Q on torroid mounting

[weinstro]

Hi,

For mounting a large torroid (2kVA), is there any issue that I should be concerned with regarding the permeability of the bolt that goes through?

For example, will the transformer tend to saturate or hum more if the mounting bolt is steel, vs. say brass, non-ferrous stainless, or even a wooden dowel?

Thanks and regards,

Rob Weinstock

 

[Eva]

The bolt is irrelevant as the windings won't induce anything on it. However, what should be avoided is making a shorted turn across the toroid, as this may unadvetedly happen through a metal chassis if the top of the bolt makes electric contact with the top cover and the bottom cover at the same time.

 

[weinstro]

The bolt is irrelevant as the windings won't induce anything on it. However, what should be avoided is making a shorted turn across the toroid, as this may unadvetedly happen through a metal chassis if the top of the bolt makes electric contact with the top cover and the bottom cover at the same time.

Thanks. I'm already aware of that issue.

This transformer will be mounted in an enclosure in close proximity (more or less on top of) to a torroid-based EMI filters. Should I be concerned about a concentration of flux lines causing coupling, and therefore induced noise?

Regards,

Rob

 

[Eva]

In a toroid inductor or transformer, the flux lines are created mostly inside the toroid. As a result, they show very good inmunity to external fields and produce very small stray fields in comparison with EI transformers.