Motor control circuit

Abstract

In a circuit, the first position sensor comprises a first sensing unit arranged to generate a voltage pattern to be provided on the first sensing terminal, based on sensing a position of a first actuatable object. Hence, the voltage pattern comprises data on a position of the first actuatable object. Furthermore, the first anode is connected to the second cathode, to the first sensor terminal and to a first circuit terminal of the circuit. The first cathode is connected to the first supply terminal and to a second circuit terminal of the circuit. The second anode is connected to the second supply terminal and to a third circuit terminal of the circuit. Furthermore, the first circuit terminal of the circuit is arranged to be connected to a first driving terminal of the first electromotor.

Description

[0001] P137991PC00

[0002] Title: Motor control circuit

[0003] TECHNICAL FIELD

[0004] The various aspects and examples thereof relate to circuits for control of electromotors. More in particular, the various aspects and examples thereof relate to circuits for driving electromotors and determining positions of rotors of the electromotors or objects driven by the rotors. Such circuits may be used in a motorised vehicle like a car or a lorry.

[0005] BACKGROUND

[0006] EP0776495A1 discloses a circuit in which a position of a rotor of an electromotor is determined based on a varying absolute value of a potentiometer. A similar configuration is provided by US5389864A. A disadvantage of such configurations is that tolerances of resistive potentiometers are relatively high - or expensive low-tolerance components need to be used. Second, the value of the resistance may also depend on ambient temperature. This means that for accurate determination of a position of the rotor or an object driven thereby can only be determined following an elaborate calibration process. Such calibration would have to be repeated frequently, as temperatures may vary over time.

[0007] US5253138 provides another system, which requires a significant amount of additional components for implementation. Furthermore, in this circuit, quite some current may be drawn by the measurement circuit.

[0008] The circuit of EP2680431A2 alleviates some of the issues of other circuits, but requires quite an amount of additional components. The same disadvantages apply to the circuit of EP3063505B1 and the circuit of US6545441B1 as well. SUMMARY

[0009] It is preferred to provide a motor circuit with a functionality similar to that of known circuits, yet while addressing one or more of the disadvantages of these circuits.

[0010] To this end, a circuit is provided for driving a first electromotor and providing position data on a first rotor of the first electromotor. The circuit comprises a first diode having a first anode and a first cathode, a second diode having a second anode and a second cathode, and a first position sensor having a first supply terminal, a second supply terminal and a first sensing terminal.

[0011] In this circuit, the first position sensor comprises a first sensing unit arranged to generate a voltage pattern to be provided on the first sensing terminal, based on sensing a position of a first actuatable object. Hence, the voltage pattern comprises data on a position of the first actuatable object. Furthermore, the first anode is connected to the second cathode, to the first sensor terminal and to a first circuit terminal of the circuit. The first cathode is connected to the first supply terminal and to a second circuit terminal of the circuit. The second anode is connected to the second supply terminal and to a third circuit terminal of the circuit. Furthermore, the first circuit terminal of the circuit is arranged to be connected to a first driving terminal of the first electromotor.

[0012] This circuit firstly provides a sensor that does not provide a resistive element parallel to motor windings. This reduces dissipation and improves accuracy.

[0013] For properly determining the position of the actuatable object by determining a signal provided by the signal terminal, it is preferred that the rotor of the electromotor does not rotate. One reason for this is that rotation of the rotor may cause a voltage to be generated over a winding of the electromotor, thus potentially adding to a signal sensed over the first terminal. It is noted that for such effect it is possible to compensate, based on information on motor speed and motor characteristics, of which data may be available.

[0014] Furthermore, this circuit comprises significantly less components than circuits known, in particular relative to circuits not having a main resistive body of a potentiometer parallel to the electromotor. This may significantly reduce cost.

[0015] The position sensor may be implemented in various ways. In one example, the position sensor may be a potentiometer, preferably a rotating potentiometer. In such case, the sensing unit comprises the wiper of the potentiometer and the sensing terminal is connected to the wiper. In another example, the position sensor may be an adjustable capacitor to enable voltage division or voltage sharing. The wiper is an example of a mechanical sensing input and the electrical wiper terminal an example of an electrical sensing output.

[0016] In again another example, the position sensor is a Hall sensor. In such example, the supply terminals of the circuit power the sensor and the sensing terminal provides a signal providing an indication of the position. In some Hall sensors, the position data is provided as a pulse-width modulation signal, with the duty cycle or average voltage providing an indication of a position of an actuatable object of which the position is to be determined. Other Hall sensors or other sensors may be used that have analogue signal output, coded, for example binary digital, signal output, other types of output or a combination of two or more thereof.

[0017] A Hall sensor does not have a mechanical connector to connect to the object to be sensed, but is, in operation, operationally connected to an object of which the position is to be sensed.

[0018] In an example, the circuit further comprises a third diode having a third anode and a third cathode, a fourth diode having a fourth anode and a fourth cathode and a second position sensor having a third end terminal, a fourth end terminal and a second signal terminal. In this circuit, the second position sensor comprises a second sensing unit arranged to generate a voltage pattern to be provided on the second sensing terminal, based on sensing a position of a second actuatable object. Hence, the voltage pattern comprises data on a position of the second actuatable object. Furthermore, the third anode is connected to the fourth cathode, to the second sensing terminal and to a fourth circuit terminal of the circuit, the third cathode is connected to the third supply terminal and to the second circuit terminal, the fourth anode is connected to the fourth supply terminal and to the third circuit terminal; and the fourth circuit terminal is arranged to be connected to a driving terminal of a second electromotor having a second rotor.

[0019] In addition to all advantages of the circuit generally described in accordance with this aspect, this circuit requires only one terminal of a driving and sensing circuit for adding one more electromotor and one more potentiometer.

[0020] In one implementation, the first sensing unit is operatively connected to the first rotor, such that a first motor movement of the first rotor results in a first sensing voltage pattern provided by the first sensing terminal. Such connection is preferably established by means of a mechanical connection, but may also be established by means of hydraulic, pneumatic, electrical or other means - or a combination of two or more thereof. This implementation allows for providing a feedback loop for controlling a position of the rotor of the electromotor or an actuatable object driven thereby.

[0021] When Hall sensors or other non-contact sensors are used, the sensing unit is provided adjacent to the actuatable object - a rotor of an electromotor or a car part driven thereby -, but preferably at a distance. Moving of the actuatable object does not result in any movement of any matter in the Hall sensor as a position sensor.

[0022] In another implementation, the first sensing unit is operatively connected to the second rotor, such that a second motor movement of the second rotor results in a first sensing voltage pattern provided by the first sensing terminal; and the second sensing unit is operatively connected to the first rotor, such that a first motor movement of the first rotor results in a second sensing voltage pattern provided by the second sensing terminal. Hence, the wipers may be directly driven by the rotors, directly driven by objects driven by the rotors or indirectly driven by either one of those.

[0023] When Hall sensors or other non-contact sensors are used, the sensing unit is proved adjacent to the actuatable object - a rotor of an electromotor or a car part driven thereby -, but preferably at a distance. Moving of the actuatable object does not result in any movement of any matter in the Hall sensor as a position sensor.

[0024] An advantage of this implementation is that when determining a position of an actuatable object driven by the first motor, the first motor does not have to be stopped, as the potential of the first wiper is determined through windings of the second motor. It is noted that, preferably, the second electromotor is halted when determining the position of the actuatable object (the rotor of the first electromotor or another object). The first electromotor is during the determining operation not necessarily halted, yet preferably, the first electromotor is not operated and running in free mode.

[0025] In a further implementation, the first position sensor is a first potentiometer and the first sensing terminal is a wiper and a rotating wiper in particular; between the first supply terminal and the second supply terminal, a resistive body is provided over which the first wiper is movable, electrically conductively connected to the resistive body. The second position sensor may be implemented in the same way. With a rotational movement being generated by the electromotor(s), a rotating wiper is simple to implement. However, a translating wiper or otherwise moving wiper on an impedance divider may be applied as well. For such implementation, for example a rack and pinion configuration may be used for transmission of movements and positions.

[0026] Again another implementation further comprises a processing unit comprising a processing circuit having a first processing terminal, a second processing terminal and a third processing terminal. In this implementation, the first processing terminal is connected to the second circuit terminal, the second processing terminal is arranged to be connected to a second driving terminal of the first electromotor and the third processing terminal is connected to the third circuit terminal. Additionally, the processing circuit is arranged to apply a first voltage pattern between the first processing terminal and the second processing terminal for driving the first electromotor in a first direction; and apply a second voltage pattern between the third processing terminal and the second processing terminal for driving the first electromotor in a second direction.

[0027] Such implementation provides an effective control of the electromotor, making use of the control circuitry.

[0028] In yet another implementation, the processing circuit is further arranged to apply a third voltage pattern between the first processing terminal and the third processing terminal; and determine at least one of a first measured voltage between the first processing terminal and the second processing terminal and a second measured voltage between the third processing terminal and the second processing terminal.

[0029] This implementation allows for further options for determining a position of the rotor of the first electromotor or an actuatable object driven thereby.

[0030] In again a further implementation, the processing circuit is further arranged not to apply the first voltage pattern and not to apply the second voltage pattern while applying the third voltage pattern and while determining the at least one of the first measured voltage and the second measured voltage. As discussed above, this implementation allows for determining voltage division over an adjustable impedance - preferably adjustable electrical resistance without interference of an electromotor of which a winding forms part, over which winding a potential is determined.

[0031] In yet another implementation, the processing circuit is further arranged to determine a position of the first rotor or an object driven thereby based on at least one of the first measured voltage and the second measured voltage. This implementation allows for increased accuracy.

[0032] In yet a further implementation, the processing circuit is further arranged to determine a position of the first rotor or an object driven thereby based on a ratio between the first measured voltage and the second measured voltage. Also this implementation allows for increased accuracy.

[0033] Another implementation further comprises a processing unit comprising a processing circuit having a first processing terminal, a second processing terminal, a third processing terminal, and a fourth processing terminal. In this implementation, the first processing terminal is connected to the second circuit terminal, the second processing terminal is arranged to be connected to a second driving terminal of the first electromotor; the third processing terminal is connected to the third circuit terminal; the fourth processing terminal is arranged to be connected to a second driving terminal of the second electromotor. Furthermore, the processing circuit is arranged to apply a first voltage pattern between the first processing terminal and the second processing terminal for driving the first electromotor in a first direction, apply a second voltage pattern between the third processing terminal and the second processing terminal for driving the first electromotor in a second direction, apply a third voltage pattern between the first processing terminal and the fourth processing terminal for driving the second electromotor in a first direction; and apply a fourth voltage pattern between the third processing terminal and the fourth processing terminal for driving the second electromotor in a second direction. This implementation allows for accurate measurement of positions of objects driven by either one of the electromotors, while employing a very small amount of discrete components of a very small area of an integrated circuit, should any components by jointly implemented thereon.

[0034] In again a further implementation, the processing circuit is further arranged to apply a third voltage pattern between the first processing terminal and the third processing terminal; and determine at least one of a first measured voltage between the first processing terminal and the second processing terminal and a second measured voltage between the third processing terminal and the second processing terminal.

[0035] In another implementation, the processing circuit is further arranged to apply a fourth voltage pattern between the first processing terminal and the third processing terminal; and determine at least one of a third measured voltage between the first processing terminal and the fourth processing terminal and a fourth measured voltage between the third processing terminal and the fourth processing terminal. This implementation allows for gathering additional information for more accurately determining positions.

[0036] In a further implementation, the processing circuit is further arranged to determine a position of the second rotor or a first object driven thereby based on a ratio between the first measured voltage and the second measured voltage. This implementation reduces or potentially removes any need for calibration prior to any determining.

[0037] In yet another implementation, the processing circuit is further arranged to determine a position of the first rotor or a second object driven thereby based on a ratio between the third measured voltage and the fourth measured voltage. This implementation reduces or potentially removes any need for calibration prior to any determining. In another implementation, an electrical circuit is provided for driving an electromotor and determining a position of an object driven by the electromotor, the circuit comprising a driving and sensing module having a first terminal, a second terminal and a third terminal. In this circuit, each terminal is arranged to be switched between at least one of a first potential and a second potential, the first potential being higher than the second potential, each terminal is arranged to be switched to a floating state, the first terminal is arranged to determine a potential applied to the first terminal, relative to at least one of the first potential and the second potential. The circuit further comprises a potentiometer comprising a resistive element, the resistive element having a first fixed contact and a second fixed contact substantially opposite to the first fixed contact; and a wiper contact arranged to be movable on the resistive element between the first fixed contact and the second fixed contact. The circuit is arranged to be connected to the electromotor between the wiper contact and the first terminal.

[0038] In this circuit, a first diode may be provided with a cathode to the second terminal and an anode to the wiper contact and a second diode may be provided with a cathode connected to the wiper contact and the anode to the third terminal. In another implementation, switches may be used.

[0039] BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The various aspects and implementations thereof will now be discussed in further detail in conjunction with drawings. In the drawings:

[0041] Figure 1: shows a car;

[0042] Figure 2: shows an electromotor and a drive train;

[0043] Figure 3: shows a first motor control circuit; and

[0044] Figure 4: shows a second motor control circuit. DETAILED DESCRIPTION

[0045] Figure 1 shows a car 100 as a motorised vehicle. At the back of the car, a battery 132 is provided for providing electrical power to the vehicle power supply network 130. In the middle of the car, a vehicle control unit 110 is located. A driver control unit 120 is located in the front of the car, preferably close to a first electromotor 200 as a first driving unit. The driver control unit 120 is operatively connected to the vehicle control unit 110 for receiving instruction data to be executed by electrical components connected to the driver control unit 120.

[0046] The first electromotor 200 is connected to a flap 190 of an active grill shutter (AGS) system. In another implementation, the first electromotor - or any other driving unit - is arranged for adjusting the position of another air guiding flap, including, but not limited to any spoilers and the like for adjusting airflow at the back, front, top and / or bottom of the car 100. In again another implementation, the first electromotor is arranged to adjust position of a rearview mirror, a valve operator for, for example, coolant circuit, another actuatable object of the car 100 or a combination of two or more thereof.

[0047] Figure 2 shows the electromotor 200 that is coupled to the flap 190 via a drive train 270. The electromotor 200 comprises a housing 202, in which housing a rotor 210 is provided. On the rotor, a first conductor 212 and a second conductor 214 are provided. Furthermore, one or more additional conductors are provided on the rotor 210. The conductors are provided for providing a current from a first brush contact 216 to the first electromagnet 222 and the second electromagnet 226, provided as coils on the rotor 210. A second brush contact 218 is provided opposite to the first brush contact 216. The first brush contact 216 is connected to a first motor terminal and the second brush contact 218 is connected to a second motor terminal. In the housing, also a first permanent magnet 224 and a second permanent magnet 228 are provided. Thus, the electromotor 200 is a commonly known DC (direct current) electromotor as generally commercially available. It is noted that the various technologies discussed here are not limited to a DC electromotor and may be applied to other electromotors as well.

[0048] The drivetrain 270 comprises a slip coupling 230 provided between the rotor 210 and a worm wheel 240. The drivetrain 270 further comprises a toothed wheel or a gear 250 that is preferably provided on an axle 258. The connection between the worm wheel 240 and the gear 250 allows for a signification reduction in rotational speed, preferably in the order or a factor 50.

[0049] The first slip coupling 230 comprises a first slip part 232 connected to the rotor 200 and a second slip part 234 connected to the worm wheel 240. In normal operation, the first slip part 232 and the second slip pat 234 rotate together. If the torque between the worm wheel 240 and the rotor 210 exceeds a pre- determined torque threshold, the second slip part 234 stalls and the first slip part 232 continues to rotate, in which operational state the slip coupling 230 is in slip mode.

[0050] If the slip coupling 230 goes into slip, usually first the full drive train 270 will stall. Subsequently, the slip coupling 230 will run into slip mode. Depending on characteristics of contact surfaces of the first slip part 232 and the second slip part 234, the slip coupling 230 will stay in slip operation or alternate between slip and stall mode.

[0051] Additionally or alternatively, a second slip coupling is provided in the gear 250. The gear 250 comprises in this embodiment an outer ring 252 and an inner ring 254. Between the inner ring 252 and the outer ring 254, the second slip coupling 256 is provided. The operation of the second slip coupling 256 is similar to that of the first slip coupling 230. The flap 190 is connected to the inner ring 256. Whereas in this embodiment the electromotor 200 is used for actuating the flap 190, in other embodiments other actuatable parts of a car or other motorised vehicle may be actuated. Such actuatable parts may be shutters for a grille, actuatable spoilers or other air guiding flaps, screen wipers, doors, other, or a combination thereof.

[0052] Figure 3 shows a motor circuit 300. The motor circuit 300 comprises an electronic data processing module 310, an electromotor 302 and a control circuit 350. The control circuit comprises a first diode 332, a second diode 334 and a potentiometer 340. The diodes are preferably solid state semiconductor diodes with an n-type material (cathode) and a p-type material (anode), but may also be implemented differently, as long as the current / voltage characteristics of a diode are provided.

[0053] The potentiometer 340 comprises a main body 344 and a wiper 342 as a sensing unit that is arranged to be relocated at different positions on the main body 344. At or near extremities of the main body 344of the potentiometer 340, fixed terminals are provided. The potentiometer 340 may be a linear potentiometer, a rotational potentiometer or any other type of potentiometer providing options for voltage sharing by means of varying impedance - including, but not limited to resistance - by varying a position of the slider relative to the main body 344.

[0054] Instead of the potentiometer 340, another position sensor like a Hall sensor may be used. In case of using a Hall sensor, additional circuit elements may be used for providing filter characteristics for adaptation of a car operational voltage to an operation voltage of the sensor. To that end, a capacitor may be provided parallel to the Hall sensor and a resistor may be provided in series with the Hall sensor. This resistor is provided only in series with the Hall sensor and not in series with diodes or the electromotor, relative to the supply. The capacitor may be provided to the Hall sensor only or to the Hall sensor and the resistor. In the motor circuit 300 and the control circuit 350 in particular, the cathode of the first diode 332 is connected to a first circuit terminal 332, with a first fixed terminal of the potentiometer 340. The anode of the first diode 332 is connected to a second circuit terminal 324, with the wiper 342 and the cathode of the second diode 334. A second fixed terminal of the potentiometer 340 is with the anode of the second diode 334 connected to a third circuit terminal 326 of the control circuit 350.

[0055] The first circuit terminal 322 is connected to a first processing terminal 312 of the electronic data processing module 310 and the third circuit terminal 326 is connected to a third processing terminal 316 of the electronic data processing module 310. The second circuit terminal 324 is connected to a first motor contact of the electromotor 302. A second motor contact of the electromotor 302 is connected to a second processing terminal 314.

[0056] The electronic data processing module 310 is arranged to control the motor circuit 300 as discussed below. To this end, the electronic data processing module 310 may be programmed to operate accordingly. The programming may be provided by means of software or dedicated hardware. The electronic data processing module 310 may be a dedicated electronic circuit. Alternatively or additionally, the electronic data processing module 310 may be provided as part of an engine control unit - ECU - of the car 100, either as a discrete part or an integral part of another electronic circuit that also provides other functionality.

[0057] In operation, the electromotor 302 is driven by applying a voltage between the first processing terminal 312 and the second processing terminal 314 to drive the electromotor 302 in a first direction. In such case, the second processing terminal 314 has a higher potential than the first processing terminal 312.

[0058] To drive the electromotor 302 in a second direction, opposite to the first direction, a voltage is applied between the third processing terminal 316 and the second processing terminal 314. In such case, the second processing terminal has a lower potential than the third processing terminal 316.

[0059] In order to determine a position of the rotor of the electromotor 302 or any actuatable object connected thereto, like the flap 190, the wiper 342 of the potentiometer 340 is operatively connected to the actuatable object, such that the position of the wiper 342 may be varied relative to the main body 344 to effectuate voltage sharing.

[0060] The operational connection is preferably implemented using a mechanical connection between the wiper 342 and the rotor of the electromotor 302 or using a mechanical connection between the wiper 342 and the actuatable objection. Such connection may be an axle, a push rod, other or a combination of two or more thereof; in the drawings, the connection is indicated by means of an axle 302. If non-contact sensors are used, like Hall sensors, the axle 302 or any other mechanical connector or mechanical connection may omitted.

[0061] With a known voltage applied to the first processing terminal 312and the third processing terminal 316, there are various ways to determine a position of the wiper 342 relative to the main body 344. And this position is an indication of a position of the actuatable object.

[0062] Firstly, a voltage between the first processing terminal 312 and the second processing terminal 314 may be an indication for the position. Second, a ratio between - firstly - the voltage between the first processing terminal 312 and the third processing terminal 316 and - secondly - the voltage between the first processing terminal 312 and the second processing terminal 314 may provide an indication of the position. Third, a voltage between the third processing terminal 316 and the second processing terminal 314 may provide an indication of the position. Fourth, a ration between - firstly - the voltage between the first processing terminal 312 and the third processing terminal 316 and - secondly - the voltage between the third processing terminal 316 and the second processing terminal 314 may provide an indication of the position.

[0063] It is noted that when determining on or more of the voltages as discussed above, one or more of the processing terminals, preferably the second processing terminal 314, is switched to a high-ohmic state. This allows to determine one or more of the voltages as discussed above, without the measurement being distorted by a voltage drop over the windings of the electromotor 302.

[0064] Furthermore, it is preferred that during determining the voltages as discussed above, the rotor of the electromotor 302 does not rotate. If such were to be the case, electromagnetic forces, resulting out of interaction between permanent magnets in the electromotor 302 and windings of the electromotor 302 during such movement, may result in a voltage drop over the electromotor 302. And such voltage drop would influence determining the voltage sharing as discussed above.

[0065] Figure 4 shows another motor circuit 400 as another implementation. The motor circuit 400 comprises an electronic data processing module 410, a first electromotor 402, a second electromotor 404 and a control circuit 460. The control circuit 460 comprises a first diode 432, a second diode 434, a third diode 436, a fourth diode 438, a first potentiometer 440 and a second potentiometer 450. As discussed above, the diodes are preferably common solid state diodes, but may be implemented differently.

[0066] The first potentiometer 440 and the second potentiometer 450 may be implemented as discussed in conjunction with Figure 3. The first potentiometer 440 comprises a first main body 444 and a first wiper and the second potentiometer 450 comprises a second main body 454 and a second wiper 452.

[0067] In the control circuit 460, the cathode of the first diode 432 is connected to a second circuit terminal 424 of the control circuit 460, with a first fixed terminal of the first main body 442 of the first potentiometer 440, a first fixed terminal of the second main body 454 of the second potentiometer 450 and a cathode of the third diode. The anode of the first diode 432, the cathode of the second diode 434 and the second wiper 452 are connected to a first circuit terminal 422 of the control circuit 460.

[0068] To a third circuit terminal 426 of the control circuit 460, the anode of the second diode 434, the anode of the fourth diode 438, a second fixed terminal of the first main body 442 of the first potentiometer 440 and a second fixed terminal of the second main body 454 of the second potentiometer 450 are connected. Lastly, to a fourth circuit terminal 428 of the control circuit 460, the cathode of the fourth diode 438, the anode of the third diode 436 and the first wiper 442 are connected.

[0069] The first circuit terminal 422 is connected to a first motor contact of the first electromotor 402 and a second motor contact of the electromotor is connected to a first processing terminal of the electronic data processing module 410. The second circuit terminal 424 is connected a second processing terminal of the electronic data processing module 410. The third circuit terminal 426 is connected to a third processing terminal 416 of the electronic data processing module 410. The fourth circuit terminal 428 is connected to a first motor contact of the second electromotor 404 and a second motor contact of the second electromotor 404 is connected to a fourth processing terminal of the electronic data processing module 410.

[0070] The electronic data processing module 410 is arranged to control the motor circuit 400 as discussed below. To this end, the electronic data processing module 310 may be programmed to operate accordingly. The programming may be provided by means of software or dedicated hardware. The electronic data processing module 310 may be a dedicated electronic circuit. Alternatively or additionally, the electronic data processing module 410 may be provided as part of an engine control unit - ECU - of the car 100, either as a discrete part or an integral part of another electronic circuit that also provides other functionality.

[0071] As discussed in conjunction with the example shown by Figure 3, rotors of the electromotors of the motor circuit 400 as depicted by Figure 4 are operatively and preferably mechanically connected to the wipers of the potentiometers. In this way, a movement of at least one of the rotors and actuatable objects driven by the rotors results in movement of a wiper of a potentiometer.

[0072] In this example, the second wiper 452 is connected to the rotor of the first electromotor 402 by means of a first axle 402 and the first wiper 442 is connected to the rotor of the second electromotor 404 by a second axle 404. In other examples, with different sensors, other mechanical connections may be provided, as discussed above. Such connection may be directly or indirectly. In the latter case, a connector may be connected to an actuatable object that may be actuated by a particular electromotor.

[0073] In case non-contact sensors are used, like Hall sensors, no mechanical connections may be required. In some examples, material may be provided between the non-contact sensors and the rotors of the electromotors or objects driven or actuated thereby to improve transfer of any electrical, magnetic, electromagnetic or other fields.

[0074] The electronic data processing module 410 as depicted by Figure 4 is in this implementation arranged to control operation of the first electromotor 402 and the second electromotor 404 by providing on the four processing terminals of the electronic data processing module 410 output as provided in the table below. CW indicates that a particular rotor of a particular electromotor is to rotate clockwise; CCW indicates that a particular rotor of a particular electromotor is to rotate counterclockwise. These directions are provided merely as illustrative examples; directions may be opposite in other implementations. In the table below, a + indicates that the applicable processing terminal of the electronic data processing module has a potential higher than another terminal associated with a The lemniscate sign, co, indicates that the applicable terminal is not conductive and preferably floating. Lastly, 'sense' indicates that the applicable terminal is used to determine a voltage. Such voltage may be determined between the terminal indicated with a '+' and the sense terminal, between the terminal indicated with a '- 'and the sense terminal, between the sense terminal and the operating voltage of the car 100, between the sense terminal and the operational voltage of the electronic data processing module 410, other, or a combination of two or more thereof.

[0075] In operation, the potential of the first wiper 442, corresponding to a position of the rotor of the first electromotor 402 or the object driven thereby, is determined through windings of the second electromotor 404. This means that any electromagnetic forces appearing in the first electromotor 402 do not have an influence on determining of the potential of the first wiper 442.

[0076] It is noted that for determining the potential of the first wiper 442, the second electromotor 404 is not to move. Furthermore, as is apparent from the table provided above, the first electromotor 402 is not powered or not drive when the potential of the first wiper 442 is determined. However, during the measurement, the rotor of the first electromotor 402 is allowed to rotate.

[0077] Likewise, the potential of the second wiper 452, corresponding to a position of the rotor of the second electromotor 404 or the object driven thereby, is determined through windings of the first electromotor 402. This means that any electromagnetic forces appearing in the second electromotor 404 do not have an influence on determining of the potential of the second wiper 452.

[0078] It is noted that for determining the potential of the second wiper 452, the first electromotor 402 is not to move. Furthermore, as is apparent from the table provided above, the second electromotor 404 is not powered or not driven when the potential of the second wiper 452 is determined.

[0079] However, during the measurement, the rotor of the second electromotor 404 is allowed to rotate.

Claims

Claims1. A circuit for driving a first electromotor and providing position data on a first rotor of the first electromotor, the circuit comprising: a first diode having a first anode and a first cathode; a second diode having a second anode and a second cathode; a first position sensor having a first supply terminal, a second supply terminal and a first sensing terminal; wherein: the first position sensor comprises a first sensing unit arranged to generate a voltage pattern to be provided on the first sensing terminal, based on sensing a position of a first actuatable object; the first anode is connected to the second cathode, to the first sensor terminal and to a first circuit terminal of the circuit; the first cathode is connected to the first supply terminal and to a second circuit terminal of the circuit; the second anode is connected to the second supply terminal and to a third circuit terminal of the circuit; and the first circuit terminal of the circuit is arranged to be connected to a first driving terminal of the first electromotor.

2. The circuit according to claim 1, further comprising: a third diode having a third anode and a third cathode; a fourth diode having a fourth anode and a fourth cathode; a second position sensor having a third end terminal, a fourth end terminal and a second sensing terminal; wherein: the second position sensor comprises a second sensing unit arranged to generate a voltage pattern to be provided on the second sensingterminal, based on sensing a position of a second actuatable object; the third anode is connected to the fourth cathode, to the second sensing terminal and to a fourth circuit terminal of the circuit; the third cathode is connected to the third supply terminal and to the second circuit terminal; the fourth anode is connected to the fourth supply terminal and to the third circuit terminal; and the fourth circuit terminal is arranged to be connected to a driving terminal of a second electromotor having a second rotor.

3. The circuit according to claim 1 or claim 2, wherein the first sensing unit is operatively connected to the first rotor, such that a first motor movement of the first rotor results in a first sensing voltage pattern provided by the first sensing terminal.

4. The circuit according to claim 2, wherein: the first sensing unit is operatively connected to the second rotor, such that a second motor movement of the second rotor results in a first sensing voltage pattern provided by the first sensing terminal; and the second sensing unit is operatively connected to the first rotor, such that a first motor movement of the first rotor results in a second sensing voltage pattern provided by the second sensing terminal.

5. The circuit according to any one of the preceding claims, wherein the first position sensor is a first potentiometer, the first sensing unit is a rotating wiper and the first sensing terminal is a conductive contact connected to the first wiper.

6. The circuit according to any one of the claims 2 and 4, wherein the second position sensor is a second potentiometer, the second sensing unit is a rotating wiper and the second sensing terminal is a conductive contact connected to the second wiper.

7. The circuit according to claim 1 or claim 3, further comprising a processing unit comprising a processing circuit having a first processing terminal, a second processing terminal and a third processing terminal, wherein: the first processing terminal is connected to the second circuit terminal, the second processing terminal is arranged to be connected to a second driving terminal of the first electromotor; the third processing terminal is connected to the third circuit terminal; and the processing circuit is arranged to: apply a first voltage pattern between the first processing terminal and the second processing terminal for driving the first electromotor in a first direction; and apply a second voltage pattern between the third processing terminal and the second processing terminal for driving the first electromotor in a second direction.

8. The circuit according to claim 7, wherein the processing circuit is further arranged to: apply a third voltage pattern between the first processing terminal and the third processing terminal; and determine at least one of a first measured voltage between the first processing terminal and the second processing terminal and a second measured voltage between the third processing terminal and the second processing terminal.

9. The circuit according to claim 8, wherein the processing circuit is further arranged not to apply the first voltage pattern and not to apply the second voltage pattern while applying the third voltage pattern and while determining the at least one of the first measured voltage and the second measured voltage.

10. The circuit according to any one of claim 8 and claim 9, wherein the processing circuit is further arranged to determine a position of the first rotor or an object driven thereby based on at least one of the first measured voltage and the second measured voltage.

11. The circuit according to claim 10, wherein the processing circuit is further arranged to determine a position of the first rotor or an object driven thereby based on a ratio between the first measured voltage and the second measured voltage.

12. The circuit according to claim 2 or claim 4, further comprising a processing unit comprising a processing circuit having a first processing terminal, a second processing terminal, a third processing terminal, and a fourth processing terminal, wherein: the first processing terminal is connected to the second circuit terminal, the second processing terminal is arranged to be connected to a second driving terminal of the first electromotor; the third processing terminal is connected to the third circuit terminal; the fourth processing terminal is arranged to be connected to a second driving terminal of the second electromotor; and the processing circuit is arranged to: apply a first voltage pattern between the first processing terminal and the second processing terminal for driving the first electromotor in a first direction;apply a second voltage pattern between the third processing terminal and the second processing terminal for driving the first electromotor in a second direction; apply a third voltage pattern between the first processing terminal and the fourth processing terminal for driving the second electromotor in a first direction; and apply a fourth voltage pattern between the third processing terminal and the fourth processing terminal for driving the second electromotor in a second direction.

13. The circuit according to claim 12, wherein the processing circuit is further arranged to: apply a third voltage pattern between the first processing terminal and the third processing terminal; and determine at least one of a first measured voltage between the first processing terminal and the second processing terminal and a second measured voltage between the third processing terminal and the second processing terminal.

14. The circuit according to claim 13, wherein the processing circuit is further arranged to: apply a fourth voltage pattern between the first processing terminal and the third processing terminal; and determine at least one of a third measured voltage between the first processing terminal and the fourth processing terminal and a fourth measured voltage between the third processing terminal and the fourth processing terminal.

15. The circuit according to one of claim 13 and claim 14 to the extend dependent on claim 4, wherein the processing circuit is further arranged to determine a position of the second rotor or a firstobject driven thereby based on a ratio between the first measured voltage and the second measured voltage.

16. The circuit according to any one of claim 14 and claim 15 to the extend dependent on claim 4, wherein the processing circuit is further arranged to determine a position of the first rotor or a second object driven thereby based on a ratio between the third measured voltage and the fourth measured voltage.

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