This bargraph circuit was found in the January 1986 issue of Radio Electronics magazine. It is based on the well-known LM3914 and has two of them in cascade driving a good number of LEDs.
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...