DIY output transformer odd voltages under test

[kia2094]

I finished building an output transformer today and I got a very odd result.

the transformer has 3:4 interleave winding (3 parallel secondary windings , 4 primary winding in series) with winding ratio of 10:1 (1500N:150N). I tested the transformer with primary voltage of 220v , expecting around 22v on secondary. the output how ever was 42V !!

Am I missing something?

 

[DF96]

How did you measure the voltage?
What frequency did you use?
What is the primary inductance?
At what current would you expect to see core saturation?
Why is a question about an output transformer in the power supplies section - and why use 220V for testing?

 

[stevenrotterdam]

First test the individual sec. windings

 

[stevenrotterdam]

I think you may have reversed 1 of the primary windings that would explain this.

 

[kia2094]

Thank you guys for the replies. Steve is right , I got it fixed but it took awhile.

The four primary windings were in series , lets say the correct pins are:

1(input) - 2 and 3 - 4 and 5(center tap) - 6 and 7 - 8(input)


so 2 and 3, 4 and 5, 6 and 7 pins must be connected to each other. I had 1 and 3 conneted and got the the 2 as one of the inputs.


I tested it under 220v/50 hz again , now im getting 20v output (2v drop sounds reasonable).

 

[stevenrotterdam]

What tube will you use it for?