Running yarn monitor - has voltage divider to set limits for automatic tolerance range adjustment after a start-up

摘要

The monitor for the running yarn at a textile machine, partic a ply twister, has a voltage (22) which determines the upper and lower voltage limits after the start-up phase. This is applied to the output signal of the yarn tension sensor through a delay unit (13). Pref the monitoring signal is passed through a second delay unit (14) to each input of the two comparators. The time constant of the second delay unit (14) is less than the time constant of the first delay unit (13). To determine the tolerance range, on a start-up, a delayed version of the electrical voltage is formed and a percentage portion of the delayed voltage establishes the upper and lower eg limits of the yarn tension band. ADVANTAGE - The tolerance range is automatically adjusted to the yarn tension, at the start of the machine.