Various aspects of home brew inverters

Author	Message
poida Guru Joined: 02/02/2017 Location: Australia Posts: 1432	Posted: 01:08pm 05 May 2017       Warpspeed: I like how the testing of the 3 inductors shows how things change as power is increased. When measuring their inductance, we test with a tiny current from the LCR meter. We need to test under realistic conditions to prevent saturation in the designs. I plan to change the toroid over to the 3kW one and test at about 1500W to see how the last 50uH steel core choke goes than. I find this result applicable to Tinker and Madness's problems with damaged fets. They had issues when using the E core chokes and we all were wondering why. Gate drive was proven to be good. I now think the E core choke is likely the source of the problem. I measured idle current with the above setup and it is about 0.27A at 27.3V DC This is about 7.5W and I wonder if it is constant over all loads. I need to read more on eddy current (and other) losses in the toroid. Now I see the need for large area primary windings, the question is where to get it. I don't want to just spend $$ on something from Jaycar or Middys. Using many strands of enameled copper inside plastic tubing seems possible. There is a 3hp 3 phase motor going to scrap at work. Maybe some wire in there... What's the best and zero cost source for the primary winding? wronger than a phone book full of wrong phone numbers