Re: Ce versus FCC
Obviously it is not the logic circuits I am refering to! The front end of the power supply has many types of scenarios that can cause high (30 MHz) frequency emissions. To name a few. Switcher pulse risetime and fall-off. As semiconductors get better adn smaller, their ft also better (to other tham EMC folks!), Rectifier diode turn-on time (same story, better, cheaper, faster), resonant circuits (unintentional ones), resonant heatsinks (yes, I've had this one) and more. Granted, they are not common everyday occurances, but they occur. Hans
Re: Ce versus FCC
In a message dated 98-07-06 20:40:33 EDT, rbus...@es.com writes: A test house explained to me that the FCC allows either CISPR or FCC limits/procedures providing that one can determine worst case. Consequently, you have to test both ways (120 V 60Hz or 230V 50Hz) to determine which way you should have tested. So, where are the time/money savings? RIck, I think it's good practice to explore your product somewhat before you go for compliance testing. It helps determine just what you need to quantify in the test lab, and what can be ignored. I have not yet met with problems going this route with any agency folks, in fact I would expect them to endorse it. Our lab makes its living helping folks make these decisions before they go to a DLS, Elite, UL etc where the charges are much higher, but the labs are certified. Derek Walton Owner L F Research EMC Design and Test Facility
RE: Ce versus FCC
Typically, the range switch on the cost-sensitive (cheap) power supplies changes the front-end topology from conventional capacitor input to a voltage -doubled one. Since the power load stays the same, the current will double. But the nature of the input current to these supplies is gulps of current rather than sinusoidal draw. At the higher voltage the conduction angle of the current pulse gets very narrow so the current spike grows even more in magnitude. This can take the cores into saturation and lead to low frequency (25-100 kHz) conducted emissions problems. The effect is related more to voltage than frequency. The logic-created frequencies are not afffected by the AC input voltage or frequency. -- From: Gary McInturff[SMTP:gmcintu...@packetengines.com] Reply To: Gary McInturff Sent: Monday, July 06, 1998 6:30 PM To: hmellb...@aol.com; dwight.hunnic...@vina-tech.com; emc-p...@ieee.org Cc: eric.lif...@natinst.com Subject: RE: Ce versus FCC That's interesting. The change from 50 to 60 Hz would change some input components and that could effect the input impedance and hence the conducted emissions signature but the voltage, especially if its a well regulated and filtered supply should be invisible. The components that radiate at that point are all of the secondary 5 or 3.3 volt oscillators and stuff. They shouldn't even know the difference in the input voltage. If using a switcher power supply it seems even more odd. The input voltage is rectified and then chopped to #$@ then more regulating and filtering stuff happens. Then it hits the electronics. Anybody else see this and have an idea why it might. I may be living in a fools paradise here. Gary McInturff Packet Engines -Original Message- From: hmellb...@aol.com [SMTP:hmellb...@aol.com] Sent: Monday, July 06, 1998 11:16 AM To: dwight.hunnic...@vina-tech.com; emc-p...@ieee.org Cc: eric.lif...@natinst.com Subject:Re: Ce versus FCC I have encountered certain European agencies requesting that not only are the conducted emissions required to be performed at 230V 50Hz but radiated emissions as well. I agree that for conducted emissions it may make a difference but I have not seen radiated emissions change when the power source is changed from 60 to 50 Hz (while keeping Voltage the same). I did, however, see recently a product change emissions when the voltage was changed from 120 to 230 V. And, it did not matter if it was 50 or 60 Hz, only the voltage was significant. Go figure! Hans
RE: Ce versus FCC
Your comment below is absolutely true. Manufacturers spend far too much time and money obtaining certifications for so many countries that have just minor differences in their standards. One standard for EMC/product safety is too simple I guess. Darrell -- From: owner-emc-p...@majordomo.ieee.org To: emc-p...@ieee.org Cc: rbus...@es.com Subject: Ce versus FCC List-Post: emc-pstc@listserv.ieee.org Date: Monday, July 06, 1998 1:10PM A test house explained to me that the FCC allows either CISPR or FCC limits/procedures providing that one can determine worst case. Consequently, you have to test both ways (120 V 60Hz or 230V 50Hz) to determine which way you should have tested. So, where are the time/money savings? As a personal note, it seems to me that there will always be slight differences whether it be, test sites, cables, input power, placement, whatever. The objective should be to reduce levels to reasonable, repeatable limits. Defining an acceptable standard or test procedure should be adequate. We should not have to incur unnecessary testing just to address a few dB one way or the other. Rick
SV: Ce versus FCC
A fools paradise or not I don't know but to say that it is only secondary
circuits that radiates is not true. I have several switch mode power
supplies which have radiated emission up to 150MHz. Especially from 40 -
100MHz I often see problems. This emission is normally very sensitive to
the power consumption/input current. But you are right a step from 115 to
230 V don't make that big different but a change from 200 to 240 can. As
I see it, it is the current flow arround switch transistor - bridge -
transformer which are the main problems. Transistor and transformer is
normally not affected by 115/230 but what about the first bridge ? here
the current will change by a factor 2 ! or am I wrong ?
Best regards,
Mr. Kim Boll Jensen
ScanView, Denmark
--
Fra: gmcintu...@packetengines.com[SMTP:MIME @INTERNET
{gmcintu...@packetengines.com}]
Sendt: 7. juli 1998 04:05
Til: hmellb...@aol.com; dwight.hunnic...@vina-tech.com;
emc-p...@ieee.org
Cc: eric.lif...@natinst.com
Emne: RE: Ce versus FCC
--
--
That's interesting. The change from 50 to 60 Hz would change some input
components and that could effect the input impedance and hence the
conducted emissions signature but the voltage, especially if its a well
regulated and filtered supply should be invisible. The components that
radiate at that point are all of the secondary 5 or 3.3 volt oscillators
and stuff. They shouldn't even know the difference in the input voltage.
If using a switcher power supply it seems even more odd. The input
voltage is rectified and then chopped to #$@ then more regulating and
filtering stuff happens. Then it hits the electronics.
Anybody else see this and have an idea why it might. I may be living in
a fools paradise here.
Gary McInturff
Packet Engines
-Original Message-
From: hmellb...@aol.com [SMTP:hmellb...@aol.com]
Sent: Monday, July 06, 1998 11:16 AM
To: dwight.hunnic...@vina-tech.com; emc-p...@ieee.org
Cc: eric.lif...@natinst.com
Subject: Re: Ce versus FCC
I have encountered certain European agencies requesting that not
only are the
conducted emissions required to be performed at 230V 50Hz but
radiated
emissions as well. I agree that for conducted emissions it may
make a
difference but I have not seen radiated emissions change when
the power source
is changed from 60 to 50 Hz (while keeping Voltage the same). I
did, however,
see recently a product change emissions when the voltage was
changed from 120
to 230 V. And, it did not matter if it was 50 or 60 Hz, only the
voltage was
significant. Go figure!
Hans
Fil: ENVELOPE.TXT
Re: Ce versus FCC
good point, Gary. Only the front end of the switcher would see the different input voltage and frequency. The high-speed oscillators on the motherboards, etc., should not be affected by input voltage/frequency, yes? Dwight Gary McInturff wrote: That's interesting. The change from 50 to 60 Hz would change some input components and that could effect the input impedance and hence the conducted emissions signature but the voltage, especially if its a well regulated and filtered supply should be invisible. The components that radiate at that point are all of the secondary 5 or 3.3 volt oscillators and stuff. They shouldn't even know the difference in the input voltage. If using a switcher power supply it seems even more odd. The input voltage is rectified and then chopped to #$@ then more regulating and filtering stuff happens. Then it hits the electronics. Anybody else see this and have an idea why it might. I may be living in a fools paradise here. Gary McInturff Packet Engines -Original Message- From: hmellb...@aol.com [SMTP:hmellb...@aol.com] Sent: Monday, July 06, 1998 11:16 AM To: dwight.hunnic...@vina-tech.com; emc-p...@ieee.org Cc: eric.lif...@natinst.com Subject:Re: Ce versus FCC I have encountered certain European agencies requesting that not only are the conducted emissions required to be performed at 230V 50Hz but radiated emissions as well. I agree that for conducted emissions it may make a difference but I have not seen radiated emissions change when the power source is changed from 60 to 50 Hz (while keeping Voltage the same). I did, however, see recently a product change emissions when the voltage was changed from 120 to 230 V. And, it did not matter if it was 50 or 60 Hz, only the voltage was significant. Go figure! Hans -- DWIGHT HUNNICUTT Sr. Compliance Engineer * dwi...@vina-tech.com * * (510) 413-1349 direct * * (510) 492-0808 fax * * VINA Technologies,Inc. * * 42709 Lawrence Place* * Fremont, CA 94538 *
RE: Ce versus FCC
That's interesting. The change from 50 to 60 Hz would change some input components and that could effect the input impedance and hence the conducted emissions signature but the voltage, especially if its a well regulated and filtered supply should be invisible. The components that radiate at that point are all of the secondary 5 or 3.3 volt oscillators and stuff. They shouldn't even know the difference in the input voltage. If using a switcher power supply it seems even more odd. The input voltage is rectified and then chopped to #$@ then more regulating and filtering stuff happens. Then it hits the electronics. Anybody else see this and have an idea why it might. I may be living in a fools paradise here. Gary McInturff Packet Engines -Original Message- From: hmellb...@aol.com [SMTP:hmellb...@aol.com] Sent: Monday, July 06, 1998 11:16 AM To: dwight.hunnic...@vina-tech.com; emc-p...@ieee.org Cc: eric.lif...@natinst.com Subject:Re: Ce versus FCC I have encountered certain European agencies requesting that not only are the conducted emissions required to be performed at 230V 50Hz but radiated emissions as well. I agree that for conducted emissions it may make a difference but I have not seen radiated emissions change when the power source is changed from 60 to 50 Hz (while keeping Voltage the same). I did, however, see recently a product change emissions when the voltage was changed from 120 to 230 V. And, it did not matter if it was 50 or 60 Hz, only the voltage was significant. Go figure! Hans
Re: Ce versus FCC
Dwight, While pursuing a TCF route, this was discussed at length with our CB. The frequency was of secondary concern to the line voltage. We tested with both frequencies anyway because we can: it made no discernable difference to our emission or immunity data.. Best regards, Derek Walton Owner: L F Research EMC Design and Test Facility
Re: CE versus FCC
Thanks, Derek These are all good examples of problems everyone can relate to. A good domestic one from a colleague of mine recently was that when he walked near a bathroom in his house while carrying his (FCC Class B) laptop computer switched on (- he is a workaholic), and if someone was bathing using their power-shower, his computer would turn the shower off. If you find the time to write some more downI'd be pleased to have them. Can I use your name if I write about your examples? Best regards Keith Armstrong lfresea...@aol.com wrote: Keith, with over 18 years in EMC I could go on a long time. Some examples this year already... My computer ( FCC Class B ) interferes with my cordless phones, to some degree on all 10 channels. My FAX machine ( FCC Class B ) interferes with my TV and some channels of my cordless phones. Garbage disposal interacted with everything! Doesn't now. Car ignition lead was replaced with non-suppressed type. Technician didn't know the difference. Small personal fan distroys my monitor picture... etc., etc., etc. Best regards, Derek.
Re: Ce versus FCC
Radiated Emissions do not appear to be impacted with respect to 50 Hz -vs- 60 Hz; however, Conducted Emissions may be impacted. All EMC testing should be conducted at the appropriate voltage and frequency. -Original Message- From: Dwight Hunnicutt dwight.hunnic...@vina-tech.com To: EMC PSTC emc-p...@ieee.org Cc: eric.lif...@natinst.com eric.lif...@natinst.com List-Post: emc-pstc@listserv.ieee.org Date: Monday, July 06, 1998 4:45 PM Subject: Re: Ce versus FCC Eric- You tossed in one line that brings up a parallel question for Europe: Note that the FCC expects conducted emissions to be measured at 115 VAC, 60 Hz. Has your experience indicated that all Euro EMC directive (emissions/immunity) testing be conducted at 50Hz? Many local EMC labs do not have 50Hz readily available... Has anyone run into a problem with a European customer or agency insisting on 50Hz? -- DWIGHT HUNNICUTT Sr. Compliance Engineer * dwi...@vina-tech.com * * (510) 413-1349 direct * * (510) 492-0808 fax * * VINA Technologies,Inc. * * 42709 Lawrence Place* * Fremont, CA 94538 *
Ce versus FCC
A test house explained to me that the FCC allows either CISPR or FCC limits/procedures providing that one can determine worst case. Consequently, you have to test both ways (120 V 60Hz or 230V 50Hz) to determine which way you should have tested. So, where are the time/money savings? As a personal note, it seems to me that there will always be slight differences whether it be, test sites, cables, input power, placement, whatever. The objective should be to reduce levels to reasonable, repeatable limits. Defining an acceptable standard or test procedure should be adequate. We should not have to incur unnecessary testing just to address a few dB one way or the other. Rick -Original Message- From: hmellb...@aol.com [SMTP:hmellb...@aol.com] Sent: Monday, July 06, 1998 12:16 PM To: dwight.hunnic...@vina-tech.com; emc-p...@ieee.org Cc: eric.lif...@natinst.com Subject:Re: Ce versus FCC I have encountered certain European agencies requesting that not only are the conducted emissions required to be performed at 230V 50Hz but radiated emissions as well. I agree that for conducted emissions it may make a difference but I have not seen radiated emissions change when the power source is changed from 60 to 50 Hz (while keeping Voltage the same). I did, however, see recently a product change emissions when the voltage was changed from 120 to 230 V. And, it did not matter if it was 50 or 60 Hz, only the voltage was significant. Go figure! Hans
Re: Ce versus FCC
I have encountered certain European agencies requesting that not only are the conducted emissions required to be performed at 230V 50Hz but radiated emissions as well. I agree that for conducted emissions it may make a difference but I have not seen radiated emissions change when the power source is changed from 60 to 50 Hz (while keeping Voltage the same). I did, however, see recently a product change emissions when the voltage was changed from 120 to 230 V. And, it did not matter if it was 50 or 60 Hz, only the voltage was significant. Go figure! Hans
Re: Ce versus FCC
Eric- You tossed in one line that brings up a parallel question for Europe: Note that the FCC expects conducted emissions to be measured at 115 VAC, 60 Hz. Has your experience indicated that all Euro EMC directive (emissions/immunity) testing be conducted at 50Hz? Many local EMC labs do not have 50Hz readily available... Has anyone run into a problem with a European customer or agency insisting on 50Hz? -- DWIGHT HUNNICUTT Sr. Compliance Engineer * dwi...@vina-tech.com * * (510) 413-1349 direct * * (510) 492-0808 fax * * VINA Technologies,Inc. * * 42709 Lawrence Place* * Fremont, CA 94538 *
Re: CE versus FCC
Keith, with over 18 years in EMC I could go on a long time. Some examples this year already... My computer ( FCC Class B ) interferes with my cordless phones, to some degree on all 10 channels. My FAX machine ( FCC Class B ) interferes with my TV and some channels of my cordless phones. Garbage disposal interacted with everything! Doesn't now. Car ignition lead was replaced with non-suppressed type. Technician didn't know the difference. Small personal fan distroys my monitor picture... etc., etc., etc. Best regards, Derek.
Re: CE versus FCC
Dear Derek and Brian If you (or anyone else) have any examples of things that didn't work well together for reasons of lack of adequate EMC I'd be pleased to have some details of them. Also of things that didn't work well because of their electromagnetic environment. E.g just recently I heard two examples where overhead travelling cranes in heavy engineering factories started moving due to interference. One was a radio controlled crane influenced by a new spindle controller drive on a CNC machine in the factory, the second was not radio controlled but although its controller used no software it was set moving by a (supposed) mains transient. I'm usually told by equipment manufacturers that their installers and users never experience any problems with interference, so (they claim) design and testing for immunity is a waste of money. But when I talk to users (especially people who construct more complex electronic systems) it seems that they always have interference problems, which usually get fixed by trial and error leading to a greater cost and lower reliability for the user than if the interference had been fixed by good design and immunity testing in the first instance. Computer networking is a field in which a lot of trial and error seems to occur to make them work adequately, and computer downtime is known to lose economies like the US several hundreds of millions, if not billions, of dollars annually (I've got the survey results somewhere). I wonder how much of this is down to a lack of adequate EMC? I may want to make some details public, so make sure to suppress manufacturers' names unless the information is already public domain. References to publications in which any examples were reported would be welcome too. Also please let me know whether you are happy to have your name, or your company's name, associated with the examples if/when I do publish them (I'll automatically leave your name off - unless you specifically say you are happy for me to use it, in which case I'll be pleased to say who provided the information.) I am up to date with all the interference incidents reported in Compliance Engineering Magazine since 1992, including all the medical equipment stuff that can out after Silberberg's first articles on interference in healthcare premises - so please don't repeat that info. For EMC examples that I have had published so far, refer to the EMC Journal's Banana Skins section, that they began in their February 98 issue (www.emc-journal.co.uk). Thanks in advance for all information, references, and anecdotes! Keith Armstrong Partner, Cherry Clough Consultants Cherry Clough House Rochdale Road, Denshaw, OL3 5UE, UK phone: +44 1457 871 605 fax: +44 1457 820 145 Email: karmstr...@iee.org lfresea...@aol.com wrote: Brian, here is the US the manufacturer has is easy... But many things we buy don't work well together! Derek.
Re: CE versus FCC
Brian, here is the US the manufacturer has is easy... But many things we buy don't work well together! Derek.
CE versus FCC
Grateful thanks to all who responded to my query reference the above. I recieved 39 replies which I am now working my way through. The basic message seems to be you guys in the US have it easy as the FCC do not require Immunity testing. Many Thanks Brian Harlowe * opinions expressed here are personal and in no way reflect the position of VG Scientific
Re: Ce versus FCC
Eric Top answer! Regards John Harrington EMC Group Manager, KTL Telephone : +44 (0) 1482 801801 Fax : +44 (0) 1482 801806 email : jharring...@ktl.co.uk
RE: Ce versus FCC
To All, For the latest proposal from the FCC on conducted emissions, look at this WEB site: http://www.fcc.gov/oet/dockets/et98-80/ Paul Rostek EMC / Safety Compliance Engineer NCR Corp. San Diego -- From: eric.lif...@natinst.com[SMTP:eric.lif...@natinst.com] Reply To: eric.lif...@natinst.com Sent: Thursday, July 02, 1998 1:08 PM To: Brian Harlowe Cc: emc-p...@ieee.org Subject: Re: Ce versus FCC The FCC has the authority to mandate immunity for Part-15 devices, but has declined to do so. The exception is for consumer telephones and other telephone equipment under FCC Part-68 rules. But in general, noise immunity is practically unregulated in the USA. The FCC expects industry to handle immunity problems (either by design or by technical support) and wants the consumer to understand that immunity problems are not a matter for FCC involvement. For example, here is the Class A (and old Class B) warning label required under Part-15 section 15.19: This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Only noise emission is regulated under Part-15. You may use CISPR-22 emission limits with ANSI C63.4 test procedures. Note that the FCC expects conducted emissions to be measured at 115 VAC, 60 Hz. Since the FCC is changing their procedures every other month or so, you should check their web page for current information (and download the rules - officially known as 47 CFR Part 15 and Part 2) at: http://www.fcc.gov Regards, Eric Lifsey Compliance Engineer/Manager National Instruments Brian Harlowe bharl...@vgscientific.com on 07/02/98 11:49:41 AM Please respond to Brian Harlowe bharl...@vgscientific.com To: emc-p...@ieee.org cc:(bcc: Eric Lifsey/AUS/NIC) Subject: Ce versus FCC Can someone out there tell a poor Englishman the basic differences between the requirements of the FCC rules and the requirements to comply with the EEC emc directive. i.e. Do you have to do immunity testing and ESD tests to comply with the FCC rules that sort of thing. Brian Harlowe * opinions expressed here are personal and in no way reflect the position of VG Scientific
RE: Ce versus FCC
Hard to do in simple words but: FCC -- many emissions requirements for digital products; lightning immunity requirements for telecom (part 68). EEC EMC Directive -- both emissions an immunity requirements; specifics depend on the product. Suggest you look at a couple of these web pages to get started : http://www.cix.co.uk/~approval/emcstan.htm http://world.std.com/~techbook/seec1_5.htm http://www.ce-mag.com/ -Original Message- From: Brian Harlowe [SMTP:bharl...@vgscientific.com] Sent: Thursday, July 02, 1998 12:50 PM To: emc-p...@ieee.org Subject: Ce versus FCC Can someone out there tell a poor Englishman the basic differences between the requirements of the FCC rules and the requirements to comply with the EEC emc directive. i.e. Do you have to do immunity testing and ESD tests to comply with the FCC rules that sort of thing. Brian Harlowe * opinions expressed here are personal and in no way reflect the position of VG Scientific
Re: Ce versus FCC
Brian, Here's the differences in a small nutshell: FCC CE Radiated Emissions x x Conducted Emissions x x Immunity x There are differences in frequency and emission limits between FCC Part 15 and EN55022 (or CISPR22). However, the FCC does allow testing to the limits of CISPR22 provided a couple of conditions are met. As far as immunity goes, EN50082-1 or 2 requires a mulititude of tests. Well, the nutshell has now become full. This has been a very simple description of the differences with virtually no details. To become more aware of the requirements of each in more detail, a seminar might be in order for you. There are a number of organizations that provide this service on different levels. I hope this helps. Best regards, Ron Pickard ron_pick...@hypercom.com __ Reply Separator _ Subject: Ce versus FCC Author: Brian Harlowe bharl...@vgscientific.com at INTERNET List-Post: emc-pstc@listserv.ieee.org Date:7/2/98 4:49 PM Can someone out there tell a poor Englishman the basic differences between the requirements of the FCC rules and the requirements to comply with the EEC emc directive. i.e. Do you have to do immunity testing and ESD tests to comply with the FCC rules that sort of thing. Brian Harlowe * opinions expressed here are personal and in no way reflect the position of VG ientific
RE: Ce versus FCC
Sorry, George, I beg to differ and to offer my two bits: 47CFR (Oct. 1, 1997) Para. 15.5 (b) states: Operation of an intentional, unintentional, or incidental radiator is subject to the conditions that no harmful interference is caused and that INTERFERENCE MUST BE ACCEPTED that may be caused by the operation of an authorized radio station, by another intentional or unintentional radiator, by industrial, scientific and medical (ISM) equipment, or by an incidental radiator. Yes, it does not call out ESD interference but neglecting to improve ESD-immunity of your equipment will at least result in nasty letters from customers. I think we should stop splitting legalistic hairs when reality has long ago surpassed the letter of regulations. Finally, 47CFR Para. 15 accepts results per CISPR22, but you can not pick and choose - once you test radiated emissions per CISPR, then you have to use CISPR for conducted emissions as well. Bogdan M. Matoga bogdan.mat...@fibre.com -Original Message- From: geor...@lexmark.com [SMTP:geor...@lexmark.com] Sent: Thursday, July 02, 1998 10:34 AM To: emc-p...@majordomo.ieee.org Subject:Ce versus FCC There are no immunity requirements for FCC, ESD or otherwise. The FCC radiated and conducted EMI limits differ a bit from the European CISPR 22 based limits, but I believe the FCC now accepts either limits. The EMC Directive specifies no particular standard, but one should either use the harmonized standards for EMI and EMS, or will need to use a Technical Construction File to show that no intereference will result. George Alspaugh Lexmark International -- Forwarded by George Alspaugh/Lex/Lexmark on 07/02/98 01:31 PM --- Brian Harlowe bharlowe%vgscientific@interlock.lexmark.com on 07/02/98 12:49:41 PM Please respond to Brian Harlowe bharlowe%vgscientific@interlock.lexmark.com To: emc-pstc%ieee@interlock.lexmark.com cc:(bcc: George Alspaugh/Lex/Lexmark) bcc: George Alspaugh/Lex/Lexmark Subject: Ce versus FCC Can someone out there tell a poor Englishman the basic differences between the requirements of the FCC rules and the requirements to comply with the EEC emc directive. i.e. Do you have to do immunity testing and ESD tests to comply with the FCC rules that sort of thing. Brian Harlowe * opinions expressed here are personal and in no way reflect the position of VG Scientific
Re: Ce versus FCC
The FCC has the authority to mandate immunity for Part-15 devices, but has declined to do so. The exception is for consumer telephones and other telephone equipment under FCC Part-68 rules. But in general, noise immunity is practically unregulated in the USA. The FCC expects industry to handle immunity problems (either by design or by technical support) and wants the consumer to understand that immunity problems are not a matter for FCC involvement. For example, here is the Class A (and old Class B) warning label required under Part-15 section 15.19: This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Only noise emission is regulated under Part-15. You may use CISPR-22 emission limits with ANSI C63.4 test procedures. Note that the FCC expects conducted emissions to be measured at 115 VAC, 60 Hz. Since the FCC is changing their procedures every other month or so, you should check their web page for current information (and download the rules - officially known as 47 CFR Part 15 and Part 2) at: http://www.fcc.gov Regards, Eric Lifsey Compliance Engineer/Manager National Instruments Brian Harlowe bharl...@vgscientific.com on 07/02/98 11:49:41 AM Please respond to Brian Harlowe bharl...@vgscientific.com To: emc-p...@ieee.org cc:(bcc: Eric Lifsey/AUS/NIC) Subject: Ce versus FCC Can someone out there tell a poor Englishman the basic differences between the requirements of the FCC rules and the requirements to comply with the EEC emc directive. i.e. Do you have to do immunity testing and ESD tests to comply with the FCC rules that sort of thing. Brian Harlowe * opinions expressed here are personal and in no way reflect the position of VG Scientific
Ce versus FCC
There are no immunity requirements for FCC, ESD or otherwise. The FCC radiated and conducted EMI limits differ a bit from the European CISPR 22 based limits, but I believe the FCC now accepts either limits. The EMC Directive specifies no particular standard, but one should either use the harmonized standards for EMI and EMS, or will need to use a Technical Construction File to show that no intereference will result. George Alspaugh Lexmark International -- Forwarded by George Alspaugh/Lex/Lexmark on 07/02/98 01:31 PM --- Brian Harlowe bharlowe%vgscientific@interlock.lexmark.com on 07/02/98 12:49:41 PM Please respond to Brian Harlowe bharlowe%vgscientific@interlock.lexmark.com To: emc-pstc%ieee@interlock.lexmark.com cc:(bcc: George Alspaugh/Lex/Lexmark) bcc: George Alspaugh/Lex/Lexmark Subject: Ce versus FCC Can someone out there tell a poor Englishman the basic differences between the requirements of the FCC rules and the requirements to comply with the EEC emc directive. i.e. Do you have to do immunity testing and ESD tests to comply with the FCC rules that sort of thing. Brian Harlowe * opinions expressed here are personal and in no way reflect the position of VG Scientific
Ce versus FCC
Can someone out there tell a poor Englishman the basic differences between the requirements of the FCC rules and the requirements to comply with the EEC emc directive. i.e. Do you have to do immunity testing and ESD tests to comply with the FCC rules that sort of thing. Brian Harlowe * opinions expressed here are personal and in no way reflect the position of VG Scientific
