This circuit triggers a small water pump when the humidity detected by the sensor is reduced in a flower bed or potted plant. The circuit must use a source according to the driven water pump.
Found in a 90's EDN this circuit can be used as a shield. The transistor is a general-purpose type and the...
This circuit was found in the November 1992 issue of Radio Electronics magazine. The circuit has...
This circuit was found in an American documentation from 1977. The circuit can be implemented with modern...