Device 1 for detecting the angular position of a shaft of an electric motor relative to a nonrotating element, comprising a reduction gear 5 comprising an input connected in rotation to the shaft 2 , and an output such that the output of the reduction gear 5 moves over an angle of less than 2π, a single-revolution angular position sensor 26 being placed to measure the angle of the output of the reduction gear 5 and an angular position sensor 27 being placed on the input of the reduction gear 5.

Device For Detecting Angular Position, Electric Motor, Steering Column And Reduction Gear

This paper presents a low-cost position sensorless control scheme for brushless dc motors. Rotor position information is extracted by indirectly sensing the back EMF from only one of the three motor-terminal voltages for a three-phase motor. Depending on the terminal voltage sensing locations, either a low-pass filter or a band-pass filter is used for position information retrieval. This leads to a significant reduction in the component count of the sensing circuit. The cost saving is further increased by coupling the sensing circuit with a single-chip microprocessor or digital signal processor for speed control. In addition, a look-up-table-based correction for the nonideal phase delay introduced by the filter is suggested to ensure accurate position detection even at low speed. This extends the operating speed range and improves motor efficiency. Experimental results are included to verify the proposed scheme.

Low-cost sensorless control of brushless DC motors with improved speed range

A body associated device comprises a housing, an adhesive layer configured to be applied to a body of a living subject, and at least one standoff located between the housing and the adhesive layer. An electronic module may be located within the housing of the body associated device. A personal communication system comprises a body associated device including an electronic module and further comprises a feedback portion coupled to the housing and to the electronic module. The feedback portion is configured to communicate information between the living subject and the body associated device. An external local node is operative to provide at least one of transmit communications to and receive communications from the body associated device.

Wearable personal body associated device with various physical configurations

A septum for use in access port for providing subcutaneous access to a patient is disclosed. More particularly, a septum including at least one topographical feature configured for identification of the septum is disclosed. An access port including such a septum is also disclosed. In addition, an access port comprising a septum and a means for identification of the septum is disclosed. Also, a method of identifying a subcutaneously implanted access port is disclosed. Specifically, an access port including a septum may be provided and at least one topographical feature of the septum of the access port may be perceived. The subcutaneously implanted access port may be identified in response to perceiving the at least one feature of the septum of the access port.

Septum including at least one identifiable feature, access ports including same, and related methods

An access port for subcutaneous implantation is disclosed. Such an access port may comprise a body for capturing a septum for repeatedly inserting a needle therethrough into a cavity defined within the body. Further, the access port may include at least one feature structured and configured for identification of the access port subsequent to subcutaneous implantation. Methods of identifying a subcutaneously implanted access port are also disclosed. For example, a subcutaneously implanted access port may be provided and at least one feature of the subcutaneously implanted access port may be perceived. Further, the subcutaneously implanted access port may be identified in response to perceiving the at least one feature.

Access port identification systems and methods

The invention relates to an electronically commutated motor in which both the drive current (i2) and the brake current (i2') are monitored. If the drive current is too high, a pulse duty factor is reduced that influences the current in the motor. If the brake current is too high, said pulse duty factor is increased. To this end, an analogous circuit with two current limiting members (131, 161) is provided and a circuit in which these functions are realized by the software of a microcontroller so that the measurement of current is no longer necessary. A combination of the two methods is also possible according to which hardware current limitation and software current limitation interact.

Electronically commutated motor

The invention relates to a method for commutating an electronically commutated motor, by way of an improved commutation process that becomes effective between the cut-off of a voltage pulse and the switching on of a subsequent voltage pulse. On the basis of the current speed a cut-off time is calculated and once this cut-off time is reached, the power supply from a DC current source to the motor is disrupted. The winding to be switched off is operated in the short-circuit operation via two MOSFET transistors, and the declining current in the winding is monitored. Once the current has reached a reduced value, the winding connections of the winding are temporarily subjected to a high-ohmic voltage before the subsequent voltage pulse starts.

Method for commutating an electronically commutated dc motor, and motor for carrying out said method

An improved fan arrangement features a radial or diagonal fan ( 370 ) with which a direct current motor ( 32 ) is associated as its drive motor, further comprising a digital control element ( 23, 24 ) which executes a program, for controlling the current flowing through the direct current motor ( 32 ), which program is so configured that it applies a substantially constant current in the motor ( 32 ) in the working rotation speed range of the fan.

Fan motor with digital controller for applying substantially constant driving current

An electronically commutated direct current machine, comprising a rotor and a stator, has a stator winding arrangement which can be supplied with power from a direct current source (73, 74) by a full bridge circuit (78). A commutation arrangement (49, 50, 52, 54) for commutating the semiconductor switches (1) (80 to 85) is provided and is configured for switching on one of the semiconductor switches in dependence on at least the position of the rotor (110) at a first bridge branch, respectively and for alternately switching on and off a semiconductor switch that is allocated to the switched on semiconductor switch of the first bridge branch, at a second bridge branch, controlled by a clocking signal (PWM2). The invention also provides an arrangement that is configured for generating a reference clocking signal (PWM1), which controls the duty ratio for the alternate switching on and off of the semiconductor switch that is allocated to the first bridge branch by its intensity. A current limiting arrangement (131, 161) which can be controlled by a current desired value signal (PWM I+; PWM I-) is also provided. When a current defined by the current desired value signal is reached in the direct current machine, said arrangement modifies the reference clocking signal in such a way that the current in the direct current machine is not greater than a limit current that is set by the current desired value signal.

Direct current machine with a controllable arrangement for limiting current

In this method, the value of a temperature-dependent motor parameter (k e ) of an electronically commutated motor ( 124 ) is determined during motor operation without a temperature sensor. The motor has a stator ( 201 ) having stator phases ( 202, 204, 206 ), and a permanent-magnet rotor ( 208 ) coacting with that stator, which rotor induces voltages (U IND ) in the stator phases during operation, a power stage ( 122 ) being associated with the stator phases in order to control their energization. In this method, energization of the stator phases is interrupted while the rotor ( 208 ) is rotating. A value (U IND ) characterizing an induced voltage, and a value (ω) characterizing a rotation speed of the motor, are ascertained. On the basis of those values, the value of the temperature-dependent motor parameter (k e ) is derived. The invention also concerns a motor for carrying out such a method. The method requires no temperature sensor, and can be integrated into an “embedded program” such as the program otherwise needed for electronic commutation.

Alexander Hahn

Papers

Electronically commutated motor

Method for commutating an electronically commutated dc motor, and motor for carrying out said method

Fan motor with digital controller for applying substantially constant driving current

Direct current machine with a controllable arrangement for limiting current

Method of operating an electronically commutated motor, and method for carrying out such a method