Frequency dependent pulsed gain modulated concealed structure locator
First Claim
1. Translator apparatus adapted to provide a pulse train therefrom having a pulse repetition rate frequency which is derived from the average, albeit varying, amplitude of a higher frequency a.c. signal coupled thereto;
- comprising;
a. a portable source of about constant level, essentially continuous wave first frequency a.c. signal;
b. portable receptor means effective to separably couple with said source, usually with various levels of efficaciousness therebetween, producing therefrom a received a.c. signal proportional to the first frequency a.c. signal level modified by the coupling effacicity;
c. digital sequence signal source means effective for producing several series of pulse train signals having different intrinsic periodicity rates therebetween while having harmonic relationship thereamongst;
d. digital-to-analog stepped signal converter means coupled with said sequence signal source, effective to receive pulse train signals therefrom and produce a composite signal comprising a repetitious continuum of various amplitude value steps, each constituent step of which has a predetermined amplitude value proportional to the signal pulse series comprising the lowest frequency pulse train instantly produced by said sequence signal source;
e. receiver means coupled with said receptor means provided with an effective signal level control input thereto coupled with said composite signal, and a converted output therefrom;
operative to combine, as by modulation, said received a.c. signal with said composite signal so as to produce a repetitive sequence comprising bursts of converted received signals having various values of predetermined amplitude; and
further including threshold detector means responsive to the instant values of said converted received a.c. signals to repetitively produce at least a first level pulse signal therefrom when said converted received signal exceeds a predetermined threshold value, and a second level pulse signal therefrom when said converted received signal shortfalls the predetermined threshold value;
f. indicant means coupled to said pulse signal produced by said threshold detector means; and
,g. electric power source means effective to provide operating voltage and current to each of the thereto coupled functional elements comprising the said translator.
0 Assignments
0 Petitions
Accused Products
Abstract
Portable concealed structure locating and surveying translator apparatus, useful for tracing the bearing and lay of cables, pipes, and other expansive structures. The translator responds to the electromagnetic field radiating from a buried structure which is excited by a constant amplitude, fixed frequency high frequency a.c. signal. The translator is directional, providing bearing indication in its preferred form. Two noncoincident receiving loops, or inducers, are closely oriented to receive the structure radiated field lines with differing positional related efficacity. The received signal levels produced in each of the receiving loops is coupled with a receiver which includes a provision for the automatic, digitally advanced, sequential step-by-step change in overall sensitivity through a range of discrete values of responsiveness. Each discrete response value recurs at a related, finite repetition rate which results in an overall characteristic stepped swept gain effect, thereby producing instantaneous variegated values of signal level which are detected as finite threshold levels and thereby usually adapted into a pair of audio frequency tones which, when coupled to an operator'"'"'s ears, serve to give a stereotonic effect with the balance of apparent pitch therebetween indicating on-course bearing, while the relative pitch imbalance wrought between the right and the left ear associated earphone gives a sense of bearing directionality to the operator.
36 Citations
16 Claims
-
1. Translator apparatus adapted to provide a pulse train therefrom having a pulse repetition rate frequency which is derived from the average, albeit varying, amplitude of a higher frequency a.c. signal coupled thereto;
- comprising;
a. a portable source of about constant level, essentially continuous wave first frequency a.c. signal; b. portable receptor means effective to separably couple with said source, usually with various levels of efficaciousness therebetween, producing therefrom a received a.c. signal proportional to the first frequency a.c. signal level modified by the coupling effacicity; c. digital sequence signal source means effective for producing several series of pulse train signals having different intrinsic periodicity rates therebetween while having harmonic relationship thereamongst; d. digital-to-analog stepped signal converter means coupled with said sequence signal source, effective to receive pulse train signals therefrom and produce a composite signal comprising a repetitious continuum of various amplitude value steps, each constituent step of which has a predetermined amplitude value proportional to the signal pulse series comprising the lowest frequency pulse train instantly produced by said sequence signal source; e. receiver means coupled with said receptor means provided with an effective signal level control input thereto coupled with said composite signal, and a converted output therefrom;
operative to combine, as by modulation, said received a.c. signal with said composite signal so as to produce a repetitive sequence comprising bursts of converted received signals having various values of predetermined amplitude; and
further including threshold detector means responsive to the instant values of said converted received a.c. signals to repetitively produce at least a first level pulse signal therefrom when said converted received signal exceeds a predetermined threshold value, and a second level pulse signal therefrom when said converted received signal shortfalls the predetermined threshold value;f. indicant means coupled to said pulse signal produced by said threshold detector means; and
,g. electric power source means effective to provide operating voltage and current to each of the thereto coupled functional elements comprising the said translator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
- comprising;
Specification