s pat no 4 823 597 the teaching of which is incorporated herein by reference the doffer e and the main cylinder d are fitted with devices ap to sense angular position devices commonly used for this purpose are optical encoders and gear wheels with proximity detectors in fig1 gear wheels and proximity sensors are intended to be shown as examples and are shown on the doffer e and the main cylinder d the input rotating member is the feed roll b which is turned by a variable speed motor h to introduce the feed mat into the carding machine cm a microcomputer a is used to input information from the sliver unit weight sensor s and the shaft encoders ap process this information and finally output a variable d c voltage which is used to determine the speed of the variable speed motor h which drives the feed roll b rotating members c d and e other than the feed roll b are typically driven at fixed rates of speed once high speed production has been started a warning signal w such as a blinking red light buzzer or the like may be employed and wired in circuit to indicate an improper condition fig2 by way of a second embodiment shows a typical drafting unit du of a textile drawframe in this application the gage plate.