Device for determining airflow rate in the inlet to a motor vehicle combustion engine based on a hot film anemometer has an integral analogue to digital converter to reduce loading on an engine control device

摘要

Device comprises a hot film anemometer operated in constant temperature mode with the hot film resistance forming one leg of a Wheatstone bridge. The voltage across the diagonal of the bridge containing the anemometer is connected to an analogue to digital converter (ADC), which converts the analogue voltages into digital values. Once the digital values have been stored they can be further processed with at least a digital output value corresponding to the mass flow delivered to a output interface. Correction software (KS) is provided for e.g. temperature compensation.