Author Topic: Questions about steel square tube as power supply housing  (Read 1092 times)

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Offline BarnyTopic starter

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Questions about steel square tube as power supply housing
« on: March 20, 2019, 11:19:09 am »
I want to use a square tube as housing.
Is there a problem when a toroidal transformer is surrounded with thick steel in short distance?

The square tube:
Dimensions:
160mm x 80mm x 4mm / 300mm long

Material:
Steel (S235)

The toroidal transformer:
Dimensions:
ΓΈ142mm / 55mm high

Prim:
230VAC

Sec:
24VAC

The fastener is a self-made bolt made of POM.


Are there some potential problems which I have to look for?
Are there traps for young-player?
Is there a reason to not use a steel square tube as housing except the weight?
 

Offline Brumby

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Re: Questions about steel square tube as power supply housing
« Reply #1 on: March 20, 2019, 11:28:38 am »
The trick with toroidal transformers is to NOT have an electrically conductive path that passes through the centre of the toroid and forms a closed loop around the toroid core.  This is a shorted turn and will cause major overload.
 
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Offline BarnyTopic starter

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Re: Questions about steel square tube as power supply housing
« Reply #2 on: March 20, 2019, 11:54:39 am »
The center-clamping bolt will be made of POM.
Its a plastic similar to PA, but with less water absorption and its better to be cut on a lathe.
POM its not as waxy and translucent as PA.

So you are saying that there is no problem with magnetic field through the air when there is steel close on the outside?
 

Online Gyro

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Re: Questions about steel square tube as power supply housing
« Reply #3 on: March 20, 2019, 12:08:33 pm »
No, in that case it will just improve magnetic shielding.
Best Regards, Chris
 
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Offline digsys

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Re: Questions about steel square tube as power supply housing
« Reply #4 on: March 20, 2019, 12:09:53 pm »
We've mounted literally 1,000s torroids on steel bases, steel caps and steel bolts clamping them in (hard rubber under the caps), no issues at all, of any kind.
Like Brumby says, as long as you don't complete the circuit, it's all good. I don't think we've ever had to use Nylon / POM etc to clamp.
Hello <tap> <tap> .. is this thing on?
 
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Offline BarnyTopic starter

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Re: Questions about steel square tube as power supply housing
« Reply #5 on: March 20, 2019, 12:22:26 pm »
Thanks for your information.

But I think  I'll stick to the POM-Bolt version, because its easier to machine and I've more of it sitting in the shelves.
 

Offline Benta

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Re: Questions about steel square tube as power supply housing
« Reply #6 on: March 20, 2019, 05:03:26 pm »
Only thing I've experienced as an issue is mechanical 50/60 Hz hum from the enclosure. With proper rubber pads it should be avoidable.
 
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Offline BarnyTopic starter

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Re: Questions about steel square tube as power supply housing
« Reply #7 on: March 21, 2019, 11:04:05 am »
Only thing I've experienced as an issue is mechanical 50/60 Hz hum from the enclosure. With proper rubber pads it should be avoidable.
Normally I'm using felt-pads (the kind which normally get stuck below chairs) or small slices of glue sticks as housing feets to avoid scratches.

I think this will be enough to decouple the housing mechanical from the desk.

Thanks to you all for your help.
 


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