Time for a new Warpinverter build

Author	Message
rogerdw Guru Joined: 22/10/2019 Location: Australia Posts: 955	Posted: 12:09pm 13 Mar 2021         Murphy's friend said   The remaining hole size depends entirely by what kind of primary wire (cable?) you have used. For my single transformer inverters I used rectangular enameled copper wire and that left plenty of hole, even with the large double stack core that has a 6 x 15mm sq in parallel (90mm sq) primary. For the warpverter I used twisted (6 outer, one center strand) enameled copper wire which was the second hand wire unwound from the aerosharps. A great way to use up leftover wire. Square or rectangular wire sounds awesome, but I hate to think how much it would cost or where to even find some. I did follow your comments and photos to twist some wire to make a secondary winding for a spot welder  ...  but of course in my usual fashion of overkill I used 20 x 1.7mm wires. It was only 2 metres long, but I'll never do that again.   Having said that, with the correct size and shape spacers I reckon I could twist it ok  ...  but needs a bit more thought put into it first  ...  and maybe an adult helper too.   Quote   A hint for that joining, make a PVC tube center that fits exactly into the hole to align both cores as you epoxy them together. You do *not* want any mis- alignment here. You also do not want the cores to come loose as you move them around while winding so epoxying is a *must* in my book Yes, I reckon I will do it that way. In fact I was considering using pvc tubing as the spacer between the core and the first winding anyway  ...  so I can leave it in there.   Quote   Regarding the heat rise, from my experience the temperature inside my fully enclosed (fan cooled) inverters stays around 10 degrees above ambient. The fan is set to come on at 50 degrees and does so only on very hot days. That's very helpful thanks too. Nothing beats real world figures and at least it gives something to go by. Here's a shot of my spot welder cable helper.