Almost all DC power supplies are switching power supplies these days, which convert AC to DC first, then use DC-DC converters to get to the final voltage. I wou

Almost all DC power supplies are switching power supplies these days, which convert AC to DC first, then use DC-DC converters to get to the final voltage. I would think AC transformers are quite rare in homes these days. Maybeeee some microwaves? But the majority of power consumption is happening after rectifiers. Edit: another thought, most chargers and other low power DC power supplies will actually work just fine if you feed them sufficiently high voltage DC rather than AC. The recifier just doesn't do anything! I used to power my laptop charger directly from a lithium battery at about 100 volts DC with no trouble.