Device for measuring the number of revolutions of the shaft of a permanent magnet electric motor.

摘要

The device (15) measures the number of revolutions completed by the shaft of a permanent magnet electric motor (M) in a period of time (t1) during which it is set in motion by the effect of its connection to a respective electrical supply source, essentially by means of calculation (2(5), 22, 23, 37) of the integral of the counter-electromotive force which the motor (M) develops in the aforementioned period of time. <IMAGE>