In this paper, the use of input current shaper converters (ICSCs) working in discontinuous-conduction mode to stabilize the discharge arc in high intensity discharge lamps without close loop control is proposed. The analysis of how the ICSC stabilizes the lamp current, the description of the proposed topology and the design methodology are presented. Experimental results indicated the feasibility to stabilize the lamp with no close loop control and obtaining high efficiency with fewer components that conventional ballasts used for this application. Experimental results when dimming is applied are included too