| 摘要 |
PURPOSE:To simplify construction of a sensor by sensing a current value used in a motor for each spindle, taking out a change in current accompanying each lifting and lowering of a ring rail, discriminating yarn breakage when the change in current is zero and simultaneously sensing trouble in the motor. CONSTITUTION:A current transformer 3 is provided in one connecting lead wire 2 of a motor 1 for driving a spindle and an output voltage of a rectifier 4 is smoothed with a capacitor 5 and inputted to a comparator 6. A charging and discharging circuit is provided between a diode 7 and the comparator 6 and a relay 16 is connected to the side of a collector of a transistor 15. A normally closed contact (16b) of the relay 16 as a switch for a lighting circuit of a lamp 17 is connected. If yarn breakage occurs, a change in current by a change in yarn tension is eliminated. If the output voltage from the comparator 6, i.e., input voltage of the transistor 15 is reduced to <=0.7V, the transistor is turned off to demagnetize the relay 16. Thereby, the normally closed contact (16b) is closed to light the lamp 17. |
