This filter that rejects a frequency range determined by the double-T was found in the August 1993 Electronics Now magazine. The source must be symmetrical.
This circuit is from Motorola's Linear Interface ICs of 1993. The circuit can be powered by...
This circuit activates a relay when the supply voltage drops below the value set in the trimpot. The...
Based on National semiconductor power operational amplifiers, uncommon today, this circuit...