A tachometer is a device designed to measure the speed of a wheel or shaft. An example of the simplest such device is a revolution counter, with which, in the presence of a stopwatch, you can measure the average rotation speed.
Instructions
Step 1
In modern cars, more complex models of tachometers are installed - digital and analog, showing the instantaneous rotation speed. In this case, all information about the speed is displayed on an electronic liquid crystal display. The principle of their operation is based on recording the number of pulses coming from the sensors, the sequence of their arrival and pauses between pulses.
Step 2
The digital tachometer includes a central processor, a liquid temperature sensor, a processor reset chip, an 8-bit ADC, a liquid crystal panel and an idle valve diagnostics optocoupler. Tachometers of this type are usually made in the form of an electronic board, which displays all the information - the number of revolutions of the engine and shaft.
Step 3
So, to read the revolutions using a laser digital phototachometer, a special reflective mark is attached to the object of rotation, which is included in the kit. During operation, the laser beam is reflected from the mark, and the signal is read by a special sensor of the device. The digital tachometer is indispensable when adjusting electronic ignition units of engines installed on vehicles.
Step 4
Analog car tachometers are more convenient. The readings of the device are reflected by an arrow moving along the dial. It includes a magnetic coil, a microcircuit, a graduated scale, an arrow and wires. An analog tachometer is an electronic device in which a signal from a shaft is transmitted through wires to a microcircuit, and that, in turn, drives an arrow on a graduated scale.
Step 5
The tachometer readings are transformed, as a rule, into certain values - hours, minutes, seconds, meters, etc. The most accurate electronic ones allow measurements to be made with an accuracy of 100 rpm. According to the installation method, tachometers are divided into standard and remote ones. So, if standard devices are mounted directly into the dashboard, remote ones are installed on a special leg on the torpedo panel. Some modern car models use tachometers, which use a stroboscopic effect, achieved using a bright flash lamp.
