This Hall effect sensor circuit was found in the July 1998 issue of Electronics Now magazine. It is suitable for experiments with magnets in laboratories and schools.
This circuit is from 1977 documentation, but can be assembled with BC548 for Q1, Q2 and Q4, BC558...
Found in American documentation from the 90s, this circuit uses components that are still common...
This high impedance input amplifier is suitable for the use with piezoelectric sources such as...