This circuit was found in a 1985 documentation. It provides an audiovisual indication of the presence of moisture or water in the sensor. The circuit can be powered by voltages from 6 to 9 V.
This configuration was found in an old technical documentation from the 70s, but it can be...
In the figure we have a converter that generates a negative voltage from a positive voltage...
This circuit was found in a 1976 magazine. The circuit emits a sound when a balance sensor placed on...