The goal of the project is to design a contactless speed sensing device (tachometer) for a Brushless DC (BLDC) motor. The traditional tachometers require a physical contact to the shaft of the motor to measure the speed. In specific applications, where it isn’t feasible to measure the speed for safety and technical reasons, it is possible for a contactless tachometer to take the readings from a certain distance.
This proposed framework utilizes the IR transmitting and receiving the technique. This is accomplished by receiving IR rays from a reflecting on the shaft of the motor. Such courses of action can measure the rate at which the IR rays are getting reflected back. The project utilizes a microcontroller of 8051 family.
A pair of sensors (Transmitter and receiver) is utilized to develop a pulse for every reflection that sends an interrupt to the microcontroller. The timer of the controller calculates the speed by each pulse received in a specific time interval and displays the same. The microcontroller is interfaced with an LCD to display the speed.
The idea of the contact-less tachometer can be enhanced and implemented in the bicycles, autos for speed measurement, avoiding from the utilization of traditional analog speedometer.