Device for supplying energy to a sensor arrangement in a rail vehicle, said device having at least: - one housing in which there is arranged at least one coil which can be inductively coupled to a motor cable carrying an alternating current, wherein the housing is embodied to enclose a partial length of the motor cable, and wherein the at least one coil is wound around an annular coil core which surrounds the motor cable concentrically or substantially concentrically, - wherein the housing is implemented in multiple parts and has at least one first and one second housing part, and - wherein the annular coil core is implemented in multiple parts and at least one first coil core part is arranged in the first housing part and at least one second coil core part is arranged in the second housing part, characterised in that - the housing is further embodied to mechanically secure the motor cable to a component of the rail vehicle and/or to mechanically connect the motor cable to at least one further motor cable, - wherein at least one first voltage converter, at least one DC intermediate circuit having a DC link capacitor, at least one second voltage converter, at least one third voltage converter, at least one energy storage arrangement and at least one fourth voltage converter are arranged in at least one of the housing parts or in a further housing, - wherein the first voltage converter is connected to the at least one coil on the input side and to the DC intermediate circuit on the output side, and wherein the first voltage converter is embodied to convert an alternating voltage of the at least one coil into a direct-current voltage of the DC intermediate circuit, - wherein the second voltage converter is connected to the DC intermediate circuit on the input side and to the sensor arrangement on the output side, and wherein the second voltage converter is embodied to convert the direct-current voltage of the DC intermediate circuit into a feeder direct-current voltage, - wherein the third voltage converter is connected to the DC intermediate circuit on the input side and to the energy storage arrangement on the output side, and wherein the third voltage converter is embodied to convert the direct-current voltage of the DC intermediate circuit into a charging direct-current voltage for the energy storage arrangement, and - wherein the fourth voltage converter is connected to the energy storage arrangement on the input side and to the sensor arrangement on the output side, and wherein the fourth voltage converter is embodied to convert a direct-current voltage of the energy storage arrangement into the feeder direct-current voltage. - one housing in which there is arranged at least one coil which can be inductively coupled to a motor cable carrying an alternating current, wherein the housing is embodied to enclose a partial length of the motor cable, and wherein the at least one coil is wound around an annular coil core which surrounds the motor cable concentrically or substantially concentrically, - wherein the housing is implemented in multiple parts and has at least one first and one second housing part, and - wherein the annular coil core is implemented in multiple parts and at least one first coil core part is arranged in the first housing part and at least one second coil core part is arranged in the second housing part, characterised in that - the housing is further embodied to mechanically secure the motor cable to a component of the rail vehicle and/or to mechanically connect the motor cable to at least one further motor cable, - wherein at least one first voltage converter, at least one DC intermediate circuit having a DC link capacitor, at least one second voltage converter, at least one third voltage converter, at least one energy storage arrangement and at least one fourth voltage converter are arranged in at least one of the housing parts or in a further housing, - wherein the first voltage converter is connected to the at least one coil on the input side and to the DC intermediate circuit on the output side, and wherein the first voltage converter is embodied to convert an alternating voltage of the at least one coil into a direct-current voltage of the DC intermediate circuit, - wherein the second voltage converter is connected to the DC intermediate circuit on the input side and to the sensor arrangement on the output side, and wherein the second voltage converter is embodied to convert the direct-current voltage of the DC intermediate circuit into a feeder direct-current voltage, - wherein the third voltage converter is connected to the DC intermediate circuit on the input side and to the energy storage arrangement on the output side, and wherein the third voltage converter is embodied to convert the direct-current voltage of the DC intermediate circuit into a charging direct-current voltage for the energy storage arrangement, and - wherein the fourth voltage converter is connected to the energy storage arrangement on the input side and to the sensor arrangement on the output side, and wherein the fourth voltage converter is embodied to convert a direct-current voltage of the energy storage arrangement into the feeder direct-current voltage.