Blower motor control unit null of air conditioner for automobile

摘要

PURPOSE:To make a blow quantity constant even when a ventilation resistance is changed by detecting the revolution number of a blower motor, determining the difference from a desired revolution number, compensating an output signal of a desired revolution number setting means corresponding to the difference, and driving the blower motor by a compensated signal. CONSTITUTION:A desired revolution number of a blower motor 2 is sent from a desired revolution number setting means 100 to a revolution number compensating means 120. In the meantime, an actual revolution number of the blower motor 2 detected by a revolution detecting means 110 is inputted to a compensating means 120. The compensating means 120 determines the difference between the desired revolution number and the detected revolution number, and compensates the output signal of the desired revolution number setting means 100. A compensated signal is outputted to a drive means 130, and the drive means 130 drives the blower motor 2 based on this input signal. In this constitution, if a ventilation resistance changes to change the revolution number, the desired value is compensated to absorb it, thereby the blow quantity can be kept constant.