EP0449037A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Position transducer
Assignee: Prima Electro SpA
•
Filing: 1991-03-13
•
Granted: —
•
Expires: 2011-03-13
Abstract
Abstract An absolute position transducer (encoder) comprising an incremental encoder (2) having a coded disk (13) connected stably to a shaft (15), and connected to a sensor (3) for emitting a signal for each complete turn of the disk (13). The incremental encoder (2) produces a first (A) and second (B) signal, each consisting of a sequence of pulses in which each pulse equals one elementary angular increment of the shaft (15); and a third signal (ZERO) consisting of a sequence of zero pulses, each emitted for each complete turn of the shaft (15). The absolute encoder (1) comprises a resettable counter (5) for counting the signal emitted by the sensor (3) and memorising the number of turns of the shaft (15) in a permanent memory (29); and a control circuit (6) enabled by a zero pulse generated by the incremental encoder (2), and cooperating with a coding circuit (7) for emitting a coded dummy zero pulse in such a manner that, in the interval between the zero and dummy zero pulses, the first (A) or second (B) signal supplies a decoding circuit (50) with a number of pulses equal to the number stored in the memory (29) of the count circuit (5).
Inventors
- 👤 Luca Di Stefano
- 👤 Domenico Peiretti
- 👤 Francesco Sgandurra
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 08:25
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/244; G01D5/245; G01D5/2454; G01D5/2455; G01D5/2457; G01D5/26; G01D5/32; G01D5/34; G01D5/36
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
237 words
A position transducer (1) comprising an incremental encoder (2) having a coded disk (13) connected stably to a rotary shaft (15); said incremental encoder (2) supplying at least three output signals: a first signal consisting of a sequence of pulses equal to an elementary angular increment of said shaft (15); a second signal similar to and out of phase in relation to said first signal, for transmitting information relative to the direction of rotation of said shaft (15); and a third signal consisting of a sequence of zero pulses, each emitted for each 360° rotation of said disk (13); each of said first, second and third signals being transmitted over a respective first, second and third line; characterised by the fact that it comprises sensor means (3) connected to said incremental encoder (2) for emitting a fourth signal for each complete turn of said coded disk (13); resettable counter means (5) for counting said fourth signal emitted by said sensor means (3) and memorising the number of turns of said disk (13) in a permanent memory (29); and first electronic means (6) enabled by the first of said zero pulses generated by said incremental encoder (2), said first electronic means (6) cooperating with second electronic means (7) for transmitting in coded manner, to means (50) for receiving the position information of said transducer (1), the information relative to the number of turns contained in said memory (29).
Claim 2
Dependent Claim
44 words
A transducer as claimed in Claim 1, characterised by the fact that said first electronic means comprise means (100, 110; 200, 210; 300, 310) for detecting the first zero pulse emitted by said incremental encoder (2) subsequent to electrical supply of said transducer (1).
Claim 3
Dependent Claim
53 words
A transducer as claimed in Claim 1 or 2, characterised by the fact that said first or second electronic means (6, 7) comprise means (131; 220; 320) for generating a coded dummy zero pulse following transmission to said receiving means (50) of said information relative to the number stored in said memory (29).
Claim 4
Dependent Claim
27 words
A transducer as claimed in Claim 3, characterised by the fact that said dummy zero pulse is transmitted over the same line (20) as said zero pulse.
Claim 5
Dependent Claim
43 words
A transducer as claimed in one of the foregoing Claims from 2 to 4, characterised by the fact that said first or second means (6, 7) comprise means (131; 220; 320) whereby they are disabled subsequent to emission of said dummy zero pulse.
Claim 6
Dependent Claim
87 words
A transducer as claimed in any one of the foregoing Claims, characterised by the fact that said first or second electronic means (6, 7) comprise means (116, 120, 130, 131) for transmitting said coded dummy zero pulse in such a manner that said zero pulse and said dummy zero pulse are separated by a time interval TO in which a number of pulses equal to the number stored in said memory (29) of said count means (5) are transmitted over said first (16) or second (17) line.
Claim 7
Dependent Claim
54 words
A transducer as claimed in one of the foregoing Claims from 1 to 5, characterised by the fact that said first or second electronic means (6, 7) comprise means (215, 219) for emitting on said third line (18), following said zero pulse, a coded pulse sequence expressing the number stored in said memory (29).
Claim 8
Dependent Claim
113 words
A transducer as claimed in one of the foregoing Claims from 1 to 5, characterised by the fact that said first or second electronic means (6, 7) comprise means (315, 316, 317) for multiplying the number stored in said memory (29) by the number of pulses per revolution (N) supplied by said incremental encoder (2), to give a second number (K); said electronic means (7) generating a train of pulses equal to said second number (K) plus the number of pulses (K1) generated by said incremental encoder (2) during transmission of said pulse train over said first or second line; said pulse train being transmitted over said first (16) or second (17) line.
Claim 9
Dependent Claim
40 words
A transducer as claimed in Claim 8, characterised by the fact that said pulse train is transmitted at a speed far greater than the average speed at which said pulses are transmitted over said first (16) and second (17) line.
Claim 10
Dependent Claim
116 words
A transducer as claimed in any one of the foregoing Claims, characterised by the fact that said means (50) for receiving said position information comprise means (150, 160; 250, 260; 350, 360) for detecting the first zero pulse generated by said incremental encoder (2) following supply; means (170, 180, 185; 270, 280, 285; 370, 380) for counting and processing said information relative to said number stored in said memory (29) and transmitted by said first or second electronic means (6, 7); means (180; 280; 380) for detecting said dummy zero pulse; and means (190; 286; 400) for continuing reception of information from said first, second and third line (16, 17, 18) of said incremental encoder (2).
Claim 11
Dependent Claim
23 words
A transducer as claimed in any one of the foregoing Claims, characterised by the fact that said sensor means comprise a Hall-effect sensor.
Claim 12
Dependent Claim
27 words
A transducer as claimed in one of the foregoing Claims from 1 to 10, characterised by the fact that said sensor means comprise a magnetic switch (REED).
Claim 13
Dependent Claim
46 words
A transducer as claimed in any one of the foregoing Claims, characterised by the fact that a detecting circuit (4) is provided between said sensor means (3) and said count means (5); said detecting circuit (4) amplifying and clipping the signal from said sensor means (3).
Claim 14
Dependent Claim
50 words
A transducer as claimed in Claim 13, characterised by the fact that it comprises a circuit for detecting error conditions in the signals supplied by said sensor means (3) to said detecting circuit (4); said circuit (4) being designed to supply an error signal to said first electronic means (5).
Claim 15
Dependent Claim
59 words
A transducer as claimed in any one of the foregoing Claims, characterised by the fact that said absolute encoder (1) is supplied by a supervising and supply circuit (10) connected to an external supply mains (55), and presents a buffer battery (11) for ensuring supply to parts of said absolute encoder (1) even in the event of power failure.
Claim 16
Dependent Claim
44 words
A transducer as claimed in Claim 15, characterised by the fact that said supervising and supply circuit (10) provides for determining the charge of said battery (11) and for emitting an error signal in the event said charge falls below a predetermined threshold value.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.