I'm thinking of encasing my power amp toroid transformers in a shield to reduce the possibility 60 hz hum pickup by the amp input. I was thinking of this as a type of Faraday cage where the goal is to cover the transformer in a electrically conductive cover.
I am planning on making the top and bottom out of .o6" PCB material. The round sides would be made out of very thin flexible PCB material (it is used in multilayer PCB construction. The edges would be covered with copper foil tape (used in stain glass craft). The top, bottom and side would be connected electrically and connected to the safety ground. I'm going to be careful to avoid a shorted turn by making sure the mounting bolt is insulated from the cover.
My question is; do you think this would be effective? In particular, is my material choice workable or does the shield have to be made of some magnetic material like steel?
Thanks,
Denis
I am planning on making the top and bottom out of .o6" PCB material. The round sides would be made out of very thin flexible PCB material (it is used in multilayer PCB construction. The edges would be covered with copper foil tape (used in stain glass craft). The top, bottom and side would be connected electrically and connected to the safety ground. I'm going to be careful to avoid a shorted turn by making sure the mounting bolt is insulated from the cover.
My question is; do you think this would be effective? In particular, is my material choice workable or does the shield have to be made of some magnetic material like steel?
Thanks,
Denis
Hi Denis
Mild Steel is your best option here, its cheap and easy to fabricate a box
to put your transformer into, use 1mm sheet or greater.
Over the years I have used this method to totally shield toroidal transformers
and it works very well.
Having said that careful placement or orientation of the AC mains primary entry
point and shielding of the mains cable can yield the same results.
Its really the mains primary entry point that most of the interference comes from a toroidal transformer.
I hope this helps
Anthony
Mild Steel is your best option here, its cheap and easy to fabricate a box
to put your transformer into, use 1mm sheet or greater.
Over the years I have used this method to totally shield toroidal transformers
and it works very well.
Having said that careful placement or orientation of the AC mains primary entry
point and shielding of the mains cable can yield the same results.
Its really the mains primary entry point that most of the interference comes from a toroidal transformer.
I hope this helps
Anthony
Anthony -
Thanks for the reply. Do you think the mild steel is needed because of its magnetic qualities or do you think it's just easier to work with? If the copper PCB would work I would prefer to use it because I know how to construct the shield with these materials. I don't have the equipment to weld steel.
Denis
Thanks for the reply. Do you think the mild steel is needed because of its magnetic qualities or do you think it's just easier to work with? If the copper PCB would work I would prefer to use it because I know how to construct the shield with these materials. I don't have the equipment to weld steel.
Denis
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