Quote Originally Posted by Kitwn View Post
When I was a lad power transistors (at least the radio frequency ones) were described to me as "the fastest fuse on three legs". In practice these things often fail as a short circuit which is what takes out the fuse to protect everything else as you say.
My degree, best part of 50 years ago now, was in electronic engineering - this at a time when a quality "transistor radio" was still populated with germanium transistors. I remember the same quote! My son once borrowed my variable-voltage bench power supply to charge a car battery. Not a good idea. At least 2N3055s are big enough to get a decent size soldering iron on! 6 of them, as I recall...