This filter for frequencies from 300 Hz to 3.4 kHz was found in the February 1995 Radio Electronics magazine. Other operational amplifiers can be experimented, and the source must be dual.
What is a dual frequency generator for? There are several possibilities of use for this circuit. The...
The circuit, illustrated in the figure, consists of the direct application of the ULN2003 in which...
This circuit was found in a Popular Electronics from the 90's. The output signal can be applied to a...