Abstract: A pulse train relay for relaying pulses of duration not exceeding a maximum value (141), the relay being characterized by the fact that it comprises a receiver (1) having an input (2) suitable for picking up the pulses of a train, and an output (3) suitable for delivering a signal as a function of each picked-up pulse, a transmitter (4) having a transmission-feeding first input (5), a transmission-controlling second input (6), and a transmission output (7), a first circuit (8) for connecting the output of the receiver to the transmission-feeding input of the transmitter, and a second circuit (9) suitable for delivering a control pulse (143) starting on reception of a pulse by the receiver and continuing for a duration (144) which is not less than the maximum duration of the pulses in the train, the second circuit connecting the output of the receiver to the transmission-controlling input of the transmitter.