This circuit is from the Texas Instruments operating amplifier manual. Any operational can be used and the font need not be symmetrical. Rf and Rg determine the gain of the circuit.
The circuit presented is from a 2006 documentation. It can turn a set of lamps on or off when...
This second-order filter was found in a 1978 publication and can use common operational amplifiers like...
This simple tone control using two transistors was found in an Electronics Today International of the 90s....