The through hole current sensors is a closed loop device and is based on the Hall effect principle and the zero balance method. The output of the current sensor is the balancing current, which is the ideal image current after the primary current is reduced by several secondary turns at any time. The current can be expressed as the voltage at which it passes through the load resistor.
The through hole current sensors is realized by measuring the magnetic field around the current carrying conductor. The conductor is electrically conductive through a flux collector that concentrates the magnetic field on the sensing element. The magnetic field is directly proportional to the current through the conductor. Therefore, there is a direct relationship between the output voltage of the current sensor and the input current level.