Disclosed are methods and apparatus for translating data within a cable network between a first voice-over-IP protocol used by a user agent and a second VOIP protocol used by a call management server, or other type of call receiver. With a main circuit in steady mode, IGBT of an auxiliary circuit are controlled and the energy of an electric current is stored in a resonant inductance. A single spatial light modulator could serve for all component colors, with multiplexed color channels.