Patent ID: 6388906
Filing Date: 2002-05-14
Classification: H02M

Abstract:
A regulator system comprising:(a) an electrical system comprising a power supply for inputting an input alternating-current waveform having a peak voltage to be regulated and a phase modulated synchronous rectifier circuit coupled to the power supply for rectifying the current therefrom; (b) a ramp generator coupled to the electrical system for generating a linear ramp cycle between a minimum and a maximum ramp voltage; (c) a zero crossing detector coupled to the ramp generator for detecting zero crossings of the input alternating-current waveform and synchronizing the linear ramp cycle of the ramp generator with the input alternating-current waveform; (d) a peak voltage detector connected to the ramp generator, said peak voltage detector storing the maximum voltage reached by the ramp generator; (e) a resistive divider connected to the peak voltage detector for reducing the peak detector voltage to a scaled voltage value corresponding to a position in time on the input alternating-current waveform below the peak voltage; (f) a timing window comparator connected to the ramp generator and the resistive divider, said timing window comparator comparing the scaled voltage value with the instantaneous value of the ramp voltage to establish a time window signal; (g) a conduction angle ramp generator for generating a conduction ramp cycle between a maximum and a minimum conduction ramp voltage, said conduction ramp cycle being synchronized with the time window signal and the zero crossing detector so that the maximum conduction ramp voltage starts at the beginning of the time window signal and the minimum conduction ramp voltage occurs at the next zero crossing of the input alternating-current waveform; (h) an error amplifier connected to the power supply, said error amplifier averaging the output voltage on the power supply to an average output voltage and comparing the average output voltage to a reference voltage to generate an error voltage; and (i) an output comparator connected to the conduction angle ramp generator and the error amplifier, said output comparator comparing the error voltage to the value of the conduction ramp voltage to generate an output comparator output, said output comparator output being connected to the rectifier circuit to activate the rectifier circuit at selected times during the input alternating-current waveform.