1999 by the Institute of Electrical and Electronics Engineers, Inc. Core materials and winding wire for audio and rf transformers have been investigated to 500C. Audio cores of 2 V Permendur had parameter stabil ity from 25 to 500C and during aging at 450C. High frequency ferrite material, Mix 63, displayed usefulness up to 300C. Both anodized al.umi.num and ceramiccoated copper wire function to 500C in low voltage or large gauge applications. Components based on these materials operate reliably to 500C.
