JPH04168917A - electronic terminal equipment - Google Patents

Abstract

PURPOSE:To realize lightning surge protection by constituting a conductive line between a signal line and an interface with other unit and interposing a surge absorber between the conductive line and the signal line. CONSTITUTION:Circuit section 2 of an electronic terminal 1 is connected through a line transformer 3 with an external signal line, i.e., a telephone line 9. A surge absorber 5 is connected between the telephone lines 9 in the electronic terminal 1. The circuit section 2 is connected through a data line 10 with the circuit section 12 of other unit 11. The other unit 11 is provided with a metal part 14 grounded through an earth terminal 15. An earth line 6 is formed between the telephone line 9 and an interface 16 in the electronic terminal 1. According to the constitution, the circuit sections 2, 12 can be protected positively against lightning surge.

Description

Detailed Description of the Invention (a) Industrial Application Field This invention relates to electronic terminal devices such as card terminal devices that may be used by being connected to other devices, and in particular to electronic terminal devices that do not have a ground terminal. Regarding equipment.

(bl Prior Art Even if the terminal device 31 is used inside a house 32 or the like shown in FIG. .

In the terminal device 31 connected to these outdoor signal lines, it is necessary to consider protection measures against lightning surges when these signal lines are struck by lightning.As a protection measure against this lightning surge, for example, as shown in FIG. In the case where the terminal device 41 is not equipped with a ground terminal and is not connected to the ground, this can be achieved relatively easily by inserting a known surge absorber between the lines that are affected by lightning surges. This is because the surge current flows only through the surge absorbers 43 and 44 and the circuit section 42 when the voltages vA and vL shown in FIG. 4 surge.
No element destruction occurs, and the voltage V m, V
For surges of c, V t, and V F, the terminal device 4
1 and the ground plane, the circuit section 42
This is because dielectric breakdown is less likely to occur.

On the other hand, as shown in FIG. 5, a terminal device 51 having a metal part 53 is generally equipped with a ground terminal 54 and is often connected to the ground. There is a problem in that the ground plane and the metal part are electrically conductive, and the fire ground appears to be close to the circuit part 52, making it easy to cause dielectric breakdown between the line 56 and the metal part 53.

(C) Problem to be solved by the invention By the way, a terminal device 4 without a ground terminal as shown in FIG.
1, as shown in FIG. 6, a terminal device such as a card terminal device is connected via a data line 61 to a circuit section 52 of a device 51 equipped with another ground terminal such as a printer or an ECR. There are cases. In such a case, if a surge voltage is applied to the telephone line 56- connected to the terminal element 41 which does not have a ground terminal, the insulation state may not be sufficient in the distance d between the circuit section 52 and the metal section 53 in the device 51. Then, dielectric breakdown occurs in that part,
A surge current flows from the telephone line 56 through the circuit section 42, the data line 61, the circuit section 52, the metal section 53, and the ground terminal 54. There was a problem where things along the route were destroyed.

In order to solve this problem, in the past, a surge absorber unit had to be separately attached to the outside of the terminal device 41, which resulted in an increase in cost.

An object of the present invention is to construct a conductive line between a signal line to which snow surge voltage is applied and an interface to which other devices are connected, and to provide a surge absorber between this conductive line and the signal line. With this feature, the lightning surge protection function is enabled both when used alone and when connected to other devices, and provides lightning surge protection at all times without using an external surge absorber unit. The purpose is to provide an electronic terminal device that can be realized.

(Means for Solving Problem d1) The electronic terminal device of the present invention is an electronic terminal device that is not equipped with a ground terminal and is equipped with an interface that connects to an outdoor signal line and other devices. The present invention is characterized in that a ground line is provided between an interface connected to another device and an interface connected to another device, and a surge absorber is provided between this ground line and an outdoor signal line.

(e) Effect In this invention, when a lightning surge voltage is applied to an external signal line when an electronic terminal device is used alone, the voltage between the two signal lines is only applied to the surge absorber. will flow. In addition, regarding the voltage between the signal line and the ground plane, there is usually a sufficient distance between the electronic terminal equipment and the ground plane, so the possibility of dielectric breakdown occurring between them is extremely small. When the device is used alone, the circuitry is not affected by snow surges.

Furthermore, when using an electronic terminal device connected to another device equipped with a ground terminal, a current path is formed from the signal line to the ground terminal of the other device via the ground line and interface, which can prevent dielectric breakdown in the circuit section. It never occurs. Therefore, protection against snow surges can be provided even when the electronic terminal device is connected to another device and used.

(f) Embodiment FIG. 1 is a diagram showing the configuration of an electronic terminal device that is an embodiment of the present invention, and shows a state in which it is connected to another device equipped with a ground terminal.

The electronic terminal device 1 does not have a ground terminal, and its circuit section 2 is connected to an ACC line 8 via an AC transformer 4. Further, the circuit section 2 is connected to a telephone line 9, which is an external signal line, via a line transformer 3. Note that the ACC deer line 8 is connected to the AC input line 7 of other devices 11. In the electronic terminal device 1, a known surge absorber 5 is provided between the lines shown in the telephone diagram B9.

The circuit section 2 of this electronic terminal device 10 is connected to the circuit section 12 of another device 11 via a data line 10. is grounded through.

Further, in the electronic terminal device 1, a ground line 6 is formed between the telephone line 9 and the interface 16, and the surge absorber 5 is located between the ground line 6 and the telephone line 9. With this configuration, the interface 18 of the other device 11 and the interface 1 of the electronic terminal device 1
6 is connected with the connector cable 17,
From telephone line 9 to surge absorber 5, ground line 6,
A current path is formed that passes through the connector cable 17 and the metal part 14 and reaches the ground terminal 15. As a result, when a lightning surge voltage is applied to the telephone port wA9, a current flows through the above-mentioned path, and the circuit section 2 and the circuit section 12 are not affected.

In this way, according to the present embodiment, the electronic terminal device 1
0 circuit section can be reliably protected from lightning surges.

FIG. 2 is a diagram showing the configuration of another embodiment of the invention.

In an electronic terminal device 21 having a plurality of terminals 26 to which external signal lines are connected, the common line of the surge absorber 25 is connected from each terminal 26 to an interface to which other devices 2 are connected, such as a printer interface 23 or an EC.
Connect to the R interface 24, etc. This configuration has the advantage that the snow surge protection function can be reliably exerted even when the electronic terminal device 21 is connected to a plurality of signal lines and a large number of other devices.

(Effects of the Phantom Invention According to this invention, when a lightning surge voltage is applied to an external signal line, current flows only to the surge absorber when it is used alone, and other When used connected to a device, by configuring a current path to the ground terminal of another device via the ground line, there is an advantage that dielectric breakdown of the circuit section can be reliably prevented in any case.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an electronic terminal device according to an embodiment of the invention, and FIG. 2 is a diagram showing the configuration of an electronic terminal device according to another embodiment of the invention. FIG. 3 is a diagram illustrating the usage state of a terminal device including the present invention, and FIGS. 4 and 5 are diagrams showing the configuration of a conventional electronic terminal device. Furthermore, FIG. 6 is a diagram showing a configuration when a conventional electronic terminal device is connected to another device. 1-electronic terminal equipment, 5-surge absorber, 6-ground line, 8-ACC nested line 9-telephone port 1a (outdoor signal line), 11-other equipment, 15-ground terminal, 17-connector cable.

Claims (1)

[Claims] (1) In electronic terminal equipment that does not have a ground terminal and is equipped with an interface that connects to outdoor signal lines and other equipment, between the interface that connects to outdoor signal lines and the interface that connects to other equipment. An electronic terminal device characterized in that a ground line is provided at the ground line, and a surge absorber is provided between the ground line and an outdoor signal line.