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.
This circuit was found in an Electronic Design from 1967. The circuit uses two triacs being T2...
Found in old American documentation, this circuit can use crystals between 27.5 and 33 MHz...
This shield from the 60's uses a germanium transistor of the time and a common type of relay of...