a circuit arrangement for monitoring the operation of an electronic yarn clearer on an automatic yarn winding machine and particularly for monitoring the operation of the output relays and yarn cutting device of the yarn clearer . logic circuitry is provided for combining the output signals of the yarn clearer circuitry and produces control and / or alarm signals when the cutting device fails to sever the yarn upon appearance of a cutting pulse , i . e . when a yarn travel signal is permanently present during a predetermined time interval commencing with the start of said cutting pulse .