An operating device for a light emitting means, the light emitting means comprising at least one light emitting diode, the operating device comprising: an emergency driver having terminals for at least one battery to provide emergency power supply, the emergency driver comprising an inductance, wherein the emergency driver is configured to store energy in the inductance and to release energy from the inductance to the light emitting means such that the emergency driver operates as a buck converter if an output voltage of the at least one battery is greater than an operating voltage of the light emitting means and the emergency driver operates as a boost converter if the output voltage of the at least one battery is less than the operating voltage of the light emitting means, wherein the emergency driver comprises a plurality of controllable switches (21, 22, 31-34; 21, 22, 31, 32a, 32b, 33, 34; 61-64; 21-23), and wherein the operating device comprises a control circuit configured to generate control signals for the plurality of controllable switches (21, 22, 31-34; 21, 22, 31, 32a, 32b, 33, 34) which depend on whether the operating voltage of the light emitting means is greater than or less than the output voltage of the at least one battery for selectively operating the emergency driver either as the buck converter or as the boost converter, characterized in that the control circuit is configured to cause at least one switch (21, 22) of the plurality of controllable switches (21, 22, 31-34; 21, 22, 31, 32a, 32b, 33, 34) to perform a plurality of switching cycles to store energy in the inductance and/or to release the energy from the inductance to the light emitting means both when the emergency driver is operated as the buck converter and when the emergency driver is operated as the boost converter. an emergency driver having terminals for at least one battery to provide emergency power supply, the emergency driver comprising an inductance, wherein the emergency driver is configured to store energy in the inductance and to release energy from the inductance to the light emitting means such that the emergency driver operates as a buck converter if an output voltage of the at least one battery is greater than an operating voltage of the light emitting means and the emergency driver operates as a boost converter if the output voltage of the at least one battery is less than the operating voltage of the light emitting means, the emergency driver operates as a buck converter if an output voltage of the at least one battery is greater than an operating voltage of the light emitting means and the emergency driver operates as a boost converter if the output voltage of the at least one battery is less than the operating voltage of the light emitting means, wherein the emergency driver comprises a plurality of controllable switches (21, 22, 31-34; 21, 22, 31, 32a, 32b, 33, 34; 61-64; 21-23), and wherein the operating device comprises a control circuit configured to generate control signals for the plurality of controllable switches (21, 22, 31-34; 21, 22, 31, 32a, 32b, 33, 34) which depend on whether the operating voltage of the light emitting means is greater than or less than the output voltage of the at least one battery for selectively operating the emergency driver either as the buck converter or as the boost converter, characterized in that the control circuit is configured to cause at least one switch (21, 22) of the plurality of controllable switches (21, 22, 31-34; 21, 22, 31, 32a, 32b, 33, 34) to perform a plurality of switching cycles to store energy in the inductance and/or to release the energy from the inductance to the light emitting means both when the emergency driver is operated as the buck converter and when the emergency driver is operated as the boost converter.