After swapping the engine out in his scooter, [James Stanley] made an unfortunate discovery. The speedometer was digitally controlled, and while the original engine had a sensor which would generate ...

30 May 2007 MASHHAD -- Iranian technicians have managed to produce the Piezo electronic speedometer sensor. Akbar Amini, the manager heading the research team, said the sensor will be used to estimate ...

In a modern car, your speedometer might look analog, but it is almost certainly digital and driven by the computer that has to monitor all sorts of things anyway. But how did they work before your car ...