4 ms·

Pleasantly surprising to see it actually works (even if on an isolated power supply for safety)

• voltagex_ 11y ago
  I don't really understand how there's 120V at the tip when it's plugged into the Apple USB powers supply. Isn't there a gap between the AC and DC electronics?
  • foldr 11y ago
    It's normal for these sorts of power supplies to have a small leakage current. Hopefully someone else will be able to explain the details, but as I understand it it's the result of capacitative coupling across the transformer and filter capacitors.
    • cellularmitosis 11y ago
      I can't explain the details, but I was able to measure the current. Interesting that I didn't measure any current from a genuine Apple charger, but enough current to cause a tingle from the cheap import chargers. https://www.youtube.com/watch?v=pjz4I69YoUA https://www.youtube.com/watch?v=pjz4I69YoUA
      • c22 11y ago
        > but enough current to cause a tingle from the cheap import chargers. You should try using a multimeter!
        • cellularmitosis 10y ago
          Um, I did, as shown in the video...
    • deleted 11y ago
      [deleted]
  • brian-armstrong 11y ago
    The voltage is mains AC, but the current is measured in microamps. It's still enough charge to cause static discharge.