This question already has an answer here:
- Is perpetual motion impossible? 6 answers
Perhaps a question that is too naive to be on Physics.SE but I let the experts here decide (and downvote at will), but there seem to a certain company that claims to have created what it calls a "magnetic generator" where, if the machine is powered externally long enough (which is in seconds or minutes) allowing an electro-magnetic contraption to reach a certain RPM, it can start producing enough electricity to keep turning the contraption, without the aid of the external power while generating surplus electricity. This sounds like perpetual motion machine, yet a bit "snake oilish". The website of this company is done very professionally, they have some slick youtube vidoes -- but scamsters can and do pull impressive illusions off. Is there plausible physics behind this setup ?
Please note that I have no interest in the company or the product, but quite interested to know if there is some real physics behind it.
Here's a link that describes the product.