Operating device and control method, especially for LEDs

Abstract

Control gear, in particular designed for dimmable operation of light sources (2), wherein the operating device in a clocked converter circuit (1) with at least one switch (S) supplies a load current (I last ) generated, and a control circuit (5) designed to control at least one switch (S) in a gap operating mode or a limit operating mode, wherein the control circuit (5) is configured to set a predetermined average load current by closing the switch (S) at a switch-on time from a set of discrete possible switch-on times and opening the switch (S) at a switch-off time, and wherein the control circuit (5) is set up to determine the switch-off time based on a corrected peak current (I pk_korr ) to determine, where the corrected peak current (I pk_korr ) is determined by the control circuit (5) In a first correction step, the switch-on time is selected by determining a compensated peak current (I). pk_komp ) compensates, and in a second correction step using a correction value (ΔI) pk ), which is based on a deviation of a measured average load current (I mess_avg ) to a given average load current (I avg_nom ) is calculated, the compensated peak current (I pk_komp ) corrected to achieve the corrected peak current (I pk_korr ) to determine, and wherein the control circuit (5) is set up to calibrate the output control variable with a gain factor depending on the current setpoint of the specified average load current, characterized by the fact that the control circuit (5) is set up, the amplification factor based on a gradient of a peak current (Ipk) as a function of the average load current (I) avg) to determine the current target value of the average load current.

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