LOAD DRIVE CIRCUIT, LOAD DRIVE METHOD, AND LUMINAIRE

摘要

A load drive circuit may include a DC power source configured to provide a DC output voltage for at least one load based on an output voltage of an AC/DC converter, the DC output voltage having a ripple, a variable resistance module connected to the load, a ripple reduction module that generates, based on a reference voltage and a feedback signal from the load, a variable resistance adjusting signal for adjusting the resistance of the variable resistance module so as to reduce a ripple of the load current, wherein the reference voltage is generated based on the DC output voltage, and a reference voltage adjusting module that adjusts the average value of the reference voltage based on the variable resistance adjusting signal, so as to make the average value of the reference voltage approach the average value of the feedback signal as much as possible.

主权项

1. A load drive circuit comprising:
a DC power source configured to provide a DC output voltage for at least one load based on an output voltage of an AC/DC converter, the DC output voltage having a ripple; a variable resistance module to be connected to the at least one load; a ripple reduction module configured to generate, based on a reference voltage and a feedback signal from the at least one load, a variable resistance adjusting signal for adjusting the resistance of the variable resistance module so as to reduce a ripple of a load current flowing through the at least one load, wherein the reference voltage is generated based on the DC output voltage; and a reference voltage adjusting module configured to adjust the average value of the reference voltage based on the variable resistance adjusting signal, so as to make the average value of the reference voltage approach the average value of the feedback signal as much as possible, wherein the ripple reduction module is configured to increase the variable resistance adjusting signal when a difference between an instant value of the reference voltage and an instant value of the feedback signal becomes larger and to decrease the variable resistance adjusting signal when the difference between the instant value of the reference voltage and the instant value of the feedback signal becomes smaller; and the variable resistance module is configured so that the resistance value of the variable resistance module becomes smaller when the variable resistance adjusting signal becomes larger and the resistance value of the variable resistance module becomes larger when the variable resistance adjusting signal becomes smaller, wherein: the reference voltage adjusting module is configured to decrease the average value of the reference voltage when a difference between a maximum value of the variable resistance adjusting signal and a reference value is higher than a predetermined threshold or when a difference between a maximum value of the variable resistance adjusting signal and a reference value is larger than a difference between the reference value and a minimum value of the variable resistance adjusting signal, and to increase the average value of the reference voltage when a difference between the reference value and a minimum value of the variable resistance adjusting signal is higher than the predetermined threshold or when the difference between the maximum value and the reference value is smaller than the difference between the reference value and the minimum value.