3 ms·

Why? A burned-out bulb fails open not closed. If it failed closed then a bulb burning out would trip the circuit breaker.

• sokoloff 3y ago
  > Why? A burned-out bulb fails closed not open. In electrical circuit terminology, "open" means "not connected" while "closed" means "connected/shorted". That's different from direct translation of Chinese (and I think several European languages) where "open the light" means to turn it on (by closing the circuit, naturally). I think it's most common English engineering usage (by far) to say that a burned out lamp fails open [circuit].
  • jefftk 3y ago
    Whoops, sorry, I had them reversed!
    • sokoloff 3y ago
      Interesting/random side note: modern mini Christmas light bulbs do burn out (mostly) closed: https://www.youtube.com/watch?v=0MOpfT0f7bQ&t=179s https://www.youtube.com/watch?v=0MOpfT0f7bQ&t=179s
• unethical_ban 3y ago
  To close a circuit is to connect it, correct? So when the filament burns out, the circuit breaks, which is an open circuit, correct?