Adjustable film resistor with fuse action - has parallel cuts forming major sector of circle on cylindrical surface to produced narrow fusible section

摘要

The adjustable film resistor has parallel cuts made in the film, affecting its resistance. They run transversally across a part of the film periphery, and their lengths are different. The above cuts (3) produce narrow sections (b1, b2) in the resistive film (1) staggered along the layer (1) length. At least one narrow section (b1) is smaller than the others (b2) and than the shortest distance between the cuts (3), providing the required fuse action.