Using a 74123 TTL this circuit was found in the Radio Elecronics magazine of June 1975. The power supply must be 5 V. The capacitor determines the activation time.
Found in a 1964 General Electric documentation, this circuit uses PUTs that are not currently...
This double tone generator uses a specific integrated circuit, having been found in a 1977 CMOS...
Found in American documentation from 1968, this circuit has an acute cut-off of the frequency to...