This awesome bit of gearing has appeared on HowStuffWorks just before. You could understand it from the electrical screwdriver short article. An automatic transmission is made up of two complete planetary gearsets folded alongside one another into just one element. See How Gear Ratios Do the job for an introduction https://gunnerrwwxw.eedblog.com/34248088/gearbox-auto-no-further-a-mystery