3 ms·

555

• notpushkin 11mo ago
  Came in for this joke.
• ErroneousBosh 10mo ago
  You can't use a 555, obviously. You need to use two of them, or a 556, because you need one half for the 30 second monostable and the other half for the astable that drives the beeper. Out of contrariness I'd use a CD4011 though.
  • jacknews 10mo ago
    You're right, but I think a 555 is maybe more than required for the buzzer. Buzz-overkill, if you like.