Measuring speed revs. of electric motor supplied with clocked drive voltage

摘要

The evaluation within respectively one interruption, begins at a specified time, following the switching off of the operating voltage. The evaluation results by measuring the voltage, with the measurement extending over a further specified time within the interruption, so that several so obtained measurement values are determined. A frequency analysis is carried out on the voltage at the electric motor (1), occurring during the interruption. The operating voltage is pulsed with a frequency of approximately 10 kHz and after respectively approximately 50 ms is interrupted for 5ms.