bocka said:
The question is not if it works but if its safe and if it legally allowed. The standards are IEC-61558 or IEC-60742. When you connect a transformator to the mains which is driven out of its specs and something hazardous occurs that one who has connected the transformator to the mains is fully responsible for its consequences. Is this really worth it?
This could be said for any DIY project - especially one with second-hand components, for which there are no guarantees that they will work, and even if they do, they are certainly not made under the mentioned standards.
As always with such projects, you make your choices, you take your chances and you have to accept the consequences.
I know what you are trying to say but this sort of legislative reasoning is preposterous in the context of tis forum or indeed in the context of engineering. Specs are not a dogma. They are made under certain conditions and when the conditions change, you may still get a completely functional and safe design BUT working at different specs. The key word of course is 'may' and there is no voodo involved, but just simple principles.
According to your post, people who for instance use mains toroids as PP output transformers may well expect armageddon because those were not how they were originally specced.
Having been involved with mil spec design and testing for 7 years, I have not typed my answers out of thin air. Even so, since the original author of the thread is working with second hand equipment, it would be quite unwise to just take all of our collective words on faith - the answer, as usual is, once you have ascertained that the given mode of operation may be well inside the specs, you test things under controlled conditions. No one is saying he should jus connect the transformers blindly and then sue us all if his house burns down. Besides, there is always a chance that could happen even if they were IEC-61558 or IEC-60742 certifie. In fact, I would trust second hand mil stuff dug out of a trash-heap that got flattened by a bulldozer more than some brand new parts you can buy that apparently have all the necessary certification (I'm not going to mention countries of origin here)...