Abstract: A method for controlling an electric motor by using the PWM technique including the steps of: applying to the clamps of the electric motor an electric voltage varying in time, which displays a square waveform and consists of a sequence of pulses having a uniform wave period and a variable width; adjusting the average value of the electric voltage by varying the width of the pulses; determining the overall required width variation; subdividing the overall required width variation in a determined number of partial variations, the overall sum of which is equivalent to the overall required width variation; and gradually varying the width amplitude of the pulses of the electric voltage by applying in a sequence a corresponding partial variation to each pulse, so that the difference between the width amplitude of a pulse and the width of a following pulse is equivalent to the corresponding partial variation.

Abstract: A method for controlling an electric motor by using the PWM technique; the control method includes the steps of: applying to the clamps of the electric motor an electric voltage varying in time, which displays a square waveform and consists of a sequence of pulses having a uniform wave period and a variable amplitude; adjusting the average value of the electric voltage applied to the clamps of the electric motor by varying the amplitude of the pulses of the electric voltage; determining, in the case of a variation of the amplitude of the pulses, the overall required amplitude variation; subdividing the overall required amplitude variation in a determined number of partial variations, the overall sum of which is equivalent to the overall required amplitude variation; and gradually varying the amplitude of the pulses of the electric voltage by applying in a sequence a corresponding partial variation to each pulse, so that the difference between the amplitude of a pulse and the amplitude of a following pulse is

Abstract: A system for diagnosing a driver and detecting circuit anomalies therein includes: voltage comparator circuits for generating diagnostic logic signals, each of which indicates the existence of a corresponding type of anomaly; and a coding circuit to receive the diagnostic logic signals and to output information relating to an overall operating state of the driver. The coding circuit includes a first portion to provide at its output first logic input signals indicating the last anomaly to occur since a system reset operation. The coding circuit also includes a second portion for coding the first logic input signals. The second portion includes a sequential logic network to receive the first logic input signals and at least one second logic signal indicating the current operating phase of the driver. The second portion provides, as a function of the first and second logic signals, a stable internal state to determine the output information in the form of an N bit coded word.