Abstract: A reader identifies coded electronic badges without contact with the latter, by simple inductive coupling of inductances, the electrical supply of the badge being ensured from a voltage at high frequency F generated by the reader. The code of the badge, composed of a sequence of bits following one another at a frequency f very much less than F, is used to modulate a voltage of intermediate frequency fi comprised between f and F and the thus modulated voltage controls an electronic switch adapted to short-circuit a resonant circuit of the badge.

Abstract: The invention relates to electronic badges equipping portable objects, such as plastified cards and capable of being identified at a distance by suitable readers in order to ensure operation such as the unlocking of a lock. These badges are of a passive type, that is to say supplied exclusively from the outside by inductive coupling and they are in addition of a type reprogrammable through channels, each comprising an inductive coupling (at the level of inductances) from a suitable apparatus. The circuitry for forming the binary coded identification signals of the badge comprise a dead memory, a life memory or buffer and a rapid reading and writing circuit which provides the connections between these two memories, as well as the connections between the dead memories and the reprogramming channels.