This simple sensitive circuit was suggested in a July 1992 Radio Electronics issue. The relay is a double-contact changeover relay. Sensitivity adjustment is made at R2.
This small signal amplifier circuit was found in Motorola's 1969 documentation. The FET and the...
This is the conventional application of the UCN4202 to control a 12 V stepper motor with current...
Found in a manual of integrated circuits from the 90s, this circuit makes use of that time...