There are many “rules” for laying out a printed wiring board (PWB) to minimize generation of EMI from a board. These cover a wide range of issues that are important. Some more than others, but all can be important. But, if you were to ask what the number one item on the hit parade would be, what would you say? What are the important factors to consider when laying out a … [Read more...]
Proposed Changes to CISPR SC I Standards
Are you familiar with CISPR 32 and CISPR 35? CISPR 32 was originally published in 2012, followed by a pair of corrigenda and then the 2nd edition was published in 2015. CISPR 32 replaced CISPR 13 (Broadcast receivers emissions) and CISPR 22 (ITE emissions). In the EU CISPR 32 is published as EN 55032 and it has superseded EN 55013 and EN 55022. By now you should all be … [Read more...]
Substitution Source Measurements
In today’s EMC testing world testing is very often automated, using well calibrated test equipment. The operator sets up the EUT and support equipment, sets up the test equipment, fires up the software on the computer designed to automate the test, clicks on “Go” and sits back to watch the blinking lights. After a while the test is complete and a file is generated containing … [Read more...]
Do your people really know how to perform a conducted emissions test to ANSI C63.4 or CISPR 32?
Oftentimes when a new person is hired to perform conducted emissions testing in a laboratory they know little about EMC and even less about how to perform a test. There is a training period where the new person learns how to perform a test using whatever software the lab has been using. The new person is well trained in how to perform the test with the automation working, … [Read more...]
An Engineering Ethics Question for Today
I’ve been presenting a seminar on engineering ethics to students in the Electrical Engineering Department at Washington State University for a number of years. I’ve started off with a video of the Challenger explosion and the questions leading up to it as expressed by Roger Boisjoly, a Morton Thiokol engineer. Roger Boisjoly had studied data showing that the field joint … [Read more...]
Summary of Commercial EMC Tests
Commercial EMC tests cover a wide range of products. These include the obvious ones like computers and their peripherals, but also cover household appliances, electric tools and a wide variety of other products. While the standards, including limits and test methods may differ, all EMC test standards have a few things in common. The most basic are the limits for emissions … [Read more...]
Summary of Military and Aerospace EMC Tests
Military and aerospace EMC tests cover a wide range of products. While the standards, including limits and test methods may differ, all EMC test standards have a few things in common. The most basic are the limits for emissions and the types and levels of susceptibility testing. Emissions tests (and their associated limits) are put in place for military and aerospace … [Read more...]
CISPR 35 – How does it compare with CISPR 24?
After 15 years of work in CISPR Subcommittee I, the IEC Central Office published CISPR 35 Edition 1.0 on Tuesday, August 16, 2016. The IEC webstore link is https://webstore.iec.ch/publication/25667. In the US, ANSI has the standard available on their website as well. Go to www.ansi.org and type in CISPR 35 in the search window for standards. You must purchase a copy of the … [Read more...]
