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 provides a negative supply for circuit biasing. The current is very low. The voltage...
This very low voltage circuit with the LMV321 was obtained from its own datasheet. The circuit can be...
This circuit was found in a Modern Electronics from 1990. It activates an old electromechanical pulse counter,...