I need a high power transformer with 240VAC primary at 10-16A and secondary of 6VAC 350-400A. I calculated that I would need a transformer core with cross sectional area of about 45cm2 to able to use about 1:1 windings per voltage.
My question is, how well will 0.5mm thick 1020 steel with 10-50micron zinc plating compete as tranformer core? I have two choices: take apart a bunch of microwave transformers or make one myself, and getting silicon steel sheets is impossible at any sensible price for me.
For getting 45cm2 CSA im planning on making a transformer EI type with core size 95x50mm, as using 100 pcs stack of 0.5mm plates.
Best Answer
If you can re-use a transformer core, do so. Dismantle and re-assemble a 2.4kw transformer if you can find one at that sort of power rating - it may be a mains isolation transformer - you may only have to rewind the secondary - or find a commercial rewinder. Or parallel a few smaller transformers.
The Si steel laminations pack together densely because they are formed with due regard for flatness, and the Si steel has relatively low loss (magnetisation) and relatively high saturation flux density. In all three of these factors you will lose out using off-the-shelf commercial sheet steel - unless you have specialist punch equipment, in which case you may be able to achieve the required flatness. (Otherwise expect it to buzz loudly and get warmer than a commercial core).
Spot welder, or heater supply for a retrocomputing project?