Design and Implementation of a Digital Tachometer

Tachometer is a measuring instrument used for measuring the speed of a rotating body. The unit of measured speed by tachometer is expressed in revolution per minute or RPM. Tachometers were purely mechanical in past. In that time, the speed measuring parameters were sent to the tachometer through mechanical coupling (cable or shaft) and the rpm is measured using a gear mechanism and it is identified using needle mechanism. The tachometers have changed a lot due to rapid development of modern electronics. This article is for a contactless digital tachometer using Arduino. Here the speed of the motor is also controlled. The RPM, the duty cycle and other information are displayed on a LCD screen