Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
256 words
Angle transducer (1) having at least one magnetically active element (6,7) that is connected with a control and signal processing unit (25) and a magnet (12) co-operating therewith and relatively thereto rotatably positioned in such a way that an electrical property of that or each magnetically active element (6,7) varies in dependence upon its angular position relative to the magnet (12), said control and signal processing unit (25) being adapted for measuring the value of a quantity related with said property and generating a signal representative for said value and thus for said relative angular position, characterized by at least one set of two mutually parallel flat thin films (6,7) of magnetically soft material that is kept in saturation by the magnet (12), said films (6,7) exhibiting resistance anisotropy, each having two current passing terminals (17,18;19,20) positioned at the ends of a first diagonal and two voltage measuring terminals (21,22; 23,24) positioned at the ends of a second diagonal positioned perpendicular to said first diagonal, said first and said second diagonals of the first film 6 forming angles of 45° with said first and second diagonals of the second film 7. control means (25) forming part of the signal processing unit for supplying electrical currents through the current passing terminals of both films; measuring means (30) forming part of the signal processing unit for measuring the voltages over the voltage measuring terminals of both films (6,7); and signal processing (33) means forming part of the signal processing unit for calculating said angular position from both voltages.
Claim 2
Dependent Claim
14 words
Angle transducer according to claim 1, characterized in that both films (6,7) are disc-shaped.
Claim 3
Dependent Claim
14 words
Angle transducer according to claim 1, characterized in that both films (55,56) are ring-shaped.
Claim 4
Dependent Claim
70 words
Angle transducer according to claim 3, characterized in that a part of the ring-shaped film (69,70) extending between a current passing terminal (17,18; 19,20) and a voltage measuring terminal (21,22; 23 24) is in the form of a plurality of concentrically arranged strips, each of said strips extending over an angle of 90°, and said strips in meander-fashion electrically connected with their ends by means of radial connection strips (67).
Claim 5
Dependent Claim
16 words
Angle transducer according to claim 4, characterized in that the connection strips (67) are electrically short-circuited.
Claim 6
Dependent Claim
18 words
Angle transducer according to any one of the preceding claims, characterized in that both films (6,7) are identical.
Claim 7
Dependent Claim
18 words
Angle transducer according to any one of the preceding claims, characterized in that both films are rotation-symmetrical (6,7).
Claim 8
Dependent Claim
24 words
Angle transducer according to any one of the preceding claims, characterized in that the amplitudes of the currents through both films (6,7) are equal.
Claim 9
Dependent Claim
86 words
Angle transducer according to any one of the preceding claims, characterized by means for compensating error-angles occurring due to the magnetical anisotropy of the thin films, in which the distance of the magnet (12) relative to the thin films (6,7), the strength of the magnet (12), and the shapes of the magnet (12) and the films are chosen in such a way, that the shape of the magnetic field (37) in the region of the thin films (6,7) and said error-angle approximately compensate for each other.
Claim 10
Dependent Claim
67 words
Angle transducer according to any one of the preceding claims, characterized in that both thin films are in the form of one film (41), that the control means (25,42,44) are adapted for successively and alternately passing currents through the one set and the other set current passing terminals (43,45) respectively, and that the measuring means (48,49,50,51,30,33) are adapted for successively and alternately measuring the voltages belonging thereto.
Claim 11
Dependent Claim
62 words
A method of manufacturing an angle transducer according to claim 3, characterized in that one manufactures a ring-shaped strip of magnetically soft material and uses the shape-preference direction extending tangentially along the ring, in order to direct the intrisic or material preference during an annealing operation, i.e. a temporary temperature increase of the ring upto in the order of magnitude of 300-350°C.