When it gets really really small is it micro-fiche??? Gary PS If you're too young to know what I'm talking about please, please don't tell me I'm already prone to talking afternoon naps wrapped in a shawl.
-----Original Message----- From: Jacob Schanker [mailto:[email protected]] Sent: Wednesday, October 24, 2001 12:18 PM To: Doug McKean; EMC-PSTC Discussion Group Subject: Re: EFT Failures..Update! Excuse a slightly peripheral question. I always called it (an oily sort of brownish paper) Fish paper. I assumed the name came from the use of fish oil to prepare it in the 1800's. I see you are referring to it (is it the same thing?) as fische paper. Is that what it is sold as? Was it invented by Mr. Frederick Fische? How about a musical variant - Phish paper. :) Jack Jacob Z. Schanker, P.E. 65 Crandon Way Rochester, NY 14618 Phone: 716 442 3909 Fax: 716 442 2182 [email protected] ----- Original Message ----- From: Doug McKean <[email protected]> To: EMC-PSTC Discussion Group <[email protected]> Sent: Tuesday, October 23, 2001 1:14 PM Subject: Re: EFT Failures..Update! | | Discussion forum problems are challenging problems to | say the least. | | One thing you might want to try is to add a ground plane | into the bottom of the case with a piece of copper plate | or foil. Connect the plate (or foil) to the return side of the | power leads. Then, if you've got some fische paper (heck | even masking tape and several sheets of printer paper will | work in a moment of crisis), use that to insulate the plate | from the bottom of the board. And get the plate as close | as possible to the bottom of the board. | | But to really understand what's going on, you'd probably | have to set up something with current probes or differential | probes to follow the effect of the pulse. | | Most likely what's happening is the power supply is | acting as the source of the pulse out to your product | (obvious but bear with me) and the power leads and | your product are simply acting as an arm of a distorted | dipole, i.e., low impedance source (the power supply), | high impedance end of the arm (your product). | | Think for a moment of the power supply is the source | of a dipole and the two cables from it, the ac input cord | and the power output cord are the arms of a dipole. | | You're whole effort here is to disrupt that construction. | | Thus, it is possible that by adding ferrites to the product | end of the power leads, you could actually enhance this | dipole effect. This is possibly why adding ferrites to the | power cord to your product may not be working. In | other words, the ferrite increases the impedance of | the end of the dipole arm (your product) even higher. | | This has been demonstrated time and again by | Doug Smith in his many demonstrations. | | The effect of the plate *hopefully* disrupts this | pseudo-dipole construction. It may, it may not. | | The position of ferrites can be important. If you're | in a real bind, then you might want to simply load up | the entire construction with ferrites all over the place | to see if that works. Start removing ferrites until you | get a minimal setup that works and go from there. | The positions of the remaining ferrites in a working | setup can sometimes telll you what's going on in | a setup that's modelled after a dipole. | | Good luck ... | | Regards, Doug McKean | | | | ------------------------------------------- | 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: | [email protected] | with the single line: | unsubscribe emc-pstc | | For help, send mail to the list administrators: | Michael Garretson: [email protected] | Dave Heald [email protected] | | For policy questions, send mail to: | Richard Nute: [email protected] | Jim Bacher: [email protected] | | All emc-pstc postings are archived and searchable on the web at: | No longer online until our new server is brought online and the old messages are imported into the new server. | ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
