit) that is connected to the signal line to the power supply line as disclosed in, for example, Patent Document 2 and Patent Document 3. However, if the misconnection detection prevention unit (misconnection notification unit) is connected to the power supply line, the problem arises that the misconnection detection prevention unit (misconnection notification unit) will operate even when the power switch is turned on in a state where there is no misconnection in the power supply output terminal and the external power supply is normally connected to the external power supply interface.

[0021] An object of the present invention is to provide an apparatus and method for preventing erroneous connection that can prevent erroneous connection to a DC power supply output terminal without any problems. [Means for solving the problem]

[0022] An erroneous connection prevention device according to one embodiment of the present invention is an erroneous connection prevention device for preventing erroneous connection to an external power output circuit provided in an electronic device, the erroneous connection prevention device comprising: an external power output interface connected to a power line extending from the external power output circuit, the external power output interface to which a peripheral circuit receiving power from the external power output circuit is to be connected; and an erroneous connection prevention device connected to the power line. Chibethe misconnection alarm unit that issues an alarm indicating a misconnection when an unintended external power source is connected to the first interface; a first opening / closing unit provided in a first path that serves as the power line, the first opening / closing unit being in an open state when there is no power supply to the electronic device and switching from the open state to a closed state when there is power supply; and a second opening / closing unit provided by being inserted into a second path that connects the power line and the misconnection alarm unit, the second opening / closing unit being in a closed state when there is no power supply to the electronic device and switching from the closed state to an open state when there is power supply to separate the misconnection alarm unit from the power line.

[0023] An incorrect connection prevention method according to one embodiment of the present invention is a method for preventing incorrect connection to an external power output circuit provided in an electronic device, in which an incorrect connection notification unit connected to a power line extending from the external power output circuit issues a notification indicating an incorrect connection when an unintended external power source is connected to an external power output interface to which a peripheral circuit that receives power supply from the external power output circuit should be connected, and a first opening / closing unit provided in a first path that constitutes the power line is in an open state when there is no power supply to the electronic device and is switched from the open state to a closed state when there is power supply, and simultaneously, a second opening / closing unit inserted in a second path connecting the power line and the incorrect connection notification unit is in a closed state when there is no power supply to the electronic device and is switched from the closed state to an open state when there is power supply, thereby disconnecting the incorrect connection notification unit from the power line. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide an apparatus and method for preventing erroneous connection to a DC power supply output terminal without any problems. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a block diagram showing the configuration of an erroneous connection prevention device according to a first embodiment. [Figure 2] 1 is a block diagram showing a configuration of a monitoring device according to a first embodiment. [Figure 3] 1 is a circuit diagram showing a specific example of the configuration of an erroneous connection reporting section 13, a first opening / closing section 14, and a second opening / closing section 15 according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In order to avoid cumbersome repetition of explanation, the same or corresponding parts in each drawing will be designated by the same reference numerals, and explanations thereof will be omitted as appropriate. [First embodiment]

[0027] A misconnection prevention device 10 according to a first embodiment of the present invention will be described below. FIG. 1 is a block diagram showing the configuration of the misconnection prevention device 10.

[0028] 1, the misconnection prevention device 10 includes an external power supply output interface 11, a misconnection notification unit 13, a first opening / closing unit 14, and a second opening / closing unit 15. The misconnection prevention device 10 may also include an external power supply input interface 12, as will be described later.

[0029] The external power output interface 11 is an interface for connecting to an internal circuit (not shown), and is, for example, a connector for connecting to an external power source. The device connected to the external power output interface 11 is not particularly limited, but is, for example, a sensor device.

[0030] On the other hand, the external power input interface 12 is an interface for connecting to an external power supply (not shown), and is, for example, a connector or terminal block for connecting an external power supply. The external power supply is not particularly limited, but is, for example, a power supply that outputs a DC voltage with an output voltage of DC 12 V, DC 24 V, DC 48 V, etc., which is a higher voltage than the electrical signal supplied to the external power output interface 11. The external power output interface 11 and the external power input interface 12 may have the same type of shape.

[0031] The incorrect connection notification unit 13 is connected to the external power output interface 11 via the second switch 15, and when an external power supply is connected to the external power output interface 11, it detects the incorrect connection while there is no power being supplied to the electronic device. Specifically, the incorrect connection notification unit 13 rectifies the output voltage of the external power supply incorrectly connected to the external power output interface 11 and supplies the rectified voltage to an alarm circuit (lamp or buzzer), thereby notifying the user of the incorrect connection. Note that the incorrect connection notification unit 13 operates while there is no power being supplied to the electronic device because the second switch 15 is closed, but does not operate when the second switch 15 is open. As will be described later, such an incorrect connection notification unit 13 can be configured by a rectifier circuit, such as a diode bridge, and an alarm circuit.

[0032] The first switching unit 14 is provided in series on a power line between the external power output interface 11 and an internal circuit (external power output circuit) of an electronic device equipped with the misconnection prevention device 10, and is connected to the external power output interface 11. The first switching unit 14 is in an open state when there is no power supply to the electronic device, and is closed by a control signal that controls opening and closing when, for example, an external power supply is connected to the external power input interface and power is supplied to the electrical device (particularly the external output power circuit). The method of determining whether power is being supplied to this electrical device (particularly the external power output circuit) may be, for example, linked to the power switch of the electronic device, or may be determined by monitoring the input of the external power output circuit.

[0033] The first opening / closing unit 14 is in an open state in the initial state when the power is not turned on, and therefore the external power output interface 11 is electrically separated from the internal circuitry of the electronic device incorporating the misconnection prevention device 10. When an external power supply is connected to the external power input interface 12, the first opening / closing unit 14 operates using the power from this external power supply and switches its state from an open state to a closed state.

[0034] When the first opening / closing unit 14 is in the closed state, the external power output interface 11 is electrically connected to the external power output circuit of the electronic device equipped with the misconnection prevention device 10. When the external power supply is disconnected from the external power input interface 12 and power is no longer supplied to the electronic device, the first opening / closing unit 14 switches from the closed state to its initial open state. Such first opening / closing unit 14 can be configured, for example, by a relay, a field effect transistor, or the like.

[0035] The second switching unit 15 is provided in parallel to the power supply line between the first switching unit 14 and the external power output interface 11, and connects the erroneous detection detection unit 13 to the power supply line. The second switching unit 15 is closed when there is no power supply to the electronic device, and is opened by a control signal that controls opening and closing when, for example, an external power supply is connected to the external power input interface and power is supplied to the electrical device (particularly the external output power supply circuit). The method for determining whether power is being supplied to this electrical device (particularly the external power output circuit) may be, for example, linked to the power switch of the electronic device, or may be determined by monitoring the input of the external power output circuit. The timing for switching the open / close state of the second switching unit 15 is linked to the timing of the first switching unit 14.

[0036] The second switching unit 15 is closed in an initial state when no power is supplied to the electronic device, maintaining an electrical connection between the external power output interface 11 and the misconnection notification unit 13. When an external power source is connected to the external power input interface 12, the second switching unit 15 operates using the power from the external power source and switches its state from closed to open. In other words, the second switching unit 15 and the first switching unit 14 alternate between conductive and non-conductive states. When there is no power supplied to the electronic device, the second switching unit 15 is closed, connecting the misconnection notification unit 13 to the power line. When there is power supplied, the second switching unit 15 is open, disconnecting the misconnection notification unit 13 from the power line. The second switching unit 15 can be configured, for example, by a relay, a field-effect transistor, or the like.

[0037] The misconnection prevention device 10 is equipped with a notification circuit that notifies a user or the like that an external power supply is erroneously connected to the external power supply output interface 11. Such a notification circuit is not particularly limited, but is preferably configured, for example, by a combination of an LED (Light Emitting Diode), an internal buzzer, an external signal output, etc. The user or the like can easily notice that the connection to the external power supply output interface 11 is erroneous because the notification circuit is activated in the event of a misconnection.

[0038] Fig. 2 is a block diagram showing the configuration of the monitoring device 1. The monitoring device 1 includes the misconnection prevention device 10 shown in Fig. 1 and an internal circuit 20 including an external power supply output circuit.

[0039] The monitoring device 1 is an example of an electronic device equipped with the misconnection prevention device 10, and is a device that monitors connected external devices, etc. In this case, the internal circuit 20 is a circuit that includes, for example, a sensor interface, etc. The internal circuit 20 also includes an external power output circuit for supplying power to the external device via the external power output interface 13.

[0040] The following description will be given assuming that the electronic device equipped with the misconnection prevention device 10 is a monitoring device 1 having a signal terminal, but this is merely an example and does not limit the present invention. The misconnection prevention device 10 can be installed in various electronic devices, not just the monitoring device 1.

[0041] 2, in a normal connection, an external device 30 is connected to the external power output interface 11. Also, in a normal connection, an external power supply 40 is connected to the external power input interface 12. This connection is normal, and power is supplied to the external device 30 using power supplied from the external power supply 40.

[0042] In the monitoring device 1, an external power supply 40 connected to the external power input interface 12 supplies power for opening and closing to the first opening / closing unit 14. In this case, the first opening / closing unit 14 operates by receiving drive power from the external power supply 40, and switches its state from an open state to a closed state. Also, the second opening / closing unit 15 operates by receiving drive power for opening and closing from the external power supply 40, and switches its state from a closed state to an open state.

[0043] When the first opening / closing unit 14 is in the open state, the external device 30 connected to the external power output interface 11 is electrically isolated from the internal circuit 20. At this time, the second opening / closing unit 14 is in the closed state, and the misconnection notification unit 13 is electrically connected to the external power output interface 11.

[0044] Then, by switching the state of the first opening / closing unit 14 to the closed state, the external device 30 connected via the external power output interface 11 is electrically connected to the internal circuit 20, and power is supplied to the external device 30. At this time, the state of the second opening / closing unit 14 is set to the open state, and the misconnection notification unit 13 is electrically disconnected from the external power output interface 11 (power output line).

[0045] On the other hand, if some external power supply is mistakenly connected to the external power supply output interface 11, this external power supply will supply power to the incorrect connection notification unit 13 if the second open / close unit 15 is in the closed state. In this case, the incorrect connection notification unit 13 will operate upon receiving power from the incorrectly connected external power supply and will notify the operator of the incorrect connection.

[0046] Also, at this time, if an external power source is not connected to the external power source input interface 12 (if the internal circuit is not receiving power), the first opening / closing section 14 maintains the state of the contact section in an open state (non-conductive state).

[0047] In this way, the illustrated misconnection prevention device 10 alerts the worker with sound and light when the external power supply 40 is erroneously connected to the external power supply output interface 11. On the other hand, if the worker supplies power to the internal circuit 20 in a state where there is no alert (i.e., a state where no power is being supplied to the external power supply output interface 11), the misdetection unit 13 is disconnected from the power output line, and the external power supply is output normally without issuing an alert using power from the external power supply output circuit.

[0048] Therefore, it is possible to prevent an operator from connecting an external power supply to the external power supply input interface 12 when an external power supply is mistakenly connected to the external power supply output interface 11 of the misconnection prevention device 10 (when an alarm is being issued).

[0049] 3 is a circuit diagram showing an example of the configuration of the monitoring device 1. A specific configuration of the monitoring device 1 will be described below with reference to FIG.

[0050] The external power output interface 11 has a + terminal 111 and a GND terminal 112. The + terminal 111 is a terminal that is connected to a + input terminal (signal +) of an external device. The GND terminal 112 is a terminal that is connected to a - input terminal (signal -, GND terminal) of an external device.

[0051] The external power supply input interface 12 has an input terminal 121 and a GND terminal 122. The input terminal 121 is a terminal that is connected to an output terminal of the external power supply. The GND terminal 122 is a terminal that is connected to a GND terminal of the external power supply.

[0052] 3 is an example and does not limit the number of terminals of each. Designers can freely change the number of terminals of the external power output interface 11 and the external power input interface 12 according to their design.

[0053] The illustrated misconnection notification unit 13 includes a diode bridge 133 and a notification circuit 134 .

[0054] The diode bridge 133 is a rectifier circuit that rectifies the output voltage of the external power supply and supplies it to the notification circuit 134 when an external power supply is erroneously connected to the external power supply output interface 11 .

[0055] More specifically, the diode bridge 133 rectifies the output voltage of the external power supply when the + output terminal of the external power supply is connected to the + terminal 111 and the GND terminal of the external power supply is connected to the GND terminal 112. The diode bridge 133 also rectifies the output voltage of the external power supply when the + output terminal of the external power supply is connected to the GND terminal 112 and the GND terminal of the external power supply is connected to the + terminal 111.

[0056] When an external power supply is erroneously connected to the external power supply output interface 11, the notification circuit 134 notifies an operator or the like of the erroneous connection using a buzzer and an LED. The misconnection notification unit 13 (notification circuit 134) may be configured by appropriately combining a notification element with an element for current limiting or voltage adjustment. Furthermore, for example, when a change is made, such as removing the notification LED, appropriate fine adjustments to the circuit configuration may be made, such as shorting the notification LED portion. Furthermore, a configuration may be adopted in which a signal indicating the misconnection is transmitted to an external device from the misconnection notification unit 13 in parallel with the notification to the operator.

[0057] That is, when there is no power supply to the internal circuit 20 and an external power supply is mistakenly connected to the external power supply output interface 11, the illustrated incorrect connection notification unit 13 rectifies the output voltage of the external power supply and activates the notification circuit 134 to notify the operator of the incorrect connection.

[0058] 3 does not limit the present invention to the circuit structure of the misconnection notification unit 13. Designers can change the configuration of the misconnection notification unit 13 as appropriate depending on the number of signal lines of the external power supply output interface 11, the connection pattern of the external power supply, the power supply voltage that may be connected, etc.

[0059] The first switching unit 14 is composed of an a-contact relay, and a movable contact is provided in series between the external power output interface 11 and the internal circuit 20 (external power output circuit 211) of the monitoring device 1. The first switching unit 14 is linked to the power supply to the internal circuit 20, and is in an open state when an external power supply is not connected to the external power input interface 12. On the other hand, the first switching unit 14 is in a closed state when an external power supply is connected to the external power input interface 12 and the switch SW is on. In other words, the opening and closing control of the first switching unit 14 is linked to the power supply to the internal circuit 20.

[0060] The second switching unit 15 is composed of a b-contact relay, and a movable contact is provided in parallel with the external power output interface 11 in the internal circuit 20 (external power output circuit 211) of the monitoring device 1. The second switching unit 15 is linked to the power supply to the internal circuit 20, and is in a closed state when an external power supply is not connected to the external power input interface 12. On the other hand, the second switching unit 15 is in an open state when an external power supply is connected to the external power input interface 12 and the switch SW is on. In other words, the opening and closing control of the second switching unit 15 is also linked to the power supply to the internal circuit 20, and is in an exchangeable relationship with the opening and closing state of the first switching unit 14.

[0061] 3 is an example, and the position of the switch SW and the presence or absence of the voltage conversion unit 123 may be changed as appropriate according to design guidelines. For example, the circuit shown in Fig. 3 assumes an external DC power supply, but an AC-DC conversion circuit may be adopted to use a commercial power supply, a circuit configuration using an AC adapter may be adopted, or a circuit configuration compatible with both AC and DC may be adopted.

[0062] 3, when an external power supply is normally connected to the external power supply input interface 12 and the switch SW is turned on, the first opening / closing unit 14 and the second opening / closing unit 15 are each switched between an open state and a closed state. At this time, if an external power supply is mistakenly connected to the external power supply output interface 11, the notification circuit 134 is operating and an operator or the like will not turn on the switch SW or make a new connection, so power will not be supplied to the internal circuit 20.

[0063] In addition, in Figure 3, the first opening / closing unit 14 and the second opening / closing unit 15 are shown using relays, but the relay is an example for ease of explanation, and the relay circuit can also be constructed by combining switching elements such as transistors.

[0064] The voltage conversion unit 123 increases / decreases the output voltage of an external power supply that is normally connected to the external power supply input interface 12. Such a voltage conversion unit 123 can be configured, for example, by a DC-DC converter or a chopper circuit. When an external power supply is normally connected to the external power supply input interface 12, the first opening / closing unit 14 and the second opening / closing unit 15 connected to the voltage conversion unit 123 switch their states as described above to electrically connect the external power supply output interface 11 and the external power supply output circuit 211.

[0065] With the above circuit configuration, the alarm circuit 13, the first opening / closing unit 14 and the second opening / closing unit 15 are configured to notify workers or the like of the incorrect connection to the DC power supply output terminal when an external power source is mistakenly connected to the first external interface 11, even if power is not being supplied to the internal circuit 20 of the monitoring device 1.

[0066] That is, this circuit configuration is configured to extract power using a diode bridge to drive an LED or buzzer and immediately notify an operator of an abnormal condition in the event of an incorrect connection to the external power supply output interface 11, even without supplying power from the electronic device. Meanwhile, the opening and closing control of the first switching unit 14 and the second switching unit 15, which are linked to the power supply state of the internal power supply 20, is realized solely by hardware. That is, damage to the electronic device's circuitry due to incorrect connection to the DC power supply output terminal can also be more reliably prevented.

[0067] If the external power supply that may be connected to the external power output interface 11 (+ terminal 111, GND terminal 112) is determined to be a 24V power supply, the circuit elements required for notification may be approximately a resistor R1 (5 kΩ) and a Zener diode D2 (Vz = 6 V). Zener diode D1 may be selected to have a value that matches the required voltage of the buzzer. Even if the external power supply that may be connected incorrectly includes a 36V power supply, it can be operated with similar values. If a higher voltage is anticipated, the resistance value of R1 may be set higher, elements with higher voltage resistance may be used, or a voltage-dividing resistor may be inserted, as appropriate.

[0068] Furthermore, by installing the above-mentioned misconnection prevention device on each of the connected electronic devices, i.e., by forming a misconnection prevention system, the misconnection prevention devices can mutually prevent malfunctions caused by incorrect connection of the external output power supply by an operator. This is because if either electronic device is able to supply power to the interface where the misconnection occurs, even if power is not being supplied to the internal circuit of the other device, the misconnection will be reported as soon as the other electronic device detects it. Furthermore, in this case, neither electronic device will malfunction, and the connection can be remade. [Explanation of symbols]

[0069] 1...Monitoring device 10. Misconnection prevention device 11. External power supply output interface 12. External power input interface 13. Misconnection notification section 14. First opening and closing section 15 Second opening and closing section 20...Internal circuit 111···+ terminal 112 GND terminal 121 Input terminal 122 GND terminal 123 Voltage conversion unit 133 Diode Bridge 134....Notification circuit

Claims

1. An incorrect connection prevention device that prevents incorrect connection to an external power output circuit provided in an electronic device, an external power output interface connected to a power line extending from the external power output circuit, the external power output interface being to be connected to a peripheral circuit that receives power from the external power output circuit; an incorrect connection notification unit connected to the power line, the incorrect connection notification unit issuing a notification indicating an incorrect connection when an unintended external power supply is connected to the external power supply output interface; a first opening / closing unit provided on a first path serving as the power supply line, the first opening / closing unit being in an open state when there is no power supply to the electronic device and being switched from the open state to a closed state when there is power supply; a second opening / closing unit inserted in a second path connecting the power supply line and the misconnection notification unit, the second opening / closing unit being in a closed state when there is no power supply to the electronic device and switching from the closed state to an open state when there is power supply to separate the misconnection notification unit from the power supply line; An incorrect connection prevention device.

2. 2. The misconnection prevention device according to claim 1, wherein the misconnection notification unit notifies the misconnection using a buzzer and / or a lamp.

3. 1. A method for preventing erroneous connection to an external power output circuit provided in an electronic device, comprising: an erroneous connection notification unit connected to a power line extending from the external power output circuit issues a notification indicating an erroneous connection when an unintended external power supply is connected to an external power output interface to which a peripheral circuit receiving power from the external power output circuit should be connected; a first opening / closing unit provided on a first path serving as the power supply line, which is in an open state when there is no power supply to the electronic device, and which is switched from the open state to a closed state when there is power supply; a second opening / closing unit inserted into a second path connecting the power supply line and the misconnection notification unit is in a closed state when there is no power supply to the electronic device, and is switched from the closed state to an open state when there is power supply, thereby separating the misconnection notification unit from the power supply line; How to prevent incorrect connections.

4. 4. The method for preventing misconnection according to claim 3, wherein the misconnection notification unit notifies the misconnection using a buzzer and / or a lamp.

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