I have a very limited knowledge of electrical engineering that almost entirely revolves around music equipment. From everything that I’ve seen, music equipment ends up converting the AC power to DC power right at the power entry point (or at least soon after). It appears they’re converting AC power to a higher voltage and current DC power. Is the only real advantage of AC power to pump more power over a line to where devices will then manipulate it to what they need in DC? Are there any common household items that actually fully operate off of AC power or does everything convert to DC at some point?
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Electric generators and motors can use dc or ac, not both.
DC generators and motors need brushes to catch the power from the spinning part, and this brushes require big big maintenance. When AC was discovered, it allowed to make generators and motors at 2/3 of the price of a DC one, and they are completely maintenance free, because they don’t need a brush system. So they won, and were adopted in mass.
Not having brushes allows to produce higher voltages without issues. Higher voltage allows to transfer the same power using thinner wires, this makes transport and the generator parts to be done with thin cheaper wires, saving even more money.
Then the power transport in cables has losses along the line, electrons flow heats the cables, with high voltage, you can transport power by moving fewer electrons but with higher force in each of them. So again, another win for high voltage systems, and again high voltage production is easier if done in AC. There are DC high voltage lines, for example, submarine cables and nation to nation lines may be high voltage DC; not so common but it’s done sometime, for example, a country with 115v 50hz AC may transform it to DC to sell it to another country that then transforms it into its own 220V 60hz AC. This is done because the 2 different AC systems are completely incompatible, because both need to transform it, they may have a DC line between them.
Add in that illumination can be done with DC or AC without difference.
Basically the only drawback for AC is computers. Computers need low voltage DC. So we use an AC line for everything, and transform it to low voltage DC only in the devices that need it. Another thing that can’t work in AC are batteries, so any system that has a battery needs to be DC. This doesn’t mean that we can’t do a AC system with a DC conversion between system and battery, sometime it’s done, it’s overly expensive but may be done.
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