We are investigaing trafos that can be bought as well as the DIY trafos. See the photos of all the tested trafos so far. Currently considered trafos are Wurth CURR SENSE XFMR 1:750 40A SMD https://www.digikey.com/en/products/detail/w%C3%BCrth-elektronik/7492540750/14617535?s=N4IgTCBcDaIOwBYCcYCsCAMdUZAXQF8g Wurth XFMR FLYBACK AC/DC CONV 1.6MH TH https://www.digikey.com/en/products/detail/w%C3%BCrth-elektronik/750341689/3992735 Power Tran. WE-UNIT Offline 175uH .85A 26Ohm https://eu.mouser.com/ProductDetail/Wurth-Elektronik/749118205?qs=AXuZnX5ayYSjlaXcMUJyIA%3D%3D AUDIO XFMR 1.6KCT / 3.2 TH https://www.digikey.com/en/products/detail/tamura/MET-23/285665 Flyback Transformers 230V/6V https://eu.mouser.com/ProductDetail/Bourns/094931?qs=1Kr7Jg1SGW9TsHJ0%2FeggYQ%3D%3D MYRRA 44301 230V/6V 16VA https://export.farnell.com/myrra/44301/transformer-16va-6v/dp/1689092 MYRRA 44121 230V/6V 2VA https://export.farnell.com/myrra/44121/transformer-2va-6v/dp/1689053 MYRRA 44163 230V/ 2x6V 3.2VA kom https://export.farnell.com/myrra/44163/transformer-2-3va-230v-2-x-6v/dp/1214587 as well as custom made trafos using cores (and corresponding coil formers) ETD49/25/16 N87AL 3800NH https://eu.mouser.com/ProductDetail/EPCOS-TDK/B66367GX187?qs=wDNl1cNI0GsHvw8cOBvW9w%3D%3D 95 ETD Core ETD29 Ind 2900 nH 25% TOL https://eu.mouser.com/ProductDetail/Fair-Rite/9595293202?qs=FPho67LvealS12h1UIWe2A%3D%3D E20/10/6 N30 https://eu.mouser.com/ProductDetail/EPCOS-TDK/B66311G0000X130?qs=%2FsLciWRBLmASyA8%252B9RDdOA%3D%3D with wires AWG14 / 1.67mm dia., 5690V HY, 54m AWG18 / 1.02mm dia., 5130V HY, 137m AWG24 / 0.51mm dia., 4400V HY, 549m AWG34 / 0.16mm dia., 2630V HY, 2220m Due to the fact that no commercially available trafos are found that satisfy the needs of O-ESD five new trafos are produced (trafos_2024-11.jpg). 1) Core: ETD49/25/16 with 12 isolated layers of AWG 34 wire for secondary coil. 2) Core: ETD29/16/10 with 10 isolated layers of AWG 34 wire for secondary coil. 3) Core: ETD29/16/10 with 20 non-isolated layers of AWG 34 wire for secondary coil. 4) Core: EF20/10/6 with 6 isolated layers of AWG 34 wire for secondary coil. 5) Core: EF20/10/6 with 12 non-isolated layers of AWG 34 wire for secondary coil. Isolation between layers is 0.2mm high-voltage isolation paper for secondary coil. Primary coil for each trafo is made from 2 to 16 turns of isolated wire. The number of turns is varied in order to get the best performances. For push-pull configuration two primaries with center-tap are made.