The invention concerns a circuit arrangement for operating a high pressure discharge lamp comprising: input terminals for connection to a supply voltage source; lamp connection terminals for connection of the lamp; power supply means coupled to the input terminals for supplying a current to the lamp consisting of successive periods of current comprising pulse generating means for generating a current pulse superpositioned to periods of the current to the lamp. According to the invention, a circuit arrangement of the kind mentioned in the opening paragraph is for this purpose characterized in that the circuit arrangement is provided with means for synchronizing the pulse generation means with an image writing signal.
