U.S. Philips Corporation

Sportident Gmbh

Siegfried Ritter

Wolfgang Tobergte

Thomas Ernst Wille

Rolf Tammer

Steffen Rauer

A measuring unit which is not easily accessible often has a power source which supplies power to the elements for the measuring operation, more particularly, the conversion of an analog measured signal into digital measured data, and for storage thereof, as required. These measured data of a measuring unit are transmitted to a base station without any contact being made the moment this base station is brought into the neighborhood of the measuring unit and transmits a signal. For a minimum load on the power source power from the power source is not supplied to the transmitter for the transmission of measured data from the measuring unit to the base station. Instead, a signal transmitted by the base station provides transmission power. In the measuring unit this signal provides a voltage for feeding the transmitter. Furthermore, via tuned circuits, during an inductive coupling between base station and measuring unit, an impedance is connected to the tuned circuit of the measuring unit via a switch which is controlled by the transmitted measured data. This change of impedance can then be evaluated in the base station by evaluating the current in the tuned circuit. The signal transmitted by the base station can also be used to recharge the power source in the measuring unit.

Method and arrangement for non-contact transmission of measured values

In order to generate a non-disturbed binary output signal from a disturbed input signal, notably if the latter is periodic in the non-disturbed state, the invention proposes a circuit arrangement which includes two circuit branches which respond to different edge directions of the input signal. Each branch includes two series-connected flipflops and there is also provided a timing member which is common to the two circuit branches. As a result of a coupling of the two circuit branches to one another it is achieved that, after the triggering of one circuit branch, the other branch is blocked. Triggering of the other circuit branch is possible only after the delay time of the timing member has elapsed. It is thus achieved that the edges of the binary output signal have a minimum temporal spacing or that the binary output signal does not exceed a maximum frequency. Furthermore, a transition of the input signal is evaluated also if it occurs prior to the elapsing of the delay time. Evaluation of the signals in both circuit branches enables formation of two non-overlapping output signals.

Circuit arrangement for generating a binary output signal

The demodulation of binary amplitude-modulated carrier signals gives rise to special problems, for example in the case of contactless data carriers, because the RF signal is then also used for generating the operating voltage which is limited to a fixed value when the energy is sufficiently high. Moreover, strong interference signals are often superposed on amplitude-modulated signals. For reliable demodulation in such circumstances, therefore, a control signal is subtracted from the input signal and the values of one polarity of the difference are integrated. In order to generate the control signal, the values of one polarity of a further difference between the input signal and a further control signal which is proportional to the former control signal are continuously integrated so as to form an integral signal which is periodically reduced by a fixed fraction. The control signals are derived from said integral signal in a non-linear fashion, preferably by way of the input characteristic of a transistor.

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Arnstadt, Germany

Siegfried Ritter