Teseq INA 703 magnetic field coil

A magnetic field coil that generates fields up to 1200 A/m during magnetic field testing is designed for testing to IEC 61000-4-8 (supply frequency magnetic fields), IEC 61000-4-9 (pulsed magnetic fields) and IEC 61000-4-10 (oscillatory magnetic fields) standards.

By using a multiturn (37-turn) configuration, the INA 703 can generate higher field levels of up to 1000 A/m using a programmable power source rated for ≥30 A. This enables testing with a current total harmonic distortion of <8%, as required by IEC 61000-4-8, that can only be met with a low distortion sine wave from a programmable AC source.

Another advantage of using a programmable power source is that various supply frequencies can be tested, not only 50 and 60 Hz as requested by IEC 61000-4-8, but also DC and 16.7 Hz as required by some railway standards (EN 50121-4).

Together with an NSG 1007 source, the coil can generate fields with frequencies from DC to 400 Hz in 0.1 Hz resolution steps.

Taps at turns one and five provide increased accuracy when generating low-amplitude fields. The required coil drive voltage is increased by reducing the turns-ratio of the coil. This establishes a suitable input voltage range that allows good regulation of the test level amplitude. The tap off at one turn is primarily used for testing to IEC 61000-4-9 and IEC 61000-4-10, since both standards only require a single turn coil.

The unit has a maximum continuous supply frequency current of 10 A, a maximum short-term supply frequency current of 35 A for 3 s, a maximum continuous supply frequency field strength of 330 A/m and a maximum short-term supply frequency field strength of 1100 A/m for 3 s. The unit has a maximum pulsed current of 1500 A (8/20 µs wave) and a maximum pulsed field strength of 1200 A/m.