RE: Signatures
I haven't found such capability in Microsoft Mail. Anyone? -Heber Farnsworth .nosig :-( -- Can anyone tell me how to create such a signature file with Windows Messaging?
Results of attached files tests
Hi All Here are the results of my test to see who could handle a SMALL attached file encoded in MIME. First let me thank all the people who responded. There were (to date!) 52 replies. Although there was 3 strange replies-2 were messages they were out of the office (Is this automatic?) The overwhelming response was that 50 people could read my WORD/MIME encoded message without any problems! Only 2 people stated they could not decode the message. Also, many told me the decoding was automatic, and although the others didnt say (I never asked!) I got the impression that it was automatic for most of them also! I also received a few comments that decoding UUE attachments was a pain I have notice a great deal of discussion about to attach or not to attach recently. I recover all my messages at home with a PC and a 14.4KB modem. I regularly recover files that are about 350k and I find the wait not too bad! But as others have pointed out, a few of these on a net can clog the system, or from a hotel etc. can be very frustrating and even costly! I was about to say that Unfortunately, I dont think there are too many files that would be 50k (as suggested) or less, that would add significant extra inf.! However, I just checked a one page WORD file that I had generated a short while ago that included two block diagrams, and it was only 28k (Note: the fax version, which is the way I sent it, was 38k) . So, we should keep up with technology-and this test seems to support that more than 90% of the subscribers can handle it. My opinion is that, right now:- 1) Any attached files should be limited in size (50k has been recommended and seems fine to me!) and definitely be in MIME format. 2) Any larger files should be available elsewhere for individual downloading, or maybe by direct request to the sender. Regards Tony OHara TMC LARCTEC Marketing--EMC Sales Colorado tonyoh...@compuserve.com
RE: Transformer: IEC 950 VS. IEC 601-1-1
Mariano Fe de Leon wrote the following: My response is below. Re: Transformer Construction.. IEC 950 VS. IEC 601-1-1 The transformer is used in an equipment evaluated per IEC 601-1-1. The primary concern is the creepage distance between the primary and secondary windings The transformer uses a multiple (triple) insulated wire for either primary or secondary windings The wire insulation consists of three (3) layers extruded FEP material, each layer is 1 mil (0.0254 mm). The wire was tested by VDE per IEC 950 Annex U and a certificate of conformity issued by VDE (certificate includes following information: 400Veff, 1000Vp; 500kHz; F; 'geprufte Abschnitte - 2.9.4.4. 5.3, Anhang C, Anhang U'). Clause 2.9.4.4 stipulates the following: * allows wound components without interleave insulation if the winding wire is insulated with polyimide or FEP and complies with annex U. * three constructional layer of insulation (of polyimide or FEP) satisfy the criteria for reinforced insulation. * two such wires crossing at an angle between 45 and 90 degrees only require an insulating sleeving or sheet material to relieve mechanical stress at the crossover point. This clause appear to indicate that the creepage distance requirement (per table 6) for reinforced insulation between the primary and secondary windings does not apply to this type of construction (using triple insulated wire for the winding). Is this a valid assumption?? Does clause 2.9.4.4 imply that both the primary and secondary windings of the transformer must be the triple insulated wire or does clause 2.9.4.4 allow the use of triple insulated wire for the primary and an enameled magnet wire for the secondary (or enameled magnet wire for the primary winding and triple insulated wire for the secondary winding)?? Comments please... As mentioned above, the transformer will be evaluated per IEC 601-1-1 to comply with the creepage distance for reinforced insulation.. If the above assumptions are valid, I am interested in receiving comments to determine if a transformer that complies with thecreepage distance requirements of IEC 950 be considered in compliance with the creepage distance requirements of IEC 601-1-1. Thanks. Mariano Fe de Leon Electrical Engineer ArthroCare Corp e-mail: fedel...@arthrocare.com Ph.: (408) 736-0224, Ext 305 Fax: (408) 736-0226 Hello Mariano: I am fairly familiar with the IEC 950 standard; Regarding the IEC 950 issues with your transformer, and coming from a transformer manufacturers point of view who is heavily into the Information Technology (IEC 950) market, I agree with Rich, and could not add much more. I recently obtained a copy of the IEC 601-1 standard, and am not too familiar with it yet. I do not, however, believe it is safe to use an IEC 950 transformer in an IEC 601-1 transformer application. The requirements, for instance, for REINFORCED or DOUBLE insulation are not the same in these two standards. For REINFORCED INSULATION, at a working voltage anywhere from 150VAC to 250VAC, IEC 601-1 table V requires a minimum 4.0 kV dielectric test. Table 18 of IEC 950 requires only a 3.0 kV dielectric test. Also, the minimum creepage distance for IEC 601-1 for REINFORCED INSULATION at 250VAC is 8.0mm (IEC 601-1 table XVI), whereas table 6 of IEC 950 requires only 5.0mm. Clearances, IEC 601-1, 5 mm, and IEC 950 table 3, 4.0mm. Also, and this is the most important to the transformer and wire in question, the layered insulation requirements of IEC 601-1 are more stringent. If using two layers of insulation, IEC 601-1 requires a minimum 0.3mm thickness per layer. IEC 950 has no such requirement. With three layers, (clause 57.9.4 e of IEC 601-1) there is no minimum thickness requirement, but the dielectric strength requirement per layer is higher than that in IEC 950. I have a sample of annex U wire (from a different vendor than you speak of), and the 0.3mm minumum thickness is certainly not met! Concerning construction and dielectric requirements of Mains Supply transformers in general (which I assume you are talking about), IEC 601-1 clause 57.9.4 requirements appear (to me) to be more stringent than IEC 950 requirements. Also, see clause 57.9.4 g) of IEC 601-1. Leadout sleeving requirement is more stringent in the 601 standard than in 2.9.4.4 of the 950 standard. Sorry to burst your bubble, but unless the transformer is overdesigned with regard to 950, I do not think it will pass IEC 601-1. hope this helps, Mel PedersenMidcom, Inc. Homologations Engineer Phone: (605) 882-8535 mpeder...@midcom.anza.com Fax:(605) 886-6752
RE: We have, under development, a large piece of equipment which
On site testing via TCF route seems to be a sensible solution. We had a very comprehensive presentation during the CE marking forum at SEMICON WEST about the subject. There are a number of competent bodies that can help you. Try http://www.semi.org/ this is a interesting site. Matthias R. Heinze TUV Rheinland -- From: James Sketoe[SMTP:jske...@mdc.com] Sent: Monday, July 21, 1997 5:01 AM To: emc-p...@ieee.org Subject: We have, under development, a large piece of equipment which We have, under development, a large piece of equipment which we plan to sell in Europe. Its size is 2.5 meters wide, 2.1 meters high, and up to 13 meters long. Its weight is hundreds, if not thousands, of kilograms. Power requirements are 3-phase 440 vac with line currents exceeding 400 amps. Obviously, the unit is a class A heavy industrial product. My request is for advice about qualifying the unit. Methods we are considering include emissions testing on-site in the manufacturing plant. Conducted emissions will be measured using a high voltage probe such as the EMCO 3701. Radiated emissions tests would be done when the ambient is low, for example Sunday between 0100 and 0300. Immunity tests are more difficult. Do you have any suggestions?
Off Topic - Telephone design info.
I'm not quite on the correct list for this but - Do any of you know of a good book that details how the phone systems work (what's a ring, what a tip, etc). Also a book that covers what regulations are involved to gizmos that connect to the phone lines in a home. Basically, if I could learn how to design a telephone I'd know what I need for an upcomming project. Thanks, Jon Bertrand j...@cirris.com
Re: Off Topic - Telephone design info.
Jon, I bought a SAMS book from Radio Shack (Tandy - to those oversees) about a dozen years ago that explained simple telephones, and a little more. Tip Ring comes from the old plugs the operators had to use to manually connect calls, the was a Tip, an insulator/ gap, and a Ring, followed by another insulator. At least that's the explaination I was given when I started in this business 15 years ago. TREG would be a better forum for this question. I hope this helps. Best regards, Stephen C. Phillips All opinions are my own. At 11:34 AM 7/22/97 MST, you wrote: I'm not quite on the correct list for this but - Do any of you know of a good book that details how the phone systems work (what's a ring, what a tip, etc). Also a book that covers what regulations are involved to gizmos that connect to the phone lines in a home. Basically, if I could learn how to design a telephone I'd know what I need for an upcomming project. Thanks, Jon Bertrand j...@cirris.com
Re: Transformer: IEC 950 Versus IEC 601-1-1
Hello from San Diego: 2.9.4.4 stipulates the following: * allows wound components without interleave insulation if the winding wire is insulated with polyimide or FEP and complies with annex U. * three constructional layer of insulation (of polyimide or FEP) satisfy the criteria for reinforced insulation. * two such wires crossing at an angle between 45 and 90 degrees only require an insulating sleeving or sheet material to relieve mechanical stress at the crossover point. This clause appear to indicate that the creepage distance requirement per table 6) for reinforced insulation between the primary and secondary windings does not apply to this type of construction (using triple insulated wire for the winding). Is this a valid assumption?? Creepage distance is the shortest distance between two conductors measured across the surface of insulation. For conventional magnet wire, the insulation is considered brittle. For safety purposes, conventional magnet wire is considered uninsulated. Therefore, the transformer construction must incorporate the applicable creepage distances between primary and secondary magnet wires. For multiple-insulated magnet wire, the insulation is considered robust. Primary and secondary insulations may be in intimate contact with each other, i.e., need not comply with creepage requirements because the insulation is considered solid insulation. In a transformer employing multiple-insulated magnet wire, creepage distance applies to the UNINSULATED (stripped) conductor, not to the insulated conductor. Does clause 2.9.4.4 imply that both the primary and secondary windings of the transformer must be the triple insulated wire or does clause 2.9.4.4 allow the use of triple insulated wire for the primary and an enameled magnet wire for the secondary (or enameled magnet wire for the primary winding and triple insulated wire for the secondary winding)?? Comments please... Sub-clause 2.9.4.4 states that insulation complying with Annex U is considered to be BASIC or SUPPLEMENTARY insulation. Two such wires that are adjacent to each other are considered to be separated by DOUBLE insulation. If your secondary winding is intended to be SELV, then you must use triple-insulated magnet wire for BOTH primary and secondary windings. In such construction, the primary wire insulation is considered BASIC insulation, and the secondary wire insulation is considered SUPPLEMENTARY insulation. If your secondary winding is either ELV or more than ELV, then you only need BASIC insulation. In this case, the secondary winding can be ordinary enamel insulation. Best regards, Rich - Richard Nute Quality Department Hewlett-Packard Company Product Regulations Group San Diego Division (SDD) Tel : 619 655 3329 16399 West Bernardo Drive FAX : 619 655 4979 San Diego, California 92127 e-mail: ri...@sdd.hp.com -
