how to install a tachometer on a small engine

• 2022-04-21

First of all, we should make clear what kind of tachometer it is. If it is a pointer tachometer of an ordinary instrument, there are usually two wiring modes, one of which is connected to the ignition module. For example, the EXT terminal attached to the ignition module of Toyota is used to connect the tachometer in the instrument, which sends out a frequency signal. However, such connection mode is rare at present, which is mainly used in the ignition mode of the old distributor. The other signal comes from the speed sensor, that is, the crankshaft angle sensor, which is usually installed in front of the engine crankshaft (behind the crankshaft pulley); The middle part of the crankshaft goes deep into the crankcase, and the counterweight on the crankshaft is used as the signal generator; The rear of the crankshaft is usually installed next to the large flywheel, and the flywheel teeth are used as the signal generator.

If it is a tachometer controlled by the instrument control module, the typical feature of this kind of instrument is the liquid crystal display. Although the tachometer signal also comes from the speed sensor, the signal is obtained by the instrument control module through the engine control module through the CAN bus.

Add a DC motor to the main shaft of the engine (e.g. next to the generator). Then measure the voltage, and then calibrate the corresponding value with the tachometer to make a scale. The speed sensor on the crankshaft flywheel counts and sends signals, which are sent to the on-board central control system through the signal transmission line, and finally displayed on the tachometer.

The electronic tachometer has a built-in microcomputer processor. The speed calculation display is extremely accurate, and there are digital display and arc light column to display the speed value. With electronic clock, maximum speed memory query and two-level display brightness selection. Reasons for installing tachometer. Why install a tachometer? At present, most cars have tachometers, but mini cars generally don't have them because of the cost (the price of the tachometer is higher than that of the instrument assembly already installed in the car). But just because it is an economy car, the engine displacement is small and the power is not very high, so driving an economy car y should pay more attention to the engine speed. The benefits of installing a tachometer. Let's talk about the relationship between engine speed and power. The power and torque output of an engine are different. At high engine speed, k output power will be more, but torque will be different. Torque can be better output only within a certain speed range of the engine, that is to say, whether the engine has power or not depends on what range the engine speed is within.