Bryan's Inverter build


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Godoh
Guru

Joined: 26/09/2020
Location: Australia
Posts: 418
Posted: 04:41am 24 Feb 2024      

Hi Bryan have you checked the Kipoint inverter over. As it was built so long ago , some of the electrolytic capacitors may have just dried up. If so they can be replaced fairly easily.
I did some hunting this week and got some wire for my transformer.
I am hoping to be able to pull around 3kw when the sun shines so put together a core from two torroids, 180mm od 90mm id and 100mm high.
I found that the 90mm id is pretty tight for a 14 volt inverter.
I wound the secondary ( 230 volt winding) with 2.8mm wire and then got hold of some flat bar for the primary. It is fibreglass insulated bar that is 12mm wide and 3.5mm thick. So that works out to be 42mm squared.
I only just had enough room in the core to fit it.
If I were to make any more 24 volt transformers I would increase the ID of the core to at min 110mm. More if I was going to use battery lead for primary cable.
The 2.8mm wire works out to be 6.158 square mm so going by the 4 amps per square mm rule it should be fine for 24.6 amps, So should handle my car charger fine.
The primary is close to the mark at 42 mm squared so should handle 168 amps.
This transformer works out to be good for around 3.5kw at best.
So make sure that your transformers are big enough.
I made mine oversized as I want to be able to pull 3kw when the sun is out and we are charging the car.
Have fun and hopefully you can get the home made inverters going fine and maybe even repair the kipoint.
Pete