This circuit was published in the July 1993 issue of Electronics Now magazine. It uses a sensor from the time and triggers a buzzer with a Sonalert-type oscillator.
We found this circuit in the January 1992 issue of Radio Electronics magazine. The circuit...
The division by eight using the 4018 is made as shown here. It isn't necessary to use additional...
May 2017 - Texas Instruments' new OPAx388 operational amplifiers can now be purchased from Mouser...