This old circuit is suitable for signaling applications. The lamp must be incandescent, and the triac must be mounted on a heat sink. The frequency is adjusted in the 1 M trimpot.
This version of an astable CMOS with the 4069, and which appears elsewhere on this site and in...
Found in na 1970 EDN this circuit has a parallel regulation providing a symmetrical output of 15 V....
This circuit is the receiver for the previous remote-control transmitter. We found it in the same...