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 generates an ultrasound whose frequency is set in P1. Reproduction is done on a...
This circuit was suggested by General Electric / RCA in a 1980s documentation. The components are of...
The circuits shown in figure 2 are suggested by Texas Instruments (www.ti.com) make use of the...