Well? They seem quite advanced for WWII technology. I can’t quite figure out how they work.
Basically, the early homing torpedoes had four hydrophones in the nose, which would “hear” noise. If the hydrophone on the right side was receiving more noise than the left, the torpedo would turn right until the left and right hydrophones were receiving equal amounts of noise. The steering controls used the technology of the time, which was a basic vacuum tube processor.