10-07-2018, 10:48 AM
"Best way with a transformer-from-scratch, is design the low voltage secondaries first, round them to a suitable integer, then fine-tune the voltage by selecting appropriate primary turns." Good idea Paul.
Talking of winding toroid primary's I haven't had a go at this yet, having always used prewound tfmr's, just replacing the secs, but guess the basic gist is to calculate the toroid core area - pretty simple so far. I saw one video where they wound the primary and checked every so often with a lightbulb in series I think with said pri until the bulb stopped glowing. For the life of me I can't figure out what they're doing here.
The tricky thing with using unknown cores is that there is no data, no BH curves or type of material used for the core etc.
Andy.
Talking of winding toroid primary's I haven't had a go at this yet, having always used prewound tfmr's, just replacing the secs, but guess the basic gist is to calculate the toroid core area - pretty simple so far. I saw one video where they wound the primary and checked every so often with a lightbulb in series I think with said pri until the bulb stopped glowing. For the life of me I can't figure out what they're doing here.
The tricky thing with using unknown cores is that there is no data, no BH curves or type of material used for the core etc.
Andy.
