LED operating assembly (1, 2, 3) for operating a plurality of serially connected LED arrays (LEDi, i = 1...n) respectively having a first and a second terminal, comprising a supply voltage (VN, VGL) connected with the series connection of said LED arrays (LEDi, i = 1...n); a plurality of circuit arrangements each of which comprising: one of said LED arrays (LEDi, i = 1...n), a bypass arrangement (20, i = a...n-1), comprising a first and a second bypass terminal (A2, A1) as well as at least one control terminal, wherein said first bypass terminal is connected with the first terminal of said LED array (LEDi, i = 1...n) and wherein said bypass arrangement (20i, i = a...n1) is designed as a controllable resistor; a current sensor (100a... n-1), wherein said current sensor (100a... n-1) includes an output for delivering an output signal, and wherein said current sensor (100a... n-1) is disposed on the downstream side of the current flow of said LED array and is configured for detecting the current flow through said LED array (LEDi, i = 1...n); and wherein said control terminal of the bypass arrangement (20i, i = a...n-1) is connected with the output of said current sensor (100a... n-1) and said controllable resistor is adjustable on the basis of said output signal in such a manner that the bypass arrangement is operable in a first operating state, which bridges said LED array (LEDi, i = 1...n), in a further operating state, which does not bridge said LED array (LEDi, i = 1...n), or in intermediate operating states between said first operating state and said second operating state; characterized in that said circuit arrangements are connected in series, wherein in each circuit arrangement said current sensor (100a,... n-1) is connected in series with said LED array (LEDi, i = 1...n) so that the current detected by said current sensor (100a... n-1) is the current through said bypass arrangement (20i, i = a...n-1) and said LED array (LEDi, i = 1...n). one of said LED arrays (LEDi, i = 1...n), a bypass arrangement (20, i = a...n-1), comprising a first and a second bypass terminal (A2, A1) as well as at least one control terminal, wherein said first bypass terminal is connected with the first terminal of said LED array (LEDi, i = 1...n) and wherein said bypass arrangement (20i, i = a...n1) is designed as a controllable resistor; a current sensor (100a... n-1), wherein said current sensor (100a... n-1) includes an output for delivering an output signal, and wherein said current sensor (100a... n-1) is disposed on the downstream side of the current flow of said LED array and is configured for detecting the current flow through said LED array (LEDi, i = 1...n); and wherein said control terminal of the bypass arrangement (20i, i = a...n-1) is connected with the output of said current sensor (100a... n-1) and said controllable resistor is adjustable on the basis of said output signal in such a manner that the bypass arrangement is operable in a first operating state, which bridges said LED array (LEDi, i = 1...n), in a further operating state, which does not bridge said LED array (LEDi, i = 1...n), or in intermediate operating states between said first operating state and said second operating state; characterized in that said circuit arrangements are connected in series, wherein in each circuit arrangement said current sensor (100a,... n-1) is connected in series with said LED array (LEDi, i = 1...n) so that the current detected by said current sensor (100a... n-1) is the current through said bypass arrangement (20i, i = a...n-1) and said LED array (LEDi, i = 1...n).