| 摘要 |
1. Circuit arrangement for a cyclically absolute measuring system comprising a position sensing transformer for determining the relative position of two parts which can be moved with respect to one another, with a digital sine/cosine generator which supplies pulse-width-modulated rectangular voltages for the sine and cosine windings of the position sensing transformer, at the output windings of which an alternating voltage is picked up which is supplied via filters to a detector which generates, for zero calibration, a calibration signal from the amplitudes of this alternating voltage which signal is supplied to a pulse and signal generator which supplies pulses for correcting the digital sine/cosine generator, characterized in that a test generator (17) is provided which, during continuous measurement, interrupts the control loop for the zero calibration during a short test period, at the same time supplies at least one signal (AB, BD) to the digital sine/cosine generator (5) which leads to a predetermined deviation from the instantaneous position, and in that a fault analysis logic (22) is provided which samples the calibration signal produced by the deviation in the detector (11) and outputs a fault signal when the calibration signal drops below and/or exceeds fixed signal levels. |
