This high sensitivity circuit was found in the July 1992 Radio Electronics magazine. The circuit drives a buzzer, but a relay can be used to activate an external load.
This circuit is from a 1966 documentation. The transistor is made of germanium of the time and the...
This simple circuit allows testing of general-purpose diodes and rectifiers and also general...
This interesting circuit of a 1988 documentation consists of a mouse trap where the sensor is left to...