This is a combined circuit of tone generator and preamplifier. We found it in a 1975 documentation. Operational amplifiers of that time can be replaced by modern equivalents.
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...