What is Engine speed sensor in vehicle?

An engine speed sensor is needed to provide an input for the electronic controller for several functions. The reluctance sensor can be used to measure engine speed. The four tabs will pass through the sensing coil for each crankshaft revolution. We count the pulses of voltage from the sensing coil in one minute and divide by four, we will know the engine speed in revolution per minute. An electronic circuit is used to start and stop the counter circuit. The counter can be used to count the number of pulses through a special signal processing circuit.