Considering EMC techniques during the design phase will minimize EMC problems and avoid disasters uncovered at EMC test time. At this time, the remedial measures are usually very painful.
In the typical case, where the electronic equipment is contained within a single enclosure, enclosure shielding along with cable filtering or shielding are commonly employed to meet EMC requirements.
Today’s electrical and electronic devices are subject to mandatory EMC requirements throughout the world. Many devices operate at high frequencies and are very small. They are placed in nonconductive plastic cases providing no shielding. Essentially, all these devices cannot meet these mandatory requirements or they may cause interference to other devices or receive interference causing susceptibility problems without a proper program of EMI control. This program consists of identifying the “suspect” components and circuits that may cause or be susceptible to EMI. This is completed early on in the program to allow for an efficient design in keeping the cost of dealing with EMI as low as possible. A complete EMC program consists of proper filtering, grounding and shielding. This article will discuss the latter, but the other factors cannot and will not be ignored or given insufficient priority.
It is common for every marketed product to contain some type of marking—label, silkscreen, engraving, stamping, or any combination of these four. Every safety standard has a section or clause that is concerned with marking. Among these markings, a label is the one that is commonly used in most products.
Designers and manufacturers of electronic products are frequently faced with the question: “How do I find a high-quality EMC testing laboratory where I can confidently test my products?” The emphasis of the great majority of design and/or manufacturing entities is on obtaining (1) quality preliminary testing of EMC characteristics to refine the design of their products and (2) quality final design testing of their product for regulatory approvals. The final design, of course, is what gets manufactured and released to the general population for their use in daily life. This article is intended to aid designers and manufacturers in finding and utilizing high-quality EMC testing laboratories.
Many manufacturers design a product first, then attempt to “fix” the design later to meet the applicable safety standard. Prior knowledge of the applicable safety standard and its requirements for the product will help meet deadlines, keep design costs down, and result in a properly designed product.
How do you construct a building without metallic components of any kind? When you are engineers charged with overseeing the design and construction of an Open Area Test Site (OATS) for your company, you find out very quickly how to build a structurally sound facility while still keeping the area free of reflective materials.
It’s been said that nobody grows up wanting to be an EMC engineer. Rather, it usually just happens. Maybe you had incriminating information on your resume, such as being a radio ham. “You’ve created interference, so you must know how to stop it, right?” Maybe you showed a knack for EMC troubleshooting, and suddenly you’re now the company expert - whether you want to be or not.
The first broadcasting station in Japan went on-air in 1925, a scant five years after the first radio station went live in the United States. A year later, Nippon Hōsō Kyōkai (NHK) was chartered by the Japanese government and is still the official public broadcast entity. The build-out of NHK’s network into the Pacific was extensive in the 1930s and during the early years of WWII and followed the expansion of Japan’s imperial armed forces across the Pacific.
