Suggested by National Semiconductor, this circuit can be applied to almost any operational amplifier. The input resistance is extremely high.
Found in the August 1970 Radio Electronics magazine, this circuit uses a CA3018 with the trigger...
Found in a 90s Electronic Design, this circuit generates harmonics from a sinusoidal input signal....
We found this touch switch in a 1992 Electronics Handbook. The circuit can be assembled with 6 or...