Electronic device

Abstract

An electronic device (1) comprises a substrate (2), a terminal (3) provided to the substrate (2), and a micro control unit (4) that is provided to the substrate (2) and has an input port (4a) for receiving input of a signal from the outside and an output port (4b) capable of outputting a signal to the outside. The substrate (2) is provided with: a filter-mounting unit (24) provided in the middle of input-side wiring (26) for connecting the terminal (3) and the input port (4a), the filter-mounting unit (24) making it possible to mount a filter circuit (6); a switch-mounting unit (25) provided in the middle of ground wiring (27) for grounding the terminal (3) to a ground (29), the switch-mounting unit (25) making it possible to mount a switch circuit (7) for switching between connecting and disconnecting the terminal (3) and the ground (29); and signal wiring (28) for connecting the switch-mounting unit (25) and the output port (4b).

Description

electronic equipment

[0001] The present invention relates to an electronic device.

[0002] Electronic devices used for control take in signals from external devices such as sensors and output signals to the controlled object. Conventionally, electronic devices that process sensor signals include, for example, a substrate with an input terminal connected to the sensor, a microcomputer provided on the substrate, and a processing IC that processes the signal from the sensor and is mounted midway along the wiring connecting the input terminal on the substrate to the input port of the microcomputer, as disclosed in JP2010-177646A.

[0003] An electronic device configured in this manner processes signals from the sensors using a microcomputer and outputs signals used for control from an output port.

[0004] JP2010-177646A

[0005] In conventional electronic devices, terminals mounted on a circuit board are connected to input ports of a microcomputer by wiring, and output ports of the microcomputer are connected to output terminals by separate wiring on the circuit board.

[0006] However, due to installation space limitations, there is a limit to the number of terminals that can be provided on a board, and while some electronic devices only use input terminals depending on their specifications, there are also cases where output terminals are required, so it is necessary to add additional output terminals depending on the specifications.

[0007] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electronic device that can suppress an increase in the number of terminals.

[0008] In order to achieve the above object, the electronic device of the present invention comprises a substrate, a terminal provided on the substrate, an input port that receives an input of a signal from outside, and an output port that can output a signal to the outside, and a microcontroller unit provided on the substrate, and the substrate has a filter mounting section provided in the middle of the input side wiring that connects the terminal to the input port, which enables the mounting of a filter circuit, a switch mounting section provided in the middle of the ground wiring that grounds the terminal to ground, which enables the mounting of a switch circuit that switches between connecting and disconnecting the terminal from ground, and a signal wiring that connects the switch mounting section to the output port.

[0009] In an electronic device configured in this manner, if a filter circuit is mounted in the filter mounting section and a switch circuit is mounted in the switch mounting section, when an external device that inputs a signal to the terminal is connected, the terminal will function as an input terminal, and when an external device that receives power from the terminal and whose switch circuit switches between connecting and disconnecting the terminal from ground to operate on and off is connected, the terminal can function as an output terminal that turns the external device on and off.

[0010] Therefore, according to the electronic device, the terminals can function as both input and output terminals, so that, for example, when the specifications require only input terminals and when the specifications require both output and input terminals, there is no need to go to the trouble of adding additional terminals when the total number of terminals is the same in both cases.

[0011] Furthermore, if an electronic device does not have a switch circuit mounted in the switch mounting section, but has a filter circuit mounted in the filter mounting section, the terminals can be made to function as input terminals by mounting the filter circuit in the filter mounting section. If output terminals are not required due to the product specifications, the terminals can be used as input terminals, preventing an insufficient number of terminals in the electronic device. Also, if the terminals are not used as output terminals, there is no need to mount a switch.

[0012] Furthermore, if an electronic device does not have a filter circuit mounted in the filter mounting section but has a switch circuit mounted in the switch mounting section, the terminals can be made to function as output terminals by mounting the switch circuit in the switch mounting section.If an output terminal is required according to the product specifications, the terminals can be used as output terminals, preventing an insufficient number of terminals in the electronic device.If the terminals are not used as input terminals, there is no need to mount a filter circuit.

[0013] Fig. 1 is a configuration diagram of an electronic device according to one embodiment. Fig. 2 is a configuration diagram of an electronic device according to one embodiment, which is equipped with a filter circuit and a switch circuit and is connected to an external device that inputs signals. Fig. 3 is a configuration diagram of an electronic device according to one embodiment, which is equipped with a filter circuit and a switch circuit and is connected to an external device that receives power and operates on and off. Fig. 4 is a configuration diagram of an electronic device equipped with only a filter circuit. Fig. 5 is a configuration diagram of an electronic device equipped with only a switch circuit.

[0014] The present invention will be described below based on the embodiment shown in the drawings. As shown in Fig. 1, electronic device 1 is configured to include a substrate 2, terminals 3 provided on substrate 2, and a microcontroller unit 4. Electronic device 1 is used, for example, to control a variable solenoid valve for adjusting the damping force of a shock absorber (not shown) interposed between the body and wheels of a vehicle.

[0015] The board 2 comprises a board body 21 on which wiring is printed, a connector 22 attached to the board body 21 and accommodating the terminal 3, a microcomputer mounting section 23 on which the microcontroller unit 4 is mounted, a filter mounting section 24, and a switch mounting section 25.

[0016] The microcontrol unit 4 has an input port 4a, an output port 4b, a microprocessor not shown, and an A / D conversion circuit not shown that converts an analog signal input from the input port 4a into a digital signal, and is capable of processing the signal input from the input port 4a and outputting a control signal from an output port not shown to a drive circuit for driving a variable solenoid valve not shown.

[0017] In this embodiment, the terminal 3 is housed in a connector 22 together with a plurality of other terminals 5. The connector 22 houses one terminal 3 and five other terminals 5, for a total of six terminals 3 and 5.

[0018] Terminal 3 is connected to both input wiring 26 extending to the microcomputer mounting section 23 printed on the substrate 2 and output ground wiring 27 serving as a ground wiring, and terminal 5 is connected to other wiring (not shown) printed on the substrate 2. The number of terminals 5 can be changed as desired. Terminal 5 is used for either input or output depending on the product specifications, and may not be used depending on the product.

[0019] When the microcontroller unit 4 is mounted on the microcomputer mounting section 23 of the substrate 2, the input port 4a of the microcontroller unit 4 is connected to the terminal 3 via the input side wiring 26, and the output port 4b is connected to the signal wiring 28 printed on the substrate 2.

[0020] The filter mounting section 24 provided on the substrate 2 is provided midway along the input wiring 26. The substrate 2 also includes an input ground wiring 30 having one end connected to ground 29 and the other end connected to the filter mounting section 24. In this way, the filter mounting section 24 is provided midway along the input wiring 26 and connected to the input ground wiring 30, and is configured in the area of ​​the substrate 2 surrounded by the dashed line in FIG.

[0021] 2, the filter circuit 6 mounted on the filter mounting section 24 comprises a resistor 6a installed midway along the input wiring 26 and a capacitor 6b installed midway along the wiring connecting the downstream side of the resistor 6a to the other end of the input ground wiring 30, forming a primary RC circuit and functioning as a low-pass filter. Note that the filter circuit 6 may be an analog high-pass filter or band-pass filter depending on the external device (described later) connected to the terminal 3, and the circuit configuration can be appropriately modified in design depending on the required specifications.

[0022] The switch mounting section 25 provided on the substrate 2 is provided midway along the output-side ground wiring 27. The substrate 2 also includes a signal wiring 28 having one end connected to the output port 4b of the microcontrol unit 4 and extending to the switch mounting section 25. In this way, the switch mounting section 25 is provided midway along the output-side ground wiring 27, which serves as a ground wiring connecting the terminal 3 to the ground 29, and is connected to the output port 4b of the microcontrol unit 4 via the signal wiring 28, and is configured in the area on the substrate 2 surrounded by the dashed line in FIG.

[0023] As shown in FIG. 2, the switch circuit 7 mounted on the switch mounting portion 25 includes a transistor 7a, a resistor 7b installed on a wiring 7d connected to the collector of the transistor 7a, and a resistor 7c installed on a wiring 7e connected to the base of the transistor 7a.

[0024] As described above, the switch circuit 7 includes resistors 7b and 7c and wirings 7d and 7e in addition to the transistor 7a that functions as a switch. When mounted on the switch mounting portion 25, the collector of the transistor 7a is connected to the terminal 3 side of the output ground wiring 27 through wiring 7d, the emitter of the transistor 7a is connected to the ground 29 side of the output ground wiring 27 and is installed midway along the output ground wiring 27, and the base of the transistor 7a is connected to the signal wiring 28 through wiring 7e. Therefore, when a high signal is output from the output port 4b of the microcontroller unit 4 to the transistor 7a of the switch circuit 7, the transistor 7a is turned on, connecting the terminal 3 and the ground 29 through the switch circuit 7. Conversely, when a low signal is output to the transistor 7a, the transistor 7a is turned off, causing the switch circuit 7 to disconnect the terminal 3 and the ground 29, thereby isolating the terminal 3 from the ground 29. Note that the switch circuit 7 may include a switching element, such as a MOSFET, that is turned on and off in response to a signal output from the microcontroller unit 4.

[0025] When an external sensor 8 as an external device is connected to the terminal 3 of the electrical device 1 configured in this manner, as shown in FIG. 2, a sensor signal consisting of an analog voltage input from the external sensor 8 to the terminal 3 passes through the filter circuit 6 mounted on the filter mounting section 24 via the input side wiring 26 and is input to the input port 4a of the microcontroller unit 4.

[0026] The filter circuit 6 is an RC circuit that functions as a low-pass filter, so it removes high-frequency noise superimposed on the sensor signal input from the external sensor 8, and the low-frequency components of the sensor signal that are equal to or lower than the cutoff frequency of the RC circuit are input to the microcontrol unit 4. The microcontrol unit 4 converts the sensor signal from which noise has been removed into a digital signal and uses it for control processing.

[0027] When the external sensor 8 is connected to the terminal 3 in this way, the sensor signal is filtered by the filter 6 mounted on the filter mounting portion 24 and input to the input port 4a of the microcontrol unit 4, so that the terminal 3 functions as an input terminal. The external sensor 8 may be any sensor that detects information necessary for controlling the controlled object of the microcontrol unit 4, and in the case where the controlled object is the variable solenoid valve described above, it may be an acceleration sensor that detects vibration information of the vehicle body or a displacement sensor that detects expansion / contraction displacement of a shock absorber. Furthermore, when the terminal 3 functions as an input terminal, the external device connected to the terminal 3 may be a proximity switch, a lever switch, or the like, in addition to the external sensor 8, as long as it inputs some kind of signal necessary for controlling the controlled object to the microcontrol unit 4 through the terminal 3.

[0028] 3, when an LED 10 is connected as an external device that receives power from the power supply 9 instead of the external sensor 8, outputting a high signal from the output port 4b of the microcontrol unit 4 applies a voltage to the base of the transistor 7a in the switch circuit 7 and the LED 10 is grounded to the ground 29 by the output ground wiring 27, so that current flows from the power supply 9 to the LED 10 and lights up the LED 10. On the other hand, when a low signal is output from the output port 4b of the microcontrol unit 4, no voltage is applied to the base of the transistor 7a in the switch circuit 7, the LED 10 is not grounded to the ground 29 by the output ground wiring 27, so that no current flows from the power supply 9 to the LED 10 and the LED 10 does not light up.

[0029] In this way, when an external device that receives power supply and is turned on / off by opening and closing the transistor 7a in the switch circuit 7 is connected to the terminal 3, the terminal 3 can function as an output terminal for turning the external device on and off. The resistor 7b, which is provided closer to the terminal 3 than the transistor 7a in the switch circuit 7, and the resistor 7c, which is provided closer to the signal wiring 28 than the transistor 7a in the switch circuit 7, are configured so that a voltage suitable for driving the LED 10 serving as the external device can be applied to the LED 10. In this way, the switch circuit 7 is configured to be suitable for driving the external device connected to the terminal 3. Furthermore, when the terminal 3 is used as an output terminal, the external device connected to the terminal 3 may be anything other than the LED 10, as long as it receives power supply and is turned on / off by the switch circuit 7 switching between connection and disconnection between the terminal 3 and the ground 29, such as an actuator or a motor.

[0030] When an external device is connected that receives power supply to terminal 3 and switches on and off by switching terminal 3 between ground 29 and switch circuit 7, a current would also flow through input wiring 26. However, since filter circuit 6 is mounted on filter mounting section 24, filter circuit 6 acts as a resistor to prevent current from flowing to input port 4a of microcontrol unit 4, and the external device can be turned on and off without any problems by inputting a signal from output port 4b of microcontrol unit 4. Furthermore, even if a current flows through input wiring 6 and a signal is input to input port 4a, microcontrol unit 4 is configured not to read the signal. When external sensor 8 is attached to terminal 3, microcontrol unit 4 is configured to output a signal from output port 4b to turn off transistor 7a in switch circuit 7.

[0031] In this way, when an external device that inputs some kind of signal, such as an external sensor 8, is connected to terminal 3, terminal 3 functions as an input terminal, and when an external device, such as LED 10 that receives power supply and turns on and off by switch circuit 7 switching between connection and disconnection of terminal 3 and ground 29, is connected, terminal 3 functions as an output terminal that turns on and off the external device. Thus, terminal 3 can function as both an output terminal and an input terminal depending on the external device connected.

[0032] As described above, the electronic device 1 of this embodiment includes a substrate 2, a terminal 3 provided on the substrate 2, and a microcontroller unit 4 provided on the substrate 2, the microcontroller unit 4 having an input port 4a that receives an input of a signal from outside and an output port 4b that can output a signal to the outside. The substrate 2 includes a filter mounting section 24 that is provided midway on the input side wiring 26 that connects the terminal 3 to the input port 4a and enables the mounting of a filter circuit 6, a switch mounting section 25 that is provided midway on the output side ground wiring (ground wiring) 27 that grounds the terminal 3 to ground 29 and enables the mounting of a switch circuit 7 that switches between connection and disconnection between the terminal 3 and ground 29, and a signal wiring 28 that connects the switch mounting section 25 and the output port 4b.

[0033] According to the electronic device 1 configured in this manner, by mounting a filter circuit 6 in the filter mounting section 24 and a switch 7 in the switch mounting section 25, when an external device that inputs a signal such as an external sensor 8 is connected to the terminal 3, the terminal 3 functions as an input terminal, and when an external device such as an LED 10 that receives power supply to the terminal 3 and is turned on and off by the switch circuit 7 switching between connection and disconnection between the terminal 3 and the ground 29 is connected to the terminal 3, the terminal 3 can function as an output terminal that turns the external device on and off.

[0034] Therefore, according to the electronic device 1 of this embodiment, the terminals 3 can function as both input and output terminals, so that, for example, when the specifications require only input terminals and when the total number of terminals is the same in both cases, there is no need to add additional terminals. As described above, according to the electronic device 1 of this embodiment, an increase in the number of terminals can be suppressed even if the specifications change. Furthermore, according to the electronic device 1 of this embodiment, since the number of terminals does not increase even if the specifications change, there is no need to change the design of the board 2 according to different specifications, and the board 2 can be standardized, thereby reducing manufacturing costs.

[0035] In the above description, only one terminal 3 that can be used for both input and output is provided on the board 2, but a filter mounting section 24 and a switch mounting section 25 may be provided between the terminal 5 and the microcontrol unit 4 so that some or all of the terminals 5 provided on the board 2 in addition to the terminal 3 can be used for both input and output in the same way as the terminal 3.

[0036] Furthermore, in the electronic device 1 of this embodiment, the filter circuit 6 is mounted in the filter mounting section 24, and the switch circuit 7 is mounted in the switch mounting section 25. In the electronic device 1 configured in this manner, whether an external device that inputs a signal, such as an external sensor 8, or an external device, such as an LED 10, that receives power and turns on and off by the switch circuit 7 switching between connection and disconnection between the terminal 3 and ground 29, is connected to the terminal 3, the terminal 3 can function in a manner appropriate for the external device, thereby improving the convenience of the electrical device 1.

[0037] As shown in FIG. 4 , the electronic device 1A may include only the filter circuit 6 mounted on the filter mounting section 24, without mounting the switch 7 on the switch mounting section 25. With the electronic device 1A configured in this manner, mounting the filter circuit 6 on the filter mounting section 24 allows the terminal 3 to function as an input terminal. Therefore, with the electronic device 1A configured in this manner, if an output terminal is not required due to product specifications, the terminal 3 can be used as an input terminal, thereby preventing a shortage of terminals in the electronic device 1. Furthermore, since the switch circuit 7 is not required when the terminal 3 is not used as an output terminal, the electronic device 1 can be manufactured more inexpensively than if both the filter circuit 6 and the switch circuit 7 are mounted. Note that, if the switch circuit 7 is not mounted, it is sufficient that the terminal 3 cannot function as an output terminal. Therefore, instead of mounting all of the components constituting the switch circuit 7, only some of the components may be mounted to prevent the terminal 3 from functioning as the switch circuit 7. Therefore, for example, in this embodiment, if some of the transistors 7a and resistors 7b and 7c are not implemented, the switch circuit 7 will not be able to function, so not implementing the switch circuit 7 also includes a configuration in which some of the transistors 7a and resistors 7b and 7c are not implemented.

[0038] 5 , the electronic device 1B may include only the switch circuit 7 mounted on the switch mounting section 25, without mounting the filter circuit 6 on the filter mounting section 24. With the electronic device 1B configured in this manner, mounting the switch circuit 7 on the switch mounting section 25 allows the terminal 3 to function as an output terminal. Therefore, with the electronic device 1B configured in this manner, when an output terminal is required according to the product specifications, the terminal 3 can be used as an output terminal, thereby preventing a shortage of terminals in the electronic device 1. Furthermore, since there is no need to mount the filter circuit 6 when the terminal 3 is not used as an input terminal, the electronic device 1 can be manufactured more inexpensively than when both the filter circuit 6 and the switch circuit 7 are mounted.

[0039] Although the electronic device 1 of the present invention has been described as being used to control a variable electromagnetic valve of a shock absorber with adjustable damping force, it goes without saying that the electronic device 1 may be used to control something other than a variable electromagnetic valve.

[0040] Although the preferred embodiment of the present invention has been described in detail above, modifications, variations and changes can be made without departing from the scope of the appended claims.

[0041] 1, 1A, 1B...Electronic device, 2...Substrate, 3...Terminal, 4...Microcontrol unit, 4a...Input port, 4b...Output port, 6...Filter circuit, 7...Switch circuit, 24...Filter mounting portion, 25...Switch mounting portion, 26...Input side wiring, 27...Output side ground wiring (ground wiring), 28...Signal wiring, 29...Ground

Claims

1. An electronic device comprising: a substrate; a terminal provided on the substrate; an input port that receives an input of a signal from outside; and an output port that can output a signal to the outside, and a microcontrol unit provided on the substrate; wherein the substrate has: a filter mounting section provided in the middle of input wiring that connects the terminal and the input port, allowing the mounting of a filter circuit; a switch mounting section provided in the middle of ground wiring that grounds the terminal to ground, allowing the mounting of a switch circuit that switches between connection and disconnection of the terminal and the ground; and signal wiring that connects the switch mounting section to the output port.

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