What are the evocative sounds and smells of your childhood? The sensations that you didn’t notice at the time but which take you back immediately? For me one of them is the slight smell of phenolic resin from an older piece of consumer electronics that has warmed up; it immediately has me sitting cross-legged on our living room carpet, circa 1975.
That phenolic smell has gone from our modern electronics, not only because modern enclosures are made from ABS and other more modern plastics, but because the electronics they contain no longer get so hot. Our LCD TV for instance nowadays uses only 50 watts, while its 1970s CRT predecessor would have used several hundred. Before the 1970s you would not find many household appliances that used less than 100 watts, but if you take stock of modern electrical appliances, few use more than that. Outside the white goods in your kitchen and any electric heaters or hair dryers you may own, your appliances today are low-powered. Even your lighting is rapidly being taken over by LEDs, which are at their heart low-voltage devices.
There are many small technological advancements that have contributed to this change over the decades. Switch-mode power supplies, LCD displays, large-scale integration, class D audio and of course the demise of the thermionic tube, to name but a few. The result is often that the appliance itself runs from a low voltage. Where once you would have had a pile of mains plugs competing for your sockets, now you will have an equivalent pile of wall-wart power supplies. Even those appliances with a mains cord will probably still contain a switch-mode power supply inside.