GB2143328A - Rotary direction transmitters using three Hall effect devices - Google Patents
Rotary direction transmitters using three Hall effect devices Download PDFInfo
- Publication number
- GB2143328A GB2143328A GB08317193A GB8317193A GB2143328A GB 2143328 A GB2143328 A GB 2143328A GB 08317193 A GB08317193 A GB 08317193A GB 8317193 A GB8317193 A GB 8317193A GB 2143328 A GB2143328 A GB 2143328A
- Authority
- GB
- United Kingdom
- Prior art keywords
- hall effect
- effect devices
- shaft
- synchronous transmitter
- magnet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
- G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
- G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D2205/00—Indexing scheme relating to details of means for transferring or converting the output of a sensing member
- G01D2205/70—Position sensors comprising a moving target with particular shapes, e.g. of soft magnetic targets
- G01D2205/77—Specific profiles
- G01D2205/775—Tapered profiles
Abstract
A rotary direction transmitter comprises three semiconductor Hall effect devices 8 mounted on a circle at 120 DEG angular intervals and supplying respective d.c. output voltages which vary in dependence on variations in a magnetic field to which each respective Hall effect device 8 is subjected and a permanent magnet 1 mounted for rotation with a shaft 2 and adjacent to the Hall effect devices 8 such that the three output voltages from the Hall effect devices 8 represent the angular position of the shaft 2. The free end of the permanent magnet 1 is shaped as shown to give a magnetic field which varies sinusoidally at the Hall effect devices 8 as the magnet 1 rotates. The transmitter is used for remote indication of marine wind direction. <IMAGE>
Description
SPECIFICATION
Synchronous transmitters
This invention relates to synchronous transmitters.
Such transmitters are suitable for the remote indication of shaft rotational positions. The present invention is particularly, but by no means exclusively, concerned with such transmitters which are suitable for use in indicating marine wind direction.
A known form of direct current synchronous transmitter is a sliding contact potentiometer device comprising a 360 resistive element with fixed taps at angular intervals of 120'. A direct current voltage is applied through two sliding contacts arranged at angular intervals of 180 on the resistive element, and which are attached to a rotatable operating shaft and connected to a voltage supply via slip rings.
Rotation of the shaft causes the voltage at each tap to vary approximately sinusoidally, thus giving an apparent three-phase voltage supply with the voltage levels on each phase dependent on the angular postion of the shaft. This therefore provides a non-ambiguous output which indicates the shaft position over a full 360 .
A problem with synchronous transmitters of this form is that the useful life of the mechanism is determined by the rate of wear between the resistive element and the sliding contacts. Another problem is the level of torque required to overcome the frictional forces between the resistive element and the sliding contacts, and this reduces the sensitivity, for example when the synchronous transmitter is used to detect wind direction. Moreover, the slip rings form another part of the mechanism where wear and failure may occur.
According to the present invention there is provided a synchronous transmitter comprising: three hall effect devices for supplying respective direct current output voltages which vary in dependence on variations in a magnetic field to which the respective said hall effect device is subjected; a rotatable shaft; and magnet means mounted for rotation with said shaft; the relative arrangement of said hall effect devices and said magnetic means being such that said output voltages represent the angular position of said shaft.
Preferably said hall effect devices are mounted on a circle at angular intervals of 120 , and the axis of said shaft passes normally through the centre of said circle.
Preferably also said magnet means is a permanent magnet of right circular cylindrical shape mounted coaxiallywith said shaft at an end of said shaft which is adjacent to said hall effect devices, the end face of said magnet which is adjacent to said hall effect devices being planar and inclined at an angle to the axis of said shaft, and said magnet being magnetised longitudinally so as to have a pole at each end face thereof.
As the flux density of the magnetic field to which any given one of the hall effect device is subjected is proportional to the square of the distance from the adjacent magnetic pole, it can be seen that by shaping the magnet in this way the flux density at each hall effect device is made to vary substantially sinusoidally with rotation of the shaft, so causing a substantially sinusoidal variation in the output voltage from each of the hall effect devices. These voltage variations may be suitably amplified to provide sufficient current to drive a three-phase direct current synchro to provide a remote indication of the angular position of the shaft.
The invention will now be further described by way of example with reference to the accompanying drawings in which:
Figure 1 is a central cross-section through an embodiment of synch ronous transmitter according to the invention;
Figure 2 is a part sectional view on the line ll-il of
Figure 1; and
Figure 3 is a circuit diagram of one amplifier output channel of the embodiment.
Referring first to Figures 1 and 2, the synchronous transmitter comprises a right circular cylindrical permanent magnet 1 mounted coaxially at one end of a rotatable shaft 2 which is supported in ball bearings 3 and 4 mounted in a housing 5 of circular section. Mounted in the housing 5 so as to be coaxial with and normal to the axis of the shaft 2 are circular printed circuit boards 6 and 7. Mounted on the circuit board 6 at angular intervals of 120 on a circle which is coaxial with the axis of the shaft 2 are three semiconductor hall effect devices 8. Each of the hall effect devices is a linear hall effect integrated circuit and may, for example, be a Honeywell type 634
SS22. Mounted on the circuit board 7 are components 9 forming the supply and amplifier output channel circuits for the hall effect devices 8.Closing the end of the housing 5 behind the circuit board 7 is a cover 10.
The magnet 1 is magnetised longitudinally so as to have poles disposed in its two end faces, and the end face adjacent to the hall effect devices 8 is planar and inclined to the axis of the shaft 2 at an angle of about 30 , so that as the shaft 2 is rotated the distance d between any given hall effect device 8 and the adjacent end face of the magnet 1 varies. In consequence the flux density of the magnetic field to which any given hall effect device 8 is subjected varies substantially sinusoidally as the shaft 2 is rotated. A direct current voltage of 10 volts is applied across each of the hall effect devices 8, and an output direct current voltage is derived from each of the hall effect devices, and these output voltages likewise vary substantially sinusoidally as the shaft 2 is rotated.If desired, the inclined end face of the magnet 1 can be profiled to make the output voltages more precisely sinusoidal.
The output voltages obtained from the hall effect devices 8 are relatively small, that is of the order of millivolts, and need to be amplified in order to drive, for example, a 100 ohm/coil three-phase direct current synchro which is located remotely from the synchronous transmitter and which provides an output replicating the rotation of the shaft 2.
Figure 3, to which reference is now made, shows an output channel for one of the hall effect devices, similar channels being provided for each of the other hall effect devices 8. Supply lines 11 and 12 which are maintained at earth potential and +10 volts, respectively, are connected across the hall effect device 8, and the output voltage is derived from a terminal 13 and amplified by amplifier stages 14, 15 and 16 to provide an amplified direct current output voltage at an output terminal 17. The amplifier stages 14 and 15 comprise operational amplifiers 18 and 19, and each ofthe amplifier stages 14,15 and 16 is supplied from the supply lines 11 and 12.
The particular embodiment which has been described is particularly, but by no means exclusively, suitable for marine wind direction indication, in which case a suitable wind vane is secured to the shaft 2 and exposed to the wind, so that the shaft 2 rotates in dependence on the wind direction. However, embodiments of the invention are generally suitable for use in a wide range of situations where remote indication of a shaft rotational position is required.
Claims (8)
1. A synchronous transmitter comprising: three hall effect devices for supplying respective direct current output voltages which vary in dependence on variations in a magnetic field to which the respective said hall effect device is subjected; a rotatable shaft; and magnet means mounted for rotation with said shaft; the relative arrangement of said hall effect devices and said magnetic means being such that said output voltages represent the angular position of said shaft.
2. A synchronous transmitter according to claim 1 wherein said hall effect devices are mounted on a circle at angular intervals of 120 .
3. A synchronous transmitter according to claim 2 wherein the axis of said shaft passes normally through the centre of said circle.
4. A synchronous transmitter according to claim 3 wherein said magnet means is a permanent magnet of right circular cylindrical shape mounted coaxially with said shaft at an end of said shaft which is adjacent to said hall effect devices, the end face of said magnet which is adjacent to said hall effect devices being planar and inclined at an angle to the axis of said shaft, and said magnet being magnetized longitudinally so as to have a pole at each end face thereof.
5. A synchronous transmitter according to any one ofthe preceding claims wherein said hall effect devices are semiconductor devices.
6. A synchronous transmitter according to any one of the preceding claims wherein each of said hall effect devices has a respective associated amplifier output channel for amplifying said respective direct current output voltage.
7. A synchronous transmitter substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.
8. A synchronous transmitter substantially as hereinbefore described with reference to Figure 1 to 3 of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08317193A GB2143328A (en) | 1983-06-24 | 1983-06-24 | Rotary direction transmitters using three Hall effect devices |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08317193A GB2143328A (en) | 1983-06-24 | 1983-06-24 | Rotary direction transmitters using three Hall effect devices |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8317193D0 GB8317193D0 (en) | 1983-07-27 |
| GB2143328A true GB2143328A (en) | 1985-02-06 |
Family
ID=10544731
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08317193A Withdrawn GB2143328A (en) | 1983-06-24 | 1983-06-24 | Rotary direction transmitters using three Hall effect devices |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2143328A (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2167191A (en) * | 1984-11-16 | 1986-05-21 | David Louis Halsey Person | Hall-effect attitude sensors |
| GB2169085A (en) * | 1984-12-19 | 1986-07-02 | Risto Tanner | Direction indicating apparatus |
| EP0270322A2 (en) * | 1986-12-05 | 1988-06-08 | The Charles Stark Draper Laboratory, Inc. | Multiple axis displacement system |
| WO1996027117A1 (en) * | 1995-03-02 | 1996-09-06 | Robert Bosch Gmbh | Distance sensor for detecting the adjustment travel of an actuator |
| EP0813066A1 (en) * | 1996-06-10 | 1997-12-17 | Niels Jörgen Therkildsen | A device for indicating wind |
| WO1998054547A1 (en) * | 1997-05-29 | 1998-12-03 | Laboratorium Für Physikalische Elektronik | Magnetic rotation sensor |
| DE19745823A1 (en) * | 1997-10-16 | 1999-04-29 | Sensor Instr Gmbh | Torque and rotation angle measuring device e.g. for motor vehicle |
| EP1016852A1 (en) * | 1998-12-31 | 2000-07-05 | Pacific Scientific Company | Apparatus for measuring the position of a movable member |
| WO2003008911A1 (en) * | 2001-07-13 | 2003-01-30 | Austriamicrosystems Ag | Measuring device for contactlessly detecting the rotation angle and the axial position of an object to be measured |
| US6566864B1 (en) * | 2000-09-01 | 2003-05-20 | Ford Global Technologies, L.L.C. | Angular position sensor for vehicle suspension |
| US7360756B2 (en) | 2005-03-31 | 2008-04-22 | Delphi Technologies, Inc. | Vibration isolating bushing with embedded speed/position sensor |
| US7370853B2 (en) | 2005-03-31 | 2008-05-13 | Delphi Technologies, Inc. | Vibration isolating bushing with embedded angular position sensor |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1219836A (en) * | 1967-03-10 | 1971-01-20 | Bbc Brown Boveri & Cie | Regulable and controllable inverter- or frequency changer-arrangement for feeding a.c. motors |
| GB1382626A (en) * | 1971-07-30 | 1975-02-05 | Delmoran Ag | Control devices |
| GB1498915A (en) * | 1975-05-02 | 1978-01-25 | Vdo Schindling | Wind direction indicating means |
| GB1543895A (en) * | 1976-02-19 | 1979-04-11 | Thomsen I | Detector for detecting the angular position of a rotatable magnet |
| GB2020813A (en) * | 1978-04-18 | 1979-11-21 | Nippon Electric Co | Rotational direction detection device for a motor or the like |
| GB1571751A (en) * | 1977-02-02 | 1980-07-16 | Illinois Tool Works | Angular position sensors |
-
1983
- 1983-06-24 GB GB08317193A patent/GB2143328A/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1219836A (en) * | 1967-03-10 | 1971-01-20 | Bbc Brown Boveri & Cie | Regulable and controllable inverter- or frequency changer-arrangement for feeding a.c. motors |
| GB1382626A (en) * | 1971-07-30 | 1975-02-05 | Delmoran Ag | Control devices |
| GB1498915A (en) * | 1975-05-02 | 1978-01-25 | Vdo Schindling | Wind direction indicating means |
| GB1543895A (en) * | 1976-02-19 | 1979-04-11 | Thomsen I | Detector for detecting the angular position of a rotatable magnet |
| GB1571751A (en) * | 1977-02-02 | 1980-07-16 | Illinois Tool Works | Angular position sensors |
| GB2020813A (en) * | 1978-04-18 | 1979-11-21 | Nippon Electric Co | Rotational direction detection device for a motor or the like |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2167191A (en) * | 1984-11-16 | 1986-05-21 | David Louis Halsey Person | Hall-effect attitude sensors |
| GB2169085A (en) * | 1984-12-19 | 1986-07-02 | Risto Tanner | Direction indicating apparatus |
| EP0270322A2 (en) * | 1986-12-05 | 1988-06-08 | The Charles Stark Draper Laboratory, Inc. | Multiple axis displacement system |
| EP0270322A3 (en) * | 1986-12-05 | 1989-05-31 | The Charles Stark Draper Laboratory, Inc. | Multiple axis displacement system |
| WO1996027117A1 (en) * | 1995-03-02 | 1996-09-06 | Robert Bosch Gmbh | Distance sensor for detecting the adjustment travel of an actuator |
| EP0813066A1 (en) * | 1996-06-10 | 1997-12-17 | Niels Jörgen Therkildsen | A device for indicating wind |
| WO1998054547A1 (en) * | 1997-05-29 | 1998-12-03 | Laboratorium Für Physikalische Elektronik | Magnetic rotation sensor |
| US6288533B1 (en) | 1997-05-29 | 2001-09-11 | Physical Electronics Laboratory | Method and apparatus for detecting rotor position by use of magnetic field sensor pairs |
| DE19745823A1 (en) * | 1997-10-16 | 1999-04-29 | Sensor Instr Gmbh | Torque and rotation angle measuring device e.g. for motor vehicle |
| EP1016852A1 (en) * | 1998-12-31 | 2000-07-05 | Pacific Scientific Company | Apparatus for measuring the position of a movable member |
| US6566864B1 (en) * | 2000-09-01 | 2003-05-20 | Ford Global Technologies, L.L.C. | Angular position sensor for vehicle suspension |
| WO2003008911A1 (en) * | 2001-07-13 | 2003-01-30 | Austriamicrosystems Ag | Measuring device for contactlessly detecting the rotation angle and the axial position of an object to be measured |
| US7360756B2 (en) | 2005-03-31 | 2008-04-22 | Delphi Technologies, Inc. | Vibration isolating bushing with embedded speed/position sensor |
| US7370853B2 (en) | 2005-03-31 | 2008-05-13 | Delphi Technologies, Inc. | Vibration isolating bushing with embedded angular position sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8317193D0 (en) | 1983-07-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |