Electrical weighing scale
AssigneeMeasurement Specialties, Inc.
InventorsDamon Germanton, Mark W. Cappiello, Richard E. Tasker, Steven P. Petrucelli
Life of this patent
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Abstract
An electrical weighing scale for measuring the weight of a user having has a substantially transparent platform, a plurality of supports, and a display assembly. Piezoresistive sensors, disposed in the supports, change resistance in response to a change in the weight applied to the scale. The piezoresistive sensors include piezoresistive elements arranged in a half bridge structure that has been calibrated to provide zero balance, span matching and impedance normalization. The sensors are coupled in parallel to a display. The parallel arrangements produces a composite output signal that enables any number of sensors to be used in the scales design.
Claims19
A scale, comprising:
- a platform for receiving an applied weight, said platform being entirely transparent;
- a plurality of support assemblies, each of which receives a peripheral portion of said platform, each of said support assemblies receiving a percentage of the weight applied to said platform and including a half bridge sensor structure which generates an analog output signal which corresponds to the percentage of the weight received by each of said support assemblies;
- a display assembly coupled to said platform, said display assembly including combining means for combining said analog output signals in parallel to obtain a composite analog output sensor signal which is representative of the weight applied to said platform, and signal conversion means for converting said analog composite sensor signal to a composite digital signal;
- and
- wire means for electrically coupling said half-bridge sensor structures to said combining means of said display assembly, said wire means extending along an outer peripheral edge surface of said platform.
A scale, comprising:
- a platform for receiving an applied weight;
- a plurality of support assemblies, each of which receives a peripheral portion of said platform, each of said support assemblies receiving a percentage of the weight applied to said platform and including a half bridge sensor structure which generates an analog output signal which corresponds to the percentage of the weight received by each of said support assemblies;
- a display assembly coupled to said platform, said display assembly including combining means for combining said analog output signals in parallel to obtain a composite analog output sensor signal which is representative of the weight applied to said platform, calibration means for enabling said half-bridge sensor structures to be individually electrically compensated, and signal conversion means for converting said analog composite sensor signal to a composite digital signal;
- and
- wire means for electrically coupling said half-bridge sensor structures to said combining means of said display assembly, said wire means extending along an outer peripheral edge surface of said platform.
A scale, comprising:
- a platform for receiving an applied weight;
- at least two support assemblies connected to said platform for receiving a percentage of said weight applied to said platform, each of said support assemblies comprising:
- an upper plate;
- a lower plate;
- at least one flexible element disposed between said upper plate and said lower plate, said flexible element having a first end coupled to said upper plate and a second end coupled to said lower plate;
- and
- at least one half bridge sensor structure with two arms, wherein each arm includes at least one piezoresistive element that varies in resistance and is disposed on said flexible element, wherein when said flexible element bends, said half bridge structure generates an analog output signal corresponding to the percentage of weight received by said support assemblies;
- a display assembly coupled to said platform, comprising:
- calibration means for enabling said piezoresistive elements of said half bridge sensor structure to be individually electrically compensated;
- combining means for combining each analog output signal from said half bridge sensor structure in parallel to obtain a composite analog output sensor signal representative of the weight applied to said platform;
- signal conversion means for converting said analog composite sensor signal to a composite digital signal;
- and
- display means for displaying a value corresponding to said composite sensor signal;
- and
- wire means for electrically coupling said half-bridge sensor structures to said combining means of said display assembly.
The scale according to claim 19, wherein said platform is transparent.
Dependencies are inferred from the claim text.