Noise suppression device

Abstract

To provide a noise generation prevention device that uses a USB port or Lightning and that can prevent noise from intruding into electronic equipment with a simple structure.SOLUTION: A noise prevention device is a circuit consisting of six elements, signal terminals D+ and D-, and voltage terminals V+ and V-. Each element consists of a coaxial cable. Three of the elements form a parallel circuit in which internal conductors of the elements are connected in parallel. Remaining three of the elements form a series circuit in which internal conductors of the elements are connected in series. Each end of the parallel circuit is connected between the elements that configure the series circuit. Connection points between the series circuit and the parallel circuit are connected with the signal terminals D+ and D-, respectively. External conductors of the six elements are connected in parallel to be connected with the voltage terminal V+. The voltage terminal V- is connected with a casing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a noise prevention device for electronic devices, and more particularly to a noise prevention device for electronic devices such as personal computers that have a USB port or Lightning. [Background technology]

[0002] Patent Document 1 discloses a technique that aims to effectively prevent external noise from entering a device and minimize adverse effects on device operation, data transmission, and the like.

[0003] The technology described in Patent Document 1 is configured to prevent external noise from entering the internal cables of a DeviceNet device by attaching a noise control board equipped with a capacitor that provides AC coupling between the signal line and the chassis to an IEC-compliant metal connector that is fixed to the device chassis to connect the DeviceNet device to the main body such as a personal computer via a signal line (Summary of Patent Document 1).

[0004] In the technology described in Patent Document 1, the noise suppression board, which is equipped with a capacitor that AC-couples between the signal line and the chassis, has a complex structure and is fixedly attached to the device. Furthermore, Patent Document 1 does not mention the concept of using a USB port. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-351344 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention aims to provide a noise generation prevention device that uses a USB port or Lightning and has a simple structure to prevent noise from entering electronic devices or to prevent the emission of electromagnetic waves generated by electronic devices. [Means for solving the problem]

[0007] The USB-type noise prevention device of the present invention is a circuit consisting of six elements, signal terminals D+, D-, and voltage terminals V+, V-, wherein the elements are made of coaxial cables, three of the elements form a parallel circuit in which the internal conductors of the elements are connected in parallel, and three of the elements form a series circuit in which the internal conductors of the elements are connected in series, the ends of the parallel circuits are connected between the elements that make up the series circuit, and the connection points between the series circuit and the parallel circuits are connected to signal terminals D+, D-, respectively, the outer conductors of the six elements are connected in parallel and connected to voltage terminal V+, and voltage terminal V- is connected to the casing.

[0008] The Lightning type noise prevention device of the present invention is a circuit consisting of six elements, signal terminals D+, D- and voltage terminals V+, V-, wherein the elements are made of coaxial cables, three of the elements form a parallel circuit in which the internal conductors of the elements are connected in parallel, and three of the elements form a series circuit in which the internal conductors of the elements are connected in series, the ends of the parallel circuits are connected between the elements that make up the series circuit, and the connection points between the series circuit and the parallel circuits are connected to signal terminals D+, D-, respectively, the outer conductors of the six elements are connected in parallel and connected to voltage terminal V+, and voltage terminal V- is connected to the casing. [Effects of the Invention]

[0009] The present invention makes it possible to prevent noise from entering electronic devices with a simple structure without incorporating it into the device's structure. In addition, because it uses a USB port or Lightning, it is possible to provide a noise prevention device that is economical because one noise prevention device can be used for multiple electronic devices. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating an embodiment of the present invention. [Figure 2] FIG. 1 is a wiring diagram showing an embodiment of the present invention. [Figure 3] FIG. 10 is a diagram showing an experiment on noise removal characteristics of an embodiment of the present invention. [Figure 4] 10 is a graph showing characteristics when the noise prevention device of the present invention is not used. [Figure 5] 10 is a graph showing characteristics when the noise prevention device of the present invention is used. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the noise prevention device of the present invention will be described in detail with reference to the accompanying drawings. [Example]

[0012] FIG. 1 is a schematic diagram showing an embodiment of a noise prevention device according to the present invention.

[0013] 1(a) shows a USB noise prevention device 2 of the present invention connected to a device 1 equipped with a USB terminal, such as a laptop computer. Connecting the USB noise prevention device 2 makes it possible to prevent external electromagnetic waves from entering the device 1, and also to prevent electromagnetic waves generated by the device 1 from being emitted to the outside.

[0014] FIG. 1(b) is a diagram showing the internal structure of the USB type noise prevention device 2. The USB type noise prevention device 2 has a casing 21 and a USB terminal 23, and the USB terminal 23 is connected to the device 1 via four pins: D+ and D-, which are data pins, and V+ and V- (GND), which are power supply pins.

[0015] The D+, D-, and V+ pins are connected to elements 22a, 22b, 22c, 22d, 22e, and 22f via wires 24a, 24b, and 24c, respectively, and the V- (GND) pin is connected to casing 21 via wire 24d.

[0016] (element) As shown in FIG. 1(c), the elements 22a, 22b, 22c, 22d, 22e, and 22f are made of coaxial cables.

[0017] In element 22a, internal conductor 221a is covered with insulator 222a, and external conductor 223a is provided to cover insulator 222a. Coating 224a is provided on the outer periphery of the element.

[0018] In this embodiment, a 3D2V coaxial cable was used. Although a coaxial cable with an impedance of 50Ω was used, a cable with an impedance of 75Ω, such as a 3C2V, may also be used.

[0019] Figure 2 shows the circuit diagram of the USB-type noise suppression device.

[0020] Of the four pins D+, D-, V+, and V- (GND) that make up the USB terminal, the D+ pin is connected via wiring 24a to one end of internal conductors 221a, 221b, and 221c that are connected in parallel, and the other end is connected between 221e and 221f of internal conductors 221d, 221e, and 221f that are connected in series.

[0021] The D-pin is connected via wiring 24b from the opposite side to the V+ pins of the internal conductors 221a, 221b, and 221c connected in parallel, and the other end is connected between 221d and 221e of the internal conductors 221d, 221e, and 221f connected in series.

[0022] The V+ pin is connected to the outer conductors 223a, 223b, 223c, 223d, 223e, and 223f via a wire 24c.

[0023] The V- (GND) pin is connected to the casing 21 of the USB type noise prevention device via a wire 24d.

[0024] FIG. 3 is a diagram showing a noise characteristic experiment according to the present invention. The USB type noise prevention device of the present invention was connected to a laptop computer, and two types of electromagnetic waves, vertically polarized and horizontally polarized, between 0 and 1000 MHz were irradiated onto the laptop computer. The noise intensity emitted from the laptop computer due to the electromagnetic wave irradiation was measured using an antenna directly below the laptop computer, and the noise intensity was compared with that when the USB type noise prevention device was not connected to the laptop computer.

[0025] The results of the above experiment are shown in FIGS.

[0026] FIG. 4(a) is a graph showing the noise intensity for horizontally polarized waves, and FIG. 4(b) is a graph showing the noise intensity for vertically polarized waves when a USB-type noise suppression device is not used.

[0027] For horizontal polarization, the electromagnetic wave values ​​were generally high, with a particularly strong peak observed at 350 MHz. Strong clipping noise was also observed at 800 MHz. For vertical polarization, the noise intensity was also generally strong, with strong peaks observed at 30 MHz and 60 MHz.

[0028] FIG. 5(a) is a graph showing the noise intensity for horizontally polarized waves, and FIG. 5(b) is a graph showing the noise intensity for vertically polarized waves when the USB type noise suppression device of the present invention is connected.

[0029] As is clear from the graph of horizontal polarization in Figure 5(a), noise is kept low overall, and the strong noise at 350 MHz and 800 MHz is particularly suppressed.

[0030] In the graph of vertical polarization in Figure 5(b), noise is kept low overall, and noise is particularly suppressed between 90 MHz and 100 MHz.

[0031] Although a 4-pin Type-A USB terminal is shown in the examples, USB connectors with 4 or more pins for USB 3.0 or higher, such as Type-B and Type-C connectors and Lightning, can also be used as long as the noise generation prevention device of the present invention is connected to the corresponding pins. [Industrial Applicability]

[0032] The present invention provides a noise prevention device that uses a USB port or Lightning and has a simple structure to prevent noise from entering an electronic device. [Explanation of symbols]

[0033] equipment 1 USB type noise suppressor 2 Casing 21 Elements (coaxial cables) 22a, 22b, 22c, 22d, 22e, 22f Inner conductors 221a, 221b, 221c, 221d, 221e, 221f Insulators 222a, 222b, 222c, 222d, 222e, 222f Outer conductors 223a, 223b, 223c, 223d, 223e, 223f USB port 23 USB terminal pins D+, D-, V+, V- Wiring 24a, 24b, 24c, 24d

Claims

1. A circuit consisting of six elements, signal terminals D+, D-, and voltage terminals V+, V-, the element comprises a coaxial cable; The three elements are a parallel circuit in which the internal conductors of the elements are connected in parallel, The three elements form a series circuit in which the internal conductors of the elements are connected in series, the ends of the parallel circuit are connected between the elements constituting the series circuit, The connection points of the series circuit and the parallel circuit are connected to signal terminals D+ and D-, respectively; The outer conductors of the six elements are connected in parallel and connected to a voltage terminal V+; A USB type noise suppression device characterized in that the voltage terminal V- is connected to the casing.

2. A circuit consisting of six elements, signal terminals D+, D-, and voltage terminals V+, V-, the element comprises a coaxial cable; The three elements are a parallel circuit in which the internal conductors of the elements are connected in parallel, The three elements form a series circuit in which the internal conductors of the elements are connected in series, the ends of the parallel circuit are connected between the elements constituting the series circuit, The connection points of the series circuit and the parallel circuit are connected to signal terminals D+ and D-, respectively; The outer conductors of the six elements are connected in parallel and connected to a voltage terminal V+; A Lightning type noise suppression device characterized in that the voltage terminal V- is connected to the casing.

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