Magnetic particle core

Claim 2

The magnetic core of claim 2 in which the magnetic particles have the following particle size distribution: about 1 part by weight average particle size about 90 microns, about 3 parts by weight average particle size about 65 microns, and about 6 parts by weight particle size average not greater than about 37 microns.

Claim 3

The magnetic core of claim 2 in which the magnetic metallic particles are separated by electrical insulation comprising the reaction product of a metallic silicate, an inert metallic oxide, a ceramic clay, and a plasticizer with the plasticizer comprising less than 0.1 percent dry weight of the magnetic metallic particles.

Claim 4

The magnetic core of claim 4 in which the electrical insulation includes sodium silicate, magnesium oxide and kaolin.

Claim 5

The magnetic core of claim 1 in which the permeability is at least 300.

Claim 6

The magnetic core of claim 1 having a toroidal configuration with its exterior coated with an electrically insulating painT and a mechanical breakstrength such that a ratio of the pounds of force required to break the core to the area in square centimeters of a radial cross-section of the core has a minimum value of 290, the breakstrength of the core being measured by applying the force to diametrically opposite sides of the outer diameter of the core.

Claim 7

The magnetic core of claim 1 characterized by improved resistance to humidity such that after conventional exterior electrical insulation coating it exhibits a decrease in permeability of less than 2 percent when exposed to at least 95 percent relative humidity in air at 150*F. for five days.

Claim 8

A pressure compacted magnetic core comprising magnetic particles and distributed non-magnetic gaps, the magnetic core having a permeability above 115 units and a core loss when operated at a frequency of 1800 Hertz no greater than 0.240 ohms per henry per unit of permeability with core loss being measured in accordance with the following formula: RAC/ Mu L ef2 + aBmf + cf wherein RAC is the total AC core losses in ohms, equal to the effective resistance minus the DC resistance losses L is the inductance in henries Mu is permeability (above 275 units) Bm is the flux density (20 gausses) f is the frequency (1800 Hertz) e is the eddy current resistance coefficient having a maximum value of 46.7 X 10 9 a is the hysteresis resistance coefficient having a maximum value of 1.3 X 10 6, and c is the residual loss coefficient having a maximum value of 23 X 10 6, and further characterized by improved resistance to humidity such that after conventional electrical insulation coating of its exterior surface it exhibits a decrease in permeability of less than 2 percent when exposed to at least 95 percent relative humidity in air at 150*F. for five days.

Claim 9

A pressure compacted magnetic core comprising magnetic particles and distributed non-magnetic gaps, the magnetic core having a permeability above 115 units and a core loss when operated at a frequency of 1800 Hertz no greater than 0.240 ohms per henry per unit of permeability with core loss being measured in accordance with the following formula: RAC/ Mu L ef2 + aBmf + cf wherein RAC is the total AC core losses in ohms, equal to the effective resistance minus the DC resistance losses L is the inductance in henries Mu is permeability (above 275 units) Bm is the flux density (20 gausses) f is the frequency (1800 Hertz) e is the eddy current resistance coefficient having a maximum value of 46.7 X 10 9 a is the hysteresis resistance coefficient having a maximum value of 1.3 X 10 6, and c is the residual loss coefficient having a maximum value of 23 X 10 6, the magnetic core having a toroidal configuration with its exterior coated with an electrically insulating paint, and further characterized by improved mechanical breakstrength such that a ratio of the pounds of force required to break the core to the area in square centimeters of a radial section of the core has a minimum value of 290, the breakstrength of the core being measured by applying force to diametrically opposite sides of the outer diameter of the core.