Found in Texas Instruments documentation from the 1980s, this circuit applies to digital signal transmission with FSK modulation. The circuit is slow, as it uses period components.
This circuit triggers an alarm in the event of a power failure. The circuit is from an 80's...
We found this circuit in the April 1978 issue of Radio Electronics magazine. The 2-digit circuit uses...
This CMNOS crystal-based circuit generates a 2 Hz signal. It was found in the October 1994 issue of...