PROCEDIMENTO PER COMANDARE UN MOTORE ASINCRONO.

摘要

The drive is for the compressor of a domestic refrigerator or freezer. The circuit employs the fact that the maximum efficiency of a given asynchronous motor always lies at the same speed independent of the loading. The subsidiary regulating circuit for the motor (1) measures the slip frequency of the motor and uses a signal derived from this value to regulate the voltage applied to the machine to keep the slip at a set value. The slip may be evaluated from the motor current measured in a resistor (4), and the required slip component extracted by a low pass filter (6).