A supply circuit adapted to provide a continuous power supply for a string of serially connected light emitting elements driven with a current source, said supply circuit including: a voltage supply capacitor connected to said string and being adapted to provide a supply voltage for a driving control unit configured to control the light emitting elements of said string; and a capacitor bypass switch connected in parallel with said voltage supply capacitor and being controlled by a local control circuit of said driving control unit, wherein said capacitor bypass switch is switched off by said local control circuit to charge said voltage supply capacitor with a charging current to maintain a continuous power supply without disturbing the current to said string of light emitting elements.