Complete module that is capable of detecting weight
Things in this module
The mount designs.
The circuit design.
The entire circuit on a PCB
Loadcells are half bridge
Typically loadcells are full bridge and are typically balanced. The loadcells were half-bridge. That is they have one compressive element and one tension element. I had to build the circuit that balances as well as magnify the signals from one loadcell.
Finalizing the concept
There are four load points. To implement this with the first concept would mean that a total of eight loadcell will be required where four of them are mounted at these load points and four of them placed as dummy. Hence concept 1 was rejected.
If concept 2 was implemented with each loadcell mounted at each load point, it can give only two load reading. This means that only the projection of CG along one axis can be obtained. This will work but the projection of CG along the lateral axis is also desired. So this concept is acceptable but a better solution was desired.
With four load point and mounting the loadcells at these load points using concept 3 will give four load reading. This means that the projection of CG along the longitudinal as well as lateral direction can be obtained. Since balancing the bridge using resistors and trim pot was successfully tested, concept 3 was chosen as it was superior to concept 1 and concept 2.