This circuit was found in a Popular Electronics from the 90s. The counter circuit is not common today. The circuit can be programmed for hourly intervals, according to the values of R4 and C2.
This circuit was obtained from a Linear Technology manual from the 1990s. The sensor is of the...
This circuit is from a PE Hobbyst Handbook from 1991. The integrated circuit is a common 555 and...
This traditional circuit with a neon lamp is a flip-flop that draws which of the two lamps will...