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A80 Pro Intelligent Diagnosis System
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Hall Effect is as follows: A tooth made of ferromagnetic material is placed on the camshaft, and the
teeth rotate with the camshaft. When the semiconductor wafer through which the current flows in the
camshaft rotational speed sensor passes the tooth, the magnetic field of the sensor deflects the flow of
electrons on the semiconductor wafer perpendicular to the direction of the current. Thus, a voltage
signal (Hall voltage) is formed in a short time, and this signal informs the ECU that the first cylinder
is in the compression stroke.
（3）Temperature sensor
The temperature sensor is used in several places: ○
1
in the cooling water circuit to infer the
engine temperature from the cooling water temperature; ○
2
used in the intake port to determine the
temperature of the intake air; ○
3
used in the oil to determine Oil temperature (optional);
（4）Air flow sensor
○
4
used in the
fuel return oil line to determine the fuel temperature (optional). The sensor has a
temperature-dependent resistance, the temperature coefficient of the resistor is negative, and the
high-sensitivity NTC (negative temperature coefficient thermistor) resistance increases with
temperature. It is a part of voltage divider circuit powered by 5V support. The voltage connected to
the resistor is read by an analog-to-digital converter, which is a measure of temperature. There is a
characteristic curve in the microprocessor of the ECU that gives the corresponding temperature for
any voltage.
In order to achieve the statutory emission limits, especially in the case of dynamic engine
operation, the air-fuel ratio must be maintained. For this purpose, sensors that accurately determine
the actual intake air mass flow are used. Changes in intake pulsation, back-flow, exhaust gas return
and camshaft control, and changes in intake air temperature must not affect the accuracy of the load
cell measurement. To achieve the above objectives, in a hot film air mass flow meter, heat is
extracted from a heated sensing element by heat transfer to the air mass flow. The micromechanical
measurement system works in conjunction with a hybrid circuit to measure air mass flow, including
flow direction. When the air mass flow is strongly pulsating, back-flow can be identified. The
micromechanical sensing element is disposed in the plug sensor flow path. The plug-in sensor can
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