This CMOS logic-based circuit was found in the April 1974 issue of Radio Electronics magazine. The circuit is based on a period display and has hour and minute indications.
The figure shows how to implement an alarm buzzer in an LM3914 to warn about crossing the scale...
This circuit can act as a shield being controlled by a microcontroller by pin 1 or 2. The...
This circuit was obtained from a 1980's QST magazine. The circuit can generate 1 to 15 MHz signals...