Hughes Aircraft Company

Charles A Goodman

Robert D Washburn

Robert F McClanahan

David M Lusher

Andrew A Shapiro

Carlos H Gonzalez

Ramona G Pond

Carol Haertling

Wilfred J Gully

A ferromagnetic material (18,20) in ink or tape form is sinterable using a same firing profile as and has approximately the same thermal shrinkage characteristics as low-temperature-cofired-ceramic (LTCC) tape, and is chemically non-reactive therewith. The ferromagnetic material (18,20) is applied to the surfaces of LTCC tape sheets (12,14,16) to form desired elements such as cores for inductors (22) and transformers and magnetic shields. Ferromagnetic vertical interconnects (vias) (54) can be formed by punching holes (56) through tape sheets (46) and filling them with ferromagnetic ink. The tape sheets (12,14,16) and ferromagnetic elements (18,20) are laminated together and cofired to form an integral structure (10). Ferromagnetic and non-magnetic components (114) can be fabricated separately and inserted into cavities (104a,-106a,108a) in tape sheets (104,106,108) prior to cofiring. A multi-layer transformer (250) includes primary (254b,-256b,258b,254d,256d,258d) and secondary (254c,256c,258c) coils, each being formed of vertically aligned, arcuate conductors which are printed on separate tape sheets (254,256,258) and vertically interconnected at their ends to form continuous electrical paths therethrough.

Low-temperature-cofired-ceramic (LTCC) tape structures including cofired

A ferromagnetic material (18,20) in ink or tape form is sinterable using a same firing profile as and has approximately the same thermal shrinkage characteristics as low-temperature-cofired-ceramic (LTCC) tape, and is chemically non-reactive therewith. The ferromagnetic material (18,20) is applied to the surfaces of LTCC tape sheets (12,14,16) to form desired elements such as cores for inductors (22) and transformers and magnetic shields. Ferromagnetic vertical interconnects (vias) (54) can be formed by punching holes (56) through tape sheets (46) and filling them with ferromagnetic ink. The tape sheets (12,14,16) and ferromagnetic elements (18,20) are laminated together and cofired to form an integral structure (10). Ferromagnetic and non-magnetic components (114) can be fabricated separately and inserted into cavities (104a, 106a,108a) in tape sheets (104,106,108) prior to cofiring. A multi-layer transformer (250) includes primary (254b, 256b,258b,254d,256d,258d) and secondary (254c,256c,258c) coils, each being formed of vertically aligned, arcuate conductors which are printed on separate tape sheets (254,256,258) and vertically interconnected at their ends to form continuous electrical paths therethrough.

A control system for controlling a direct current powered motor in which the direct current voltage, which may not be constant, is reversibly commutated across the coil or winding of the motor during the predetermined commutation time intervals and chopped at high frequency during each commutation time interval by a variable duty cycle, pulse width modulated voltage, in which the width of each voltage pulse, determined by a reference voltage, is varied as an inverse function of the magnitude of the direct current voltage which exists during each voltage pulse interval.

Variable duty cycle pulse width modulated motor control system

Growing community of inventors

Garden Grove, CA, United States of America

Charles A Goodman