I am trying to power a 5v circuit from any voltage between 100-240v. I know it is possible to do this with a transformerless power supply, but only for a single voltage (e.g. 120v only), but how do I make it work with the entire 100-240v range?

So if I power the circuit in the U.S. (120v) or Britain (230v), the circuit should still work.

  • \$\begingroup\$ It is called SMPS. Switching mode power supply. Look for that. \$\endgroup\$ – Chupacabras Feb 28 '19 at 6:01
  • \$\begingroup\$ @Chupacabras How exactly does the SMPS allow for the entire 100-240v range? I've been reading efxkits.us/switch-mode-power-supply-smps-works, but I'm not seeing how it can accept this voltage range. \$\endgroup\$ – Alex Feng Feb 28 '19 at 6:38
  • \$\begingroup\$ Your question, I'm afraid, will be closed as "too broad". Designing an SMPS requires specialist knowledge and understanding of safety, etc., so it's not something you can be taught in an answer on this site. Study and return here if there is a specific detail you need help with. \$\endgroup\$ – Transistor Feb 28 '19 at 7:26
  • \$\begingroup\$ @Transistor I don't need help with designing the SMPS. I just want to know how it functions to convert 100-240v to the same DC voltage? Why can it take any voltage between 100-240v and still produce the same DC output? \$\endgroup\$ – Alex Feng Feb 28 '19 at 7:43
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    \$\begingroup\$ A SMPS operates, in the most general sense, by pulsing the input voltage at different duty cycles through a filter that smooths the output to spec. The frequency or duty cycle of the pulses determines the output voltage, so in your case it simply becomes a question of component ratings. All of the relevant voltage ratings must support the highest voltage in question, highest potential current, it must switch fast enough for either voltage and the sense circuit must operate over that range. \$\endgroup\$ – K H Feb 28 '19 at 7:52

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