I'm trying to build a welder from microwave transformers, but I got this weird looking transformers instead. Answered
I recently got two old microwaves from a junk yard and wanted to build an arc welder with its transformers by connecting both in series and getting an output of around 40V all together. But when I open the microwave instead finding the big chunky laminated iron core transformer as shown by many youtube videos, i found a small weird looking transformers instead. ( as shown in the pictures)
I read somewhere stating that the primary coil should at least have 1 turn per volt. However, this transformer only had around 17 turns in the primary. The core was also not laminated and it had a copper wire holding it in place. The primary coil was made of a thick litz wire and the secondary was a very thin wire.
Anyhow, I still continued the project and I experimented with one first. I use the same primary and made my own copper wire for the secondary. I made the secondary by using thick copper wire which I found in some antenna wire and I stacked it up and twisted it and put a heat shrink tube on it. Base on a few tutorials i saw i need an output of 20V from each transformer coming from an input of 240V AC. So with 17 turns in the primary i need around 1.5 turns in the secondary.
When i finished everything and connected it to the power supply, it vibrated for awhile and then blew the 13A fuse in the plug. So i added a light bulb in series hoping to increase the resistance and reduce the current but this time nothing happen and it didn't even vibrate but the bulb did light up. I think its because the primary coil has a resistance around 5 ohm and the bulb have resistance of 100 ohm so the potential differences is very low on the primary coil.
I am not sure why isn't it working. Please help me as i can't find any tutorials on how to make a welder with this form of transformer. There were no other transformer in the microwave so this was definitely the main transformer. Is the problem because it has too little turns in the primary coil or it has too low resistance? I don't know please help me. Thank you!!