Automotive tachometer: purpose, types

A car tachometer is a device that is used to determine the number of revolutions of rotating parts of a running engine. The measurement is performed per unit time or according to the speed of linear motion. The car tachometer helps in choosing the right gear and as a result contributes to the extension of the life of the power unit. This means that at the moment when the arrow of the device approaches the red zone, immediately switch to higher gear. Tachometer for cars Often used for adjustment work: at idle speed and for the purpose of real-time monitoring of the speed of rotation of the motor shaft while driving the machine. The principle of operation of such a device is to detect the pulses coming from the sensors. In addition to counting their number, the car tachometer records the order of their arrival, as well as the pauses between the counted pulses. In this case, the calculation itself can be carried out either directly or indirectly, and, if necessary, also mixed, that is, in both directions.

As a result, the received indicators are transformed into different values, such as seconds, minutes, hours, meters, etc. If necessary, the car tachometer can be reset, thereby resetting all collected values. However, when using such devices, it must be remembered that the accuracy of the measured data is very conventional and is about 500 rpm, in the best electronic devices it reaches 100 rpm.

Automotive tachometers are of two types: analog and digital.

Digital devices are executed in the form of an electronic scoreboard, which displays all the counted information, namely the speed of the engine and shaft. Such a tachometer is very useful for carrying out adjusting operations with the electronic ignition unit of car engines, as well as installing thresholds in the economizer, etc.

Analog devices are very popular in the automotive industry. They show the speed of the power unit by means of a dial dial. The operation of such a device is done electronically. This means that the signal from the sensor located on the motor shaft is transferred to the microcircuit. The latter specifies the movement of the pointer (arrows) on a graduated scale. Any analog car device and a tachometer for a boat engine work according to one principle. The first is an elementary counter of the impulses of the electrical system of the engine. It directly depends on the speed of the crankshaft. Tachometers of outboard motors also consider electrical pulses, but they receive "information" directly from the magdino lighting coil, which plays the role of a generator.

In any car it makes sense to additionally have a digital tachometer. It is useful for regulating the idling speed and checking the efficiency of the economizer control unit, as well as the correctness of the standard analog device. This is due to the high measurement accuracy of digital devices. However, when driving a car, it is better to use a pointing device, since it is more obvious for the driver.