US 12,460,961 B2
Surface acoustic wave scale
Arnold Gordon, Woodmere, NY (US); and Li Feng, Plainview, NY (US)
Assigned to Circuits & Systems, Inc., East Rockaway, NY (US)
Appl. No. 18/002,699
Filed by Circuits & Systems, Inc., East Rockaway, NY (US)
PCT Filed Jul. 6, 2021, PCT No. PCT/US2021/040485
§ 371(c)(1), (2) Date Dec. 21, 2022,
PCT Pub. No. WO2022/010879, PCT Pub. Date Jan. 13, 2022.
Claims priority of provisional application 63/048,931, filed on Jul. 7, 2020.
Prior Publication US 2023/0243692 A1, Aug. 3, 2023
Int. Cl. G01G 3/16 (2006.01); G01G 3/13 (2006.01); G01G 3/18 (2006.01)
CPC G01G 3/16 (2013.01) [G01G 3/13 (2013.01); G01G 3/18 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An electronic weighing apparatus for determining weight of a load, comprising:
a displaceable elastic member that is displaced by the load such that displacement of the elastic member is related to the weight of the load;
a first piezoelectric transducer comprising a first surface acoustic wave (SAW) transmitter spaced from a first SAW receiver, said first piezoelectric transducer being coupled to said elastic member;
a first amplifier having an input and an output, said input of said first amplifier being coupled to said first SAW receiver and said output of said first amplifier being electrically coupled to said first SAW transmitter such that said first SAW receiver, said first amplifier and said first SAW transmitter form a first delay line oscillator circuit that is configured to generate a first oscillating signal in response to displacement of said elastic member;
a magnet spaced from a Hall effect sensor, wherein the magnet is configured to produce a magnetic field and the Hall effect sensor is configured to measure strength of the magnetic field which is related to displacement of said elastic member and the weight of the load;
circuitry operably coupled to the first delay line oscillator circuit, wherein said circuitry is configured to generate first frequency data that characterizes frequency of said first oscillating signal, wherein the first frequency data is related to displacement of said elastic member and the weight of the load; and
a processor operably coupled to the circuitry and the Hall effect sensor, wherein said processor is configured to store calibration data for said electronic weighing apparatus, and wherein said processor is further configured to determine the weight of the load from at least the strength of the magnetic field measured by the Hall effect sensor, the calibration data and the first frequency data;
wherein the first oscillating signal of the first delay line oscillator circuit is within one mode of a plurality of modes that share frequencies; and
wherein the processor is configured to store a mapping function that relates data based on strength of the magnetic field as measured by the Hall effect sensor and the plurality of modes and use the mapping function to determine the one mode given the strength of the magnetic field measured by the Hall effect sensor.