摘要:
A MEMS microphone having an improved noise performance due to reduced DC leakage current is provided. For that, a minimum distance between a signal line of the MEMS microphone and other conducting structures is maintained. Further, a DC guard structure fencing at least a section of the signal line is provided.
摘要:
A MEMS microphone having an improved noise performance due to reduced DC leakage current is provided. For that, a minimum distance between a signal line of the MEMS microphone and other conducting structures is maintained. Further, a DC guard structure fencing at least a section of the signal line is provided.
摘要:
A procedure is introduced to test the functional capability of a secondary air system of an internal combustion engine, wherein values of a pressure are acquired, which arises in the secondary air system between the secondary air pump and a secondary air flow cross section, which can be controlled, when the secondary air pump is activated and the actuation of the secondary air flow cross section is increased; in that a measurement for the pressure is developed from the acquired values and is compared with a set point value, and the functional capability of the secondary air system is assessed as a function of a result of the comparison. The procedure characterizes itself in such a way, that in a secondary air system, whose secondary air flow cross section is controlled by two secondary air valves, wherein one of the two secondary air valves is actuated to close, while the other one of the two secondary air valves is actuated to open, and the assessment of the functional capability for a section of the secondary air system occurs in the section, in which the secondary air valve actuated to open is disposed. In addition a control unit is introduced, which controls the sequence of such a procedure.
摘要:
A controller for controlling a reactive series compensator serially inserted at compensator terminals into a power transmission line for controlling the line current. The controller includes a current control loop and a voltage control loop. A current controller outputs a control voltage (ccout) indicating a desired compensator terminal output voltage (uc). A control method selector means generates, in a low output voltage region, a constant reference voltage (uDCref) for the voltage control loop and a variable modulation index mq of a modulation signal m=md cos (&ohgr;t) −mq sin (&ohgr;t). In a high output voltage range, the control method selector outputs a constant modulation index mq and a variable reference voltage (uDCref). The voltage controller outputs the modulation index md of the modulation signal m. Furthermore, the control method selector can include a rate limiter for limiting the change rate of the reference voltage (uDCref). In connection with the control method selection and/or the rate limiter, a decoupling control for making the voltage and current control loops independent from each other can be used. The controllers find particular application in transformerless reactive series compensators for single-phase or three-phase control.
摘要:
A controller for generating a modulation signal m applied to a transformerless reactive series compensator connected serially in a power transmission line. A modulation signal generator generates a modulation signal m in the form of m=md cos (&ohgr;t)−mq sin (wt). The controller includes a current control loop with a current controller outputting the modulation index mq of the modulation signal m. A voltage control loop including a DC voltage controller outputs the modulation index md, of the modulation signal m. The current control loop and the voltage control loop are respectively provided for outputting indices mq′, md′ in order to control a line current and a DC capacitor voltage of a capacitor of the compensator to reference values. The controller includes a decoupler so that the line controller and the capacitor voltage are independent of the output of the current controller. Therefore, the amplitude of the line current and the magnitude of the DC capacitor voltage can be controlled completely independently from each other, i.e., the control loops are decoupled.
摘要:
The invention relates, inter alia, to a method in which, by reducing the spectral power density in an underfrequency range (UB) of a transmitting/receiving unit, the fact that the underfrequency range (UB) should not be used to send data is indirectly transmitted. This method is particularly suitable for xDSL processes.
摘要:
A procedure is introduced to test the functional capability of a secondary air system of an internal combustion engine, wherein values of a pressure are acquired, which arises in the secondary air system between the secondary air pump and a secondary air flow cross section, which can be controlled, when the secondary air pump is activated and the actuation of the secondary air flow cross section is increased; in that a measurement for the pressure is developed from the acquired values and is compared with a set point value, and the functional capability of the secondary air system is assessed as a function of a result of the comparison. The procedure characterizes itself in such a way, that in a secondary air system, whose secondary air flow cross section is controlled by two secondary air valves, wherein one of the two secondary air valves is actuated to close, while the other one of the two secondary air valves is actuated to open, and the assessment of the functional capability for a section of the secondary air system occurs in the section, in which the secondary air valve actuated to open is disposed. In addition a control unit is introduced, which controls the sequence of such a procedure.
摘要:
The invention relates, inter alia, to a method in which, by reducing the spectral power density in an underfrequency range (UB) of a transmitting/receiving unit, the fact that the underfrequency range (UB) should not be used to send data is indirectly transmitted. This method is particularly suitable for xDSL processes.