HOME | CR4 | Instrumentation | Electronic Test Equipment Blog

Electronic Test Equipment Blog

The Electronic Test Equipment Blog is the place for conversation and discussion about test instruments, board & assembly test, inspection & test, test equipment, and anything else related to the electronic testing field. Here, you'll find everything from application ideas, to news and industry trends, to hot topics and cutting edge innovations.

Previous in Blog: Contact in an Uncertain Future

Next in Blog: For Whom the Bell Tolls

Rate this

Comments: Nested

Coping with Interference

Posted July 15, 2009 7:35 AM

When the European Union first proposed the current stringent regulations on electromagnetic interference, non-European manufacturers, especially in the U.S., protested that the limits were unattainable and would adversely affect their ability to compete. Since then, protests have quieted considerably. How have you addressed the European EMI standards? Have you changed design, test, and certification procedures to meet them? Have you reduced your presence in the EU and concentrated product efforts elsewhere? Do you target specific European markets rather than try to provide products continent-wide?

The preceding article is a "sneak peek" from Electronic Test Equipment, a newsletter from GlobalSpec. To stay up-to-date and informed on industry trends, products, and technologies, subscribe to Electronic Test Equipment today.

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Join CR4, The Engineer's Place for News and Discussion!

tom Power-User Join Date: Apr 2005 Location: Scotland Posts: 157 Good Answers: 6	#1 Re: Coping with Interference 07/16/2009 4:30 AM
	One of the worst causes of conducted noise is the thyristor/triac used in solid state relays. These switch off and on at below 2volts either side of the zero crossing point and this 100Hz switching produces probably more noise than the whole apparatus! The line filters needed to get rid of the noise are expensive and add more problems. My Company has developed a new type of solid state relay, (patented 2008) which produces very little conducted noise - well below the EU EMC limits at 240V 80Amp and this relay is certified as fully compliant with the EMC Directive. The new relay is available for use with 115V, 240V and 440V, loading from 25 to 80amps - a 3phase version will be available later in 2009. Independent tests have been carried out by TT Group and BAe Systems and the comparisons with standard solid state relays is remarkable. BAe Systems are now using the relay. The relay has also been used to switch/test a pulsed sonar for 24 hour periods which is probably the 'inductive load from hell' - normal SSRs last only a few minutes with this type of load. Most manufacturers put the whole apparatus through EMC testing without realising just how much time and money they could save by changing the SSR. More details are available at www.root2.ltd.uk
	Reply