This circuit appears elsewhere in this section and on this site. The circuit generates a linear ramp having been found in 1980s documentation. The transistor is a general purpose type.
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...