Power module for electronic control of a dc motor

Claim 1

A power supply module for electronic control of a pulse-operated motor, said module comprising, in succession: an input filter providing an output; a bidirectional current supply module delivering a voltage pulse of variable duration derived from a nonregulated voltage source and accompanied by a current of controlled amplitude; a bridge stage having bidirectional switches and associated diodes, said bridge stage having first and second terminals each coupled to a pair of said switches, with diagonally opposite ones of said switches being simultaneously excited, said switchs being connected to one winding of said motor, a current flowing in said winding being a parameter to be regulated by comparison with a sine wave type reference value; a source of clock signals; an error amplifier receiving a current reference value as one input and a current value from said bridge as another input; a current control cell connected to the current supply module and receiving a signal from said clock, a signal from said output of said input filter, and a signal from said error amplifier; a DC-DC converter connected to the output of the input filter for ensuring that auxiliary voltages and controlling clock signals are well distributed; said current supply module generating a pulse of variable duration τ which is applied to said first bridge stage terminal for providing in said winding a triangular current waveform varying between a minimum value and a maximum value, which waveform, within each period, comprises first and second linear portions of opposite slope, the first portion having the form (V-Vo)t/L during charging, and the second portion having the form -(Vo)t/L during discharging, the amplitude of said triangular current being controlled by controlling said duration τ.