I do a fair amount of oversees travel and have always brought a 220 to 110 voltage converter with me. Then I woke up one day and noticed that the little print on some of the adapters to my electronic devices said, “input 110-220 volts AC”. Hallalujah!. I no longer needed the converted as long as I had a plug adapter (which sometimes wasn’t needed). My Mac Book can be plugged in any old place.
To me this is a great technological advance like anti-lock brakes and GPS. However, I don’t ever remember any publicity about the fact that the makers of electronic adapters were incorporating this technology. Was there an advance that allowed this to become common or was it just basic electrical design and the manufacturers quit being lazy?
I asked a friend who is pretty savvy about these things and he had the same observation that I did so I’m not the only one. What’s the SD?
The popularity of switching power supplies.
The change has been slowly occurring over the last 25 years or so. Now that most electronic devices are powered with highly-efficient “Switching” regulators, it’s pretty easy to get them to accept a wide range of input voltages (90-240v, 50-60Hz). There is still a slight premium over fixed-input voltage power supplies, but it’s so small that almost all manufacturers are using “universal” power supplies. I should note that the EU has really pushed this change. It’s now illegal to use the old transformer-style power adapter, because the EU has power factor efficiency standards that those devices can’t meet.
Of course, it should go without saying that electrical devices that don’t have the built-in voltage adapter (hair dryers, some radios, most non-electronic stuff) will still need a transformer.
As a manufacturer, it’s great because you can reduce your complexity. You can also eliminate the need to build and stock two versions of the product, and only need to have different power cords.
Products with higher power consuption can be an issue, especially at higher voltages. My company has had issues with power supplies, but mostly in Europe. We never run into them in Japan, which has 100 V.