This circuit was found in an American 1990s documentation. It can directly trigger a triac when light is detected by the sensor. The integrated circuit is common, like the 741.
This circuit was found in an English magazine from 1977. Signal inputs and outputs must be...
This circuit triggers producing a loud sound when a change in temperature is detected. The circuit...
With 3 transistors, we found this receiver in a documentation from 1966. The circuit has an output...