Atmel Germany Gmbh

C-max Europe Gmbh

Atmel Corporation

Horst Haefner

Roland Polonio

Hans-Joachim Sailer

Hans-Peter Waible

Wolfgang Roeper

Reinhard Reimann

Juergen Schnabel

Burkhard Gehring

Hermann Hammel

Friedemann Schmidt

Thorsten Fahlbusch

Gerald Krimmer

Juergen Eckert

Michael Vogt

Hans-Werner Groh

Michael Hecker

Wolfgang Schneider

A method for extracting time information from a received, amplitude-modulated time signal is provided. The method provides that the time signal is demodulated, the analog signal thus obtained is digitized by a comparator, and the digital signal thus obtained is analyzed to extract the time information. In addition, a characteristic value of the time duration of at least one signal phase of a specific signal level of the digital signal is compared to a target value, and a comparator threshold of the comparator is altered as a function of a result of the comparison such that the time duration of at least the applicable signal phase of the digital signal approaches the target value. In this way, an improved system sensitivity is achieved according to the invention in a receiver for receiving time signals. In particular, the frequency of occurrence of errors due to misreading of pulse lengths is reduced here, and distorted received signals are better detected as being distorted on account of their temporal deviation from the applicable target value. In addition, compensation of manufacturing tolerances of the various components in the described circuit arrangement is possible.

Radio clock and method for extracting time information

Time signals transmitted by a time signal transmitter and received by a receiver are processed for gaining time information and for reducing demodulation errors to increase the demodulation certainty. For this purpose the following steps are performed in a time signal receiver: a) scanning of received time signals, b) storing of scanned values of the time signal, c) detecting from the scanned and stored values an amplitude change in said time signal, d) measuring the duration of any detected amplitude changes, e) evaluating the measured time durations relative to a predetermined time duration (&#x394;t) and f) excluding from further processing amplitude changes that have a measured duration that is shorter than the predetermined duration. Amplitude changes of longer duration than (&#x394;t) are demodulated and further processed. The receiver circuit is equipped to perform the foregoing steps, particularly in a radio-controlled clock.

Method for gaining time information and receiver for implementing the method

Time signals for controlling a radio clock are transmitted by a transmitter and received by a receiver as amplitude modulated time signals, formed of a multitude of time frames. Each time frame has a constant duration. These time signals are first automatically amplified. A so-called telegram of at least one received time signal is stored in a memory. At least one change of an amplitude of a time signal is determined in advance or predetermined and such amplitude change has a duration that is longer than a given or determined duration (&#x394;t). When a predetermined amplitude change begins the automatic amplification is locked-in. The present circuit arrangement for operating a radio-controlled clock is equipped with components for performing the foregoing operations.

Radio-controlled clock and method for gaining time information

A d.c. signal controlled oscillator includes a frequency-determining network having a control input and a modulation input. A phase regulating loop includes the oscillator and components that provide a control signal to the control input. A circuit apparatus for driving the oscillator includes a modulation generator that provides a modulation signal to the modulation input, and a circuit arrangement that autonomously generates a signal depending on and representing a slope of the modulation and provides this slope signal to the modulation generator, which generates the modulation signal dependent on the slope signal. A method of operating the oscillator involves switching a frequency divider successively to two different frequencies, respectively sampling and holding the two different arising control voltages, forming a difference between the two control voltages, and activating the modulation generator so that a modulation swing of the modulation signal is determined by this difference between the control voltages.

Method and apparatus for driving a direct current or voltage controlled oscillator with modulation slope feedback

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Heilbronn, Germany

Horst Haefner