Abstract: Methods and systems for digitally generating sound from phase and amplitude information of a narrow bandwidth signal, such as a narrow bandwidth locator signal. Phase-derivative information is determined from the phase information. The bandwidth of the phase-derivative information is spread out, or stretched, over a wider bandwidth, so that the frequency variations will be more perceptible to users. The result is combined with an audio band carrier frequency, the result of which controls an oscillator. The oscillator output is combined with the amplitude information to generate an analog audio signal that is modulated with the amplitude information and the phase-derivative information. The amplitude information wider bandwidth phase-derivative information are used to modulate an audio carrier in both frequency and amplitude.

Abstract: A signal generator controls power output on the basis of the output from a &Dgr;-&Sgr; modulator or oscillator. That output may be generated in real time by the modulator or oscillator and fed to a switch control logic unit which controls a power switching stage to output switchably switched power from a power supply to an output, preferably via a filter. Alternatively the output of a &Dgr;-&Sgr; oscillator or modulator may be stored in a switchable memory to be retrieved when needed. A further alternative is to control the power switching stage by a processor with a program which reproduces the control effect of the &Dgr;-&Sgr; oscillator/modulator. Feedback from the output may be used to control the &Dgr;-&Sgr; modulator/oscillator and/or the power supply.

Abstract: A system and method for detecting a concealed current carrying conductor is presented. A first and a second field strength signal proportional to an electromagnetic field is generated. A value is determined for the first field strength signal. This value is used to divide the second field strength signal and form an indicator signal. A value for the indicator signal is determined. If the value of the indicator signal is equal to or greater than a predetermined value (i.e., not less than the predetermined value), a conductor detection signal is generated and used to alert a user to the presence of a concealed current carrying conductor.

Abstract: A signal generator controls power output on the basis of the output from a &Dgr;-&Sgr; modulator or oscillator. That output may be generated in real time by the modulator or oscillator and fed to a switch control logic unit which controls a power switching stage to output switchably switched power from a power supply to an output, preferably via a filter. Alternatively the output of a &Dgr;-&Sgr; oscillator or modulator may be stored in a switchable memory to be retrieved when needed. A further alternative is to control the power switching stage by a processor with a program which reproduces the control effect of the &Dgr;-&Sgr; oscillator/modulator Feedback from the output may be used to control the &Dgr;-&Sgr; modulator/oscillator and/or the power supply.

Abstract: A signal generator controls power output on the basis of the output from a &Dgr;-&Sgr; modulator or oscillator. That output may be generated in real time by the modulator or oscillator and fed to a switch control logic unit which controls a power switching stage to output switchably switched power from a power supply to an output, preferably via a filter. Alternatively the output of a &Dgr;-&Sgr; oscillator or modulator may be stored in a switchable memory to be retrieved when needed. A further alternative is to control the power switching stage by a processor with a program which reproduces the control effect of the &Dgr;-&Sgr; oscillator/modulator Feedback from the output may be used to control the &Dgr;-&Sgr; modulator/oscillator and/or the power supply.

Abstract: A system and method to locate electronic marker balls includes receiving a signal representative of a detected marker ball. The signal includes the resolved in-phase and quadrature-phase (I and Q) components, each centered about a first frequency. The I and Q components are filtered in order to shift the first frequency to a second frequency and match the second frequency I and Q components to exponential decay characteristics associated with the marker balls. The second frequency I and Q components phase integrated in order to distinguish the components from noise. The integrating is based upon predetermined gain coefficients and produces integrated I and Q components in accordance with the predetermined gain coefficients. Next, a magnitude of the integrated I and Q components is determined to produce an I and Q magnitude vector and a noise variance associated with the magnitude vector is determined. Finally, the recursive coefficients are adjusted in accordance with the determined noise variance.

Abstract: A system and method for detecting a concealed current carrying conductor is presented. A first and a second field strength signal proportional to an electromagnetic field is generated. A value is determined for the first field strength signal. This value is used to divide the second field strength signal and form an indicator signal. A value for the indicator signal is determined. If the value of the indicator signal is equal to or greater than a predetermined value (i.e., not less than the predetermined value), a conductor detection signal is generated and used to alert a user to the presence of a concealed current carrying conductor.

Abstract: Methods and systems for digitally generating sound from phase and amplitude information of a narrow bandwidth signal, such as a narrow bandwidth locator signal. Phase-derivative information is determined from the phase information. The bandwidth of the phase-derivative information is spread out, or stretched, over a wider bandwidth, so that the frequency variations will be more perceptible to users. The result is combined with an audio band carrier frequency, the result of which controls an oscillator. The oscillator output is combined with the amplitude information to generate an analog audio signal that is modulated with the amplitude information and the phase-derivative information. The amplitude information wider bandwidth phase-derivative information are used to modulate an audio carrier in both frequency and amplitude.

Abstract: A system and method to locate electronic marker balls includes receiving a signal representative of a detected marker ball. The signal includes the resolved in-phase and quadrature-phase (I and Q) components, each centered about a first frequency. The I and Q components are filtered in order to shift the first frequency to a second frequency and match the second frequency I and Q components to exponential decay characteristics associated with the marker balls. The second frequency I and Q components phase integrated in order to distinguish the components from noise. The integrating is based upon predetermined gain coefficients and produces integrated I and Q components in accordance with the predetermined gain coefficients. Next, a magnitude of the integrated I and Q components is determined to produce an I and Q magnitude vector and a noise variance associated with the magnitude vector is determined. Finally, the recursive coefficients are adjusted in accordance with the determined noise variance.

Abstract: A signal generator controls power output on the basis of the output from a &Dgr;-&Sgr; modulator or oscillator. That output may be generated in real time by the modulator or oscillator and fed to a switch control logic unit which controls a power switching stage to output switchably switched power from a power supply to an output, preferably via a filter. Alternatively the output of a &Dgr;-&Sgr; oscillator or modulator may be stored in a switchable memory to be retrieved when needed. A further alternative is to control the power switching stage by a processor with a program which reproduces the control effect of the &Dgr;-&Sgr; oscillator/modulator Feedback from the output may be used to control the &Dgr;-&Sgr; modulator/oscillator and/or the power supply.