3 ms·
https://en.wikipedia.org/wiki/Switched-mode_power_supply https://en.wikipedia.org/wiki/Switched-mode_power_supply Stepping AC up/down is relatively easy, all y
by _whiteCaps_ 7y ago
https://en.wikipedia.org/wiki/Switched-mode_power_supply https://en.wikipedia.org/wiki/Switched-mode_power_supply
Stepping AC up/down is relatively easy, all you need is a transformer. I'd say the invention of the transistor / IC made it possible for DC. But it took a while to perfect those designs - wall warts changed from transformers in the 1990s?