Abstract: An apparatus for capacitive ascertaining and/or monitoring of the fill level of a medium in a container. The apparatus includes at least one probe unit, which is electrically insulated relative to the medium, and at least one electronics unit, which supplies the probe unit with at least one electrical, actuating signal, receives an electrical measurement signal from the probe unit, and evaluates the measurement signal as regards the fill level The actuating signal is an electrical alternating voltage signal. The electronics unit is embodied in such a manner that it supplies the probe unit with the actuating signal in a measuring phase, and supplies the probe unit with a test signal in a test phase, and that it receives a test measurement signal in the test phase from the probe unit, wherein the test signal is selected in such a manner that it has at least one section with an essentially constant voltage value.

Abstract: An apparatus for mounting a plurality of heat sinks onto a circuit board during testing while the circuit board is tested in a fixed manufacturing station. The apparatus has a polygonal shaped frame with a size that is limited to an area on the circuit board which contains a plurality of data processing elements to be cooled. At least four apertures are on the frame, wherein each of the apertures corresponds to a different one of the plurality of data processing elements to be cooled. A slot is positioned on the frame to receive oversized processing elements. At least four pillars extend from the frame and mount into mounting holes provided on the circuit board. The apertures on the frame support the heat sinks above the data processing elements to be cooled. No additional screws, adhesives, clips or other fixing mechanisms are required to secure the heat sinks.

Abstract: A field device electronics with a sensor unit for process measurements, wherein the field device electronics is connected with the sensor unit over corresponding signal paths, and wherein the field device electronics receives analog measurement signals (S1) of the sensor unit and produces analog drive signals (S5) for the fundamental wave excitation of the sensor unit and transmits to the sensor unit. Present for producing the drive signal(S5) are an analog/digital converter, a digital phase shifter and a digital/analog converter, wherein the analog measurement signals (S1) are digitized by the analog/digital converter and forwarded to a digital phase shifter, and wherein the output signal (S4) of a phase shifter is converted by the digital/analog converter into the analog drive signal (S5) for the sensor unit.

Abstract: The invention relates to a method for servicing, especially checking, an apparatus for capacitive ascertaining and/or monitoring at least one process variable of a medium, wherein the apparatus has at least one probe unit (3) with a probe electrode (6) and an auxiliary electrode (7). The invention includes that the probe electrode (6) and/or the auxiliary electrode (7) are/is supplied at least with one test signal or connected with at least one electrical potential, that at least one response signal is tapped from the probe unit (3), and that, at least from the response signal and a predeterminable desired value, information is obtained concerning the apparatus.

Abstract: A method for manufacturing-side calibration of a measuring device for capacitive fill level measurement of a medium, wherein at least one probe unit of the measuring device is activated with an electrical, alternating voltage of a predeterminable frequency. As a function of the frequency of the activating signal, a conductivity range is determined, within which the fill level measurement is essentially independent of a change of the electrical conductivity of the medium; for such conductivity range, at least a first reference matching between a predeterminable, first fill-level value and a first capacitance value belonging to the first fill-level value is produced; and the first reference matching between the first fill-level value and the first capacitance value is recorded. Additionally, the invention relates to a corresponding measuring device.

Abstract: A field device electronics with a sensor unit for process measurements, wherein the field device electronics is connected with the sensor unit over corresponding signal paths, and wherein the field device electronics receives analog measurement signals (S1) of the sensor unit and produces analog drive signals (S5) for the fundamental wave excitation of the sensor unit and transmits to the sensor unit. Present for producing the drive signal (S5) are an analog/digital converter, a digital phase shifter and a digital/analog converter, wherein the analog measurement signals (S1) are digitized by the analog/digital converter and forwarded to the a digital phase shifter, and wherein the output signal (S4) of a phase shifter is converted by the digital/analog converter into the analog drive signal (S5) for the sensor unit.

Abstract: The invention concerns a method for regulating the rotation speed, of a motor with which a digital rotation speed controller is associated and which, during operation, furnishes an actual-value signal for the rotation speed in the form of a rotation speed frequency signal, toward a target rotation speed setpoint defined in the form of a setpoint frequency signal, having the following steps: in a first time segment, a first numerical frequency value that characterizes the rotation speed of the motor is ascertained from the rotation speed frequency signal; in a second time segment that is substantially simultaneous with the first time segment, a second numerical frequency value that characterizes the frequency of the setpoint frequency signal is ascertained from the setpoint frequency signal; by means of the first and second numerical frequency values, the rotation speed of the motor is regulated in the digital rotation speed controller to a rotation speed that is associated with the setpoint frequency signal a

Abstract: An improved method, for obtaining a datum concerning the rotation speed (n) of a rotating object, such as a motor rotor (32), offers high precision. Typically, the motor has a sensor (61) which supplies a sensor signal that has, for each revolution of the rotor, a plurality A of events such as pulses or pulse edges which are counted by a microprocessor (23) associated with the motor. In order to keep the computation load on the microprocessor from increasing as the rotor speed increases, yet maintain high precision, the measurement is done over a full rotation of the rotor, starts at a first signal event (176), and ends after a third or nth signal event (182) which happens at the same rotational position as the first signal event.

Abstract: The invention relates to a method for adjusting a real value (actual value) of a physical quantity to a preset value (target value) with the following steps:(a) the difference between the target value and the actual value (referred to below as the control deviation) and its sign (referred to below as the control sign) is determined repeatedly at interval; (b) the control deviation is converted into at least one electrical signal during or after each measurement, and the duration thereof (referred to below as the control deviation duration) is proportional to the absolute value of the control deviation at least in the range of the target value, and the value thereof is a function of the control sign; (c) the charge of an analog electrical memory arrangement is affected by this at least one electrical signal during the control deviation duration; (d) depending on the value of the charge of the memory arrangement, the physical quantity is directly or indirectly affected to keep it in the range of the target valu

Abstract: In a method of starting a two-pulse electronically commutated dc motor, which is designed for operation in a preferred direction, for purposes of startup in a desired direction, the following steps are carried out: after start-up, the rotor of the motor is driven, according to a start routine (S118), by supplying current alternately in a first and a second direction, into forced oscillation about a rest position; during the start routine, monitoring (as to whether the rotor has started up) is performed; whenever it is determined that the rotor has started up, the start routine is exited. Further, a method is provided, by means of which the rotational position of the rotor, at which the current of a winding phase is switched on, is optimized as a function of rotation speed and rotation direction.

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.