http://www.imsolidstate.com/archives/500 Always improving things... Sun, 05 Sep 2010 16:02:52 -0600 http://wordpress.org/?v=2.8.4 hourly 1 http://www.imsolidstate.com/archives/500/comment-page-1#comment-497 imsolidstate Mon, 15 Feb 2010 01:38:46 +0000 http://www.imsolidstate.com/?p=500#comment-497 I would recommend load cells for a scale application. You could use four load cells, one at each corner of the platform and sum the outputs. I did a prototype a while back of a 4-point force measurement, it's pretty straightforward. Measurement Specialties has affordable load cells available at digikey or the like that have very good outputs. Use in-amps to amplify the load cell outputs, and then a G.P. op-amp to sum the four values. From there you can feed the data into an ADC. Assuming you used an AVR's 10bit ADC, and a 400lbs absolute max weight, you would have a best-case resolution of 0.4lbs. Then output the value (with scaling) to an LCD. I would recommend load cells for a scale application. You could use four load cells, one at each corner of the platform and sum the outputs. I did a prototype a while back of a 4-point force measurement, it’s pretty straightforward. Measurement Specialties has affordable load cells available at digikey or the like that have very good outputs. Use in-amps to amplify the load cell outputs, and then a G.P. op-amp to sum the four values. From there you can feed the data into an ADC. Assuming you used an AVR’s 10bit ADC, and a 400lbs absolute max weight, you would have a best-case resolution of 0.4lbs. Then output the value (with scaling) to an LCD.

]]> http://www.imsolidstate.com/archives/500/comment-page-1#comment-491 Jack Grimes Sun, 14 Feb 2010 17:42:15 +0000 http://www.imsolidstate.com/?p=500#comment-491 Would this this work as a scales? I have need for 4-5 scales that will allow a wheelchair to roll on to a platform to weigh kids in our group homes rather than put them in a van and bring them ten miles to the main facility every week or so. Max weight would be about 300 pounds. Would this this work as a scales? I have need for 4-5 scales that will allow a wheelchair to roll on to a platform to weigh kids in our group homes rather than put them in a van and bring them ten miles to the main facility every week or so. Max weight would be about 300 pounds.

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