Patent ID: 8806958

Claim:
A flow sensor, comprising: a duct having an inner surface and an outer surface, the inner surface defining a flow passage through which fluid may flow in a flow direction; a plurality of ultrasonic transceivers coupled to a portion of the outer surface of the duct, each of the ultrasonic transceivers configured to (i) transmit ultrasonic waves into the fluid, (ii) receive ultrasonic waves, and (iii) supply sensor signals representative of the received ultrasonic waves; and signal processing circuitry in operable communication with each of the ultrasonic transceivers, the signal processing circuitry configured to: supply separate excitation signals to each of the ultrasonic transceivers, receive the sensor signals supplied by each of the ultrasonic transceivers, and generate, in response to the sensor signals, a flow signal representative of fluid flow in the flow passage, wherein each of the excitation signals has a different phase, such that the ultrasonic waves transmitted by each of the ultrasonic transceivers at least selectively combine to propagate in an adjustable direction relative to the flow direction.