RE: Graphing Software
I just found GRAPH at http://padowan.dk it's easy to use, it's free and will calculate the best-fit expression for your data. Fred From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Wan Juang Foo Sent: Sunday, May 18, 2003 10:31 PM To: lfresea...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: Graphing Software I have been using gnuplot (http://www.gnuplot.info/) for several years and it is free. :-) Tim Foo 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Self Oscillating Flyback Converters
Hi All, Does anyone out there know of a good source for theory of operation and design of self-oscillating flyback converters? Particularly the variable "on" time, "off" time, variable frequency types, also referred to as RCC circuits. Thanks, Fred Waechter SMPS Consulting --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com 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: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
Re: Temperature Measuring of Magnetic Components
Kamran, As John Crabb pointed out, making measurements at different points will give you some variation due to hot spots etc. What most people miss is that thermocouple readings are affected by magnetic fields. To get a correct reading, turn power off and take a reading immidiately after the reading stabilizes. I have seen the reading change as much as 10-15 degrees when the power is turned off. Usually the reading jumps higher. I also noticed that how much the reading changes depends on where I placed the thermocouple. Usually the biggest change is when the thermocouple is placed between the core and the coil. When trying to correlate your readings with your vendor's make sure you're using the same type of thermocouple and measure at the same point. Find out if they made the measurement with power on or off. Several years ago I had the same problem. I called the manufacturer of the thermocouple I was using. They could not tell me how much my reading would change but recommended taking the reading with power off. Hope this helps. Regards, Fred Waechter Kamran Mohajer wrote: > Hello EMC-PSTCers, > > I wonder if anyone knows of the method of measuring temperature limits on > magnetic components. I happen to get involved in this and found that my > results are different than the vendors result by as much as 10-15 degrees on > measuring on a same magnetic component. Even applying the thermocouple to > different location on a coil seems to give you different results. Is there a > method that I should be following to measure temperature with thermocouples > methods, not change of resistance, on magnetic parts such as transformers, > coils, etc.? > > Thanks, > > > *** > Kamran Mohajer > DSL Compliance Lead > Cisco Systems, Inc. > Phone(408)-525-6121 > Fax(408)527-0495 > kmoha...@cisco.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). -- Fred Waechter Sr. Applications Engr. SMPS Consulting w...@skybest.com Phone/FAX: 336-246-5236 - 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).
Inductance bridge
I have a need for an inductance bridge which can measure the inductance of power chokes with high DC currents up to 50 amps. Can anyone tell me where I can buy such equipment? Thanks, Fred Waechter w...@skybest.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).
Bellcore GR1089
Hi all, I'm a consultant to a power supply manufacturer on the west coast. They have a potential customer who asked if a particular power supply could meet Bellcore GR1089. Neither the factory or I are familiar with this standard. Does anyone know what it refers to and/or where I can get a copy of this standard? Thanks in advance for your help. -- Fred Waechter Sr. Applications Engr. SMPS Consulting w...@skybest.com Phone/FAX: 336-246-5236 - 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: Ground Hog Day.
Hi Chris, The same thing is happening to me. I was wondering if there was a problem with my local server not deleting my files after I download. I was just getting ready to call my local provider when I got your message. Anyone know what's going on? Fred Waechter Chris Dupres wrote: > Hi EMC and safety folk. > > Is it me, or is something re-sending a load of mails from the group over > and over again. > > I clear my mail box, and during the next few hours a whole load of mails > dated 20 Feb re-appear in my box. I clear them, and it happens again. > I've received the same mails on FCC stuff and CTI about five or six times > thus far. They were interesting the FIRST time! > > Anyone else getting this phenomenon? > > Chris Dupres > Surrey, UK.
Design Software
Hi, I am looking for some design software for switch mode power supplies. Software for transformers/chokes, circuit design, emi/emc, etc. If anyone knows of a good source for these items please let me know. Also any comments of your personal experience with these programs would be useful in helping me make a decision on what to buy. Thank you. -- Fred Waechter Sr. Applications Engr. SMPS Consulting w...@skybest.com Phone/FAX: 910-246-5236
Re: Where to get Mil-Std
Tom Bao wrote: > > Anyone please tell me where to get Mil-Std? I used to > know it's somewhere in Princeton, NJ or Philidelphia > area. Your help is greatly appreciated. > > Regards, > Tom > > > RCIC - http://www.rcic.com > Regulatory Compliance Information Center > Tom, Try: Standardization Document Order Desk 700 Robins Ave. Building 4, Section D Philadelphia, PA 19111-5094 (215) 687-2687 I got this address out of my MIL-HDBK-217F. If this is the correct address please inform the rest of us. Thanks, -- Fred Waechter Sr. Applications Engr. SMPS Consulting w...@skybest.com Phone/FAX: 910-246-5236
EN61000-3-2
Hi All, I keep hearing conflicting stories about when EN61000-3-2 takes effect. Is it still June 1998 or has it been delayed until Jan. 1, 2001. Does anyone know. Please help! Thanks. -- Fred Waechter Sr. Applications Engr. SMPS Consulting w...@skybest.com Phone/FAX: 910-246-5236
IEC1000-3-2
Hi all, I represent a company which manufactures low end/low cost power supplies. We are very concerned with the new harmonic standards which will become effective in Europe in mid 1998. We are looking for a low cost solution to improving power factor/harmonics in our products. Using one of the many power factor correction IC's available on the market is usually too expensive, not to mention overkill, for most low end power supplies. The problem we are running into is that customers want power factor correction but are unwilling to pay for it. Any idea where we can get some help? Thanks, Fred Waechter Sr. Applications Engr. SMPS Consulting w...@skybest.com
IEC801-2
This is in relation to testing a Class II, 2 wire system to the European IEC801-2 electrostatic discharge requirements. The system is used in an environment that may have no earth ground, or earth may be tied back at the substation, or earth may be tied at multiple points along the AC neutral, or an earth ground rod me be available at the users end installation. On application of an ESD pulse to this system, the energy in the ESD pulse will try to find the shortest path to earth ground. 1. Is there a preferred test method to insure conformity of testing between test laboratories, and also the users end installation as their methods of earthing may certainly differ? 2. Would different methods of earthing result in differing results due to differing amounts of system discharge before the next ESD pulse is applied to the system? These questions were prompted by results obtained at two different test laboratories. The systems passed when tested at an independent test lab. in Taiwan. The same units failed when tested by a lab. in the U.S. Thanks for your help.
Fuse Selection
Hi all, One of my colleagues has posed the following questions. He has contacted several fuse manufacturers without much success. Can anyone out there help him out? I need some ideas/help regarding correct fuse selection. 1. When testing to IEC801-5 surge test, I want to be sure that the fuse will open but not physically disintegrate. There is a MOV directly after the fuse. 2. For fuse selection in an environment threatened by lightning, is IxIxT rating or interrupt rating more important? I assume IxIxT for normal operation and interrupt rating for surge operation. 3. IEC127 Fuse Standard defines interrupt rating between 35A - 1500A @ 250Vac. UL198.G/CSA 22.2 No. 59 defines interrupt rating of 10,000A @ 125 Vac. 4. IEC801-5 calls out waveform Voltage 1.2us/50us 6000V Current 8us/20us 3000A 5. Question - How can I be sure for European fuse application, if I apply 3000A current surge, that fuse will not disintegrate, as fuse standard calls out 1500A? I accept different manufacturers will probably have different ratings which will exceed 1500A spec., by different amounts. Thanks for your help.
IEC1000-3-2
I am trying to understand the IEC1000-3-2 standard. My equipment is classified as Class D. Table 3 - Limits for Class D Equipment, has two columns for the limits, one is maximum harmonic current per watt and the other is maximum permissible harmonic current. The two columns don't appear to agree. Since the maximum input power for Class D equipment is 600W, should the maximum permissible harmonic current for the third harmonic not be 600x.0034 or 2.04A? The table gives a maximum limit of 2.30A. The only harmonic that agrees with my interpretation is the fifth. All the rest are higher than when doing the calculation. Am I missing something? I do not have a copy of EN61000-3-2, what is the difference between the two standards? Thanks for you help. Fred Waechter SMPS Consulting w...@skybest.com
