A solenoid causing serious electromagnetic compatibility – say it ain’t so! Ken Javor
Phone: (256) 650-5261 ________________________________ From: Scott Douglas <[email protected]> List-Post: [email protected] List-Post: [email protected] List-Post: [email protected] Date: Mon, 21 Sep 2009 22:13:53 -0700 To: "Price, Edward" <[email protected]> Cc: <[email protected]> Subject: Re: EMC Directive and solenoid valves In a past life I had a real problem with a solenoid causing serious EMC, primarily from the coil discharge. Diodes across the coil helped some, but we ended up having to create a soft drive and a discharge circuit in order to tame the unruly beast. So how anyone can say solenoids are benign from an EMC standpoint is beyond me. Scott Douglas Price, Edward wrote: -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Gordon,Ian Sent: Monday, September 21, 2009 12:32 AM To: White, Ian Cc: IEEE EMC & SAFETY PSTC Subject: RE: EMC Directive and solenoid valves Ian et al We manufacture solenoid operated vacuum valves (amongst other things) and obtained a statement from ERA to the effect that they were benign as far as the EMC directive is concerned. Ian Gordon When the solenoid is de-energized, isn't there a large and fast voltage generated? When a solenoid manufacturer puts a diode across the coil to limit the voltage, doesn't the large current flowing through the diode and coil create a spectral distribution of energy? Perhaps the Directive ignores the short duration burst, but I don't think you can call a solenoid coil completely benign. Ed Price [email protected] WB6WSN NARTE Certified EMC Engineer Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 Military & Avionics EMC Is Our Specialty - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> <mailto:[email protected]> <mailto:[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> <mailto:[email protected]> <mailto:[email protected]> Mike Cantwell <[email protected]> <mailto:[email protected]> <mailto:[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> <mailto:[email protected]> <mailto:[email protected]> David Heald: <[email protected]> <mailto:[email protected]> <mailto:[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]>
