Current transformers are used to measure alternating currents in high-power electronic systems and switched mode power supplies, where they provide indirect coupled floating signals for measuring and control functions. For this purpose, coils with a high transformation ratio are used. The currents that have been substantially minimized can now easily be used for electronic systems.
A Rogowski coil is a closed coil with a non-magnetic core around a conductor. The magnetic field produced in the primary conductor induces a voltage in the Rogowski coil that can be measured.Advantages:
- No magnetic core is needed for the Rogowski coil, hence the output signal is not influenced by saturation or non-linearity behaviour and, therefore, entirely linear.
- The core (former) of the Rogowski coil is made of a a moulded [plastic] part, the coil can be adapted to whatever shape the primary conductor may have.
- External electromagnetic fields are negligible.
A prerequisite for fully benefiting from the above advantages is a homogenous core winding. For the coil to receive a sufficient output signal, often enough the number of turns per unit length must be very high. Egston has developed its own production process and is capable of producing high-quality and high-precision Rogowski coils at extremely competitive prices.