RE: MIL-STD-461E
The only difference that I am aware of is that MIL-STD-461E merges -461D and 462D into one document (list members, please correct me on this if I am in error.) If you are looking for HEMP, you can refer to MIL-STD-464. It has unclassified requirements, but not test methods. DB -- From: Darrell Locke[SMTP:dlo...@advanced-input.com] Reply To: Darrell Locke Sent: Thursday, January 25, 2001 8:51 AM To: 'EMC-PSTC - forum' (E-mail) Subject: MIL-STD-461E Dear Members, I have received the new revision of MIL-STD-461 revision E. It contains much more detail on testing to the existing requirements. I have also been told by another source that it contains unclassified sections for HAEMP testing and parameters. However, I do not see any reference to HAEMP in the E revision. Can any of you military experts help me out here. 1. What are the differences between 461D and 461E? 2. Are there HAEMP requirements buried in the E revisions somewhere? Thanks Darrell Locke Advanced Input Devices --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Zo
William, If you want to calculate the impedance, the equation for a lossless line is simply Z = sqrt(l/c) where l = per unit length inductance c = per unit length capacitance. For lossy line, it gets more complex: Z = sqrt((r+jwl)/(g+jwc)) where unit length parameters are r = resistance (series, as a function of frequency) w = radian frequency g = conductance (line to line) DB -- From: wo...@sensormatic.com[SMTP:wo...@sensormatic.com] Reply To: wo...@sensormatic.com Sent: Thursday, January 11, 2001 8:25 AM To: emc-p...@majordomo.ieee.org Subject: RE: Zo My experience is that it is in the order of 75-150 ohms and depends upon the material, lay and shielding, if any. Increased lay and shielding will reduce the impedance. Richard Woods -- From: William D'Orazio [SMTP:dora...@cae.ca] Sent: Thursday, January 11, 2001 9:49 AM To: EMC Posting (E-mail) Subject: Zo Does anybody know the characteristic impedance of a twisted pair? Thanks in advance, ...OLE_Obj... William D'Orazio CAE Electronics Ltd. Electrical System Designer Phone: (514) 341-2000 (X4555) Fax: (514)340-5552 Email: dora...@cae.ca --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Mil Spec 55110
A quick search netted a result for MIL-PRF-55110F, PRINTED WIRING BOARD, RIGID, GENERAL SPECIFICATION FOR, 27 NOV 1998 Ed Price recently posted a link to a site for all MIL documents. You can probably find it there. DB -- From: Peter Merguerian[SMTP:pmerguer...@itl.co.il] Reply To: Peter Merguerian Sent: Tuesday, January 02, 2001 5:13 AM To: EMC-PSTC (E-mail) Subject: Mil Spec 55110 Happy New Year Everyone! Does anyone know the title and scope of Mil-Std-55110? Where can this standard be purchased? Peter Merguerian Managing Director Product Testing Division I.T.L. (Product Testing) Ltd. Hacharoshet 26, POB 211 Or Yehuda 60251, Israel Tel: 972-3-5339022 Fax: 972-3-5339019 e-mail: pmerguer...@itl.co.il website: http://www.itl.co.il TO LEARN ABOUT AUSTRALIAN AND NEW ZEALAND REQUIREMENTS, CONTACT ME AT THE EARLIEST STAGES OF YOUR DESIGN; REQUIREMENTS CAN BE TRICKY! --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: SAE Spec Question
Ed, This may be what you are looking for: This is from SAE ARP5412, Aircraft Lightning and Related Test Waveforms Table 5 - Individual Conductors test level due to Current Component A, lists waveform 4, level 4 as Vo=750 Io=150 Table 6 - Cable Bundle test level due to Current Component A, lists waveform 4, level 4 as Vo=750 Io=1500 The units are volts and amps, respectively. In Table 9, The waveshape is defined as 1.094*Vo(exp(-beta*t)-e(-alpha*t)) or 1.094*Io(exp(-beta*t)-exp(-alpha*t)) where alpha=11354 sec^(-1) beta=647265 sec^(-1) The resulting waveform should give you a peak level of Vo or Io, respectively. From Figure 24 - Double Exponential Voltage Waveform 4 Time to 10% =.15 usec Time to 90% = 3.0 usec Time to peak should be 6.4 usec +/- 20%, time to 50% of peak (decay side) should be 69 usec +/- 20% Hope this helps. DB -- From: Price, Ed[SMTP:ed.pr...@cubic.com] Reply To: Price, Ed Sent: Thursday, December 14, 2000 2:43 PM To: 'emc-p...@ieee.org' Subject: SAE Spec Question Can anyone tell me what is the shape and amplitude for a pulse which meets the requirements of SAE AE4L-81-2, Section 5.3, Waveform 4, level 4? Thanks! Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA. USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Rechargeable Batteries
In my personal experience, I have noted cases where the equipment did not perform properly using rechargeable batteries. In particular, I recall experiencing this problem for a wireless microphone / guitar set that I purchased a few years ago. The system simply did not work properly when a rechargeable 9V battery was used in the transmitter. However, it worked great when an alkaline cell was used. The set came with a disclaimer, similar to the one noted below. So to answer your question, in this case, it was a functionality issue that must have drove the disclaimer. DB -- From: m...@cjbdev.demon.co.uk[SMTP:m...@cjbdev.demon.co.uk] Reply To: m...@cjbdev.demon.co.uk Sent: Wednesday, November 22, 2000 9:27 AM To: emc-p...@ieee.org Subject: Rechargeable Batteries I hope you'll all be patient with what might be a question with an obvious answer: why do so many battery operated equipments state that they must not be operated using rechargeable batteries? I appreciate that NiCads have a nominal voltage of 1.2V compared to Alkaline and Zinc Chloride's 1.5V, but is there something else of which I'm not aware? Higher output impedance as they grow old? Greater chemical toxicity? More likely to leak corrosive material? More likely to explode?! Is it functionality, safety or EMC that worries the instruction book writers? Regards, Mark -- Mark Hone Wellman CJB Limited Email: m...@cjbdev.demon.co.uk Airport Service Road Tel: +44 (0)2392 629239 (Direct) Portsmouth, HampshireTel: +44 (0)2392 664911 PO3 5PG, ENGLAND Fax: +44 (0)2392 697864 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Holes, waveguides and honeycombs
The formula for honeycomb panels agrees with the one I have found in a shielding design guide, provided by a commercial shielding products manufacturer. (If you want to know which one, contact me directly.) The last term in the equation is similar to that for multiple vent hole openings, where the thickness (depth) is much smaller than the opening. In this case, the depth is greater than the opening, but you still have to account for multiple apertures. You can't ignore it. If you think about it, each hole acts as an antenna source on the other side of the panel. The effect of each one individually may be small, but collectively, they add up. The result is (obviously) an overall reduction in shielding effectiveness. The advantage of honeycomb, or any waveguide below cutoff, is that the attenuation is very high below the cutoff frequency. Even with multiple apertures, the shielding should still be very high below the cutoff frequency. DB -- From: jim_bac...@mail.monarch.com[SMTP:jim_bac...@mail.monarch.com] Reply To: jim_bac...@mail.monarch.com Sent: Friday, October 20, 2000 7:31 AM To: Paolo Roncone; emc-p...@majordomo.ieee.org Subject: Re:Holes, waveguides and honeycombs forwarding for pronc...@cisco.com Reply Separator Subject:Holes, waveguides and honeycombs Author: Paolo Roncone pronc...@cisco.com Date: 10/20/00 12:03 PM Group, We are working on a couple of designs of telecom gear contained in metal s.u.b.-racks and we have to meet emission limits up to 40 GHz. I need some advice on the workings of waveguides below cut-off and honeycombs, because we have to include ventilation openings without possibly degrading the shielding effectiveness. First, I made an inquiry on textbook formulas for circular and rectangular waveguide cut-off frequencies. I was happy to find consistency among three different sources (I found the same formulas although rearranged in different fashions). From Ott's Noise reduction techniques in electronic systems I found: fc = [6.9/d] GHz for circular waveguides fc = [5.9/l] GHz for rectangular waveguides where fc = cutoff frequency d = diameter of circular section (inches) l = longer side of rectangular section (inches) Now my question is: what about honeycomb panels ? Can I use the same formulas for honeycombs ? Here the single cells are neither circular nor rectangular. Can I still apply these formulas with good accuracy ? If not, anyone knows of other formulas that apply in this case? As for attenuation (shielding effectivenes) of one single waveguide opening, if the frequency is well below cutoff , this is proportional to the ratio of length/diameter of the waveguide. The recommended ratio is 2:1 to 4:1 in order to get good attenuation. Now, I just found a formula for attenuation of honeycomb panels as function of frequency, length-to-width ratio of each cell and also number of cells: S [dB] = 20log(fc/f) + 27.3(t/W) - 10log(n)(f fc/10) where: S [dB] = Shielding Effectiveness in dB fc = cutoff frequency of waveguide f = frequency t = cell length (or thickness) W = cell section width n = number of cells in honeycomb panel I have no problems with the first two terms in the above equation. As for the third term, that means that increasing the number of cells (n) in the honeycomb panel degrades the shielding effectiveness of the panel (ex. 1000 cells means 30 dBs lost). Before finding this formula I had a feeling that due to the skin-effect each honeycomb cell could be treated as a single cell. So far I wasn't able to find other formulas for honeycomb panels. So I'd like to have some feedback on this. I hope to get some useful directions. Thank you in advance, Paolo Roncone Cisco Photonics, Italy --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: comparison of ESD per MIL - 1686B to EN61000-4-2
I don't know if this is what you are after: MIL-STD-1686B rates ESD sensitivity of class 3 parts, assemblies or equipment at sensitivity levels ranging from 4000 to 15999 volts. I don't see a subclass rating (i.e., 3a) Appendix C of this standard requires testing at 2000 volts for assemblies and 4000 volts for equipment. Hope this helps DB -- From: Michael Taylor[SMTP:mtay...@hach.com] Reply To: Michael Taylor Sent: Tuesday, October 10, 2000 10:32 AM To: emc-p...@ieee.org Subject: comparison of ESD per MIL - 1686B to EN61000-4-2 Does any one have Mil Std 1686B handy??? Need to compare test levels between Mil Std 1686B, Class 3a and EN61000-4-2. Any help will be appreciated. M. Taylor Hach Company Loveland, Colorado --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Electron Flow
I feel compelled to interject, having some experience in the area of lightning.
It's true that the majority of lightning return strokes are negative. However,
positive return strokes, usually occurring toward the end of a storm, do occur.
They also tend to have a larger magnitude, on average, than the more common
negative return strokes.
DB
--
From: pwmc...@ra.rockwell.com[SMTP:pwmc...@ra.rockwell.com]
Reply To: pwmc...@ra.rockwell.com
Sent: Thursday, October 05, 2000 9:46 AM
To: Lichtenstein, Ross
Cc: 'Barry Ma'; emc-p...@majordomo.ieee.org
Subject: RE: Electron Flow
Barry,
I believe Ross is right for the last and larger half (LARGER half??
{poetic license}) of a lightning strike. As I understand the current
lightning model the initial strike is a positive Leader coming from the
cloud to the ground. The Leader is a thin column of air that has been
ionized by the excessive potential between the cloud and ground. The
electrons move back towards the cloud, the positive air (nitrogen, oxygen,
water vapor, etc.) ions move towards the ground breaking down the air and
creating more ions as they go. The path is dependant on the instantaneous
breakdown potential of the closest air molecules to the leader causing the
characteristic jagged nature as it comes down. Once the leader reaches the
earth (tree, building, dirt...) The excess electrons rush back to the cloud
along the ionzed leader.
The lightening is a positive stroke downward followed by a large
Negative stroke upwards.
Paul McCoy
Lichtenstein, Ross ross.lichtenst...@owenscorning.com@ieee.org on
10/05/2000 09:54:21 AM
Please respond to Lichtenstein, Ross ross.lichtenst...@owenscorning.com
Sent by: owner-emc-p...@ieee.org
To: 'Barry Ma' barry...@altavista.com, emc-p...@majordomo.ieee.org
cc:
Subject: RE: Electron Flow
Barry,
I could be wrong, and if so I would stand corrected, but from my basic
electronics training,
I recall that electron flow is from negative to positive.
I also recall being taught that lightning actually travels from earth (neg.
charge) upward
to the positive charge of the clouds. Then there is also the case of
lightning between clouds
of opposite charge, and again the electron flow direction is from neg. to
pos.
Ross
-Original Message-
From: Barry Ma [mailto:barry...@altavista.com]
Sent: Wednesday, October 04, 2000 5:58 PM
To: emc-p...@majordomo.ieee.org
Subject: Re: ESD Opportunities
Please allow me to ask a relevant question only for curiosity.
We have no idea of what charge (positive or negative) would go to the DUT
in
ordinary ESD.
That's why we have to test two polarities in ESD immunity test.
Lightning is a kind of ESD happened between a charged cloud and objects on
earth surface. Some figures imply that an electron current flows from the
charged cloud to the earth. Is it possible to have an opposite direction -
electron flows from earth to cloud?
Thanks.
Barry Ma
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RF Immunity levels
Hi, group Here's a question for you test lab folks out there, or anyone familiar with current test lab capabities - What are the maximum E field levels achievable between 2 GHz and 40 GHz? I'm looking for a maximum at each frequency (narrowband nulls excluded). Even if peak levels at discrete frequencies are all that can be achieved, I'd like to know that, too. I'd appreciate a test house contact in the US if anyone has an answer. Thanks, DB --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Radiated Susceptibility up to 100 GHz
List Members: Does anyone have experience performing radiated susceptibility (immunity) testing at frequencies up to 100 GHz? If so, what labs are equipped to provide this service, and what field levels are achievable? Thanks, DB --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Ambient Cancellation Device for OATS
I would like to add that one must be careful when it comes to using such a system. I apologize if this has been pointed out already, but it can't be emphasized enough. When using a system like this, you take the risk that the ambient environment will mask significant emissions from the EUT. You may never see these emissions under such conditions, and it will bite you later. I am particularly concerned when I hear this being touted as a panacea for testing in traditionally noisy environments, such as development labs. Be careful folks. My 2 cents. DB -- From: Price, Ed[SMTP:ed.pr...@cubic.com] Reply To: Price, Ed Sent: Thursday, March 23, 2000 9:01 AM To: 'Doug'; emc-p...@majordomo.ieee.org Subject: RE: Ambient Cancellation Device for OATS Doug: As I understand the process, there isn't actually cancellation AT the OATS. They have a monitor antenna nearby, but relatively far from the EUT on the OATS. A real EUT signal should fall off considerably by the time it reaches the monitor antenna, but an ambient emission will be relatively constant at the monitor and measurement antennas. All you have to do is sample the ambient, invert it, and sum it with the measurement antenna voltage. This should delete the ambient from the measurement data. (Easy to say! All you need is enough computing power and sufficiently capable processing algorithms.) The cancellation takes place as a data operation within the Cassper hardware (or it's controlling computer), and not as an energy cancellation of the propagating fields actually on the OATS site. And yes, I would also like to know more about how Cassper manages to do this. But, I also realize they can't give away their trade secrets either. Ed :-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-) Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA. USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis :-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-) -Original Message- From: Doug [SMTP:dmck...@gte.net] Sent: Wednesday, March 22, 2000 11:38 PM To: emc-p...@majordomo.ieee.org Subject:Re: Ambient Cancellation Device for OATS Perhaps it's because I've never understood ... How exactly does one do ambient cancellation at an OATS? --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Shielded Enclosures Standards.
IEEE STD 299, Measuring the Effectiveness of Electromagnetic Shielding Enclosures was adopted for use by the DoD on 24 Oct 97. The latest version of the document as far as I am aware is the 1997 version, IEEE STD 299-1997 -- From: Ken Javor[SMTP:ken.ja...@emccompliance.com] Reply To: Ken Javor Sent: Friday, November 19, 1999 6:43 AM To: David Monreal; emc-p...@majordomo.ieee.org Subject: Re: Shielded Enclosures Standards. MIL-STD-285 is an old (probably obsolete) military standard which defined how and at what frequencies to measure the shielding effectiveness of shield rooms. NSA 65-6 is more in use nowadays, borrowed from the TEMPEST world. I don't know what commercial standards govern such rooms. -- From: David Monreal dmonr...@advancedshielding.com To: emc-p...@majordomo.ieee.org Subject: Shielded Enclosures Standards. Date: Fri, Nov 19, 1999, 2:02 AM Heya there, I'm looking for the standards a shielded enclosure should acomplish. Is there any specific standard for enclosures? Thanks a lot. David Monreal Marketing Office Manager Telf: +34 93 475 14 80 FAX: +34 93 377 64 64 http://www.advancedshielding.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Conducted Emissions for PS output
Maybe I've been working on space systems too long...you can draw your own conclusions about that. At any rate, even though it isn't likely to be what Derek was after in the first place, let me try to make my statement clearer: What I was referring to was the distinction between a power converter (e.g., dc-dc converter) for a single LRU in a large system, in contrast to a unit that is a power supply (like a DDCU on the space station) that is converting power from an unregulated source (let's say a solar panel) and providing regulated power to a number of units on a power bus. The former would typically have a much more stringent output ripple requirement (as indicated by Robert Macy) than the latter. DB -- From: Ken Javor[SMTP:ken.ja...@emccompliance.com] Sent: Wednesday, November 17, 1999 3:39 PM To: Brumbaugh, David; EMC Discussion Group; 'Derek Walton' Subject: Re: Conducted Emissions for PS output Re this: If the power supply is for a single unit utilizing a common power bus for the power supply input, then the output ripple of the supply might need to be controlled more stringently, perhaps on the order of tens of millivolts. Huh? Maybe I've been in Alabama too long, but I don't understand what you are saying. -- From: Brumbaugh, David david.brumba...@pss.boeing.com To: EMC Discussion Group emc-p...@ieee.org, 'Derek Walton' l...@rols1.net Subject: RE: Conducted Emissions for PS output Date: Wed, Nov 17, 1999, 7:52 AM If the power supply is for a single unit utilizing a common power bus for the power supply input, then the output ripple of the supply might need to be controlled more stringently, perhaps on the order of tens of millivolts. - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Conducted Emissions for PS output
Derek In my experience in the aerospace industry, the output voltage ripple is typically specified. However, the amount of acceptable ripple and the frequency range of concern depends on the application. An example is the ripple level specified by MIL-STD-1541A which calls for a ripple limit of 500 mV peak to peak, as measured in the time domain. Of course, that specification is geared toward the power bus of a dc system, such as a spacecraft 28 vdc bus. If the power supply is for a single unit utilizing a common power bus for the power supply input, then the output ripple of the supply might need to be controlled more stringently, perhaps on the order of tens of millivolts. DB -- From: Derek Walton[SMTP:l...@rols1.net] Reply To: Derek Walton Sent: Tuesday, November 16, 1999 6:33 PM To: EMC Discussion Group Subject: Conducted Emissions for PS output HI, would anyone like to suggest a specification for controlling conducted emissions from the output of a power supply or battery charger. The market place is either the USA or Europe. Thanks, Derek. -- Derek Walton Owner L. F. Research EMC Design and Test Facility 12790 Route 76, Poplar Grove, IL 61065. www.lfresearch.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: EMI from nearby welding
Mark If you can't disconnect or ground the interfaces, you might try installing ferrites (e.g., clamp on type or empirical test fixtures found in product sample kits) on the sensitive circuit cables. This will help attenuate the peak voltages coupled to your circuits. Whether this will be sufficient to protect your circuits is another question, but you can determine how much attenuation you will get using a network analyzer and current probes to inject a low level current, and measure the effect at the sensitive circuit interface (with and without the ferrites) using a probe closely matched to the first. You will need to make sure that the ferrites are sized sufficiently to handle the current that you expect to see on the cable shield. DB -- From: Price, Ed[SMTP:ed.pr...@cubic.com] Reply To: Price, Ed Sent: Tuesday, October 12, 1999 3:39 PM To: 'm...@cjbdev.demon.co.uk'; emc-p...@ieee.org Subject: RE: EMI from nearby welding Mark: Old CMOS design may not have much protection. I would suggest that you play it conservatively. Unplug the cluster of input wires from your controller. Or, pull the boards from the backplane if you can. If this is somehow impossible, I would short the inputs to ground using wire braid or an impromptu woven wad of bronze wool. Regards, Ed -Original Message- From: m...@cjbdev.demon.co.uk [SMTP:m...@cjbdev.demon.co.uk] Sent: Tuesday, October 12, 1999 9:30 AM To: emc-p...@ieee.org Subject:EMI from nearby welding The query I'd like to put to the readers of this list is not exactly EMC related, but is close enough that I hope you'll forgive me asking. Can anyone give me an idea of the voltages likely to be induced in the unprotected input wiring of a process plant control system, when welding is carried out nearby? Or point me to a resource that may give me some help? The welding cables will be close (within a metre of the inputs to the control system, perhaps even touching the control system metal case). The welding transformer will be tens of metres away. The process plant control system is an old logic design based around 4000 series CMOS. The control system will not be energised when the welding is going on, so my main worry is induced voltages/currents blowing up the CMOS. Should I worry, or sleep happy? All advice gratefully received (except if someone tells me to throw away the control system and get something better protected, as that's not an option...) Regards, Mark -- Mark Hone Wellman CJB Limited Email: m...@cjbdev.demon.co.uk Airport Service Road Tel: +44 (0)2392 629239 (Direct) Portsmouth, Hampshire Tel: +44 (0)2392 664911 PO3 5PG, ENGLAND Fax: +44 (0)2392 697864 - :-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-) Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA. USA 619-505-2780 (Voice) 619-505-1502 (Fax) Military Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis :-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-) - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: EMC Safety Standards
For non ionizing radiation limits, refer to ANSI/IEEE C95.1 -- From: Muriel Bittencourt de Liz[SMTP:mur...@grucad.ufsc.br] Sent: Monday, August 02, 1999 11:42 AM To: Lista de EMC da IEEE Subject: EMC Safety Standards Dear Group, I'm making a study on EMC Safety Standards, and some questions appeared. I'd like to post them to the group to see if someone can help me. The questions are: # Safety standards seem only to aim the protection the equipment... And the operator/user of the equipment? Is there any standard for protection of the user/operator? # The VCCI Standard is more restrictive than the European Norms (ENs)?? # Is there any standard which covers the effects of Non-Ionizing Radiation (Electromagnetic Radiation) on the human health? I think that's all... Thanks in advance for those who can help! Best Regards, Muriel -- == Muriel Bittencourt de Liz GRUCAD - Grupo de Concep ção e Análise de Dispositivos Eletromagnéticos Universidade Federal de Santa Catarina Caixa Postal - 476 88040-900 - Florianópolis - SC - BRASIL Fone: +55.48.331.9649 - Fax: +55.48.234.3790 e-mail: mur...@grucad.ufsc.br ICQ#: 9089332 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: RELIABILITY TO MIL-HDBK-217
Information Handling Services has it. (There may be a subscription fee required to use their services.) It can be downloaded in PDF, GIF or TIFF. A search result at their site will bring up the most recent change. However, all previous versions of the document are available by clicking on Document Summary, and scrolling to the bottom of the page, where links to all the previous released versions are listed. Here is the link to IHS: http://www.ihs.com/ihsgroup.html Hope this helps. DB -- From: Arun Kaore[SMTP:kao...@sg.adi-limited.com.au] Sent: Thursday, July 29, 1999 5:36 PM To: 'emc-p...@majordomo.ieee.org' Subject: RELIABILITY TO MIL-HDBK-217 Hi all, Could someone guide me on where to down load from the net or purchase the latest version of MIL-HDBK-217 and approximately how much it would cost. It is a Reliability/MTBF related issue. Thanks in advance. Regards Arun Kaore EMC Engineer ADI Limited Systems Group Test Evaluation Centre Forrester Road, St Marys NSW 2760 P O Box: 315, St Marys NSW 1790 Tel: 61 2 9673 8375 Fax: 61 2 9673 8321 Email: kao...@sg.adi-limited.com.au mailto:kao...@sg.adi-limited.com.au - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: transient event recorder
Susan, A few years ago I used a Dranetz 658 Power Quality Analyzer for doing such measurements. As the name implies, it is designed for monitoring power lines, but it can be used to monitor signal lines as well, at least for transients. At that time, it was made by Hawker-Siddelly (sp?). Now, it appears that the company goes by Dranetz-BMI. Looks like they still market the 658, along with other products. Here's a link. Good luck. http://www.dranetz-bmi.com/Products/prodsel.htm Dave -- From: Beard, Susan[SMTP:sbe...@ge-harris.com] Sent: Tuesday, July 06, 1999 8:10 AM To: 'emc-p...@ieee.org' Subject: transient event recorder Does anyone know of a device that could be connected to an interface (e.g., LON) that would record transient type events? Susan Beard - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: ESD-Pink Poly Bags
It's been a while, but my recollection is that the pink poly bags do not protect the device in the bag. Their only advantage is they don't hold or generate static. I think your assessment is correct, you need a metallized bag to shield the device inside. DB -- From: John Juhasz[SMTP:jjuh...@fiberoptions.com] Sent: Tuesday, April 06, 1999 8:38 AM To: 'emc-p...@ieee.org' Subject: ESD-Pink Poly Bags I am having a running debate with regards to the ESD protection properties of those 'pink poly bags' for packaging electronic products. It is my understanding that these 'pink poly bags' DO NOT protect the printed circuits FROM ESD, but merely prevent the generation of static. If the requirement is to protect the printed circuits from an ESD event, the boards should be packaged in the metallized bags. Can anyone clarify/confirm this?? John A. Juhasz Product Qualification Compliance Engr. Fiber Options, Inc. 80 Orville Dr. Suite 102 Bohemia, NY 11716 USA Tel: 516-567-8320 ext. 24 Fax: 516-567-8322 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Standards updates
You might want to try http://www.ihs.com/ For a fee, you can access a wide array of standards online. They seem to keep them up to date. DB -- From: Biggs, Daniel (IndSys, GEFanuc, NA)[SMTP:bigg...@gemischova.ge.com] Sent: Monday, March 22, 1999 7:30 AM To: emc-p...@majordomo.ieee.org Subject: Standards updates Hi all, Is there any sites and/or services that can provide updates/changes to standards in a reasonabvly quick timeframe? I am interested in worldwide standards. Forgive me if this is an unreasonable or dumb question. Thanks, Dan - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Surge immunity
Peter I would want to capture the output waveforms on the power supply, which means using a digitizing oscilloscope, or a device like a Dranetz power quality analyer. I don't see how anybody can get a meaningful transient response using a multimeter. My opinion only. DB -- From: peterh...@aol.com[SMTP:peterh...@aol.com] Sent: Sunday, March 07, 1999 10:08 PM To: emc-p...@majordomo.ieee.org Subject: Surge immunity Hello all, Please could someone advise me how to monitor the performance of a component level power supply such as open frame type during a surge immunity test? I.e what instrument is used to observe the output of the power supply during the test? I have been told by an EMI lab that they use normal multimeter whereas another lab uses a type of LED. Are these really the correct way of monitoring the performance A, B and C as described in the standard? Thanks Peter - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: equation for standard gain horns
Susan The equation for the gain of a pyramidal horn, from section 36.2, p 877, Electrical Engineering Handbook by Dorf, 1993 CRC Press, ISBN 0-8493-0185-8 Gain = 0.5*(4*pi/lambda^2)*Lx*Ly where lamda = wavelength Lx and Ly are the dimensions of the horn. Hope this helps. DB -- From: Beard, Susan[SMTP:sbe...@ge-harris.com] Sent: Thursday, January 07, 1999 1:30 PM To: 'emc-p...@ieee.org' Subject: equation for standard gain horns Can someone point me to the equation for calculating the gain of a standard gain horn antenna based on the physical measurements of the aperture? Thanks, Susan Beard - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: EMC Directive Field Testing of Large Equipments
Doug A bulk current injection test (MIL-STD-461D, CS114, CS115, CS116) can be considered in lieu of radiated immunity, at least up to VHF and low UHF frequencies. DB -- From: Doug Frazee[SMTP:dfra...@windermeregroup.com] Sent: Friday, December 18, 1998 1:22 PM To: 'emc-p...@majordomo.ieee.org' Subject: EMC Directive Field Testing of Large Equipments I would like to compile thoughts and techniques that members of this group use to perform in situ tests on large industrial apparatus. Considerations I have typically encountered include: Current draw in excess of available LISN capacity. Use CISPR voltage probe Current draw in excess of available EFT surge coupling network capacity. EFT, use 33nF cap. Surge,? 3 or 10m EUT to antenna distance not achievable and/or high ambients. Lab type radiated immunity not practical due to interference potential. Large equipments requiring multiple antenna locations or search and optimize considerations for radiated emissions. I am especially interested in potential alternate techniques for radiated immunity. Potential solutions may include ad hoc testing using actual transmitters, eg cell phones, VHF, etc. Testing at discrete frequencies of known public broadcast bands. Extended frequency conducted immunity testing. If you have thoughts or other considerations, please respond to the group. As US labs are granted CAB status, consensus on these, and other issues will be helpful. Doug Frazee Lead Compliance Engineer Windermere Military/Commercial Compliance Laboratory Annapolis, MD USA dfra...@windermeregroup.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
MIL-STD-461 C vs D
Hi group, Here's one for all of you that make products for US military/gov't customers: I was reviewing MIL-STD-461D (I know, a little late to be commenting at this point) and I noticed that although CS101 in -461D corresponds to CS01 in -461C, there is no counterpart to -461C's CS02 requirement. In other words, the conducted susceptibility test on power leads has been deleted above 50 kHz in -461D. The bulk current injection test (CS114) covers the range up to to 400 MHz, but that is a common mode test, and doesn't necessarily impose the voltage levels that can be present on a power bus above 50 kHz. In my experience, most of the noise that is of concern ranges between 50 kHz, and a few megahertz, especially with the switching frequencies used in today's power supplies. Is anyone else concerned about this? Is there some rationale that supports the -461D version in this regard? There is no discussion on this in the application guide to -461D. I'd be interested in any comments or shared concern out there. Thanks in advance David Brumbaugh The Boeing Company Phantom Works - Electromagnetic Effects M/C 8H-11 POB 3999 Seattle, WA 98124-2499 Phone: 253-773-3733 Pager: 800-759-7243, PIN 5474642# Fax:253-773-4173 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Equivalent radiators
I haven't seen a reply to this post, so I'll give it a shot. I'm not really an antenna expert, so feel free to correct me. The slot antenna is a dual of the dipole, or in this case, a short monopole. If you know the radiation resistance of the monopole, then you can easily calculate the current. For a short dipole, the radiation resistance is Rr = 80*pi^2*(h/lambda)^2 = 8 ohms for this case (4 inch antenna at 100 MHz) where h is the height of the antenna. For a quarter wave monopole over a ground plane, the radiation resistance is half that of a half wave dipole. I don't know if the same holds true for a short monopole vs.dipole. This should give you a ball park for the current required to eqivalently drive your slot antenna. Regards, DB -- From: Robert Macy[SMTP:m...@california.com] Sent: Wednesday, November 18, 1998 11:49 AM To: emc-p...@ieee.org Subject: Equivalent radiators What is equivalent to : a 4 inch long wire excited at one end with 3 Vpp at 100MHz a 4 inch long slot with swirling current of how much to be equivalent radiators? - Robert - PS My guess was 10-100mA, but I would like to get a true qualitative answer. - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Grounding of screen room
Peter If you can locate the facility electrical drawings, I would recommend starting with those. It's considered good design practice if you have isolated facility power (air handlers, lights, etc.) and technical power (designated for exclusive use by instrumentation and other equipment requiring clean power.) Some facilities use a separate ground grid, and others are grounded via existing conduit. In either case, you want the tech power and facility power connected together at only one point, to avoid cluttering up your tech power with facility power noise. DB -- From: peterh...@aol.com[SMTP:peterh...@aol.com] Sent: Monday, October 05, 1998 10:56 PM To: emc-p...@majordomo.ieee.org Subject: Grounding of screen room Hello group, Can someone tell me what is the best method to find out and ensure that a screen room is adequately grounded? I have access to an screen room for conducted emissions, but I am not sure about its grounding. Any hint is appreciated. Thanks Peter Hays - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: How to Upgrade an HP8566A
Steve I know that we have upgraded at least several HP8566A's to B's. I believe we did this by returning them to HP to perform the upgrade service. I would recommend contacting your local HP rep directly. Or, try their Test Measurement call center at 800-542-4844. DB -- From: Steve Kuiper[SMTP:aegisl...@email.msn.com] Sent: Wednesday, September 30, 1998 10:43 AM To: EMC-PSTC Subject: How to Upgrade an HP8566A Hello folks, Anyone familiar with an upgrade service or consultant who can convert an HP8566A to an HP8566B??? In terms of commercial EMI testing, would this be a good, reliable inexpensive alternative compared to using an original HP factory built 8566B or newer HP spec analyzer / receiver model??? A few months back, I heard there was a contact in the San Diego, CA area. Any names or numbers heard of preferrably in the Southern California Area? Kind regards, Steve Kuiper - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Radiation Monitors
From the CE buyer's guide: (All US phone numbers) All-Spec Static Control 800-537-0351 Amplifier Research 215-723-8181 Antenna Research301-937- Chase EMC 973-252-8001 Credence Technologies 408-459-7488 Electro-Metrics 518-762-2600 Electro-Tech Systems215-887-2196 EMC Technologists 732-919-1100 EMCO512-835-4684 http://www.emctest.com Ergonomics, Inc 800-862-0102 Fischer Custom Com. 310-891-0635 NRD, Inc. 716-773-7634 Test Lab Co.800-442-5835 DB -- From: slong...@masoncom.com[SMTP:slong...@masoncom.com] Sent: Tuesday, September 22, 1998 3:42 AM To: emc-p...@ieee.org Subject: Radiation Monitors I've been given the task to find a metre that will measure the field strength from antennas, this device must be hand held. Does anyone know where I can purchase one?? Many Thanks Simon Longstaff - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Odd Immunity Problems
Keith You can probably find what you need to know about US regs at http://www.fcc.gov/ FCC regs specify max power at various commercial and amateur frequencies. I can tell you that a 1 kW PA on a CB radio is illegal in the US. DB -- From: Keith Armstrong[SMTP:karmstr...@iee.org] Sent: Wednesday, July 08, 1998 8:43 AM To: Scott Douglas Cc: emc-p...@majordomo.ieee.org Subject: Re: Odd Immunity Problems Dear Scott Must be the first example of EMC affecting social relationships! Can anyone tell me what the rules are in the US and Europe for the use of such powerful PAs? I know that truckers and radio amateurs in the UK sometimes use such powerful PAs when they shouldn't, and create havoc, but when is it OK to use them? Best regards Keith Armstrong Partner, Cherry Clough Consultants phone: +44 (0)1457 871 605 Fax: +44 (0) 1457 820 145 Email: karmstr...@iee.org Scott Douglas wrote: Since you brought it up, I am reminded of a time in my youth before the Hey Good Buddy... craze hit the CB world. Back when it was a serious citizens band, licenses were required and I was young and foolish. I had a 5 channel 1 watt Johnson Messenger One CB. Had great fun 'til I bought a one kW linear amplifier for it. Was talking to someone several states away (hundreds of miles) when a knock came at the door upstairs. Heard my neighbor from across the street screaming at my mother. My voice was coming through their stereo speakers even though the power was off! That wasn't the worst part, he heard me talking about spending time with their daughter, whom I was forbidden to see! Sure had no clue what EMI was then but, boy, did I ever learn about angry fathers! Today I am a Compliance Engineer, but did not marry his daughter. Regards, Scott s_doug...@ecrm.com
Tantalum Capacitors
Can anyone tell me if there are any drawbacks in using tantalum capacitors in dc power supply filters? My recollection is that they can pop if the voltage polarity is reversed, or if there are large negative voltage swings during transients. TIA, David Brumbaugh The BOEING Company Information, Space Defense Systems Electromagnetic Effects M/C 8H-11 POB 3999 Seattle, WA 98124-2499 Phone: Kent Space Center (253) 773-3733
RE: Modelling
You might try the NEC listserver to see if someone in that group can answer your question. To join, send a message with your name and e-mail address in the text to Dave Michelson: da...@ee.ubc.ca. If you want to post a message, just send it to: nec-l...@ee.ubc.ca For additional recources, you might also try the EMC lab at UMR, at the following URL: http://www.emclab.umr.edu/numer.html Good luck. DB -- From: Keith Armstrong[SMTP:karmstr...@iee.org] Sent: Tuesday, June 23, 1998 8:38 AM To: Chong Chien Jin Cc: emc-p...@majordomo.ieee.org Subject: Re: Modelling Dear Mr Chong There are people who can model this sort of thing, but I can't tell you who are the best people to go to. I've no doubt that other emc-pstc subscribers will have some good contacts or specialist knowledge in this area - can I ask that anyone who does gets in touch with Mr Chong? All the very best! Keith Armstrong Partner, Cherry Clough Consultants Chong Chien Jin wrote: Thanks Keith... One more question: What about modelling of EMC in machines and instrumentation? Do you know any modelling concerning EMC? C.J.CHONG ee39...@eng.usm.my
RE: Emissions or not?
You might also be getting a passive intermod product from something on the italian car reacting to your transmitter. DB -- From: mikonc...@aol.com[SMTP:mikonc...@aol.com] Sent: Tuesday, June 16, 1998 12:08 PM To: emc-p...@ieee.org Subject: Re: Emissions or not? Tim: Your receiver frequency is very close to the third harmonic of your transmitter frequency. Perhaps the reflection off the adjacent car reinforced that harmonic to just exceed the rejection characteristics of the receiver. You might test that with a different (reflecting) car (with the same angular location relative to your vehicle) to see if it was a mixing/retransmitting phenomena or just a reflection (or something else!). By the way, great question re emissions during immunity. That would sure open a Pandora's box! Mike Conn Owner/Principal Consultant Mikon Consulting
RE: Technical Papers
Hi, Paul 40 years of IEEE symposia (1955-1995) are available on CD rom from AMC Applied Microfilm at (617) 893-7863. I don't know, however, if that includes symposia held outside the US. David Brumbaugh Boeing ISDS Electromagnetic Effects -- From: Paul Smith[SMTP:smi...@stranduk.com] Sent: Thursday, March 26, 1998 12:27 AM To: emc-p...@majordomo.ieee.org Cc: smi...@stranduk.com Subject: Technical Papers Hello all, Does anybody know where I could get hold of the papers presented at the EMC International Symposium, Sendai, Japan from 1994 ? Any information greatly appreciated, Regards, Paul Smith EMC Engineer Strand Lighting Ltd, Mitchelston Industrial Estate, Kirkcaldy. Fife. KY1 3LY Tel: 01592 652333 Fax: 01592 653528 e-mail: smi...@stranduk.com
RE: Looking For Anechoic Foam
Jeff You didn't describe your lab, but if you have flourescent lighting in your lab (I assume this is a shielded enclosure?) all the foam and tiles in the world won't help. Use incandescent lighting instead. As for foam absorber suppliers, here are a few: Emerson Cuming 617-828-3300 Cuming Corporation 508-580-2660 Rantec 512-835-4684 Good Luck, Dave -- From: Bailey, Jeff[SMTP:jbai...@sstech.on.ca] Sent: Monday, March 16, 1998 7:06 AM To: 'emc-p...@ieee.org' Subject: Looking For Anechoic Foam Hello group, I am in the process of setting up a lab for doing pre-compliance EMI/RFI scans on our products, I am having a problem with ambient noise below 250MHz, the noise is thick and is greater than my limit lines. I am trying to come up with a solution more cost effective than ferrite tiles. I am thinking about anechoic foam. If anyone can provide me with leads to suppliers of new or used foam or for that matter any other suggestions it would be greatly appreciated. Thank You, Jeff Bailey Regulatory Compliance SST jbai...@sstech.on.ca
