Re: [PSES] Interference Caused by Microwave Oven
In message 1f28.6030...@gmail.com, dated Thu, 14 May 2015, Doug Powell doug...@gmail.com writes: My question is this. If the RF generated inside the oven does not stop prior to the opening of the RF seal on the door, which testing is responsible to identify this problem, EMC or the Safety testing Not 'either/or': emission with the door open violates CISPR 11/EN 55011, it's also a violation of the Section of IEC/EN 60335-2 (too late here to look it up) and potentially a violation of the regulatory EMF exposure limits as measured according to IEC 62233. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
In message blupr02mb1162688d885f918f36748fdc1...@blupr02mb116.namprd02.prod.outlook .com, dated Thu, 14 May 2015, Brian Oconnell oconne...@tamuracorp.com writes: Think that CISPR32 is supposed to address very short-term stuff, but since is not recurring and periodic, would a few hundred mSec affect test limits? CISPR 32 doesn't apply to microwave ovens: CISPR 11 applies. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
This isn't a particularly helpful contribution, but when I use my microwave (used correctly, with the door closed), my Bluetooth speaker completely stops working and any WiFi activity grinds to a halt. I try to keep the kids away from the microwave when it's in use, as much as I can. Michael. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: 14 May 2015 23:42 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 1f28.6030...@gmail.com, dated Thu, 14 May 2015, Doug Powell doug...@gmail.com writes: My question is this. If the RF generated inside the oven does not stop prior to the opening of the RF seal on the door, which testing is responsible to identify this problem, EMC or the Safety testing Not 'either/or': emission with the door open violates CISPR 11/EN 55011, it's also a violation of the Section of IEC/EN 60335-2 (too late here to look it up) and potentially a violation of the regulatory EMF exposure limits as measured according to IEC 62233. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] [External] Re: [PSES] Interference Caused by Microwave Oven
IEC/EN 60335-2-25 and IEC/EN 60335-2-90 have limits on the radiation emitted from the microwave with the door open. This includes testing with the seal broken and the door closed, when possible. The limits are pretty strict so I would be a little surprised by this. I haven’t read the article, nor do I know the history of the standard so there maybe something there too. Josh -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Thursday, May 14, 2015 5:42 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [External] Re: [PSES] Interference Caused by Microwave Oven In message 1f28.6030...@gmail.com, dated Thu, 14 May 2015, Doug Powell doug...@gmail.com writes: My question is this. If the RF generated inside the oven does not stop prior to the opening of the RF seal on the door, which testing is responsible to identify this problem, EMC or the Safety testing Not 'either/or': emission with the door open violates CISPR 11/EN 55011, it's also a violation of the Section of IEC/EN 60335-2 (too late here to look it up) and potentially a violation of the regulatory EMF exposure limits as measured according to IEC 62233. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] [External] Re: [PSES] Interference Caused by Microwave Oven
It's possible the noise quite soon after the door is opened is still below the limit for unintentional or incidental emitters. That's enough to interfere with radiotelescopes. Cortland Richmond -Original Message- From: Wiseman, Joshua E BIS joshua.e.wise...@carrier.utc.com Sent: May 15, 2015 8:55 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] [External] Re: [PSES] Interference Caused by Microwave Oven IEC/EN 60335-2-25 and IEC/EN 60335-2-90 have limits on the radiation emitted from the microwave with the door open. This includes testing with the seal broken and the door closed, when possible. The limits are pretty strict so I would be a little surprised by this. I haven’t read the article, nor do I know the history of the standard so there maybe something there too. Josh -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Thursday, May 14, 2015 5:42 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [External] Re: [PSES] Interference Caused by Microwave Oven In message 1f28.6030...@gmail.com, dated Thu, 14 May 2015, Doug Powell doug...@gmail.com writes: My question is this. If the RF generated inside the oven does not stop prior to the opening of the RF seal on the door, which testing is responsible to identify this problem, EMC or the Safety testing Not 'either/or': emission with the door open violates CISPR 11/EN 55011, it's also a violation of the Section of IEC/EN 60335-2 (too late here to look it up) and potentially a violation of the regulatory EMF exposure limits as measured according to IEC 62233. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
In message 001001d08f24$621e6c60$265b4520$@pctestlab.com, dated Fri, 15 May 2015, dward dw...@pctestlab.com writes: The solution to that is simple - get a new microwave but don't buy the same brand. :) What is the Bayesian probability that the new brand will be worse? (;-) -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
The solution to that is simple - get a new microwave but don't buy the same brand. :) Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: Michael Derby [mailto:micha...@acbcert.com] Sent: Friday, May 15, 2015 12:02 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven This isn't a particularly helpful contribution, but when I use my microwave (used correctly, with the door closed), my Bluetooth speaker completely stops working and any WiFi activity grinds to a halt. I try to keep the kids away from the microwave when it's in use, as much as I can. Michael. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: 14 May 2015 23:42 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 1f28.6030...@gmail.com, dated Thu, 14 May 2015, Doug Powell doug...@gmail.com writes: My question is this. If the RF generated inside the oven does not stop prior to the opening of the RF seal on the door, which testing is responsible to identify this problem, EMC or the Safety testing Not 'either/or': emission with the door open violates CISPR 11/EN 55011, it's also a violation of the Section of IEC/EN 60335-2 (too late here to look it up) and potentially a violation of the regulatory EMF exposure limits as measured according to IEC 62233. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
I was wondering the same regarding “capacitor hold-up” keeping the magnetron working for up to a half sine. As for the radio astronomy frequency allocations, here is the internationally recognized list: http://www.astrosurf.com/luxorion/radioastro-frequencieslist.htm http://www.ukaranet.org.uk/basics/frequency_allocation.htm Note that there is a band from 2655 to 2690 MHz and another from 2690 to 2700 MHz. Microwave ovens operate nominally at 2.45 GHz. However if you actually look at the spectrum when the oven is on, you’ll observe it uses much (maybe more?) of the 2.4 to 2.5 GHz ISM band. Conceivably, the signals could slop over to the nearest astronomy band. You’ll see this on the last page of my article on wireless interference: http://www.edn.com/electronics-blogs/the-emc-blog/4438663/3/Wi-Fi-network-interference--analysis--and-optimization http://www.edn.com/electronics-blogs/the-emc-blog/4438663/3/Wi-Fi-network-interference--analysis--and-optimization The real time spectrum analyzer used (Tek RSA306) only had a RT bandwidth of 40 MHz, so much of the signal lies off the chart”. It’s interesting to note that the frozen capture of the instantaneous signal (orange line) clearly shows the pulsed 16 ms periodicity of the half-wave rectifier in the magnetron power supply. Ken ___ Kenneth Wyatt Wyatt Technical Services, Inc. 56 Aspen Dr. Woodland Park, CO Phone: (719) 310-5418 Email Me! mailto:k...@emc-seminars.com | Web Site http://www.emc-seminars.com/ | Blog http://design-4-emc.com/ The EMC Blog (EDN) http://www.edn.com/blog/The-EMC-Blog Subscribe to Newsletter http://www.emc-seminars.com/Newsletter/Newsletter.html Connect with me on LinkedIn http://www.linkedin.com/in/kennethwyatt On May 15, 2015, at 4:09 PM, Ed Price edpr...@cox.net wrote: Interestingly, many news sources quote the oven emission as “1.4 GHz” which is very unlikely for a consumer oven. They didn’t mention if the telescope was being used in the 2.4 GHz band (again unlikely), so I wonder if the telescope was being overloaded by the out-of-band 2.4 GHz oven fundamental, if the oven harmonics were to blame or if the telescope data-processing equipment was actually the victim. One story at least admitted that researchers were suspicious of the signals, as they only were a problem during “working hours.” - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
One-half sine wave is 8/10 ms, and even that seems like a lot of hold-up time for an HV capacitor and several hundred Watts dissipated. Even at 8 ms, the time between depressing the switch and opening the door is going to be longer than that. Ken Javor Phone: (256) 650-5261 From: Ed Price edpr...@cox.net Reply-To: Ed Price edpr...@cox.net Date: Fri, 15 May 2015 15:09:57 -0700 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven Old microwave ovens (like the one from 1988) were electrically quite simple; a relay applied AC power to a step-up transformer, and the secondary output was grounded (one side) and connected to a diode (other side). The diode allowed a low-capacitance HV capacitor to charge and the magnetron to produce RF output. It was a simple half-wave rectifier circuit. When the door safety switch open, the relay would drop out (anywhere along the AC sinewave), and the magnetron would continue to produce RF until the capacitor voltage dropped below the minimum magnetron ³excitation² voltage. I can¹t recall magnetron current nor the capacitor size, but the decay was ³pretty darn fast.² I wonder if the capacitor was large enough to sustain RF output through the negative half of the AC power? So, although electrical shut-down was quick, you have to take slack in the door safety switch mechanism into consideration. Best if the switch was linked to a safety latch, but not so good if the switch was sensing door position. New microwave ovens, more computer than appliance, and with a switching power supply, might have a larger HV capacitor, and thus longer decay time when being shut down. People who have built their own ham gear or have built lab equipment such as pulse generators, know the hazards of HV and interlock systems, but when your whole experience is built around 5 3.3 VDC equipment, RF door leakage may come as a big surprise. I think EMC engineers would be aware of this, but the issue is much more under the domain of safety. If nothing else, an EMC engineer should flag this to the safety guy for proper evaluation. Interestingly, many news sources quote the oven emission as ³1.4 GHz² which is very unlikely for a consumer oven. They didn¹t mention if the telescope was being used in the 2.4 GHz band (again unlikely), so I wonder if the telescope was being overloaded by the out-of-band 2.4 GHz oven fundamental, if the oven harmonics were to blame or if the telescope data-processing equipment was actually the victim. One story at least admitted that researchers were suspicious of the signals, as they only were a problem during ³working hours.² Ed Price WB6WSN Chula Vista, CA USA From: Ken Wyatt [mailto:k...@emc-seminars.com] Sent: Friday, May 15, 2015 8:55 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven Hi All, I recently wrote an article on wireless interference, with microwave ovens being one source of that interference. Fortunately, the use cycle of microwave ovens is relatively short, so any interference is short-term. However, any leakage is certainly an issue for those standing nearby - maybe listening to popcorn, etc.? http://www.edn.com/electronics-blogs/the-emc-blog/4438663/Wi-Fi-network-inte rference--analysis--and-optimization In this article, I show a real-time spectral plot of microwave oven leakage at 12 inch distance from the oven. The peaks were around -20 dBm using a short ³rubber duck² antenna on the Tek RSA306 analyzer. The leakage limit is 1 mW/cm^2 with a test load (water) and 5 mW/cm^2 without a test load (measured at 5 cm from the oven surface). I measured mine just now at 0.1 mW/cm^2 loaded and 0.5 mW/cm^2 unloaded. The Australian Government did a study on the subject in 2004 and includes some interesting background on the door interlock designs: http://www.arpansa.gov.au/pubs/emr/microwave.pdf Health Canada also did a survey of several new and used microwave ovens in the Ottawa area: http://www.hc-sc.gc.ca/ewh-semt/pubs/radiation/microwave_ovens-micro_ondes/i ndex-eng.php Cheers, Ken ___ Kenneth Wyatt Wyatt Technical Services, Inc. 56 Aspen Dr. Woodland Park, CO Phone: (719) 310-5418 Email Me! mailto:k...@emc-seminars.com | Web Site http://www.emc-seminars.com | Blog http://design-4-emc.com/ The EMC Blog (EDN) http://www.edn.com/blog/The-EMC-Blog Subscribe to Newsletter http://www.emc-seminars.com/Newsletter/Newsletter.html Connect with me on LinkedIn http://www.linkedin.com/in/kennethwyatt On May 15, 2015, at 9:00 AM, Ken Javor ken.ja...@emccompliance.com wrote: My microwave oven used correctly interferes with wi-fi and Bluetooth, but with blue tooth if I bring the devices close together I can overpower the incidental oven radiation, right next to the oven. I can't do that with wi-fi at home, because of the fixed location of the wi-fi base station at the other end of the house from the oven
Re: [PSES] Interference Caused by Microwave Oven
I would have thought that the output cap on a switcher would be smaller than the cap for rectified ac line, just due to what it takes to deliver the same amount of ripple potential. Ken Javor Phone: (256) 650-5261 From: Ken Javor ken.ja...@emccompliance.com Date: Fri, 15 May 2015 16:43:36 -0700 To: EMC-PSTC@LISTSERV.IEEE.ORG Conversation: [PSES] Interference Caused by Microwave Oven Subject: Re: [PSES] Interference Caused by Microwave Oven One-half sine wave is 8/10 ms, and even that seems like a lot of hold-up time for an HV capacitor and several hundred Watts dissipated. Even at 8 ms, the time between depressing the switch and opening the door is going to be longer than that. Ken Javor Phone: (256) 650-5261 From: Ed Price edpr...@cox.net Reply-To: Ed Price edpr...@cox.net Date: Fri, 15 May 2015 15:09:57 -0700 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven Old microwave ovens (like the one from 1988) were electrically quite simple; a relay applied AC power to a step-up transformer, and the secondary output was grounded (one side) and connected to a diode (other side). The diode allowed a low-capacitance HV capacitor to charge and the magnetron to produce RF output. It was a simple half-wave rectifier circuit. When the door safety switch open, the relay would drop out (anywhere along the AC sinewave), and the magnetron would continue to produce RF until the capacitor voltage dropped below the minimum magnetron ³excitation² voltage. I can¹t recall magnetron current nor the capacitor size, but the decay was ³pretty darn fast.² I wonder if the capacitor was large enough to sustain RF output through the negative half of the AC power? So, although electrical shut-down was quick, you have to take slack in the door safety switch mechanism into consideration. Best if the switch was linked to a safety latch, but not so good if the switch was sensing door position. New microwave ovens, more computer than appliance, and with a switching power supply, might have a larger HV capacitor, and thus longer decay time when being shut down. People who have built their own ham gear or have built lab equipment such as pulse generators, know the hazards of HV and interlock systems, but when your whole experience is built around 5 3.3 VDC equipment, RF door leakage may come as a big surprise. I think EMC engineers would be aware of this, but the issue is much more under the domain of safety. If nothing else, an EMC engineer should flag this to the safety guy for proper evaluation. Interestingly, many news sources quote the oven emission as ³1.4 GHz² which is very unlikely for a consumer oven. They didn¹t mention if the telescope was being used in the 2.4 GHz band (again unlikely), so I wonder if the telescope was being overloaded by the out-of-band 2.4 GHz oven fundamental, if the oven harmonics were to blame or if the telescope data-processing equipment was actually the victim. One story at least admitted that researchers were suspicious of the signals, as they only were a problem during ³working hours.² Ed Price WB6WSN Chula Vista, CA USA From: Ken Wyatt [mailto:k...@emc-seminars.com] Sent: Friday, May 15, 2015 8:55 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven Hi All, I recently wrote an article on wireless interference, with microwave ovens being one source of that interference. Fortunately, the use cycle of microwave ovens is relatively short, so any interference is short-term. However, any leakage is certainly an issue for those standing nearby - maybe listening to popcorn, etc.? http://www.edn.com/electronics-blogs/the-emc-blog/4438663/Wi-Fi-network-inte rference--analysis--and-optimization In this article, I show a real-time spectral plot of microwave oven leakage at 12 inch distance from the oven. The peaks were around -20 dBm using a short ³rubber duck² antenna on the Tek RSA306 analyzer. The leakage limit is 1 mW/cm^2 with a test load (water) and 5 mW/cm^2 without a test load (measured at 5 cm from the oven surface). I measured mine just now at 0.1 mW/cm^2 loaded and 0.5 mW/cm^2 unloaded. The Australian Government did a study on the subject in 2004 and includes some interesting background on the door interlock designs: http://www.arpansa.gov.au/pubs/emr/microwave.pdf Health Canada also did a survey of several new and used microwave ovens in the Ottawa area: http://www.hc-sc.gc.ca/ewh-semt/pubs/radiation/microwave_ovens-micro_ondes/i ndex-eng.php Cheers, Ken ___ Kenneth Wyatt Wyatt Technical Services, Inc. 56 Aspen Dr. Woodland Park, CO Phone: (719) 310-5418 Email Me! mailto:k...@emc-seminars.com | Web Site http://www.emc-seminars.com | Blog http://design-4-emc.com/ The EMC Blog (EDN) http://www.edn.com/blog/The-EMC-Blog Subscribe to Newsletter http://www.emc-seminars.com/Newsletter/Newsletter.html Connect with me on LinkedIn http
Re: [PSES] Interference Caused by Microwave Oven
Old microwave ovens (like the one from 1988) were electrically quite simple; a relay applied AC power to a step-up transformer, and the secondary output was grounded (one side) and connected to a diode (other side). The diode allowed a low-capacitance HV capacitor to charge and the magnetron to produce RF output. It was a simple half-wave rectifier circuit. When the door safety switch open, the relay would drop out (anywhere along the AC sinewave), and the magnetron would continue to produce RF until the capacitor voltage dropped below the minimum magnetron excitation voltage. I can't recall magnetron current nor the capacitor size, but the decay was pretty darn fast. I wonder if the capacitor was large enough to sustain RF output through the negative half of the AC power? So, although electrical shut-down was quick, you have to take slack in the door safety switch mechanism into consideration. Best if the switch was linked to a safety latch, but not so good if the switch was sensing door position. New microwave ovens, more computer than appliance, and with a switching power supply, might have a larger HV capacitor, and thus longer decay time when being shut down. People who have built their own ham gear or have built lab equipment such as pulse generators, know the hazards of HV and interlock systems, but when your whole experience is built around 5 3.3 VDC equipment, RF door leakage may come as a big surprise. I think EMC engineers would be aware of this, but the issue is much more under the domain of safety. If nothing else, an EMC engineer should flag this to the safety guy for proper evaluation. Interestingly, many news sources quote the oven emission as 1.4 GHz which is very unlikely for a consumer oven. They didn't mention if the telescope was being used in the 2.4 GHz band (again unlikely), so I wonder if the telescope was being overloaded by the out-of-band 2.4 GHz oven fundamental, if the oven harmonics were to blame or if the telescope data-processing equipment was actually the victim. One story at least admitted that researchers were suspicious of the signals, as they only were a problem during working hours. Ed Price WB6WSN Chula Vista, CA USA From: Ken Wyatt [mailto:k...@emc-seminars.com] Sent: Friday, May 15, 2015 8:55 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven Hi All, I recently wrote an article on wireless interference, with microwave ovens being one source of that interference. Fortunately, the use cycle of microwave ovens is relatively short, so any interference is short-term. However, any leakage is certainly an issue for those standing nearby - maybe listening to popcorn, etc.? http://www.edn.com/electronics-blogs/the-emc-blog/4438663/Wi-Fi-network-inte rference--analysis--and-optimization In this article, I show a real-time spectral plot of microwave oven leakage at 12 inch distance from the oven. The peaks were around -20 dBm using a short rubber duck antenna on the Tek RSA306 analyzer. The leakage limit is 1 mW/cm^2 with a test load (water) and 5 mW/cm^2 without a test load (measured at 5 cm from the oven surface). I measured mine just now at 0.1 mW/cm^2 loaded and 0.5 mW/cm^2 unloaded. The Australian Government did a study on the subject in 2004 and includes some interesting background on the door interlock designs: http://www.arpansa.gov.au/pubs/emr/microwave.pdf Health Canada also did a survey of several new and used microwave ovens in the Ottawa area: http://www.hc-sc.gc.ca/ewh-semt/pubs/radiation/microwave_ovens-micro_ondes/i ndex-eng.php Cheers, Ken ___ Kenneth Wyatt Wyatt Technical Services, Inc. 56 Aspen Dr. Woodland Park, CO Phone: (719) 310-5418 Email Me! mailto:k...@emc-seminars.com | Web Site http://www.emc-seminars.com | Blog http://design-4-emc.com/ The EMC Blog (EDN) http://www.edn.com/blog/The-EMC-Blog Subscribe to Newsletter http://www.emc-seminars.com/Newsletter/Newsletter.html Connect with me on LinkedIn http://www.linkedin.com/in/kennethwyatt On May 15, 2015, at 9:00 AM, Ken Javor ken.ja...@emccompliance.com wrote: My microwave oven used correctly interferes with wi-fi and Bluetooth, but with blue tooth if I bring the devices close together I can overpower the incidental oven radiation, right next to the oven. I can't do that with wi-fi at home, because of the fixed location of the wi-fi base station at the other end of the house from the oven. Obviously I can bring the wi-fi device closer to the base station and at the same time farther from the oven and make the problem go away, but that is hardly surprising. But the point of the news item was that it seemed the interference was tied to the oven door opening, which is problematic, at least to me. I don't buy the delay thing someone posited - I'm thinking that it is a switch activating a relay interrupting power to the magnetron, and that happens before any
Re: [PSES] Interference Caused by Microwave Oven
Hi Ken, I suspect that the health impact of the microwave popcorn far exceed the leakage from the oven. This stuff is bad, not fit for human consumption. Doug Douglas C. Smith University of Oxford Tutor Department for Continuing Education Oxford, Oxfordshire, United Kingdom -- ___ _Doug Smith \ / ) P.O. Box 60941 = Boulder City, NV 89006-0941 _ / \ / \ _TEL/FAX: 702-570-6108/570-6013 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o | Email: d...@dsmith.org \ _ /]\ _ / Web: http://www.dsmith.org -- On 5/15/15 08:54, Ken Wyatt wrote: Hi All, I recently wrote an article on wireless interference, with microwave ovens being one source of that interference. Fortunately, the use cycle of microwave ovens is relatively short, so any interference is short-term. However, any leakage is certainly an issue for those standing nearby - maybe listening to popcorn, etc.? http://www.edn.com/electronics-blogs/the-emc-blog/4438663/Wi-Fi-network-interference--analysis--and-optimization In this article, I show a real-time spectral plot of microwave oven leakage at 12 inch distance from the oven. The peaks were around -20 dBm using a short “rubber duck” antenna on the Tek RSA306 analyzer. The leakage limit is 1 mW/cm^2 with a test load (water) and 5 mW/cm^2 without a test load (measured at 5 cm from the oven surface). I measured mine just now at 0.1 mW/cm^2 loaded and 0.5 mW/cm^2 unloaded. The Australian Government did a study on the subject in 2004 and includes some interesting background on the door interlock designs: http://www.arpansa.gov.au/pubs/emr/microwave.pdf Health Canada also did a survey of several new and used microwave ovens in the Ottawa area: http://www.hc-sc.gc.ca/ewh-semt/pubs/radiation/microwave_ovens-micro_ondes/index-eng.php Cheers, Ken ___ Kenneth Wyatt Wyatt Technical Services, Inc. 56 Aspen Dr. Woodland Park, CO Phone: (719) 310-5418 Email Me! | Web Site | Blog The EMC Blog (EDN) Subscribe to Newsletter Connect with me on LinkedIn On May 15, 2015, at 9:00 AM, Ken Javor ken.ja...@emccompliance.com wrote: My microwave oven used correctly interferes with wi-fi and Bluetooth, but with blue tooth if I bring the devices close together I can overpower the incidental oven radiation, right next to the oven. I can't do that with wi-fi at home, because of the fixed location of the wi-fi base station at the other end of the house from the oven. Obviously I can bring the wi-fi device closer to the base station and at the same time farther from the oven and make the problem go away, but that is hardly surprising. But the point of the news item was that it seemed the interference was tied to the oven door opening, which is problematic, at least to me. I don't buy the delay thing someone posited - I'm thinking that it is a switch activating a relay interrupting power to the magnetron, and that happens before any pressure on the oven door gasket has been released. Ken Javor Phone: (256) 650-5261 From: Michael Derby micha...@acbcert.com Reply-To: Michael Derby micha...@acbcert.com Date: Fri, 15 May 2015 08:02:00 +0100 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven This isn't a particularly helpful contribution, but when I use my microwave (used correctly, with the door closed), my Bluetooth speaker completely stops working and any WiFi activity grinds to a halt. I try to keep the kids away from the microwave when it's in use
Re: [PSES] Interference Caused by Microwave Oven
My microwave oven used correctly interferes with wi-fi and Bluetooth, but with blue tooth if I bring the devices close together I can overpower the incidental oven radiation, right next to the oven. I can't do that with wi-fi at home, because of the fixed location of the wi-fi base station at the other end of the house from the oven. Obviously I can bring the wi-fi device closer to the base station and at the same time farther from the oven and make the problem go away, but that is hardly surprising. But the point of the news item was that it seemed the interference was tied to the oven door opening, which is problematic, at least to me. I don't buy the delay thing someone posited - I'm thinking that it is a switch activating a relay interrupting power to the magnetron, and that happens before any pressure on the oven door gasket has been released. Ken Javor Phone: (256) 650-5261 From: Michael Derby micha...@acbcert.com Reply-To: Michael Derby micha...@acbcert.com Date: Fri, 15 May 2015 08:02:00 +0100 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven This isn't a particularly helpful contribution, but when I use my microwave (used correctly, with the door closed), my Bluetooth speaker completely stops working and any WiFi activity grinds to a halt. I try to keep the kids away from the microwave when it's in use, as much as I can. Michael. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: 14 May 2015 23:42 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 1f28.6030...@gmail.com, dated Thu, 14 May 2015, Doug Powell doug...@gmail.com writes: My question is this. If the RF generated inside the oven does not stop prior to the opening of the RF seal on the door, which testing is responsible to identify this problem, EMC or the Safety testing Not 'either/or': emission with the door open violates CISPR 11/EN 55011, it's also a violation of the Section of IEC/EN 60335-2 (too late here to look it up) and potentially a violation of the regulatory EMF exposure limits as measured according to IEC 62233. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas
Re: [PSES] Interference Caused by Microwave Oven
Sinicism - a word made up from Latin for Chinese (sinicus) and Greek for belief, ideology or style (ism). Meaning - a Chinese method or style extended meaning - a certain negative belief about products made in China - of which may result in missing the good things. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Friday, May 15, 2015 12:16 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven And I'm not disappointed. Ken Javor Phone: (256) 650-5261 From: John Woodgate j...@jmwa.demon.co.uk Reply-To: John Woodgate j...@jmwa.demon.co.uk Date: Fri, 15 May 2015 19:50:26 +0100 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 002e01d08f35$4068c0f0$c13a42d0$@pctestlab.com, dated Fri, 15 May 2015, dward dw...@pctestlab.com writes: May your Sinicism not cause you to miss the good things in life. I'm not Chinese! And I'm not of the canine persuasion, which is what the word you aimed at originally alluded to. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
Hmm -odd - It's not in my dictionary - or online! Best Regards Charles Grasso Compliance Engineer Echostar Communications (w) 303-706-5467 (c) 303-204-2974 (t) 3032042...@vtext.com (e) charles.gra...@echostar.com (e2) chasgra...@gmail.com -Original Message- From: dward [mailto:dw...@pctestlab.com] Sent: Friday, May 15, 2015 1:34 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven Sinicism - a word made up from Latin for Chinese (sinicus) and Greek for belief, ideology or style (ism). Meaning - a Chinese method or style extended meaning - a certain negative belief about products made in China - of which may result in missing the good things. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Friday, May 15, 2015 12:16 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven And I'm not disappointed. Ken Javor Phone: (256) 650-5261 From: John Woodgate j...@jmwa.demon.co.uk Reply-To: John Woodgate j...@jmwa.demon.co.uk Date: Fri, 15 May 2015 19:50:26 +0100 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 002e01d08f35$4068c0f0$c13a42d0$@pctestlab.com, dated Fri, 15 May 2015, dward dw...@pctestlab.com writes: May your Sinicism not cause you to miss the good things in life. I'm not Chinese! And I'm not of the canine persuasion, which is what the word you aimed at originally alluded to. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas
Re: [PSES] Interference Caused by Microwave Oven
The fact that this seems an anomaly says the Bayesian probability is satisfied by reason and uniformity - that being, there are more satisfactorily operating devices than lemons. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Friday, May 15, 2015 9:04 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 001001d08f24$621e6c60$265b4520$@pctestlab.com, dated Fri, 15 May 2015, dward dw...@pctestlab.com writes: The solution to that is simple - get a new microwave but don't buy the same brand. :) What is the Bayesian probability that the new brand will be worse? (;-) -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
May your Sinicism not cause you to miss the good things in life. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Friday, May 15, 2015 9:50 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 002701d08f2c$fbcc7d40$f36577c0$@pctestlab.com, dated Fri, 15 May 2015, dward dw...@pctestlab.com writes: The fact that this seems an anomaly says the Bayesian probability is satisfied by reason and uniformity - that being, there are more satisfactorily operating devices than lemons. May you never be disillusioned. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
It's there, keep looking. :) Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: Grasso, Charles [mailto:charles.gra...@echostar.com] Sent: Friday, May 15, 2015 12:43 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven Hmm -odd - It's not in my dictionary - or online! Best Regards Charles Grasso Compliance Engineer Echostar Communications (w) 303-706-5467 (c) 303-204-2974 (t) 3032042...@vtext.com (e) charles.gra...@echostar.com (e2) chasgra...@gmail.com -Original Message- From: dward [mailto:dw...@pctestlab.com] Sent: Friday, May 15, 2015 1:34 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven Sinicism - a word made up from Latin for Chinese (sinicus) and Greek for belief, ideology or style (ism). Meaning - a Chinese method or style extended meaning - a certain negative belief about products made in China - of which may result in missing the good things. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Friday, May 15, 2015 12:16 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven And I'm not disappointed. Ken Javor Phone: (256) 650-5261 From: John Woodgate j...@jmwa.demon.co.uk Reply-To: John Woodgate j...@jmwa.demon.co.uk Date: Fri, 15 May 2015 19:50:26 +0100 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 002e01d08f35$4068c0f0$c13a42d0$@pctestlab.com, dated Fri, 15 May 2015, dward dw...@pctestlab.com writes: May your Sinicism not cause you to miss the good things in life. I'm not Chinese! And I'm not of the canine persuasion, which is what the word you aimed at originally alluded to. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help
Re: [PSES] Interference Caused by Microwave Oven
Clever etymology, but incorrect, at least politically. Ken Javor Phone: (256) 650-5261 From: dward dw...@pctestlab.com Date: Fri, 15 May 2015 12:34:04 -0700 To: 'Ken Javor' ken.ja...@emccompliance.com, EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] Interference Caused by Microwave Oven Sinicism - a word made up from Latin for Chinese (sinicus) and Greek for belief, ideology or style (ism). Meaning - a Chinese method or style extended meaning - a certain negative belief about products made in China - of which may result in missing the good things. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Friday, May 15, 2015 12:16 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven And I'm not disappointed. Ken Javor Phone: (256) 650-5261 From: John Woodgate j...@jmwa.demon.co.uk Reply-To: John Woodgate j...@jmwa.demon.co.uk Date: Fri, 15 May 2015 19:50:26 +0100 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 002e01d08f35$4068c0f0$c13a42d0$@pctestlab.com, dated Fri, 15 May 2015, dward dw...@pctestlab.com writes: May your Sinicism not cause you to miss the good things in life. I'm not Chinese! And I'm not of the canine persuasion, which is what the word you aimed at originally alluded to. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac
Re: [PSES] Interference Caused by Microwave Oven
Apologies to John for inferring a problem with certain areas of the manufacturing world. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: dward [mailto:dw...@pctestlab.com] Sent: Friday, May 15, 2015 12:34 PM To: 'Ken Javor'; 'EMC-PSTC@LISTSERV.IEEE.ORG' Subject: RE: [PSES] Interference Caused by Microwave Oven Sinicism - a word made up from Latin for Chinese (sinicus) and Greek for belief, ideology or style (ism). Meaning - a Chinese method or style extended meaning - a certain negative belief about products made in China - of which may result in missing the good things. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Friday, May 15, 2015 12:16 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven And I'm not disappointed. Ken Javor Phone: (256) 650-5261 From: John Woodgate j...@jmwa.demon.co.uk Reply-To: John Woodgate j...@jmwa.demon.co.uk Date: Fri, 15 May 2015 19:50:26 +0100 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 002e01d08f35$4068c0f0$c13a42d0$@pctestlab.com, dated Fri, 15 May 2015, dward dw...@pctestlab.com writes: May your Sinicism not cause you to miss the good things in life. I'm not Chinese! And I'm not of the canine persuasion, which is what the word you aimed at originally alluded to. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message
Re: [PSES] Interference Caused by Microwave Oven
Hi All, I recently wrote an article on wireless interference, with microwave ovens being one source of that interference. Fortunately, the use cycle of microwave ovens is relatively short, so any interference is short-term. However, any leakage is certainly an issue for those standing nearby - maybe listening to popcorn, etc.? http://www.edn.com/electronics-blogs/the-emc-blog/4438663/Wi-Fi-network-interference--analysis--and-optimization http://www.edn.com/electronics-blogs/the-emc-blog/4438663/Wi-Fi-network-interference--analysis--and-optimization In this article, I show a real-time spectral plot of microwave oven leakage at 12 inch distance from the oven. The peaks were around -20 dBm using a short “rubber duck” antenna on the Tek RSA306 analyzer. The leakage limit is 1 mW/cm^2 with a test load (water) and 5 mW/cm^2 without a test load (measured at 5 cm from the oven surface). I measured mine just now at 0.1 mW/cm^2 loaded and 0.5 mW/cm^2 unloaded. The Australian Government did a study on the subject in 2004 and includes some interesting background on the door interlock designs: http://www.arpansa.gov.au/pubs/emr/microwave.pdf http://www.arpansa.gov.au/pubs/emr/microwave.pdf Health Canada also did a survey of several new and used microwave ovens in the Ottawa area: http://www.hc-sc.gc.ca/ewh-semt/pubs/radiation/microwave_ovens-micro_ondes/index-eng.php http://www.hc-sc.gc.ca/ewh-semt/pubs/radiation/microwave_ovens-micro_ondes/index-eng.php Cheers, Ken ___ Kenneth Wyatt Wyatt Technical Services, Inc. 56 Aspen Dr. Woodland Park, CO Phone: (719) 310-5418 Email Me! mailto:k...@emc-seminars.com | Web Site http://www.emc-seminars.com/ | Blog http://design-4-emc.com/ The EMC Blog (EDN) http://www.edn.com/blog/The-EMC-Blog Subscribe to Newsletter http://www.emc-seminars.com/Newsletter/Newsletter.html Connect with me on LinkedIn http://www.linkedin.com/in/kennethwyatt On May 15, 2015, at 9:00 AM, Ken Javor ken.ja...@emccompliance.com wrote: My microwave oven used correctly interferes with wi-fi and Bluetooth, but with blue tooth if I bring the devices close together I can overpower the incidental oven radiation, right next to the oven. I can't do that with wi-fi at home, because of the fixed location of the wi-fi base station at the other end of the house from the oven. Obviously I can bring the wi-fi device closer to the base station and at the same time farther from the oven and make the problem go away, but that is hardly surprising. But the point of the news item was that it seemed the interference was tied to the oven door opening, which is problematic, at least to me. I don't buy the delay thing someone posited - I'm thinking that it is a switch activating a relay interrupting power to the magnetron, and that happens before any pressure on the oven door gasket has been released. Ken Javor Phone: (256) 650-5261 From: Michael Derby micha...@acbcert.com Reply-To: Michael Derby micha...@acbcert.com Date: Fri, 15 May 2015 08:02:00 +0100 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven This isn't a particularly helpful contribution, but when I use my microwave (used correctly, with the door closed), my Bluetooth speaker completely stops working and any WiFi activity grinds to a halt. I try to keep the kids away from the microwave when it's in use, as much as I can. Michael. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: 14 May 2015 23:42 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 1f28.6030...@gmail.com, dated Thu, 14 May 2015, Doug Powell doug...@gmail.com writes: My question is this. If the RF generated inside the oven does not stop prior to the opening of the RF seal on the door, which testing is responsible to identify this problem, EMC or the Safety testing Not 'either/or': emission with the door open violates CISPR 11/EN 55011, it's also a violation of the Section of IEC/EN 60335-2 (too late here to look it up) and potentially a violation of the regulatory EMF exposure limits as measured according to IEC 62233. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee
Re: [PSES] Interference Caused by Microwave Oven
I can't wait for the response to this post! Ken Javor Phone: (256) 650-5261 From: dward dw...@pctestlab.com Reply-To: dward dw...@pctestlab.com Date: Fri, 15 May 2015 10:33:26 -0700 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven May your Sinicism not cause you to miss the good things in life. Dennis Ward This communication and its attachements contain information from PCTEST Engineering Laboratory, Inc., and is intended for the exclusive use of the recipient(s) named above. It may contain information that is confidential and/or legally privileged. Any unauthorized use that may compromise that confidentiality via distribution or disclosure is prohibited. Please notify the sender immediately if you receive this communication in error, and delete it from your computer system. Usage of PCTEST email addresses for non-business related activities is strictly prohibited. No warranty is made that the e-mail or attachments(s) are free from computer virus or other defect. Thank you. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Friday, May 15, 2015 9:50 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven In message 002701d08f2c$fbcc7d40$f36577c0$@pctestlab.com, dated Fri, 15 May 2015, dward dw...@pctestlab.com writes: The fact that this seems an anomaly says the Bayesian probability is satisfied by reason and uniformity - that being, there are more satisfactorily operating devices than lemons. May you never be disillusioned. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
In message 002701d08f2c$fbcc7d40$f36577c0$@pctestlab.com, dated Fri, 15 May 2015, dward dw...@pctestlab.com writes: The fact that this seems an anomaly says the Bayesian probability is satisfied by reason and uniformity - that being, there are more satisfactorily operating devices than lemons. May you never be disillusioned. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
Think that CISPR32 is supposed to address very short-term stuff, but since is not recurring and periodic, would a few hundred mSec affect test limits? So what is the SAR for 2.5GHz stuff? Is it an integral effect for exposure time? Is safety issue per new LVD (2014/35/EU), and would need a good rationale per required risk analysis. Bet that most of you EMC engineers would have this figured out in a few hours. PhD astronomers and rocket scientists, 17 years - meh. Brian From: Doug Powell [mailto:doug...@gmail.com] Sent: Thursday, May 14, 2015 3:18 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Interference Caused by Microwave Oven All, Today Interference Technology published on their website, Astronomers Discover 17-Year Interference Caused by Microwave Oven Link: http://www.interferencetechnology.com/astronomers-discover-17-year-interference-caused-by-microwave-oven/?utm_source=itnewsletterutm_medium=emailutm_campaign=20150514 My question is this. If the RF generated inside the oven does not stop prior to the opening of the RF seal on the door, which testing is responsible to identify this problem, EMC or the Safety testing? Thanks, Doug Douglas E Powell http://www.linkedin.com/in/dougp01 - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
I had this same question: why doesn¹t the rf shut off when the door is opened? And a second one: why was it deemed worthy of publishing an article that a microwave oven interfered with data collection since 1988? Not something I¹d want to publicize... Ken Javor Phone: (256) 650-5261 From: Doug Powell doug...@gmail.com Reply-To: Doug Powell doug...@gmail.com Date: Thu, 14 May 2015 16:18:16 -0600 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Interference Caused by Microwave Oven All, Today Interference Technology published on their website, Astronomers Discover 17-Year Interference Caused by Microwave Oven Link: http://www.interferencetechnology.com/astronomers-discover-17-year-interfere nce-caused-by-microwave-oven/?utm_source=itnewsletterutm_medium=emailutm_c ampaign=20150514 http://www.interferencetechnology.com/astronomers-discover-17-year-interfer ence-caused-by-microwave-oven/?utm_source=itnewsletteramp;utm_medium=email amp;utm_campaign=20150514 My question is this. If the RF generated inside the oven does not stop prior to the opening of the RF seal on the door, which testing is responsible to identify this problem, EMC or the Safety testing? Thanks, Doug Douglas E Powell http://www.linkedin.com/in/dougp01 - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher j.bac...@ieee.org David Heald dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
[PSES] Interference Caused by Microwave Oven
All, Today Interference Technology published on their website, Astronomers Discover 17-Year Interference Caused by Microwave Oven Link: http://www.interferencetechnology.com/astronomers-discover-17-year-interference-caused-by-microwave-oven/?utm_source=itnewsletterutm_medium=emailutm_campaign=20150514 My question is this. If the RF generated inside the oven does not stop prior to the opening of the RF seal on the door, which testing is responsible to identify this problem, EMC or the Safety testing? Thanks, Doug Douglas E Powell http://www.linkedin.com/in/dougp01 - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
On 5/14/2015 6:58 PM, Ken Javor wrote: why doesn’t the rf shut off when the door is opened? And a second one: why was it deemed worthy of publishing an article that a microwave oven interfered with data collection since 1988? It does, but probably not instantly. Just guessing, but ... A magnetron is a thermal diode that can continue to generate RF as long as there's enough emission, and enough voltage to move electrons past its cavity resonators. The door uses a choke joint to prevent RF from escaping, and as that's being opened, it can radiate. And it's newsworthy because people smart enough to run a radio telescope should be smart enough to run down something like this. IMO! Cortland Richmond KA5S (semi) retired from EMC engineering - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
Correct, microwave ovens have, in series, several safety interlock switching devices that control the HV transformer. But opening the door prior to the set time-out will not immediately de-energize the magnetron; that is, the delay is programmatic, not electro-mechanical. Brian -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Thursday, May 14, 2015 4:26 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven Newsworthy indeed, but hardly something to self-promote through publication! And I would think that the interlock would interrupt magnetron operation as soon as the latching mechanism was depressed, which is before the door actually even begins to open, so that the gasket should still be making the seal. Ken Javor Phone: (256) 650-5261 From: CR k...@earthlink.net Reply-To: k...@earthlink.net Date: Thu, 14 May 2015 19:21:42 -0400 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven On 5/14/2015 6:58 PM, Ken Javor wrote: why doesn¹t the rf shut off when the door is opened? And a second one: why was it deemed worthy of publishing an article that a microwave oven interfered with data collection since 1988? It does, but probably not instantly. Just guessing, but ... A magnetron is a thermal diode that can continue to generate RF as long as there's enough emission, and enough voltage to move electrons past its cavity resonators. The door uses a choke joint to prevent RF from escaping, and as that's being opened, it can radiate. And it's newsworthy because people smart enough to run a radio telescope should be smart enough to run down something like this. IMO! Cortland Richmond KA5S (semi) retired from EMC engineering - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] Interference Caused by Microwave Oven
Newsworthy indeed, but hardly something to self-promote through publication! And I would think that the interlock would interrupt magnetron operation as soon as the latching mechanism was depressed, which is before the door actually even begins to open, so that the gasket should still be making the seal. Ken Javor Phone: (256) 650-5261 From: CR k...@earthlink.net Reply-To: k...@earthlink.net Date: Thu, 14 May 2015 19:21:42 -0400 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Interference Caused by Microwave Oven On 5/14/2015 6:58 PM, Ken Javor wrote: why doesn¹t the rf shut off when the door is opened? And a second one: why was it deemed worthy of publishing an article that a microwave oven interfered with data collection since 1988? It does, but probably not instantly. Just guessing, but ... A magnetron is a thermal diode that can continue to generate RF as long as there's enough emission, and enough voltage to move electrons past its cavity resonators. The door uses a choke joint to prevent RF from escaping, and as that's being opened, it can radiate. And it's newsworthy because people smart enough to run a radio telescope should be smart enough to run down something like this. IMO! Cortland Richmond KA5S (semi) retired from EMC engineering - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com - 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 emc-p...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas sdoug...@ieee.org Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
