ELECTROMAGNETIC SYSTEM Russian patent published in 2024 - IPC G01R5/00 H02M11/00 

FIELD: physics.

SUBSTANCE: electromagnetic system (EMS) is intended for use in mass metrology (watt balance (Kibble)). It consists of a circular magnetic field source (CMFS) and a multi-turn measuring coil, which provide the required value of the “force-current” conversion coefficient. CMFS is made in the form of a cylinder consisting of: a hollow inside cylindrical housing (CH) and an internal cylindrical magnetic conductor (ICMC) (both elements are made of soft magnetic material (SMM)), forming collectively annular cavity (AC) inside CH, permanent magnets inside AC in form of two tightly assembled rings of trapezoid-shaped magnets identical in size and magnetic moment, installed in geometric centre of AC opposite each other on inner surface of CH and on surface of ICMC with opposite magnetic poles facing each other. On the pole surfaces of both rings forming the annular space (AS) there are pole tips also in the form of a ring with radial thickness which is an order of magnitude smaller than that of the magnets and the same height as the SMM magnets. Ends of CH and ICMC are tightly closed by round plates from SMM with diameter equal to external diameter of CH, forming together with CH a closed magnetic conductor of the whole CMFS. In AS there is a multiturn measuring coil (MC) placed on a special frame, which converts energy of electric current into mechanical work.

EFFECT: increased efficiency of using magnetic flux of magnets for creation of circular magnetic field in AS, and high accuracy of measuring the mass of bodies with a value of up to one kilogram when using EMS in watt balances, due to the absence of an additional contribution to the magnetic field of the AS from the passed electric current through the MC winding placed in the AS, and the absence of a gradient of the MC inductance value when it moves in the CMFS AS central region.

1 cl, 7 dwg