How can I make an electronic balance that would output a voltage and light a series of LEDs?

The display will be used to represent weight (weight would be between 1 and 100 lbs) and will be used in a competition in which coins will be added into buckets setting on the scales or load cell platforms at varying rates. I will make two identical units and would like for the displays to remain active throughout the competition which should last less than 20 minutes. The purpose will be to represent which bucket has the most weight at any given moment and the accuracy only needs to be the same for each device. In other words, if the buckets were switched, the results would be repeatable (accurate within one LED (or perhaps a better light arrangement may be suggested)).

Thank you

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lemonie7 years ago

Could you funnel the coins to trip a switch? That way you'd be able to count all the coins.

benglish777 (author)  lemonie7 years ago
Thank you for the idea. Kind of you to respond.

I'm thinking of a big funnel with a small trap-door linked to a micro-switch. You'd need a counter & display (electronics kits)

First find your load cell. Bathroom scales ?
benglish777 (author)  steveastrouk7 years ago
That is a good thought. I will look into the bathroom scale idea. I imagine several of the newer scale models us load cells.

The load cell will output a voltage based on the force applied. It may take some calibration to get it spot on for accuracy.

Then take that signal, feed it (likely) into a computer, likely a microcontroller, and use that to drive your favourite led display.

Each portion of the above has been detailed rather well in several instructables.
benglish777 (author)  frollard7 years ago
Thanks. I am not sure I know enough about the computer to make use of it but you are probably right on with the microcomputer idea.