Patent ID: 6169378
Filing Date: 2001-01-02
Classification: H02P

Abstract:
An arrangement comprising an electronically commutated motor, a first rectifier connected to AC mains, a DC link having an input connected to an output of said first rectifier and an output which supplies windings of said motor, during operation, with a first DC voltage of over 100 V, further comprising a power supply subcircuit including a transformer, having a primary winding coupled to said AC mains and a secondary winding, and a second rectifier, said secondary winding of said transformer supplying electronic elements of the motor, via said second rectifier, with a second DC voltage lower than said first DC voltage, further comprising a user interface for controlling the motor, this user interface being galvanically separated from the motor and being associated with a current supply that is galvanically separated from the motor, said user interface comprising a comparator device which is supplied with a fluctuating DC voltage generated by rectifying a mains-dependent AC voltage, said fluctuating DC voltage being compared with a predetermined signal, in order to generate a pulse-width-modulated (PWM) signal whose duty ratio is defined by the predetermined signal, said user interface including a device for galvanically separated transmission of this pulse-width-modulated signal from the user interface to the motor.