Other Coils

Magnetising Coils and Fixtures

Magnetising syststems use a capacitive discharge magnetiser as the power supply and a Magnetising coil or Fixture to take that power and deliver the magnetising field in the appropriate pattern and field strength.

Magnetising lower coercivity permanent magnet materials such as Alnico and Ferrite is often acheived using a coil with a soft iron or steel path in the magnetic circuit. Higher coercivity mateials such as NdFeB ( Neodymium Iron Boron) and SmCo ( Samarium Cobolt) need higher fields than the saturation of Iron. The coils used to magnetise thes materials do not generally have Iron and are referred to as air-cored coils or magnetising coils.

Some standard Magnetising Coils and Fixtures are offered by Hirst, but for most applications a fixture specific to an parts being magnetised must be designed and built. To help us meet your requirements see the magnetising coil enquiry sheet.

For magnetising systems the fixture could produce a variety of magnetising fields.  The most common fixture type is a simple coil where the required field is within the coil and aligned along the axis of the coil.

J2a Fixture
J2A Fixture.

Another common fixture (J2A) consists of a U shaped iron core where interchangeable pole pieces are secured to the top of the iron core.  The required magnetic field is produced between the adjustable pole pieces.

Demagnetising coils usually consist of a simple coil arrangement where the part to be demagnetised is placed inside the coil.  The fixture may be round or rectangular to allow easy loading of the components containers.  The fixture may be supplied as a floor standing unit with roller conveyor for heavy components.

Dependent upon the frequency of operation and energy used, the fixture may require external cooling to prevent overheating of the coil.  This could be achieved using compressed air, water or oil circulating through the fixture.  Hirst can supply complete cooling systems to compliment our fixtures as a complete turnkey solution.

Custom fixtures may also contain embedded search coils to be connected to a Hirst Integrating Fluxmeter as part of a quality control or magnet calibration system.

Our fixtures are usually supplied with the windings of the coils fully encapsulated in epoxy resin.  This provides a good mechanical support for the windings and provides operator safety by insulating the windings which can see voltages of up to 3,000 volts.

Hirst can also manufacture coils to suit a customer's particular application or to interface with 3rd party magnetiser.