Schloder MGA_HCST_50-28 50 / 46 / 42 cm Helmholtz Coil

Helmholtz Coils

Several Helmholtz coils are available for susceptibility tests. Our company also offers tri-axial Helmholtz coils which are suitable for MGA1030. To achieve 1000 A/m at 1 kHz, it is absolute necessary to use our Helmholtz coils and an optional compensation board.

Helmholtz coil arrangements of greater complexity can produce interference fields in different spatial axes. In the case of 3-axis Helmholtz coils, three coil pairs are arranged in the X, Y and Z directions. By means of a suitable control unit, the test specimen can thus be fully exposed to the interference field over a wide frequency range in all three spatial axes.

If the geometry is fixed, the magnitude of the magnetic field is directly proportional to the number of windings and the applied current. When designing the coils it is attempted, on one hand, to provide the highest possible number of windings in order to keep the necessary current (and thus the amplifier power) small. On the other hand, a high number of windings at higher frequencies (the MIL-STD-461E requires, for example, tests up to 100 kHz) leads to large coil impedances which, in turn, result in impractically high amplifier output voltages.

Since the required field strength decreases with increasing frequency (for the MIL-STD-461E mentioned above, the required test level at 100 kHz falls to less than one thousandth of the output value at 60 Hz), the ideal solution is the construction of a Helmholtz coil with two separate windings as in the MGA_HCS Helmholtz coils. The basic design is shown in the following figure:

If the output of a power amplifier is connected to the "blue" and "black" jacks, a Helmholtz coil with a high coil factor is available, ideal for generating high field strengths at low frequencies where the coil inductance is not yet important. If the output of a power amplifier is connected to the "white" and "magenta" jacks, a low inductance Helmholtz coil is available, ideal for generating medium field strengths at higher frequencies

General structure of MGA_HCS Helmholtz coils

The Helmholtz coils of the MGA_HCS series are completely made of wood materials. There are no metallic parts other than wire and connectors. The coils are completely clad with a durable laminate - the wire is not visible and thus protected against damage.