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.
This circuit is from Ferranti documentation from 1967. The operational is of the time, but the...
This simple circuit can be used in a robot that follows the light directly feeding a small motor....
This circuit makes the simple test of SCRs that have a low maintenance current, with those of the...