This notch filter was found in National Semiconductor documentation from the 1980s. Operational amplifiers are from that era. The configuration can be adapted to use modern operational amplifiers.
This circuit drives two-color LEDs at a speed that is set in the 100k pot. The circuit can be...
The circuit shown was found in a 1967 RCA manual. Modern equivalent components can be used. The...
Indicated for automotive applications, this circuit was found in the November 1980 issue of Radio...