RE: Heat Calculation
http://www.ios.doi.gov/pam/eneratt2.htm Give the above link a try. 3412 BTU = 1 kWh 1 watt = 3.412 BTU/Hr 293 watts = 1000 BTU/Hr. Watts dissipated = watts inDon't confuse volt amps with watts. Jim Allan Senior Compliance Engineer Milgo Solutions Inc. E-mail james_al...@milgo.com -Original Message- From: s_doug...@ecrm.com [SMTP:s_doug...@ecrm.com] Sent: Tuesday, April 27, 1999 10:47 AM To: emc-p...@majordomo.ieee.org Subject: Heat Calculation Hello, Does anyone know how to compute heat dissipation for a product given mains power input (volts, amps, watts)? Our spec sheets always list heat dissipation (e.g. 1,000 BTU/hour) for each product and I wonder where the number comes from and why it never changes from one product to the next. Thanks for any comments received. Scott s_doug...@ecrm.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). - 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: Characterizing a screen room
You cannot perform a characterization that will mean anything. The room will have standing waves that will be strongly dependant upon the size and placement of the unit under test, the placement of the antenna and the frequency. The best that you can do is perform a pretest to find the frequencies of interest then move to the OATS for a final test. A screen room can be used for before and after comparison of EMI fixes, as long as the unit under test is not moved. But once you have a fix, you will still have to test on the OATS. Actually, you can perform diagnostic tests in a lab if you set the antenna 1 m away. Just keep other sources a few meters away from the antenna. To do what you want to do, you will need a compact semi-anechoic chamber at a cost of about $140, 000 including the turn table. We just started using one that complies with the NSA test given the constrant that we can't run the antenna up to 4 m. We have found up to 6 dB of variation between the chamber and the OATS. However the variation is small enough that we pretest and fix in the chamber and only move to the OATS once we have confidence that we have at least 6 dB of margin. So far so good, but I don't doubt that some day we will end up out of compliance at the OATS even with 6 dB of margin in the chamber. -- From: plaw...@west.net [SMTP:plaw...@west.net] Sent: Tuesday, April 27, 1999 12:22 PM To: emc-p...@majordomo.ieee.org Subject: Characterizing a screen room My company is planning to purchase a screen room for radiated emissions precompliance testing. I'm aware that reflections can cause resonances and drastically influence readings. What kind of testing could I do to characterize the room (aside from simple experience)? -- Patrick Lawler plaw...@west.net - 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: Heat Calculation
Scott, 1W/hr = 3.413BTU/hr 1Kw/hr = 3,413 BTU/hr John A. Juhasz Product Qualification Compliance Engr. Fiber Options, Inc. 80 Orville Dr. Suite 102 Bohemia, NY 11716 USA Tel: 516-567-8320 ext. 324 Fax: 516-567-8322 -Original Message- From: s_doug...@ecrm.com [mailto:s_doug...@ecrm.com] Sent: Tuesday, April 27, 1999 10:47 AM To: emc-p...@majordomo.ieee.org Subject: Heat Calculation Hello, Does anyone know how to compute heat dissipation for a product given mains power input (volts, amps, watts)? Our spec sheets always list heat dissipation (e.g. 1,000 BTU/hour) for each product and I wonder where the number comes from and why it never changes from one product to the next. Thanks for any comments received. Scott s_doug...@ecrm.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). - 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: Heat Calculation
Hi Scott: Under the law of the conservation of energy, all of the energy going into a product must be accounted for. Energy is measured in joules. One joule is one watt-second. One watt is one joule/second. All of the watts entering the product must be accounted for. All of the watts are converted to some other form of energy. If the product has moving parts, some of the electrical energy is converted to kinetic energy. (The kinetic energy is ultimately converted to thermal energy in the friction of the mechanical system.) If the product has light output (i.e., LEDs, CRT), some of the electrical energy is converted to light energy. (This conversion is very inefficient; very little energy is converted to light energy.) If the product has semiconductors and resistors and similar devices, some of the electrical energy is converted to thermal energy in those devices. So, for all practical purposes, all of the electrical energy is converted to thermal energy. One watt is 3.41443 BTU/hour. So, for all practical purposes, the product dissipates 3.41443 BTU/hour/watt. If your product is disspating 1000 BTU/hour, then its input must be 1000/3.41433 or 293 watts The BTU/hour is a function of the input power (watts). If the input power changes from product to product, then the BTU/hour must likewise change from product to product. Best regards, Rich - Richard Nute Product Safety Engineer Hewlett-Packard Company Product Regulations Group AiO Division Tel : +1 619 655 3329 Effective 6/12/99: +1 858 655 3329 16399 West Bernardo Drive FAX : +1 619 655 4979 Effective 6/12/99: +1 858 655 4979 San Diego, California 92127 e-mail: ri...@sdd.hp.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: Heat Calculation
Scott, One British thermal unit (Btu) is the quantity of heat or thermal energy required to raise the temperature of one pound of pure water one degree F. The unit for thermal energy is the joule (J). One kilojoule = 0.9478 Btu. The watt (W), equal to joule per second (J/s), is used for power, where one watt = 3.412 Btu per hour. Regards, Kevin J. Hight -- Regulatory Compliance Engineer Exabyte Corporation 1777 Exposition Drive, Building #7 Boulder, Colorado 80301 Phone: 303-417-5534; Fax: 303-417-5710 Pager: 303-855-7029; Email: kev...@exabyte.com -Original Message- From: s_doug...@ecrm.com [mailto:s_doug...@ecrm.com] Sent: Tuesday, April 27, 1999 8:47 AM To: emc-p...@majordomo.ieee.org Subject: Heat Calculation Hello, Does anyone know how to compute heat dissipation for a product given mains power input (volts, amps, watts)? Our spec sheets always list heat dissipation (e.g. 1,000 BTU/hour) for each product and I wonder where the number comes from and why it never changes from one product to the next. Thanks for any comments received. Scott s_doug...@ecrm.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). - 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: Colors of indicators
It is not so much that red not be used, but that it not be used for safe, normal, expected conditions of the equipment. One example of this is a PREFERENCE stated in EN 60204-1 section 10.3.2. (It does allow deviations based on specific agreement with customers.) I think the underlying thought is that red lights tend to indicate dangerous conditions from which an operator should run away or seek help immediately. I think an old spin on red lights may be that red for power on, for example, means this thing is armed and ready to fire, so watch out. However, it is expected these days that idle equipment is not hazardous and will not start up or take actions unexpectedly. Now power on is a normal safe condition for equipment (or should be, at least) and so the 'proper' color for power on lights is green or white. Other benign equipment states, such as indicators for moving parts being in a normal, expected location, should be treated similarly. Red LED's appeared in products alot because they were originally the cheapest, most available color. I only have access to UL 1950, but its 1.7.8.2 seems nearly in line with EN 60204-1 in that it allows red indicators provided that it is clear that safety is not involved. Lauren Crane Eaton Corporation. -Original Message- From: Allan, James [SMTP:james_al...@milgo.com] Sent: Tuesday, April 27, 1999 8:27 AM To: 'emc-pstc' Subject: Colors of indicators Several years ago I remember that indicators could not be red in color. This requirement seems to have gone away per EN60950 1.7.8.2. Could the group provide me with a bit of history as to where the original requirement to be not red came from. Was it a part of the German GS mark requirements or did it have a wider application in Europe than just GS marking? No great acts hang in the shadow of the answer, just a bit of curiosity. Jim Allan Senior Compliance Engineer Milgo Solutions Inc. E-mail james_al...@milgo.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). - 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: Heat Calculation
Multiply watts by 3.415 to obtain BTU/hour. To compute the input power you need to multiply the rms voltage, rms current and power factor. Or you can cheat and use a wattmeter. -- From: s_doug...@ecrm.com [SMTP:s_doug...@ecrm.com] Sent: Tuesday, April 27, 1999 10:47 AM To: emc-p...@majordomo.ieee.org Subject: Heat Calculation Hello, Does anyone know how to compute heat dissipation for a product given mains power input (volts, amps, watts)? Our spec sheets always list heat dissipation (e.g. 1,000 BTU/hour) for each product and I wonder where the number comes from and why it never changes from one product to the next. Thanks for any comments received. Scott s_doug...@ecrm.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). - 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: Harmonics
From what I remember in High School and College, Fo (actually it was omega-naught) was originally used to designate the resonant frequency of an LC network. I would then surmise that Fo, over the years, has been carried over to designate the primary frequency of oscillation. Fourier series and harmonic numbering have liberally used Fo as the fundamental frequency but, I have also seen technical texts with F1 as the fundamental especially when other hamonics are mentioned. As someone already stated, it is a matter of semantics and who wrote it. --- ed.pr...@cubic.com wrote: Robert and Scott: I agree that the fundamental is the First Harmonic. Now, to muddy things up some more, how does all this discussion square with calling the fundamental Fo? ;-) Ed snip === Best Regards Hans Mellberg EMC Consultant _ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.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).
Characterizing a screen room
My company is planning to purchase a screen room for radiated emissions precompliance testing. I'm aware that reflections can cause resonances and drastically influence readings. What kind of testing could I do to characterize the room (aside from simple experience)? -- Patrick Lawler plaw...@west.net - 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: Heat Calculation
According to a table of Conversion Factors that I found on page 18 of the December 1991 Electrical Manufacturing magazine, and keep stashed in my dictionary here at work: Watts * 3.413 = BTU's/hour I use the maximum input power (wattage) that we have measured for a product in its various operating modes, after it has been turned on and warmed up for a while. Every time that I have been asked the question it is in the context of calculating the air-conditioning requirements for a customer site. John Barnes Advisory Engineer Lexmark International s_douglas%ecrm@interlock.lexmark.com on 04/27/99 10:47:28 AM Please respond to s_douglas%ecrm@interlock.lexmark.com To: emc-pstc%majordomo.ieee@interlock.lexmark.com cc:(bcc: John Barnes/Lex/Lexmark) Subject: Heat Calculation Hello, Does anyone know how to compute heat dissipation for a product given mains power input (volts, amps, watts)? Our spec sheets always list heat dissipation (e.g. 1,000 BTU/hour) for each product and I wonder where the number comes from and why it never changes from one product to the next. Thanks for any comments received. Scott s_doug...@ecrm.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). - 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).
Heat Calculation
Hello, Does anyone know how to compute heat dissipation for a product given mains power input (volts, amps, watts)? Our spec sheets always list heat dissipation (e.g. 1,000 BTU/hour) for each product and I wonder where the number comes from and why it never changes from one product to the next. Thanks for any comments received. Scott s_doug...@ecrm.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).
Colors of indicators
Several years ago I remember that indicators could not be red in color. This requirement seems to have gone away per EN60950 1.7.8.2. Could the group provide me with a bit of history as to where the original requirement to be not red came from. Was it a part of the German GS mark requirements or did it have a wider application in Europe than just GS marking? No great acts hang in the shadow of the answer, just a bit of curiosity. Jim Allan Senior Compliance Engineer Milgo Solutions Inc. E-mail james_al...@milgo.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).
Jobs in Canada
To everyone, I have just arrived in Canada from France and have landed immigrant status. I am looking for work in either EMC, Regulatory Compliance or Quality Management. I have a PhD in Electronics with a specialization in EMC and six years experience in this field. I have knowledge of Safety, Telecommunications and Radio requirements. I am also certified in Quality Management. If anyone knows of any opportunities in Canada in these fields, could you please let me know. I would be happy to pass on a copy of my resume. Thank you very much. Damien Warin d_wa...@yahoo.com _ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.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).
Jobs in Canada
To everyone, I have just arrived in Canada from France and have landed immigrant status. I am looking for work in either EMC, Regulatory Compliance or Quality Management. I have a PhD in Electronics with a specialization in EMC and six years experience in this field. I have knowledge of Safety, Telecommunications and Radio requirements. I am also certified in Quality Management. If anyone knows of any opportunities in Canada in these fields, could you please let me know. I would be happy to pass on a copy of my resume. Thank you very much. Damien Warin d_wa...@yahoo.com _ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.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).
NPSS, Inc. 1999 Meeting Schedule, Next Meeting 4/28/99 (fwd)
The Northeast Product Safety Society, Inc. 2 Milliston Rd. Suite 2GN, Millis, MA 02054 U.S.A. The Northeast Product Safety Society, Inc. meets on the fourth Wednesday of each month (except for July, August and December) and the third Wednesday in November. Unless otherwise noted (See June and November dates), meetings are held at EMC Corporation's Customer Briefing Center at 42 South St., Hopkinton MA at 7 p.m. NPSS, Inc. was incorporated as a non-profit organization (501(c)3) in 1991, after approximately 3 years of informal activities. Directions: On I-495 take exit 21B, turning right and make a left onto South St. at the first traffic light. Take your second right into EMC's parking lot. The meeting starts at 7:30 p.m. The group usually gathers at 7 for light refreshments (thanks to EMC Corporation) and networking. Pre-meeting social and dinner: Socializing at O'Tooles Pub-North Pond House from 5:00 to 6:45 PM, where food and drink may be purchased. O'Tooles is on South Street, on the right, a bit past the meeting site, noted above. You will often find us in the dining room (to the rear of the building). Park in back of the restaurant and enter thru the back door. - AdCom Meeting: April 28th, Hopkinton MA, 5:30 p.m. (Dynasty Chinese Rest.) - 1999 Meeting Schedule: January 27th, 1999Speakers: Mr. Jim Linehan, Operations Mgr, ITS Mr. Chuck Kolifrath, Dir. Of Quality, Conformity Americas Div., ITS Subject: The CB Scheme - An Update February 24th, 1999 Subject: Current Status of the EN 61000-3-2 3 Harmonics and Flicker Requirements Speaker: Mr. Tom Mahr, Gen. Mgr. Voltech Inst's Morrisville NC March 24th, 1999 Subject: Surge Standards for UPS and Surpressors in Accordance with UL-1449 (Tentative) Speaker: Mr. Ron Bell, Engineer, American Power Conversion Corp. April 28th, 1999 Subject: EN 60950, Clause 6 - Telecom Additions; Definitions Limits of TNV circuits Separation requirements for TNV circuits Accessibility Battery Compartments Protection of Telecom Network Personnel TNV Leakage Current Tests Protection from network overvoltage Australian National Deviations Speaker: Mr. Dan Clarkson, Compliance Engineer, BABT Product Service May 26th, 1999Subject: Sheparding Proposals thru the NEC/NFPA; Methods employed to successfully change the status-quo within a highly structured and necessarily bureaucratic process. The lessons learned are directly applic- able to any effort to change any Code or Standard that employs ANSI's consensus code revision process. Speaker: Mr. Bill Keezer, Project Manager, Bose Corporation; At Bose since 1973 Bill is responsible for some of Bose's most cri- tically acclaimed product designs. He is a holder of 5 patents and active in a wide variety of national committees. June 23rd, 1999 Subject: ANNUAL RECRUITMENT DINNER Holiday Inn, Marlborough MA Speaker: Mr. Bill von Alven, (FCC, retired) July - No Meeting August - No Meeting September 22nd, 1999 Subject: Joint Meeting with IEEE EMC Society Subject To Be Announced Speaker: October 27th, 1999Subject: Speaker: November 17th, 1999 Subject: 5th Annual Vendors' Night, Holiday Inn, Marlborough MA December - No Meeting - Happy Holidays !!! Messages, Questions Comments can be sent to n...@safetylink.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
