28-09-2014, 11:49 AM
This has more to do with the standby power consumption initiatives...
A good quality mains transformer can easily waste less than a watt of heat when quiescent. But in my experience of these sorts of supplies, they don't. They are pretty crappy. Just think about how hot many of them get.
If you're wanting an OEM to make power supplies that satisfy the standby requirements, you're going to get a switcher. Because - perhaps astonishingly - in this day and age, it's cheaper to make an efficient switcher than a decent quality 50Hz mains transformer. And that's before you consider the savings in shipping because of the much reduced weight. And the fact that a switcher might not need adjusting for worldwide mains voltage - just swap the part of the case that carries the metal prongs that fit into the mains socket.
From the manufacturers' point of view, it's obvious why switchers are universal today. Our concerns about them are literally "lost in the noise".
A good quality mains transformer can easily waste less than a watt of heat when quiescent. But in my experience of these sorts of supplies, they don't. They are pretty crappy. Just think about how hot many of them get.
If you're wanting an OEM to make power supplies that satisfy the standby requirements, you're going to get a switcher. Because - perhaps astonishingly - in this day and age, it's cheaper to make an efficient switcher than a decent quality 50Hz mains transformer. And that's before you consider the savings in shipping because of the much reduced weight. And the fact that a switcher might not need adjusting for worldwide mains voltage - just swap the part of the case that carries the metal prongs that fit into the mains socket.
From the manufacturers' point of view, it's obvious why switchers are universal today. Our concerns about them are literally "lost in the noise".
