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Majromaxtoday at 2:05 AM0 repliesview on HN

With modern technologies, that's power over ethernet or USB-C. Other comments in this thread point out that the telephone service also routinely used 48V for the ring signal.

However, higher DC voltage is riskier, and it's not at all standard for electrical and building code reasons. In particular, breaking DC circuits is more difficult because there's no zero-crossing point to naturally extinguish an arc, and 170V (US/120VAC) or 340V (Europe/240VAC) is enough to start a substantial arc under the right circumstances.

Unfortunately for your lighting, it's also both simple and efficient to stack enough LEDs together such that their forward voltage drop is approximately the rectified peak (i.e. targeting that 170/340V peak). That means that the bulb needs only one serial string of LEDs without parallel balancing, making the rest of the circuitry (including voltage regulation, which would still be necessary in DC world) simpler.