3 Cable selection and laying
Because the cable can receive radiation and electromagnetic wave antenna efficiently, also is the good conduction channel of the interference, the vast majority of the equipment EMC problem is caused by cable, in order to solve the problem of cable, the main method is shielding the cable, so this equipment selected the cable with good shield quality (low impedance), and ensure that cable shielding layer and the case 360.. low impedance lap makes the shielding layer and the chassis constitute a complete shield, to a certain extent, to solve the problem of cable radiation. Meanwhile, in denso wiring, power distribution lines and other requirements of all kinds of lines keep 150 mm distance, sensitive circuits and interference circuit will lay in individual, can’t cross overlap, and increase the wire harness in spacing, avoid the coupling between the cables.
4 The power cord filter
In order to restrain the influence that the power input high frequency interference signals have to this system, the EMC power filter was installed. Filter is different from other electronic components ( Testing Electronic Components ), its performance have very big relations with installation, so a series of measures have been taken in the filter of installation. First filter input and output line should stay away in order to avoid the bad effects due to high frequency filtering on both ends of the couple; Secondly, the filter shell and chassis low impedance contact, at the same time shorter the cable between power and the filter, when current through the case the first flows through filters, and then to other each unit. Finally power port and filter attachment also to be shielded, so outside electromagnetic interference can’t flow through the equipment, the electromagnetic interference in the case cannot spread case, cause interference launch to exceed bid.
Grounding of the electronic equipment is a very important question, it can make the whole circuit system all unit have no circuit potential difference with ground to ensure that equipment can steadily work.
This vehicle equipment are installed on the rear panel grounding column, namely the chassis. Cabinet can make the accumulated electronics in the chassis that cased by electrostatic induction bleed off through ground, avoid the current of circuit that gathered by electrostatic discharge when large current into equipment to the circuit harm and interference the instrument, reasonable connecting with ground is very important to the whole shielding case effectiveness.
About Lisun Group:
Lead in CFL and LED Tester. Click to our product lists:
Colorimeter and Photometer
LED Test Instruments
CFL and CCFL Tester
Electronic Ballast Tester
Equipments for Testing Electronic components
Electrical Safety Tester
AC and DC power supply