Rotational angle transducer

Claim 2

A contactless rotational angle transducer for generating an output signal indicative of the angular position of a rotatable member, comprising: a stator plate divided into a plurality of electrically insulated sector members; means for impressing exciting voltages having a triangular waveform on adjacent ones of said sector members, the phase of each impressed voltage differing by 2 pi /n from that impressed on adjacent members where n equals the number of sector members; a confronting plate disposed in parallel spaced-apart and aligned relationship to said stator plate so as to develop an induced voltage in response to said impressed exciting voltages on said sector members; a sector rotor plate rotatably coupled to said rotatable member and disposed in parallel relationship between said stator plate and said confronting plate For modifying the voltage induced on said confronting plate; and signal generating means responsive to the phase difference between the signal induced in said confronting plate and the voltage impressed on a selected one of said sector members for generating a pulse-modulated output signal indicative of the angular position of said rotatable member.

Claim 3

A rotational angle transducer as defined in claim 1 wherein the face area of the rotor plate is substantially the same as that of each of the sector members.

Claim 4

A rotational angle transducer as defined in claim 1 wherein said sector members each extend over an angle of approximately 2 pi /n about the rotational axis of said rotatable member.

Claim 5

A rotational angle transducer as defined in claim 3 wherein said sector rotor plate extends over an angle of approximately 2 pi /n about the rotational axis of said rotatable member.

Claim 6

A rotational angle transducer as defined in claim 4 wherein n is an integer greater than or equal to 3.

Claim 7

A rotational angle transducer as defined in claim 5 wherein said sector members and said rotor plate are substantially wedge-shaped in cross-section.

Claim 8

A rotational angle transducer as defined in claim 6 wherein said confronting plate is annular in cross-section, and said rotor plate, stator members and confronting plate are of substantially equal radius.

Claim 9

A rotational angle transducer as defined in claim 1 wherein said exciting voltages have substantially identical peak levels.

Claim 10

A rotational angle transducer as defined in claim 1 wherein said signal generating means comprise means responsive to the phase of said impressed exciting voltages for initiating an output pulse, and means responsive to the phase of said induced voltage on said confronting plate for terminating said output pulse, thereby generating an output pulse having a width indicative of the angular position of said rotatable member.

Claim 11

A contactless rotational angle transducer for generating an output signal indicative of the angular position of a rotatable member, comprising: a stator plate divided into n electrically insulated sector members each of which extends over an angle of approximately 2 pi /n about the rotational axis of said rotatable member; means for impressing exciting voltages having a triangular waveform on adjacent ones of said sector members, the phase of said impressed voltages differing by 2 pi /n between adjacent members; a confronting plate disposed in parallel spaced-apart relationship to said stator plate so as to develop an induced voltage in response to said impressed exciting voltages on said sector members of said stator plate; a sector rotor plate rotatably coupled to said rotatable member and extending over an angle of approximately 2 pi /n about the rotational axis of said rotatable member, said rotor plate being disposed in parallel relationship between said stator plate and said confronting plate; and signal generating means responsive to the phase difference between the exciting voltage impressed on a selected one of said sector members and the voltage induced on said confronting plate for generating a pulse-modulated output signal indicative of the angular position of said rotatable member.

Claim 12

A contactless rotational angle transducer for generating an output signal indicative of the angular position of a rotatable member, comprising: a stator plate divided into n electrically insulated sector members each of which extends over an angle of approximately 2 pi /n about the rotational axis of said rotatable member; means for impressing exciting voltages having a triangular waveform on adjacent ones of said sector members, the phase of said impressed voltages differing by 2 pi /n between adjacent members; a confronting plate disposed in parallel spaced-apart relationship to said stator plate so as to develop an induced voltage in response to said impressed exciting voltages on said sector members of said stator plate; a sector rotor plate rotatably coupled to said rotatable member and extending over an angle of approximately 2 pi /n about the rotational axis of said rotatable member, said rotor plate being disposed in parallel relationship between said stator plate and said confronting plate; and signal generating means responsive to the phase difference between the exciting voltage impressed on a selected one of said sector members and the voltage induced on said confronting plate for generating a pulse-modulated output signal indicative of the angular position of said rotatable member.

Claim 13

A rotational angle transducer as defined in claim 10 wherein said sector stator members and said rotor member are substantially wedge-shaped in cross-section, and said confronting plate is substantially annular in cross-section.

Claim 14

A rotational angle transducer as defined in claim 11 wherein said rotor, stator and confronting plates are of substantially equal radius.

Claim 15

A rotational angle transducer as defined in claim 10 wherein said signal generating means comprise a bi-stable switching element which is switched to one state upon occurrence of a predetermined phase condition in said impressed exciting voltage, and to its other state upon occurrence of a predetermined phase condItion in the signal induced on said confronting plate.

Claim 16

A rotational angle transducer as defined in claim 13 wherein a first monostable multivibrator is provided for applying the signal induced on said confronting plate to one input terminal of said bi-stable switching element, and wherein a second monostable multivibrator is provided for applying the signal impressed on said selected sector member to the other input terminal of said bi-stable switching element.

Claim 17

A rotational angle transducer as defined in claim 10 wherein a pulse position modulated signal is obtained from said signal generating means.