Trafo orientation

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sergio
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Trafo orientation

Post by sergio »

Hi, I'm going to build a new project(hibrid SSS),and I have big trafos but little room!!

It's a bad choice placed the trafos like the photo?
I seen Someone here in the forum that already done!but the electromagnetic field can introduce hum!

Some suggestion?
Thanks
S.
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xtian
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Re: Trafo orientation

Post by xtian »

Yes, bad. You need to rotate either the PT or the OT 90 degrees to cancel the hum. They can be close together, but the coils must not face the same direction. Use the headphone trick to listen to the placement: carefully isolate or tape off all PT secondaries, and apply power to the PT primary. Connect a set of headphones to the OT secondary (ground and any tap) and listen for the hum as you move the trannies around.
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sergio
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Re: Trafo orientation

Post by sergio »

Thanks xtian , I think to rotate the PT. I will check the Hum with your headphone method also!
S.
larsvictor
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Re: Trafo orientation

Post by larsvictor »

Sergio,

seems that at least one builder made good experiences with this transformer orientation...

:wink:

Lars
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sergio
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Re: Trafo orientation

Post by sergio »

Did some test:

With headphones actually noise is present but if I turn Pt or Ot 90 degree , the Hum noise go away!

With oscilloscope in Ac 20mV /div with trafo in line and 90 degree, se pics!
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Roe
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Re: Trafo orientation

Post by Roe »

what kind of transformers did you choose?
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sergio
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Re: Trafo orientation

Post by sergio »

Heyboer!!
Krinkle
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Re: Trafo orientation

Post by Krinkle »

sergio wrote: Sat Jan 07, 2017 2:25 pm Did some test:

With headphones actually noise is present but if I turn Pt or Ot 90 degree , the Hum noise go away!

With oscilloscope in Ac 20mV /div with trafo in line and 90 degree, se pics!
Which way were the transformers positioned with the noise gone?
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sergio
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Re: Trafo orientation

Post by sergio »

Rotate the PT 90 degree!! :wink:
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Krinkle
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Re: Trafo orientation

Post by Krinkle »

Thanks
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mhartman
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Re: Trafo orientation

Post by mhartman »

Great. With custom builds I usually test multiple positions for hum before committing to one direction or the other.
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