Method for solving problem of electromagnetic interference of handheld point-of-sale (POS) terminal

Abstract

The invention relates to the technical field of electromagnetic interference, in particular to a method for solving the problem of electromagnetic interference of a handheld point-of-sale (POS) terminal. The method is applicable to a handheld POS terminal machine of which the inner part is provided with at least two overlapped printed circuit boards (PCB), and is realized according to the following manner that: ground networks mutually corresponding in the vertical direction between the PCBs are respectively subjected to bare copper treatment; conductive foam is fixed between bare copper; and the ground networks in front of row seats of the PCBs are automatically and closely connected through the conductive foam. The method has the advantages that through changing a backflow path of a common mode current and reducing the impedance of the ground plane, electromagnetic interference of the handheld POS terminal is reduced and thereby the stability of the handheld terminal is strengthened.

Description

technical field [0001] The invention relates to the technical field of solving electromagnetic interference, in particular to a method for solving electromagnetic interference of a hand-held POS terminal. Background technique [0002] At present, data communication technology is developing rapidly, and people's life is increasingly inseparable from various payment terminals. The number of people who consume by swiping cards is increasing, so the demand for various POS terminals continues to increase, especially hand-held POS terminals. Its obvious advantage is that it is easy to move and easy to operate. In the realization of human-computer interaction, it is more suitable for the needs of consumers and users. However, integrating a large number of functional modules on a small POS machine will inevitably bring various instabilities and electromagnetic interference. [0003] See figure 1 , figure 1 It is the spatial structure diagram of the mainboard module of the existi...

AI Technical Summary

Problems solved by technology

The impedance of the ground plane of the main board and the ground plane of the sub-board is very small. Only the ground network impedance on the cable is relatively large. The common mode current passes through the high impedance ground cable. According to Ohm's law, the common mode current will cause the signal line to be on the main board and There is a voltage difference on the sub-board, and the voltage difference is relatively large. It flows through the main board core processing chip MCU on the left side of the main board cable seat, which will directly cause the system to crash, restart and white screen.

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