RE: EN 61000-3-3 compliant heater controller
So rather than educating the public on the cause of flicker, we get saddled with a useless design requirement. Typical bureaucracy - don't fix the problem, make it LOOK like you're doing something, at someone else's expense. Just like the harmonics standard - fix a problem that doesn't exist. Ghery Pettit Opinions expressed are my own and may not necessarily reflect those of my employer... -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Monday, January 21, 2002 2:28 PM To: emc-p...@majordomo.ieee.org Subject: Re: EN 61000-3-3 compliant heater controller I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote (in 20020121193650.LDSV11289.femail7.sdc1.sfba.home.com@[65.11.150.27] ) about 'EN 61000-3-3 compliant heater controller', on Mon, 21 Jan 2002: I have some questions which are just for my own education. I understand Mr. Woodgate's comments and they make sense to me. But I wonder why there is a problem in the first place. I assumed that the lack of compliance was certain, because I have no up- front evidence to sustain a doubt. I believe all power in Europe is at 200 Volts or higher, which makes an 800 Watt heater a four Amp device. I don't believe inrush on a heater is greatly in excess of steady-state current, Suppose, just as an example, it's an 800 W IR lamp, used as a heater? therefore the mechanism is switching a four Amp load on and off every few minutes. Why is this a problem requiring specification control in the first place? Because lamp flicker is a disturbance that worries people and they often complain to the electricity suppliers. Some elderly people get very worried about the supply breaking down or causing a fire. The reference single-phase supply impedance used for IEC/EN61000-3-3 is 0.47 ohms (actually 0.4 + j0.25 ohms). So switching a 4 A load causes a dmax (maximum relative voltage drop, based on 230 V) of 0.8%. That is not likely to result in a Pst or Plt failure to comply, so there IS something we don't know - maybe a high inrush current or a faulty measurement. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Pacemaker
cecil.gitt...@kodak.com 18-Jan-02 1:20:16 PM From: Cecil A. Gittens If someone has a pacemaker and wants to use a APS Camera with an internal clock 8MHz on the main CPU circuit board. My question is it safe for that person to use the APS Camera Reply: APS camera is a traditional 35mm system camera. APS is a magnetic code stripe on the film which records exposure data for use by the color paper printing machine. It has the added benefit of drop in loading. There may be a clock in the autofocus mechanism but the camera is not a digital camera, it does not generate an image file, so why the 8MHz clock? Or was this a trick question from Kodak? --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EN 61000-3-3 compliant heater controller
I read in !emc-pstc that Ken Javor ken.ja...@emccompliance.com wrote (in 20020121193650.LDSV11289.femail7.sdc1.sfba.home.com@[65.11.150.27] ) about 'EN 61000-3-3 compliant heater controller', on Mon, 21 Jan 2002: I have some questions which are just for my own education. I understand Mr. Woodgate's comments and they make sense to me. But I wonder why there is a problem in the first place. I assumed that the lack of compliance was certain, because I have no up- front evidence to sustain a doubt. I believe all power in Europe is at 200 Volts or higher, which makes an 800 Watt heater a four Amp device. I don't believe inrush on a heater is greatly in excess of steady-state current, Suppose, just as an example, it's an 800 W IR lamp, used as a heater? therefore the mechanism is switching a four Amp load on and off every few minutes. Why is this a problem requiring specification control in the first place? Because lamp flicker is a disturbance that worries people and they often complain to the electricity suppliers. Some elderly people get very worried about the supply breaking down or causing a fire. The reference single-phase supply impedance used for IEC/EN61000-3-3 is 0.47 ohms (actually 0.4 + j0.25 ohms). So switching a 4 A load causes a dmax (maximum relative voltage drop, based on 230 V) of 0.8%. That is not likely to result in a Pst or Plt failure to comply, so there IS something we don't know - maybe a high inrush current or a faulty measurement. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. PLEASE do NOT copy news posts to me by E-MAIL! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Zero Crossing Question
John, Or another example where different companies' equivalent parts are not equivalent-- this is one that I ran into in 1977. I had designed a Power-On-Reset (POR) circuit using a 555 timer, and had tested the circuit on a solderless breadboard. I was being sneaky in my design, and used the RESET, TRIGGER, and THRESHOLD inputs as three separate inputs to the 555. When we built the first tester the POR circuit didn't work. I then discovered that there were two flavors of 555 timers-- TI's and most companies 555's obeyed TRIGGER if(TRIGGER 1/3*VCC) AND (THRESHOLD 2/3*VCC). But the National Semiconductor LM555, which we used when we built the tester, obeyed THRESHOLD instead... Since this is an undefined input state for the 555, the chip designers did as they pleased. I have heard of many other cases where engineers have used components outside the published specifications, and gotten burned for their trouble. Bob Pease has written several Pease Porridge columns in Electronic Design about specmanship, and about how Design Engineers and Applications Engineers at chip manufacturers *try* to write honest datasheets over the objections of the marketeers. His best advice was: 1. If in doubt, try it out. 2. If an unspecified characteristic is important to you, contact the manufacturer and get them to guarantee it in writing. You may find yourself having to retest your design every time the chip manufacturer does a die shrink or moves the chip to a different process or plant. But you are much better off to find this out early, and have time to find a suitable alternative part or make a lifetime buy of the older (working) part than to suddenly have 100% of your products fail in production. John Barnes Advisory Engineer Lexmark International (soon to be Chief Engineer, dBi Corporation) --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
SV: Company close down due to EMC phenomena
To all of you who responded, here is the latest info. I have picked up the following: 1. 15000 units have been placed on the marked and 2 complains have been reported to the Telecommunications Authorities. They could not produce any evidence that the PLC made the problems, but they were unfortunately installed close by the victim. The victim might have had poor immunity . who knows 2. The conducted emission is far above the limits (50-60dB) in the transmission band so it do not fulfil EN55022 or any other emission standard. 3. Finally, the telecommunications Authorities will do a more thorough investigation next time a problem/complain pops up. So, from this it seems that they are not closing down yet .. I agree 100% about your statements that you have to be aware the technical regulations before you start up any type of electrical/electronic business. I do not know these PLC folks, but they might have followed this doctrine If it is allowed in US, then it must be allowed in EU ... ... in good faith Amund -Opprinnelig melding- Fra: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]På vegne av am...@westin-emission.no Sendt: 16. januar 2002 21:17 Til: emc-p...@majordomo.ieee.org Emne: Company close down due to EMC phenomena Well, this might be the reality in a case I have been introduced to lately. Case: A company are manufacturing PowerLine Communication products. They communicate via the power lines and a typical link is between a consumer residence and the nearest power station. The products can of course also communicate inside the consumers residence. The communication protocol is called CEBus http://www.cebus.org/which and make use of the frequency band 100kHz-400kHz and the amplitude is approximate 2-5V. A typical length of a transmission is 25ms and occurs approximate one time pr hour. First of all, AFAIK PowerLine Communication and PowerLine Transmission (broadband 1.6MHz-30MHz) are now coming will full force in EU and CENELEC/ETSI are working together regulate this type of transmission path and also coming up with standards. The problem for the manufacturer is the conducted emission requirements in EU. According to the EN55022B levels the maximum quasi-peak emission is 66dBuV@150kHz, and a typical PLC (under transmission) which has been measured, showed the value of 120dBuV (peak). With no transmission it had a margin of 10dB (quasi-peak) and 30dB (average). The radiated emission had a margin of 10dB. Well, conducted emission is the problem when transmitting. But, as I said, the transmission occurs only 25ms/hour. The national authority will not allowed this product to be placed into the marked because it do not fulfil the EN55022B limits (100kHz-400kHz) under transmission mode. No way. Other national authorities have other approaches on this case, they say as long as you do not disturb other equipment, install it. If you do disturb, we will come and remove it. They also say install it even if it does not fulfil EN550022B, but we will remove it if it disturb others. Two completely different approaches as you see. Questions: 1. Is it possible to have different approaches within EU ? 2. Since PLC/PLT is quite new technology and since we do not have any EU product standard (no standard for whose who are using 100kHz-400kHz band), I like the approach as long as you do not disturb other equipment, install it. If you do disturb, we will come and remove it. What is your opinion about this? 3. The transmission occurs very seldom. 25ms/hour, that is 7e-6 and approximate 0,001% transmission rate. Can this seldom transmission rate be an argument to not test the PLC product under continuous transmission ? I would say yes, but which rate is acceptable / reasonable ? So, why should the company close down ? Because if the national authority gets what they want, there will be one sale. Logical, but is it a correct prohibition the authority call? Best regards Amund Westin, Oslo/Norway --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site
Re: EN 61000-3-3 compliant heater controller
I have some questions which are just for my own education. I understand Mr. Woodgate's comments and they make sense to me. But I wonder why there is a problem in the first place. I believe all power in Europe is at 200 Volts or higher, which makes an 800 Watt heater a four Amp device. I don't believe inrush on a heater is greatly in excess of steady-state current, therefore the mechanism is switching a four Amp load on and off every few minutes. Why is this a problem requiring specification control in the first place? -- From: Leszek Langiewicz leszek_langiew...@phogenix.com To: emc-p...@majordomo.ieee.org Subject: EN 61000-3-3 compliant heater controller Date: Mon, Jan 21, 2002, 12:01 PM Dear list-members, Would anybody know of the shelf controller design to meet EN61000-3-3 for 500W heater. Thanks in advance for your support. Best Regards, Leszek M. Langiewicz Homologation / Power Distribution Phogenix Imaging, LLC A joint venture of Kodak and HP Phogenix Imaging LLC 16275 Technology Dr. San Diego, CA 92127-1815 www.phogenix.com Phone: (858) 798-8004 Cell: (858) 722-8004 Fax: (858) 798-8113 E-mail: leszek_langiew...@phogenix.com -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Sunday, January 20, 2002 6:30 AM To: emc-p...@majordomo.ieee.org Subject: Re: Corrective Actions for EN 61000-3-3 Plt; Pst Failures I read in !emc-pstc that IEEE-EMC User Group ieee-...@itl.co.il wrote (in 2D1037012914D4118DB8204C4F4F5020275AB4@ITLLTD01) about 'Corrective Actions for EN 61000-3-3 Plt; Pst Failures', on Sun, 20 Jan 2002: A product (800W input power) having a heating element that is controlled by ON/OFF action (1-2 sec. interval) of a thermostat failed the subject requirements due to large input current variation resulting from the above action. It's unusual to have such a powerful heater in a product with such a low thermal inertia that the thermostat cycle is as short as 1 to 2 s. What will be a practical corrective action in this case? To answer properly, more details about the product would be required. It might be possible to split the heating element into two parts, not necessarily of equal powers, and to have one permanently on (apart from an over-temperature cut-out) while the other one is switched in and out by the thermostat. The cycle time should then become much longer, and the 'dmax' value is reduced. Another solution is to use the electronic control method known as 'burst firing', in which the thermostat switches on a control circuit that sends trains of complete cycles of the supply current to the heater. With different designs, the switching of the load is either very fast (e.g. 5-cycle bursts of current, lasting 100 ms on 50 Hz mains) or very slow. In either case, the Pst value is low. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators:
RE: Zero Crossing Question
Hi Folks Could this ON Semiconductors problem be something to do with: a) The fact that the neutral is generally not at ground potential, but has floated up due the current flowing in it? or b) The actual PSU has a filtering arrangement that is non-symmetrical wrt true ground? (Often evidenced by the leakage current differing when Line and Neutral are reversed) John Allen -Original Message- From: Bouse, John [mailto:john.bo...@perkinelmer.com] Sent: 21 January 2002 14:20 To: emc-p...@majordomo.ieee.org Subject: Zero Crossing Question Hi Group, Our manufacturing personnel encountered a strange problem: when the mains plug used on a 230V/50Hz equipment that has an internal zero crossing reference integrated circuit (specifically, a CA3059) is reversed (this can occur in countries such as Germany, Italy, France and Switzerland), the zero crossing pulses appear with a 20 millisecond spacing, rather than the expected 10 millisecond spacing. Harris or Intersil IC's work properly regardless of the mains polarity. ON Semiconductor IC's appear to be polarity sensitive. They will produce the proper number of pulses with only one mains polarity. The incorrect spacing of these zero crossing pulses affects the normal operation of the equipment. Has anyone encountered and, hopefully, solved this problem? Regards, John Bouse PKI --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Zero Crossing Question
Zero Crossing QuestionJohn, I think you already have the answer to the problem. You stated that Harris or Intersil IC's work properly regardless of the mains polarity. Some years back I had an issue where another manufacturer's replacement was substituted for a Sprague ULN2003 Darlington Array that I had specified in a design. I was using the ULN2003 to buffer a reset pulse distributed in a system. The other brand was not capable of switching quickly enough in this application. Replacing the ICs with the specified part solved the problem. I would not waste valuable engineering time resolving an issue that only occurs with one vendor's part. Just one man's opinion, Scott Lacey Simplicate, don't complicate! -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Bouse, John Sent: Monday, January 21, 2002 9:20 AM To: emc-p...@majordomo.ieee.org Subject: Zero Crossing Question Hi Group, Our manufacturing personnel encountered a strange problem: when the mains plug used on a 230V/50Hz equipment that has an internal zero crossing reference integrated circuit (specifically, a CA3059) is reversed (this can occur in countries such as Germany, Italy, France and Switzerland), the zero crossing pulses appear with a 20 millisecond spacing, rather than the expected 10 millisecond spacing. Harris or Intersil IC's work properly regardless of the mains polarity. ON Semiconductor IC's appear to be polarity sensitive. They will produce the proper number of pulses with only one mains polarity. The incorrect spacing of these zero crossing pulses affects the normal operation of the equipment. Has anyone encountered and, hopefully, solved this problem? Regards, John Bouse PKI
RE: pacemakers
It is well known in the medical device community that the immunity standards for implanted medical devices and the emissions standards for electrical devices are not compatible. Pacemakers have an operations mode that is used when excessive noise is detected. That mode goes by several names including fixed rate pacing, noise mode and reversion. The FDA is well aware of the issue and finds that the reversion mode is safe. Nevertheless, in some noise cases the PM may not properly detect the noise situation and operation may become affected including loss of a pacing pulse or an extra pulse may be generated. In the case of rate adaptive PMs, the pulse rate may increase. In some cases, the patient may become aware of the affected operation and find the effect to be undesirable. This is why the patient manual warns to avoid many types of field sources or specifies how the patient should not linger near other types of sources. Again, the FDA is well aware of the noise issue but has concluded that the PM design is acceptable when accompanied by the user warnings. No patient should be overly concerned, but should discuss the situation with their doctor in consultation with the medical device manufacturer. In all cases, they should follow the advice of their doctor. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: geor...@lexmark.com [mailto:geor...@lexmark.com] Sent: Friday, January 18, 2002 4:26 PM To: emc-p...@ieee.org Subject: pacemakers A few observations.. APS--An APS camera is one that uses Kodak's patented Advanced Photo System film cartridge. The only big difference from other 35mm film cartridges is that you just pop it in and close the lid. It self winds. No film trailer to fool with. Electronics--An APS camera's electronics is not that much different from any other electronic camera. All such devices must operate at very low power levels to avoid changing batteries every month. My wife's APS can go a year or more on a battery, and that's including use of the built in flash. Pacemakers--My father-in-law had one of these twenty years ago. The early models were (or were thought to be) susceptible to higher than ambient electromagnetic waves. Wearers were warned to avoid microwave ovens and the like. However, note that microwave ovens operate at 100s of watts, not microwatts, like consumer portable electronics. Opinion--It is my opinion that any electrical appliance that falls under FCC (and similar) guidelines will not produce adequate EMF to interfere with today's pacemakers. I think I'd be more cautious of non-regulated appliances which one might have near their chest cavity, e.g. electric blankets, electric razors, hairdryers, etc. George Alspaugh --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Zero Crossing Question
Hi Group, Our manufacturing personnel encountered a strange problem: when the mains plug used on a 230V/50Hz equipment that has an internal zero crossing reference integrated circuit (specifically, a CA3059) is reversed (this can occur in countries such as Germany, Italy, France and Switzerland), the zero crossing pulses appear with a 20 millisecond spacing, rather than the expected 10 millisecond spacing. Harris or Intersil IC's work properly regardless of the mains polarity. ON Semiconductor IC's appear to be polarity sensitive. They will produce the proper number of pulses with only one mains polarity. The incorrect spacing of these zero crossing pulses affects the normal operation of the equipment. Has anyone encountered and, hopefully, solved this problem? Regards, John Bouse PKI
IEE Guide to EMC and Functional Safety
Dear all Following comments made in the correspondence on 'EMC-related safety issues' early in January I asked for everyone who was interested to read at least the beginning of the IEE's guide and let me know their opinions. Also to ask their colleagues and anyone else who might be interested. I was hoping for a good response from a number of knowledgeable and experienced people which would help me to get the guide improved in future. But so far, after about 2 weeks, I have had just two replies on this from US-based engineers. Neither of them complained about the engineering guidance in the guide, both complained about the way it is presented but without (so far) being specific or offering any alternatives so I can't (yet) tell if it is simply a UK-US cultural or language thing that is the cause of their complaints. Please consider this a last reminder (in this forum, anyway) to have your say. But please don't merely complain, please try to be constructive to help us improve the guide. Just to remind you of the basic engineering guidance at the heart of this guide, it recommends: QUOTE: To control EMC correctly for functional safety reasons, hazard and risk assessments must take EM environment, emissions, and immunity into account. The following should be addressed: 1) The EM disturbances, however infrequent, to which the apparatus might be exposed; 2) The foreseeable effects of such disturbances on the apparatus 3) How the EM disturbances emitted by the apparatus might affect other apparatus (existing or planned)? 4) The foreseeable safety implications of the above mentioned disturbances (what is the severity of the hazard, the scale of the risk, and the appropriate safety integrity level?) 5) The level of confidence required to verify that the above have been fully considered and all necessary actions taken to achieve the desired level of safety. UNQUOTE Please note that the word addressed in the above simply means: seriously considered or, if you prefer: seriously thought about. You can download the IEE's guide from www.iee.org.uk/Policy/Areas/Electro in Word or PDF formats (note: the URL may be case sensitive). I suggest you download the 'Core' document and at least read the first few sections of it, pass it around, etc. etc. I look forward to your inputs. Regards, Keith Armstrong
Re: EMC-related safety issues
Dear John Sorry to be so late replying. I am pleased that you now understand the situation that I attempted to describe earlier, where an HCMOS inverter with an unterminated input was the cause of surprisingly powerful radiated emissions at 200MHz, due to an unfortunate, unlikely, but not impossible combination of events. All the very best! Keith In a message dated 14/01/02 18:54:00 GMT Standard Time, j...@jmwa.demon.co.uk writes: Subj:Re: EMC-related safety issues Date:14/01/02 18:54:00 GMT Standard Time From:j...@jmwa.demon.co.uk (John Woodgate) Sender:owner-emc-p...@majordomo.ieee.org Reply-to: A HREF=mailto:j...@jmwa.demon.co.uk;j...@jmwa.demon.co.uk/A (John Woodgate) To:emc-p...@majordomo.ieee.org I read in !emc-pstc that cherryclo...@aol.com wrote (in 14b.7351131.297 42...@aol.com) about 'EMC-related safety issues', on Mon, 14 Jan 2002: I'm sure I said in my original posting on this example, that the HCMOS was 'hard switching' and not producing a sine wave. A hot device was, of course, the first thing I looked for, and didn't find any. See the additional information above. Yes, you did, BUT I wrote: The absence of harmonics even suggests that this gate was producing a sine-wave, which makes the figures even higher and less credible. The presence of the high-Q resonant structure that you describe is clearly the real reason why no harmonics were observed. It is not only a good antenna *but it very probably cannot radiate odd harmonics*, which should be the only ones present if the drive waveform was square. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero.
Re: EMC-related safety issues
Dear Bob Sorry to be so late replying. Thank you for this reference, I was unaware of it. I shall add it to my list of EMC-related safety references. If anyone wants a copy of my list, I'll be pleased to email it to them in Word format. If anyone knows of any books, articles, or papers on the issue, I'll be pleased to hear from them about them. Regards, Keith In a message dated 15/01/02 04:08:48 GMT Standard Time, john...@itesafety.com writes: Subj:RE: EMC-related safety issues Date:15/01/02 04:08:48 GMT Standard Time From:john...@itesafety.com (Robert Johnson) Sender:owner-emc-p...@majordomo.ieee.org Reply-to: A HREF=mailto:john...@itesafety.com;john...@itesafety.com/A (Robert Johnson) To:emc-p...@ieee.org The latest IEC Just Published points to an article on this subject http://www.iec.ch/etech/etech-live/frames-prod-e.htm It discusses the application of IEC 61000-1-2. Also of related significance when talking about safety of complex systems and the impact of outside influences like EMC is IEC 61000-1-2 FAQs http://www.iec.ch/61508/Index.htm Bob Johnson
Query for India reguration
Hi, I would like to know about India reguration for EMC Radio. Please give me the information. Tetsuya Hashimoto A-PEX International Co., Ltd. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: CE rules
I think that is possible find something on the directive 99/44/CE Ciao Paolo At 16:42 1/17/02 -0500, Michael Gusel wrote: Dear Group, I am looking for CE rules (Directive, Article, ...) for maximum period of time that the manufacturer must provide repair and service after the equipment has been discontinued. Please advise. Thank you. Michael Gusel Datascope Corp. Tel: 201-995-8362 800 MacArthur Blvd. Fax: 201-995-8614 Mahwah, NJ 07430E-mail: michael_gu...@datascope.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. -- Paolo Gemma Siemens Information and Communication Network spa Microwave Networks MW RD NSA EMC SS Padana sup. KM 158 20060 Cassina de'Pecchi (MI) Italy phone +39 02 9526 6587fax +39 02 9526 6203 mobile +39 348 3690185 e-mail paolo.ge...@icn.siemens.it --
