To optimize engine operating conditions, accurate measurements are needed, which can be done with the help of modern instruments - electronic tachometers. Such a mechanism with high accuracy will show the angular velocity of the motor shaft, which is expressed in rpm. Using special devices, it is possible to determine the linear speed of the rotating mechanism, it is expressed in m / s. The electronic tachometer is successfully used in production during commissioning. It helps to correctly calibrate the engine and optimally configure the control system. Instrumentation and control services actively use this device in their daily work.
In addition, the electronic tachometer is successfully used in the automotive industry. It helps motorists monitor
engine speed and select the most optimal mode of operation. For example, when changing the season or in the cold / hot period, this device becomes an indispensable assistant, because it extends the life of the car.
This device has long been used in the most critical industries, where it is necessary to constantly monitor the frequency of rotation of the shaft of an electric motor, internal combustion engine, turbine, etc. In aircraft construction, an electronic tachometer is one of the main instruments that control the operation of a turbo engine. The life of the entire crew and passengers directly depends on his testimony. Failure of the tachometer can lead to disaster.
Let's look at the operation of this device as an example of a small circuit, which is easy to find on the network. Any electronic tachometer should receive information from the sensor, which measures the number of revolutions of the engine or its linear speed. This is achieved by direct contact of the moving part of the device with the motor shaft or remotely using induction or laser sensors.
In our case, 70-90 turns of PEV-1 wire wound around the main ignition wire of the car play the role of an induction sensor, which our homemade electronic tachometer uses for its work. The wire connection diagram is simple - one end of the coil goes to ground, and the other to the control circuit. The rest of the circuit consists of a trigger that selects a useful signal and transmits it to a counting device based on counters. The quantity calculated per unit time
pulses are given to the matching circuit, which makes this information understandable to a digital indicator. The operating cycle of the device is set using a multivibrator or
a pulse generator based on a quartz element.
Such an electronic tachometer can have a wide variety of options. Other solutions are also used for its implementation. The computational part may well be constructed on the basis of a microprocessor. It is good practice to write programs for its work. In this case, it is best to use microprocessors with the ability to reprogram. When designing, do not forget about the noise immunity of the device.