David, my suggestion is to determine which is the worst case EMC environment - the applicable standards or the actual environment - and design for that. We had a similar problem with a particular CCTV installation. The CCTV rf immunity standard specifies 10 V/m; however, the guard watching the CCTV monitor was using a hand held radio that produced a field much higher and the interference was unacceptable to the customer. We had to add fixes to increase the immunity level far beyond what the standard required. You may have a similar problem. Good luck. Richard Woods Sensormatic Electronics Tyco International
-----Original Message----- From: David Sproul [mailto:[email protected]] Sent: Thursday, December 05, 2002 2:19 PM To: EMC-PSTC Subject: Vehicle Mounted PCB's Dear group, A customer has been asked to redesign a board to stop it malfunctioning due to vibration, temperature and radio interference. They have been given a control PCB which they are told is the main culprit for the malfunctions. They circuit is mounted in an armoured vehicle as part of a security system which sprays bank notes with red ink when it believes a robbery is taking place. Apparently it sprays ink if it gets too hot, too cold, gets bumped, or if a radio or mobile phone is operated too close to it. The bad news is that this is on the market and being used by security firms within the UK and mainland Europe, with no real evidence of previous compliance with anything. Should this comply with any of Vehicle directive requirements? Are there any peculiar EMC requirements other than the usual 61000 series? What standard is likely to cover this device for use in vehicles? Although they haven't asked, what would be the most appropriate standard to cover safety requirements for this device. (Although is runs of only 12V, I am concerned about a fault causing a short across the battery, for example)? There was mention of selling it in the US too. If any has thoughts on what such a device should comply with there, all comments would be gratefully received. If you are thinking of writing back and suggesting the device be thrown in the bin, then I'm sorry to say that someone else has beaten you to it. Best regards, David Sproul,
