The signal from this transmitter is injected into a cable that you want to follow along a pipeline. Monitoring is done using an ordinary AM receiver out of season.
The TTL circuit shown in the figure generates a 1 MHz rectangular signal depending on the 20-200 pF...
The sensor for this circuit, found in a 1992 publication, is a phototransistor. The power is...
An irregular signal can be converted into a pulse of duration determined by the switching...