The All American Five

[ppppenguin]

There's plenty of live chassis kit around today. Think of central heating programmers, electric toothbrush chargers etc. All have passed safety tests. No reason why a radio or TV shouldn't have a live chassis and be safe. Except that in practice once you're beyond a certain level of complexity you've usually got interfaces that need to be safe so it's cheaper and easier to design in a SMPS with isolation or put the live bits in a wallwart.