A little help, PLEASE

T

tymeonadime

Junior Member
I am currently working on a couple MOT (microwave oven transformers) and out of my small collection of five of them, two have shoddy primaries.
I wat to re-wrap them, but having never wrapped a transformer I am at a loss.
I noticed that in my dead MOTs the primary is made of TWO coils, a very short one onfabout ten wraps and a large one of ~+/-90 wraps.
I honestly am not sure if it's intentional or a defect/damage. I have the wire to re wind these coils , but wanted to ask about the short coils and if y'all know rather or not they are intentional.
Sorry for the noob question....
Thanx for Anya and all help.
 
The short coil will produce a higher voltage output. I would need to see the schematic to know what the second primary coil is there for.
 

I am going to be winding a secondary, to draw high current low voltage.
That being said would the short film be needed?

That doesn't look right.... I mean voltage around <15 and as much amperage as possible. I can and probably will run two or more of these in series. When I am done I will be building a spot welder capable of joining auto body panels. I have a small version using only one MOT that will do nice slugs on thinner metal
 

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When I said two coils on the primary, I may have been misleading.
On one INPUT a wire about 14 inches long makes a few wraps and then terminates. It's not physically attached to anything. The the other INPUT is the remainder of the ~121 turns. The end of that one also dead ends. Both faulty primaries are made that way.
I am relatively sure that are purposely made this way, however my knowledge of transformers and coils in general is. lacking to say the least.
 
Another question,

The coils from an AC fan motor, being extracted from their housing, an dbeing supplied with mains current, would it then behave as an electromagnet? OR would I have to rectify the the AC into DC via bridge or uad diode arrangement?
 

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