fixing torodial xformers to a chassis

[reapersdirge]

howdy folks,
im new to all this diy audio stuff. anyway im bangin a power amp together and ive a fair idea but just need to check with you the good folks of the community, about affixing a torod transformer to a chassis. as far as i understand you can epoxy the center or put a cap on it (shaped like a cymbal) with two rubber mats one for top and bottom i suspect and a bolt through it.

1 - how would an epoxy centre work.
is it just glued into place?

2 - how does the bolt and cap work?
i think it goes rubber mat torod rubber mat metal cap with the cap concave into the transformer. from there the bolt goes down the middle from the top and is bolted on the bottom. sound about right?

im just not to sure how it all goes together. if anyone has any handy links or youtube vids that'd be tops. cheers all

[Kay Pirinha]

The mounting sequence is: Metal 'cap' - rubber mat - totoid - rubber mat - chassis. please have a look at my stereophonic ELEKTOR Crescendo amp, you can see what I mean:

[AndrewT]

The plate and securing bolt MUST NEVER touch a metal top plate.
That would short the transformer.

If you don't know much about mechanical fixtures then don't consider cobbling together an epoxy fixing.
Use the top plate method.

[jitter]

Originally Posted by reapersdirge

howdy folks,
but just need to check with you the good folks of the community, about affixing a torod transformer to a chassis. as far as i understand you can epoxy the center or put a cap on it (shaped like a cymbal) with two rubber mats one for top and bottom i suspect and a bolt through it.

My advice would be to use whatever is supplied with the toroid.

1 - how would an epoxy centre work.
is it just glued into place?

The epoxy indeed acts as a glue, but the bond is incredibly strong. I have seen equipment returned that fell during transport. The aluminium plate on which the toroid was hung would be bent, but the toroid itself was undamaged.

2 - how does the bolt and cap work?

The toroid is clamped to a chassis.

i think it goes rubber mat torod rubber mat metal cap with the cap concave into the transformer. from there the bolt goes down the middle from the top and is bolted on the bottom. sound about right?

Yes, the toroid must always be in contact with the rubber discs and never any metal.

im just not to sure how it all goes together. if anyone has any handy links or youtube vids that'd be tops. cheers all

[dirkwright]

Originally Posted by AndrewT

The plate and securing bolt MUST NEVER touch a metal top plate.
That would short the transformer.

Only if it's steel. It doesn't make a damn bit of difference otherwise.

[dirkwright]

Originally Posted by jitter

Yes, the toroid must always be in contact with the rubber discs and never any metal.

The only reason for this is to prevent vibration from the toroid rubbing the plastic cover off of the windings and causing a short (after it rubbed through the coating on the wire also of course).

[dirkwright]

Originally Posted by reapersdirge

2 - how does the bolt and cap work?
i think it goes rubber mat torod rubber mat metal cap with the cap concave into the transformer. from there the bolt goes down the middle from the top and is bolted on the bottom. sound about right?

im just not to sure how it all goes together. if anyone has any handy links or youtube vids that'd be tops. cheers all

You can use a steel rivet nut on the bottom in place of the nut. It makes for a neater installation.

[barrymagrec]

Originally Posted by dirkwright

You can use a steel rivet nut on the bottom in place of the nut. It makes for a neater installation.

Yes - make sure that it`s fitted the right way round though or it can pull out with the weight of the toroid - I`ve seen this happen after kit has been shipped imperfectly packed.

[Juergen Knoop]

Originally Posted by reapersdirge

howdy folks,
im new to all this diy audio stuff. anyway im bangin a power amp together and ive a fair idea but just need to check with you the good folks of the community, about affixing a torod transformer to a chassis. as far as i understand you can epoxy the center

Depends...small toroids sometime come with glued in mounting nuts, yet most and larger ones use steel mounting sets. You usually don't epoxy toroids yourself!

[AndrewT]

Originally Posted by dirkwright

Only if it's steel. It doesn't make a damn bit of difference otherwise.

Any conductive material will short out the transformer.
Steel is actually a bad conductor compared to aluminium. Copper and silver are even better conductors.
Carbon fibre is a bad conductor, but it will still short out the transformer.