CIRCUIT ARRANGEMENT FOR CONTROLLING A LED UNIT AND METHOD OF OPERATING THE SAME

摘要

A circuit arrangement (3, 3′) for controlling the brightness of at least one LED unit (2) is provided, comprising an input (8) for receiving a phase-cut operating voltage from a power supply (4), a signal processor (14, 14′), connected with said input (8) and adapted to provide a dimming signal (12) for said at least one LED unit (2) from said operating voltage. To allow an efficient reduction of noise in the dimming signal (12) but simultaneously to allow an improved dimming of said LED unit (2), said signal processor (14, 14′) is being configured to operate at least in a noise suppression mode (30) and a dimming mode (31). A control device (15, 15′) is provided, connected with said signal processor (14, 14′) and configured to set the mode of said signal processor (14, 14′) in dependence of the variation in said operating voltage.

主权项

1. A circuit arrangement for controlling the brightness of at least one LED unit, comprising
an input for receiving a phase-cut operating voltage from a power supply, a signal processor, connected with said input and adapted to provide a dimming signal for said at least one LED unit from said operating voltage, said signal processor being configured to operate at least in a noise suppression mode and a dimming mode and a control device, connected with said signal processor and configured to set the mode of said signal processor in dependence of the variation in said operating voltage, and to determine said variation by comparing said operating voltage with a reference signal; wherein said reference signal corresponds to said dimming signal.