| 摘要 |
1357927 Electro-physical measurement of yarn quality; measuring capacitance ASAHI KASEI KOGYO KK 31 Aug 1971 [29 Aug 1970] 40480/71 Headings GIN and G1U In a yarn thickness detector the capacitor measuring cell 10, 11 is connected in an R.F. energized bridge circuit having a controllable element such as capacitor diodes 13, 1 in the opposite arm controlled by means of D. C. bias from terminal 19 regulated by resistor 18, for ZERO ADJUSTMENT (according to required yarn thickness.) The output from the diagonal points of the bridge is rectified by diodes 64 and applied to a differential amplifier. Feedback from the amplifier is applied through a delay circuit 33 to the capacitor diodes 13, 14, or to a lamp cooperating with a photo-electric element to cancel LONG-TERM DRIFT (e.g. yarn defects which persist for 100 metres or more). Yarn thickness (as opposed to variation in thickness) may be measured by momentarily removing the yarn from between the capacitor plates and measuring the amplitude of the resultant pulse in the measuring circuit. This is accomplished Fig.2 (not shown), by a controlled S. C.R. 50 which discharges capacitor 49 through electromagnet 46 to momentarily pull down the spring-loaded yarn-guide 36. |
