Heh - I vaporised a fairly large soldering iron tip (probably 4mm copper cylindrical bar?), when I fucked up soldering a connector to a big 7 cell ~6000mAHr LiPo battery and shorted the terminals. Quite how I didn't end up blind or in hospital I don't know. It reinforced just how much respect you need to pay to even low-ish voltage DC when the available current was likely able to exceed 700A by a fair margin momentarily. I think those cells were rated at 60C continuous and 120C for 5 seconds.

> DC arcs aren't self-extinguishing, unlike AC arcs. At one point I stuck a voltage probe in, and the arc stuck with it as I pulled the probe away. It also vaporized the metal tip of the probe.

It would have self-extinguished if you waited long enough for the probe to vaporize.

The 'what is safer' question for DC and AC at the same effective current and power has a mixed set of answers depending on conditions. For instance, DC is more likely to cause your muscles to contact and not let go (bad), but AC is more likely to send your heart into ventricular fibrillation (sp?, also bad).

AC arcs are easier to extinguish than DC arcs, but DC will creep much easier than AC and so on.

From a personal point of view: I've worked enough with both up to about 1KV at appreciable power levels and much higher than that at reduced power. Up to 50V or so I'd rather work with DC than AC but they're not much different. Up to 400V or so above that I'd much rather have AC and above 400V the answer is 'neither' because you're in some kind of gray zone where creep is still low so you won't know something is amiss until it is too late. And above 1KV in normal settings (say, picture tubes in old small b&w tvs and higher up when they're color and larger) and it will throw you right across the room but you'll likely live because the currents are low.

HF HV... now that's a different matter and I'm very respectful of anything in that domain, and still have a burn from a Tronser trimmer more than 45 years after it happened. Note to self: keep eye on SWR meter/Spectrum analyzer and finger position while trimming large end stages.

Really depends on what we're talking about. A lot of electrical safety equipment has a DC rating, usually something like 90VDC/300VAC. Also, most DC equipment just isn't going to have the stored energy to generate a big arc. Well, except batteries, and we're already piling them all around us.

Agreed!

I spent a few years getting flown out around the world to service gear at different datacenters. I learned to pack an IEC 60320 C14 to NEMA 5-15R adapter cable and a dumb, un-protected* NEMA 5-15R power strip. While on-site at the datacenters, an empty PDU receptacle was often easy to find. At hotels, I'd bring home a native cable borrowed from or given to me by the native datacenter staff or I'd ask the hotel front desk to borrow a "computer power cable," (more often, I'd just show them a photo) and they generally were able to lend me one. It worked great. I never found a power supply that wasn't content with 208 or 240V.

Example adapters: https://www.amazon.com/dp/B0FD7PHB7Y or https://www.amazon.com/dp/B01IBIC1XG

*: Some fancier power strips with surge suppression have a MOV over-voltage varistor that may burn up if given 200V+, rendering the power strip useless. Hence, unprotected strips are necessary.

Taking it to an extreme, the house I lived in while in grad school had wall lamp fixtures that doubled as electric and gas lamps. At some point I imagine it would have been possible to choose between using electric or gas by either flipping the switch or turning a valve. They said "Edison Patent" on them. We could have lit the house on AC, DC, or gas.

Thinking about the failure modes gave me the heebie jeebies, but the gas had been disconnected ages prior.

Your modern fridge is probably going to have an inverter-driven motor, so you're right back to using DC.

Lower voltage makes voltage drop across the line proportionally worse. Depending on the purpose PoE is probably the way to go since the wiring and hardware is all standardized and safety certified.

Unless you mean running AC and installing inverters in the wall? What is this even for? All my electronics are DC but critically they all require different voltages. The only thing I might benefit from would be higher voltage service because there are times that 15 A at 120 V doesn't cut it.

The power adapters became so efficient that we have to transition to wireless charging to keep it down

The irony...