Hermann Rappenecker

Bio: Hermann Rappenecker is an academic researcher from ebm-papst. The author has contributed to research in topics: Rotor (electric) & Stator. The author has an hindex of 16, co-authored 75 publications receiving 740 citations.

Electronically commutated motor

Abstract: 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.

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

Abstract: 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.

Fan motor with digital controller for applying substantially constant driving current

Abstract: 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.

Method of limiting current in a DC motor and DC motor system for implementing said method

Abstract: The invention relates to a method of current limitation in a direct current motor, with the following steps: in successive cycles, the motor is turned on at a predetermined place in the cycle and, after lapse of a predetermined time interval, the motor current is tested in a first test and, if found to be too high, the current is shut off; after lapse of another interval measured from the first test, the motor current is tested again during the same cycle and, if found to be too high, is shut off if it was not shut off previously; after lapse of a third interval, measured from the second test, the motor current is turned on, insofar as it was shut off at either of the two tests, and the cycle is repeated.

Direct current machine with a controllable arrangement for limiting current

Abstract: 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.

Motor controller having a multifunction port

Abstract: In one aspect, a control circuit to control a speed of a motor includes a control logic circuit connected to a multifunction port. The control logic circuit is configured to receive a control signal provided at the multifunction port and to provide response signals based on the control signal to place the motor in at least two of a sleep mode, a brake mode and a pulse-width modulation (PWM) mode. The motor control circuit also includes an H-bridge circuit configured to control the motor based on the response signals.

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

Abstract: 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.

Protective device for an electrical supply facility

Abstract: The present invention is directed to a protective device configured to be disposed in an electrical distribution system between a source of electrical power and an electrical load. The electrical distribution system includes at least one line hot conductor, a line neutral conductor, and a line ground conductor. The line neutral conductor is connected to the line ground conductor at a termination point in the electrical distribution system. The electrical load includes at least one load hot conductor, a load neutral conductor, and a load ground conductor, the device comprises a conditioning circuit configured to monitor a differential current flowing through the plurality of line termination elements and configured to generate a conditioning signal in response thereto. The conditioning signal propagates in a path formed by the line neutral conductor and the line ground conductor to thereby reduce a differential current propagating in the at least one line hot conductor and the line neutral conductor. The conditioning circuit also is configured to neutralize a substantial portion of a current associated with a non-fault related electrical perturbation.

Electric bending endoscope

Abstract: An electric bending endoscope includes a temperature sensor that detects the temperature of a motor as a state value indicating the driving state of a bending drive unit. A bending control device comprises: a temperature detection unit that receives the data of the temperature detected by the temperature sensor; a record unit in which the limits of motor temperature inputted in advance are recorded; a comparison unit that compares the data of the temperature sent from the temperature detection unit with the limits of motor temperature recorded in the record unit; and a notification unit that notifies that the driving state of a motor is approaching the limit.

Cooling module and related control circuits useful therefor incorporating a communication port for receiving digital command signals to control module

Abstract: A cooling module includes, for certain embodiments, a brushless DC fan and integral fan control circuitry which independently implements a self-contained start and run motor control loop and also includes a communications port to accept commands from a host processor and to provide status and other data in response to queries from the host processor. In one embodiment, a fan module interfaces with a two-wire serial bus, such as an I2C bus or SMbus, and accepts commands and provides status and data in a serial digital format. A variety of commands such as on/off, and various speed control settings may be received from the host system, and the actual speed of the fan may be reported back when queried by the host system. In some embodiments a temperature within or near the fan housing or of the air flow through the fan may be reported back when queried. The entire fan control circuit may preferably be incorporated within the fan housing, including a serial interface and power terminals for the fan, resulting in a compact four-wire interface for the fan module.