EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: BurningTantalum on May 03, 2020, 11:44:24 am
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I am constructing a spot welder for Li-ion cells so removed the secondary winding from a couple of microwave transformers. One transformer was wound with aluminium wire and was from a 'no brand' cheapo oven. The other had copper wire and was from a Panasonic oven. I decided to use the copper wire unit, but noticed that it had extra laminations in the slot between the primary and secondary windings. The aluminium transformer did not. I may have to remove these laminations to get another turn of the heavy gauge secondary wire and wondered what their function was before I do so. Any theories?
BT
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It's called a magnetic shunt. There is a good answer on Quora (as much as I dislike that website):
https://www.quora.com/What-is-the-purpose-of-the-magnetic-shunt-that-is-in-most-microwave-power-transformers-Can-the-shunt-be-safely-removed-when-winding-a-single-replacement-secondary (https://www.quora.com/What-is-the-purpose-of-the-magnetic-shunt-that-is-in-most-microwave-power-transformers-Can-the-shunt-be-safely-removed-when-winding-a-single-replacement-secondary)
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Thanks for that info.
Fascinating, and something that I was unaware of. I did lash up the welder on the bench and it worked well so I have tidied it into a case, but I will experiment with the transformer in the light of this new info before I go any further.
BT