TRANSDUCER OF ROTATIONAL SPEED Russian patent published in 1999 - IPC

FIELD: measurement technology. SUBSTANCE: transducer is meant to convert rotational speed of driving shaft to frequency of electric pulses, specifically, in system measuring speed of automobile. Transducer incorporates multipolar magnet put on drive shaft and comparator of magnetic induction. Magnet is made in the form of ring from magnetically hard material and has radially magnetized heteropolar zones. Sensitive element is placed above circular surface of magnet. Transducer is provided with concentrator of magnetic induction in the form of bent plate produced from magnetically soft material. One part of plate is located above sensitive element and its other part is provided with window or groove embracing drive shaft. Shaft is magnetic circuit. Comparator of magnetic induction has unipolar switching thresholds and magnet has heteropolar zones with different magnetization. EFFECT: simplified design of transducer, reduced dimensions and cost of it. 1 cl, 4 dwg