摘要:
A DC voltage converter and a method for converting a DC voltage into a plurality of output-side DC voltages are disclosed. A reference variable for a control loop is provided at one output, while a respective threshold value comparison is carried out at the other outputs. An energy store at the input of the DC voltage converter can be changed over to different output branches in a manner dependent on the threshold value comparison. The energy store is driven using the control loop. The proposed principle makes it possible, with a high degree of efficiency, to provide various DC voltages with little crossover influence between the outputs and, at the same time, with constant output voltages.
摘要:
In a method for qualification of the transmission quality of a frequency channel in a wire-free communication system that has two or more frequency channels, units in the system communicate via the frequency channels. Data is transmitted in time slots in a time pattern using a time slot method. The influence of possible interference sources is determined in a measurement time slot in which no data is received, in that the field strength is measured at the frequencies of two or more frequency channels, and the field strength information is used for qualification decisions relating to the frequency channels.
摘要:
A digital GMSK filter for use for frequency modulation of a carrier signal in a GMSK transmission system is described. The GMSK filter uses a large number of individual current sources, whose current values are individually weighted. The current sources are driven via a control logic module using a shift register with a thermometer code, such that this results in a total current with a Gaussian characteristic, which is converted across a resistor to a voltage and drives a voltage controlled oscillator (VCO). The filter provides exact implementation of the sample values, virtually without any quantization error, and requires only a small chip area for its implementation.
摘要:
The invention relates to a method and an apparatus for preventing interference, particularly in telecommunications systems operating in burst mode, where the interference arises particularly when the signal has a signal level below a threshold level value and/or the signal has a constant amplitude over time. An artificial interference signal having at least one interference signal frequency is added in the processing path in the system so that the signal level exceeds the threshold level value or at least one amplitude that is constant over time is prevented.
摘要:
A digital telecommunication facility has a base station and one or more cordless mobile units that communicate with the base station through a TDMA process. The mobile units and the base station change the transmitting/receiving frequency within which they communicate only once per TDMA frame and the retain the new transmitting/receiving frequency for a time corresponding to an entire TDMA frame.
摘要:
A digital telecommunications system has a base station and one or more wireless mobile parts. The mobile parts and the base station communicate according to the TDMA method. The frames of the TDMA method used in the telecommunications system have time slots of different lengths alternately succeeding one another within a TDMA frame.
摘要:
A control circuit (1) for an electronically commutated, direct current motor (M) without a collector with a semiconductor end stage (2) which is controlled by an electronic commutation control (4) via a driver stage (6) for the time-offset control of the stator coils (U,V,W) of the motor (M) for the purpose of producing a magnetic rotating field for a rotor depending on the rotor rotation position. Two redundant stall protection units (10, 12) monitor the motor (M) during operation for rotation of the rotor, whereby in the case of a determined stall situation, the first stall protection unit (10) deactivates the driver stage (6) and the second stall protection unit (12) shuts off the supply voltage (UVCC) for the driver stage (6).
摘要:
A frame structure for transmitting data over a digital interface has a plurality of data frames. In this plurality of data frames a first sampling data frame is based on at least one sampling word and dedicated to a first logical channel. A set of data frames follows the first sampling data frame and carries in a compressed format a plurality of predefined status data words dedicated at least to the first logical channel. A first further sampling data frame follows the set of data frames. It is based on at least one further sampling word and dedicated to the first logical channel.
摘要:
A DC voltage converter is provided that cyclically converts an input-side supply voltage into an output voltage. The converter includes an inductive storage element connected between a terminal for the supply voltage and, in a manner such that it is coupled via a first switch, a reference potential terminal. The capacitively buffered output voltage terminal is connected, via a second switch, between the inductive storage element and the first switch. Provision is furthermore made of a third switch, which is intended to selectively short the inductive storage element that is connected in parallel and is controlled by a control circuit. The control circuit is controlled, on the input side, by a control voltage that is tapped off at the second terminal of the inductive storage element.
摘要:
A DC voltage converter is provided that cyclically converts an input-side supply voltage into an output voltage. The converter includes an inductive storage element connected between a terminal for the supply voltage and, in a manner such that it is coupled via a first switch, a reference potential terminal. The capacitively buffered output voltage terminal is connected, via a second switch, between the inductive storage element and the first switch. Provision is furthermore made of a third switch, which is intended to selectively short the inductive storage element that is connected in parallel and is controlled by a control circuit. The control circuit is controlled, on the input side, by a control voltage that is tapped off at the second terminal of the inductive storage element.