I thought it would be a great idea to open a thread on proper ways to mount transformers/chokes/Output transformers.
I cannot find my copy of a great book on the subject.
I was looking for the do / not do of mounting flat chokes on a chassis. I could not find anything on the subject.
1. Rule : never place metal across laminations
I cannot find my copy of a great book on the subject.
I was looking for the do / not do of mounting flat chokes on a chassis. I could not find anything on the subject.
1. Rule : never place metal across laminations
The outside of the lams can be welded together (and are in some transformers, motors and inductors), since they aren't in the magnetic path. But mounting holes are inside the magnetic path and when two or more screws make contact with the outer lams, a shorted turn is created, through which part of the magnetic flux passes. This reduces inductance and the current loop created is lossy. Any screws that pass through the core must be insulated from the surface and inside of the lam stack.
With toroids, if you mount with a center screw, be sure only one end of that screw is connected to the chassis. With a top bracket or a can with a bolt through it, use an insulating shoulder washer on at least one end.
With toroids, if you mount with a center screw, be sure only one end of that screw is connected to the chassis. With a top bracket or a can with a bolt through it, use an insulating shoulder washer on at least one end.
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Use the OEM system type replacement parts. My Zenith PT goes like this... Bolt head, end bell, lams, end bell, star washer, nut. But my Dynaco trannies add one fiber washer under the bolt head but then on the nut side it has bell, star washer, nut. My Harman Kardon tranny has star washers under the head and nut, against the bells.
Nylon washers , even rubber grommets , there are many choices they absorb vibrations and decouple a good gap with chassis
Exactly what I was looking for!
I removed one end bell and placed it flat with loss of choke inductance and it is caused by the screw bolted down under the chassis
The screw on top on the choke has a nylon spacer
Prior to mounting a transformer, weather new or used take a quick ohm meter reading of all of the windings.
On one occasion I built a set of 4 mono amps and 2 had open primary windings in the opt.
Once I potted my own brand new power transformer for a preamp build and somehow ended up with an open winding. Expensive slag.
(I soldered to the wrong terminal before potting)
Prior to getting financially and emotionally involved in a build, check to see that your transformers are actually good.
Do it sooner rather than later...
On one occasion I built a set of 4 mono amps and 2 had open primary windings in the opt.
Once I potted my own brand new power transformer for a preamp build and somehow ended up with an open winding. Expensive slag.
(I soldered to the wrong terminal before potting)
Prior to getting financially and emotionally involved in a build, check to see that your transformers are actually good.
Do it sooner rather than later...
Whenever I spruce up a transformer, I always replace the bolts with either brass or nonmagnetic SS and then use nylon shoulder washers between the head, nut and the end bells. Sometimes I have to drill out the bolt holes in the end bells for the shoulder as they can be smaller than the bore through the lams.
I think this thread is officially off the rails. Rule #1 sent it spinning... lost in translation.
I think everything said is interesting, and on topic, reducing too much the subject leads to the idea of knowledge without it.
At one point we will resume the info and hopefully it will help many of us
At one point we will resume the info and hopefully it will help many of us