Hi. When I learned to calculate and build transformers with an iron core, I did it assuming that the primary winding is the one that coils first, that is, near the core, and the secondary windings, above the primary. I have also seen and built other windings in halves. Recently I discovered that a large number of amplifiers (Technics, JVC, Toshiba, etc.) first build the secondary and on top of it, the primary. Does this have any advantages or disadvantages that windings the other way?
Primary = line input
Secondary = useful output
Primary = line input
Secondary = useful output
To a first approximation, it does not matter. ALL the turns are 99+% coupled together.
In some work, it is expedient to wind the primary (a standard design) ahead of time, and then wind a secondary to the customer's need.
In practice, some plans work better than others. Primary is usually thin wire. Bending FAT (how-V high current) secondary wire around fine-wire winding is liable to crush and cut the fine wire winding. Starting with the fat wire you have solid support from bobbin or mandrel, you can lay the fat wire tight and leave good support for the fine secondary. OTOH a high-voltage winding (for tubes) might lay better when put on last. Of course all influenced by operator preference and how much fishpaper can be laid between windings.
In some work, it is expedient to wind the primary (a standard design) ahead of time, and then wind a secondary to the customer's need.
In practice, some plans work better than others. Primary is usually thin wire. Bending FAT (how-V high current) secondary wire around fine-wire winding is liable to crush and cut the fine wire winding. Starting with the fat wire you have solid support from bobbin or mandrel, you can lay the fat wire tight and leave good support for the fine secondary. OTOH a high-voltage winding (for tubes) might lay better when put on last. Of course all influenced by operator preference and how much fishpaper can be laid between windings.
Hi. When I learned to calculate and build transformers with an iron core, I did it assuming that the primary winding is the one that coils first, that is, near the core, and the secondary windings, above the primary. I have also seen and built other windings in halves. Recently I discovered that a large number of amplifiers (Technics, JVC, Toshiba, etc.) first build the secondary and on top of it, the primary. Does this have any advantages or disadvantages that windings the other way?
Primary = line input
Secondary = useful output
i have repaired a lot of japanese audio amplifiers and the way they did their traffos was to use bobbins that you can actually separate the primary coils from the secondary coils, each with its own coils forms...
this i would say is a very neat way to convert from the 100 volt japanese standard line voltage to the 230 volt standard in my country..
and the good thing is that the secondary is left untouched....
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