Patent ID: 6490752
Filing Date: 2002-12-10
Classification: H02M,H02P

Abstract:
An inverter control circuit, suitable for use in a motor-driven blower for an electric vacuum cleaner, controlling an inverter circuit which has a plurality of switching elements and AC-drives the motor-driven blower according to periodical switching between these switching elements, based on detected value of physical quantity detecting means which detects physical quantities related to the electric vacuum cleaner, comprising:means for setting a period in which a rotation velocity of the motor-driven blower is calculated; means for performing interrupt processing including a calculation of the rotation velocity of the motor-driven blower based on the detected value of the physical quantity detecting means; and means for generating a pulse signal according to a carrier wave having a period shorter than a period in which the rotation velocity of the motor-driven blower is calculated, and longer than the time required to perform interrupt processing including the calculation of the rotation velocity of the motor-drive blower, and inputting the pulse signal into a drive circuit which drives the switching elements of the inverter circuit according to the input pulse signal.