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 couples 600-ohm signals to a line of the same impedance consisting of an amplifier stage....
This circuit is suggested by RCA and is based on a dedicated integrated circuit that is the...
The power supply shown has protection against short circuits and can eventually be mounted with...