PREMO GROUP introduces new HCT series, sensing device to measure AC and DC currents. The well-known Hall effect technology in semiconductors allows to convert the magnetic field B, usually created in a magnetic core by the current to be measured, in a voltage signal proportional to it. This effect happens for DC and AC signal of the magnetic field, therefore this is a straight way to reproduce easily and faithfully every current waveform to measure.
Based on the Hall effect, that its output voltage is proportional to the density of magnetic flux, therefore, this principle permits to reproduce the waveform of the current that induces the density of magnetic flux in a magnetic core.
Output voltage signal of the Hall sensor element (semiconductor), that makes the transduction, is conditioned and amplified electronically to measure properly this output signal.
The Hall principle and the signal conditioning circuits have permitted the existence of two kind of operating principles of measuring with this transducers:
A ) Open-loop operating principle:
In this principle, the current about to measure, magnetizeses the magnetic gapped core. In the gap of this magnetic core, is placed the Hall sensor element (semiconductor) that senses this induced density of magnetic flux, transforms this in a voltage output that is conditioned. Therefore, the output signal of the transducer is voltage and its typical frequency bandwidth. From DC to tenths of kHz.
B) Closed-Loop operating principle:
This working principle is similar to the open-loop case, the difference is that the output signal of the Hall sensor element is involved in a circuit where a current is created and applied on a winding, placed in the core, that compensates the density of flux induced by the current to be measured.
Therefore the output signal is a current signal. Electronic circuit involved in this process, permits an improving of featuring electric parameters than open-loop principle (accuracy, linearity, offset, thermal drift, hysteresis error, frequency bandwidth).
In this case, the current measured in the Burdeen resistance, RB, follows the same law as in the current transformers and the resistance necessary to make a proper measurement follows the equation:        

   
Where K M is the conversion ratio.
PREMO Inductive Components offers the longest customized inductive components range, in different formats, as well as line and planar transformers, inductive components for Switched mode power supply, distributed power architectures in power supplies and current transformers.