This circuit for very long-time intervals was found in the March 1993 Radio Electronics magazine. Times of several days or even weeks can be achieved depending on the value of C1.
This circuit was found in an old publication about transistors. The circuit can be used to drive...
September 2017 - STMicroelectronics STBR3012-Y high voltage rectifier for automotive use is in...
Found in a Popular Electronics from the 80s, this circuit is intended to indicate the presence of...