From: "Terrell W. Fritz"
Date: Fri, 25 May 2001 14:37:50 -0600
Subject: Re: [TSSP] Loss due to ultrasonic mechanical vibration of
Hi Paul, I notice in my solid state gap work that you can hear the current going through the wires (everything else is dead silent). Magnetostriction I think is the term and there is the magnetic attraction between wires with opposing currents. By knowing the current profile and the distance and mass of the conductors, one could work out the force and how far they move. I am sure the secondary vibrates a bit but I would think the currents in the secondary would cause far less vibration. My SS coil does not seem to vibrate the secondary but it would be at 350kHz which is hard to hear :-)) I have never heard of polyurethane cracking or wear in secondary wiring do to vibration of this type. There is also corona around the coils and stuff here and there (like off the tope edge of the secondary) that is a loss that may be significant. the field stress plots coming up will show these points. Cheers, Terry At 10:46 AM 5/25/2001 +0100, you wrote: >Hi All, > >Fishing around for additional loss mechanisms for a secondary coil, >has anyone ever looked into the possibility that mechanical vibration >of the winding at the RF frequency could be responsible for some part >of the overall dissipation? > >Perhaps a winding which is less than perfectly rigid might cause >minute inelastic deformations of the winding/former, especially in >something like sonotube which presumably damps sound vibrations >rather well. > >Just something to ponder. > >Cheers, >-- >Paul Nicholson, >Manchester, UK. >--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.