This circuit uses an unusual PLL, the 4046 CMOS. We found it in the October 1994 issue of Electronics Now. The circuit also uses a 4093 gate as a trigger.
May 2017 - In stock at Mouser Electronics DGD Dgate drivers from Diodes Incorptrated ara...
This circuit is from the 1977 RCA Linear Integrated Circuits Manual. The circuit has a...
The sensor is S1 in this alarm that we found in a Radio Electronics magazine from May 1971....