Patent ID: 8421479

Claim:
A low power measurement system for measuring a parameter comprising: a medium where the parameter to be measured affects the medium; a transducer coupled to the medium at a first location where the transducer emits a pulsed energy wave into the medium in response to a pulse; and a reflective surface coupled to the medium at a second location where the pulsed energy wave propagates through the medium to the second location and where the reflective surface reflects the pulsed energy wave back to the first location; and a pulsed system including: an edge detect circuit for detecting an edge of a signal from the transducer; and a first pulse circuit far generating a pulse to initiate a subsequent measurement sequence in response to a detected edge by the edge detect circuit where a transit time of the pulsed energy wave is measured and the transit time or change in transit time corresponds to the parameter where the system includes an amplifier having an input coupled to an output of the edge detect circuit and an output coupled to the transducer.