Back to results
US 5,508,491 AGranted
Electronic mass airflow sensor circuit and method for manufacturing same
AssigneeFord Motor Company
InventorJames M. Sherman
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeFord Motor Company
InventorJames M. Sherman
Estimating the term…
An improved electronic mass airflow sensor circuit and method for manufacturing that circuit are disclosed. The circuit includes primary and secondary sensor elements having non-zero temperature coefficients of resistance. The circuit further includes a thick film resistor electrically connected to the secondary sensor element to form a combination element such that resistance ratio of the primary sensor element to the combination element remains constant over varying temperatures. The method includes the steps of detecting the resistance of the primary and secondary sensor elements, generating primary and secondary electrical signals corresponding thereto, and placing the thick film resistor in electrical contact with the secondary sensor element to form the combination element. The method also includes the steps of processing the primary and secondary electrical signals to determine operating temperatures for the primary sensor element and an optimum resistance for the thick film resistor such that the resistance ratio of the primary sensor element to the combination element remains constant over varying temperatures. The method further includes the step of sizing the thick film resistor in accordance with the optimum resistance determined.
A method for manufacturing a mass airflow sensor for use with primary and secondary sensor elements having non-zero temperature coefficients of resistance, and a thick film resistor having a substantially zero temperature coefficient of resistance, the method comprising the steps of:
A method for manufacturing a mass airflow sensor for use with primary and secondary sensor elements having non-zero temperature coefficients of resistance, and a thick film resistor having a substantially zero temperature coefficient of resistance, the method comprising the steps of:
A method for manufacturing a mass airflow sensor for use with primary and secondary sensor elements having non-zero temperature coefficients of resistance, and a thick film resistor having a substantially zero temperature coefficient of resistance, the method comprising the steps of:
Dependencies are inferred from the claim text.