Sensors engine management systems

Sensors engine management systems help the controller to determine what happens with the engine and cars in general, at some point in time. Based on the signals of these sensors, the controller will perform complex calculations, and then send signals that encourage the management of the actuators. TPS (Throttle Position Sensor) signal coming from the throttle position sensor is used controller engine management system to calculate the angular position of the throttle body itself. TPS will be mounted on the throttle tube, when the throttle is turned barrier, its axis will pass its motion directly to the sensor. TPS has the potentiometric resistor type. On one arm of the potentiometer is fed to the controller reference voltage, while the second arm is connected to the "masses". The third switch contact is connected to the movable contact of potentiometer. The output signal proportional to the TPS to change the outcome of the angle of the throttle. When the valve is completely closed on the sensor voltage is 0,35-0,7 V, while at open throttle - 4,05-4,75 V. The minimum voltage value, which will be determined by the sensor controller in operation at idle, it uses the system as a starting point of reference, in other words, 0% open throttle. Fully enclosed throttle similar to idling. When the opening angle is too large, the transition occurs on the power mode, in which case the maximum torque, at the minimum engine power. When the throttle is opened partially, the controller maintains a proper level of stoichiometric fuel mix. Based on these data, TPS controller determines the load that must be entrusted to the engine. To compensate for short-term depletion of the mixture when the throttle is opened rapidly, the controller calculates the fuel additive in the base, using the information, which receives a signal from the TPS. Knock sensor (DD) in internal combustion engines with the ignition by a spark in some circumstances there may be ringing combustion processes that may lead to the fact that decreases efficiency and engine power. Such an undesirable phenomenon called the mechanics of detonation. It is a consequence of the fact that the air-fuel mixture, which is not in flames, ignited by itself. If the process of internal combustion and compression pistons it started normally, is caused by high temperature and gas pressure, and this is the main factor that ignited mixture itself. It is also important to note that the rate of fire can exceed 2000 m / s, while the rate in normal combustion rate rarely exceeds 30 m / sec. In the case of such rapid combustion in the chamber there is certainly a lot of pressure. If detonation is long, a similar thermal load and high blood pressure can lead to mechanical damage to the cylinder head and gaskets, as well as head and piston in the zone valves. Typical variations of combustion during detonation will be recorded knock sensor, which converts the electrical signal and sends it to the controller engine management system. In fact knock sensor - is an accelerometer or a piezoelectric ceramic device that can convert mechanical vibrations of the engine into an electrical signal. Or you can say that this receiver sound waves in solids. When there is vibration, inertia mass begins its impact on the piezoelectric element with a certain frequency and gain, resulting in an piezoelectric, and electrical signal contacts appears. The controller knock sensor signal at the output of a specially processed to detect the moment when it came knock, and began spontaneous combustion of the fuel mixture. Is very important is where will you install the sensor. When choosing, guided by the following methods: should not vary by level of detonation signals from each of the cylinders, the signal must be required for further processing by value; interference arising from other noises in the engine work, should be as small as possible. One of the important characteristics of the sensor is: a range of temperatures. The sensor can operate only at temperatures from 150 to 220oS. resonant frequency of the sensor. According to this principle when determining the existence of detonation, distinguish devices that are designed to determine the bandwidth and resonance wavelength. In a system with sensors resonance value of their resonant frequency coincides with the frequency that occurs during detonation in the cylinder oscillations, far above the resonance frequency in systems with a broadband transducer. However, the band with a certain area, which is in the range where there detonation swing, in other words, determines the conversion factor. He will show us how to relate the amplitude of the oscillation of detonation with an amplitude of the output signal at the spot where the sensor is installed. Sensor phase (DP) Camshaft controls exhaust and intake valves in the engine. It often happens that its rotation in a couple of times lower than the frequency with which rotates the crankshaft. When the piston is almost close to top dead center, then by lowering the value of the crankshaft is unrealistic to determine which of the cycles of the engine problem occurred: on the exhaust stroke when the exhaust gases are released or on the compression stroke, when the flammable fuel / air mixture. This sensor will be important for the phased injection system where fuel is fed through a nozzle into one cylinder, so directly and there is compression stroke before the intake valve is opened. In order for the controller was clear which of all the jets he had to manage at this moment and used the signal received from the transmitter of a camshaft. It is also called sensor phases. In engines WHA used the so-called Hall-effect sensor. You probably know the principles of non-contact ignition systems for gasoline engines. Installed a sensor that controls the communicator, who works on the principle of a Hall sensor. Registers the data he passage of the metal shutters with cutouts, which is connected to the shaft of the distribution, after which transmits signals to the control communicator. Blind passes between the sensor itself and the permanent magnet, and this interrupts the flashing line of permanent magnet, in other words just blocking it. In the case between the sensor and the magnet is cut, the sensor will emit a signal that after a little processing to be used for device control. Speed ??Sensor (DS). This sensor is the engine management system provides a great service by revealing information about the movement of the car and its current speed. It is located on the gearbox, and throws just six pulses per one meter of the machine. It also used the Hall effect, and output signals are identical to those that emanate from the probe phase. The main element is a disk that is mounted on the inside of the axis of the sensor, where next to it is a multipolar magnet. There are two types of sensors: no-go and continuous. No-go - installed on a machine with an electric instrument cluster. Globe - set to break rope anchoring the speedometer.