OPTICAL TENSION TRANSDUCER :AB
Original Publication Date: 1985-Sep-01
Included in the Prior Art Database: 2005-Feb-19
Illustrated is a transducer providing an output voltage proportional to applied tension. The device consists of a combination tension arm with optical flag 10, a spring 11, two light sensors 12 and 14, two light sources 13 and 15, a summing amplifier 16 and a difference amplifier 17. A force is applied by the spring 11 to the tension arm 10 so as to pull against an externally applied tension. An integral part of the tension arm is a flag having a position that can be sensed optically as the applied tension varies. The flag position is sensed by two source- sensor pairs such that only half of the available light from each source reaches its respective sensor when nominal tension is applied.