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Toroid transformer cover?

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#3
Try dollar stores in the pots and pans section. You can find some very attractive covers in those stores. I found some stainless drawn drinking mugs that work nicely as covers for some toroids I have after removing the handles.
 
#4
Be careful not to complete a circuit with the metal parts. For example in a standard flat rack chassis, if you mount a toroid on the floor panel, and run a steel bolt through the center, if that steel bolt contacts the top panel, it completes a "turn" through the toroid. A SHORTED turn.

So one would use a nylon mounting bolt or make sure a steel bolt doesn;t contact the top panel. If you use a metal cover, take the same precautions. Either the cover must have an insulator between the floor and the cover, or the mounting screw through the center must be plastic, or insulated with plastic shoulder washers, or embed a nut in epoxy in the center hole, or something. Whatever method you use, you cannot make a complete metal path through the center and back to the other end
 
#5
rcavictim has the perfect answer:
This small saucepan in pic nicely fits over the toroid. Cut it neatly with a disk or patience with a hacksaw.

richy
 

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#6
I found a couple of stainless kitchen things in the local supermarket. I guess I looked a bit weird walking about with a vernier in my hand but hey who cares.
I cut them down, not easy and made a spot welder to weld on some studs.
Cheers Matt.
 
#10
PVC pipes cut to size work very well for lots of reasons such as the different dimensions (if you're using different size transformers), available covers etc.. Some need some sanding before you paint them.

Just a thought... Good luck!
 
#14
If you cover top of the tube be prepared to use a fire extinguisher.
Transformers are usually calculated for 10 percent of power loss that means if you draw 300W from your transformer 30W will be radiated. Now, cover some 30W electric bulb by a PVC cover and see for yourself what happens...
But I have to warn you that burning PVC is poisonous.
 
#16
Some valid points, my toroids are over-sized and don't break a sweat, even after hours of playing. I made the covers from PVC, lightly sanded and painted, for end caps I utilized loudspeaker grills from Madisound. In the past I built a KT88SE with toroidal OT's and cut a few circles out of walnut wood and covered them with the same type of loudspeaker grills. This ensures ventilation and, IMHO, makes it look very neat. Unfortunately I'm still "at sea" so I don't have any photographs to share 🙁 sorry...
 
#17
I've been mulling over what to use for toroid covers myself. I see it as a perfect excuse to learn how to braize metals... I was thinking to use aluminum tubing with a round end plate braized to it. Of course, a separate project will be to sand and polish the darn thing. One could also bead blast it for a nice satin finish.

~Tom
 
#19
You cant really braze ally. You can get some solders that will work but not really. Also there are some welding rods available that you can use with a flame. They contain ally, magnesium and a load of other stuff and are more of a thermit type weld. They are hard to use. TIG is the way.
If you are going to make ally torroid caps then the best bet is to find a large enough ally tube and turn a tophat shaped end to be a press fit in the tube. Then turn and face off the OD of the whole thing.
turning from solid for one ones and twos is not really cost effective in time or cost. With a CNC set up it would be but only for a load, and then the swarf and scrappy bits would be sold for recycling.

You could use brass/copper sheet and silver or soft solder it for the steam engine look.

With my stainless Morrisons specials. I just found a couple of big pot thingys. They are like the smaller tea, coffee and sugar things but 7 1/4in diameter and were about 12in deep. I cut them down with a little cut off disk in the Dremmel. Then I made small spot welder from a microwave tranny and welded some stainless studs in round the rim. It does leave a couple of blued spots where each stud is on the outside but I like to see how stuff is put together. Practice on the offcuts first.

Cheers Matt
 
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