A device for supplying electricity to at least one secondary electric load (30) on-board a turbomachine rotor (12) including a main circuit for transmitting main electric power to at least one main on-board electrical load (16), includes a device (15) for rotatably and electrically connecting the stator and the rotor, and at least one secondary circuit for transmitting a secondary electric power including at least one secondary conductor (28) of the stator connected to a secondary electric power source (29) suitable for outputting a secondary power in the form of a power signal with a secondary frequency selected such as to enable selective, interference-free transmission of the secondary power via the rotary electric connection device (15), separately from the main power transmission.