Force conversion into an electrical signal by a load cell is usually carried out indirectly and in two stages.
The first stage conversion is done through a mechanical arrangement in which the force being sensed deforms the strain gauge.
This strain gauge then converts the deformation (strain) to electrical signals. One can also get load cells with one or two strain gauges.
The electrical signal generated by strain gauge is in the order of a few millivolts which needs further amplification by an instrumentation amplifier.
The output of the transducer is fed to an algorithm calculator to calculate the force applied to the transducer.
First, a force is applied to the mechanical system, which transfers the force to the strain gauge, which is basically an elastic foil connected to a wheatstone bridge configuration.
This wheatstone bridge configuration is the electronic device that the strain gauge uses to convert a certain amount of strain into electrical output. Essentially, the mechanical system and strain gauge are used to convert a force into an electrical output.
This electrical output is generally very small, so it is amplified using a form of electric amplification, for which an integrated circuit or transistor may possibly be used.
The electrical output is measured and the plugged into a computer algorithm. The algorithm uses the amount of electricity to tell a user how much force was applied to the load .