This circuit was found in an Australian publication from 1991. It is a transmitter that transmits a signal when it detects moisture. The range is on the order of a few tens of meters.
This circuit was found in Radio Electronics magazine from August 1966. The transistors are from...
We found this circuit in an old documentation for radio amateurs. The circuit uses an analog...
This circuit is found in a 2005 Linear Technology application manual. The circuit monitors the High...