Weighing machine

Discussion in 'General Electronics Chat' started by olla, Dec 21, 2010.

  1. olla

    Thread Starter New Member

    Apr 25, 2010
    I'd like to know how a weighing machine works, i open one and i saw some wire going out of one leg?, 2 metal strips to either side, 9v battery, what's about the wires going of the 2 strips?. i tried to turn on the segments one by one with the 9v battery, but i got 888, since i dont know how to turn 'em on i connected the 9v to each of the dysplay #.TIA
  2. retched

    AAC Fanatic!

    Dec 5, 2009
    The two strips COULD be strain gauges.

    As more weight is added, more stress is "seen" by the strain gauge, changing the resistance of the strip.

    This resistance is converted to weight.

  3. Wendy


    Mar 24, 2008
    If you aren't a tech you should be. The first step every tech goes through is taking things apart to see what makes them tick. Some of us even put them back together afterwards (and some of those even work after reassembly). :D
  4. iONic

    AAC Fanatic!

    Nov 16, 2007
    Boy, if that doesn't strike a chord.

    I recently labored to take apart a PUR faucet water filter LED indicator to see how it was telling me that I needed to change the filter. It uses a small pressure sensor that feeds data to a chip. Not sure what the chip was, so I still do not know if they are cheating me out of my cash or not. If it's just some sort of counter that triggers Green, Yellow, and Red LED's then they could be siphoning from my wallet. But if it's a combination of pressure and time, then they could very well have a fairly accurate way of measuring the volume of water used. Bottom line, I still keep pumping the water out, even on Red, for a while before changing the filter out. He He...