T
treez
Guest
Hello,
Page 18 to 20 of the below app note concerns the design of a transformer for a 65W Flyback SMPS.
The primary and the bias winding are simply specified to be wound with “magnet wire”. As you know, “Magnet wire” is not a brand, so it could be any type of Enamelled copper wire in theory.
The problem is that the bias winding output, and the drain end of the primary winding output, suffer pulsed voltages of some 500V between each other. Some types of “magnet wire” may not be able to handle this. I appreciate that the primary and the bias winding are not next to each other on the bobbin……however, as the wires are brought out of the bobbin to be terminated, they are highly likely to rest alongside each other…
..As such, why does the app note not make any stipulation for the isolation rating of the “magnet wire”? (As you know, they could have avoided this by specifying that the “magnet wire” termination ends gets wrapped with insulaion tubing, but they have neglected to do this.)
For example, does anyone know what is the insulation rating of this “magnet wire”?
https://www.farnell.com/datasheets/1683415.pdf
(The quoted British standard in the datasheet costs £102)
Der 243
https://ac-dc.power.com/sites/default/files/PDFFiles/der243.pdf?download=1
Page 18 to 20 of the below app note concerns the design of a transformer for a 65W Flyback SMPS.
The primary and the bias winding are simply specified to be wound with “magnet wire”. As you know, “Magnet wire” is not a brand, so it could be any type of Enamelled copper wire in theory.
The problem is that the bias winding output, and the drain end of the primary winding output, suffer pulsed voltages of some 500V between each other. Some types of “magnet wire” may not be able to handle this. I appreciate that the primary and the bias winding are not next to each other on the bobbin……however, as the wires are brought out of the bobbin to be terminated, they are highly likely to rest alongside each other…
..As such, why does the app note not make any stipulation for the isolation rating of the “magnet wire”? (As you know, they could have avoided this by specifying that the “magnet wire” termination ends gets wrapped with insulaion tubing, but they have neglected to do this.)
For example, does anyone know what is the insulation rating of this “magnet wire”?
https://www.farnell.com/datasheets/1683415.pdf
(The quoted British standard in the datasheet costs £102)
Der 243
https://ac-dc.power.com/sites/default/files/PDFFiles/der243.pdf?download=1