This sensitive circuit was found in an Electronics Hobbyists Handbook from the 1990s. The circuit can use common general-purpose transistors in place of the original ones.
This Sample & Hold circuit configuration is from an American 1980s documentation. The circuit uses...
By LED flashes you can get an idea of the degree of moisture in the soil. The sensors are wires...
Found in an old Popular Electronics, the purpose of this circuit is to give a strong discharge in an...