Tips for mount toroidal transformer

[spoontex]

Hello,


can you tell me, how you do mount toroidal transformers into a rack enclosure?


I know, with the bolt, rubber pads and steel washer. But, for do it this way I need to drill the chassis and the bolt has a big head, and If you mount the rack into cabinet with other devices, this will be a problem with the bolt.



Any advice?


Thanks!!

 

[analogguru]

If there is enough space you can mount inside a plate with smaller screws with a hole for the big transformer screw.

Or you arrange for deep-drawing of the chassis how it is done by many companies.

Or you look for someone who welds the screw to the chassis (inside).

 

[Bo Deadly]

Whatever you do, don't connect the inside end of the bolt to anything metal that also contacts the chassis. That will create a transformer "turn" that will short out the transformer.

Use a larger counter sink bolt and a fender washer or ratchet socket or similar to create a dimple / impression in the chassis metal. Then use a smaller low profile bolt.

 

[moamps]

can you tell me, how you do mount toroidal transformers into a rack enclosure?...

If it is a small transformer, you can use a screw with countersunk head and some spacers.
I use M3 screws for small transformers (up to 50VA)  in a 1HE chassis.

 

[Tubetec]

A cup head bolt can work well , first drill a hole in the chassis , file it out  to fit the square  , put the bolt through , add washers to pack out the square section up to the threads then  a  lock nut or two torqued down snug .

Always make sure its impossible  for the bolt  to make contact  with the chassis top to bottom.  If it does it completes a circuit  and makes  a very fat shorted secondary turn on the transformer , molten metal will fly everywhere .

 

[weiss]

I always use Frank's NRG case which has ventilation holes on the sides. It's easy to fit a screw through there. No need to drill or damage anything. Works with at least 2U cases though.
For me this is the most elegant solution. I also don't like to fit screws at the bottom of the case.

 

[PRR]

Get your big socket wrenches. Find a big one, and the smaller one which fits inside the big socket with good clearance. And a long bolt w/nut. Put the large socket on the inner surface, socket to panel. Put the small socket on outside. Bolt through. If the panel is soft, you can tighten the nut and dimple the panel. If it is hard, support the socket so the bolt is free, and whack it with the big hammer. (Wear ear-muffs!)

Masking tape or bleach-bottle scrap may help reduce scars on panel. (Beware scars on hands.)

Use good-grade sockets. The economy sockets can shatter when abused.

 

[spoontex]

It's possible to upload some photos?

Thanks for the advice!

 

[johnheath]

Hi...

It might be possible to use rubber feet if the the head of the bolt is small enough... in Europe the bolt, for toroidal transformers, are usually not larger than 5mm and there are many of those with small heads enough to have space enough if you use small self-sticking rubber feet.


Best regards

// John

 

[PRR]

It's possible to upload some photos?

https://www.diyaudio.com/forums/power-supplies/345505-tips-mount-toroidal-transformer-post5982456.html

 

[spoontex]

I did a kind of base with freecad and print with a 3d printer. I think it's better to countersunk M3 bolts than M6.

What do you think?

https://ibb.co/xS4Wh1X

https://ibb.co/McnsGZK

 

[gyraf]

Will it hold together if you drop the box on the floor, hitting on edge?

 

[spoontex]

Yes,

I drop the box few times on the flor, and all hold down!!