This 50 Hz rejector or notch filter was found in a 1975 documentation. Other frequencies can be obtained by changing components. The filter uses a Wien network and must use a symmetrical power supply.
This simple circuit for a high impedance magnetic phone (500 ohms or more) has been found in a...
This 3 V rail to rail buffer was found in a National Semiconductor documentation. The gain is unit....
We found this circuit in the September 1971 issue of Radio Electronics magazine. The sensor is an...