Concept:
The rotational speed is the physical quantity of the ratio of the number of revolutions of the rotating body to the time. It is usually expressed as the rotational speed = the number of revolutions / time, which is an important parameter describing the rotational motion of the object. Electricians often need to measure the speed of the motor and its dragging equipment, using a portable tachometer. A tachometer is a meter used to measure motor speed and line speed. There are many types of tachometers, and there are generally mechanical centrifugal tachometers and digital electronic tachometers.
working principle:
The tachometer will receive the digital pulse signal (issued by the sensor), directly read into the counting port of the cpu after processing, calculate the speed and the corresponding position of the pointer through the software, and then drive the stepping motor through the control port of the cpu. Rotate in the positive and negative directions to indicate the corresponding speed value (the pointer is directly mounted on the rotating shaft of the stepper motor), and the stepping motor takes only one-third of a step.
