Jon Gabay writes:
Current measurement and control are an integral part of any power sensitive system. While most of us have used ammeters to measure current, it is unlikely that budget, space and other practical constraints will allow design engineers to specify an ammeter as part of a finished product; more likely, we will embed some current measurement technique within a given design.
Current measurement has a wide range of uses. Some of these are:
- Making sure a power supply is not damaged by receiving too much current.
- To estimate the rotational speed of a motor (the speed of a motor is directly proportional to the amount of current applied to it).
- To check whether an LED has correct illumination.
- To determine how much current is being applied to a battery pack during charging (so as to prevent overcharging or overheating the batteries).
- To measure the amount of current being applied to a circuit from the battery pack, enabling estimation of the battery life.