Claims
- 1. A system for determining a temperature of exhaust gases from an engine, comprising:
an exhaust gas sensor having an electric heating coil, said sensor communicating with the exhaust gases; an electrical circuit for generating a signal indicative of the resistance of said heating coil when said coil is not energized; and, a controller receiving said signal and calculating said temperature of said exhaust gases based on said signal.
- 2. The system of claim 1 wherein said electrical circuit comprises a Wheatstone bridge circuit operatively coupled to said exhaust gas sensor.
- 3. A method for determining a temperature of exhaust gases from an engine, comprising:
generating a signal indicative of a resistance of a heating coil in an exhaust gas sensor when said coil is not energized; and, calculating a temperature of the exhaust gases based on said signal.
- 4. A system for determining a temperature difference of exhaust gases from an engine, the engine being coupled to an emission catalyst, the system comprising:
a first exhaust gas sensor having a first electric heating coil, said first sensor communicating with exhaust gases upstream of the catalyst; a second exhaust gas sensor having a second electric heating coil, said second sensor communicating exhaust gases downstream of the catalyst; a first electrical circuit generating a first signal indicative of a resistance of said first heating coil when said first coil is not energized; a second electrical circuit generating a second signal indicative of the resistance of said second heating coil when said second coil is not energized; and, a controller calculating a temperature difference between exhaust gases communicating with said first and second exhaust gas sensors based on said first and second signals.
- 5. A system for determining a temperature difference of exhaust gases from an engine, the engine being coupled to an emission catalyst, the system comprising:
a first exhaust gas sensor having a first electric heating coil, said first sensor communicating with exhaust gases upstream of the catalyst; a second exhaust gas sensor having a second electric heating coil, said second sensor communicating exhaust gases downstream of the catalyst; an electrical circuit generating a first signal based on both a resistance of said first sensor heating coil and a resistance of said second sensor heating coil; and a controller calculating a temperature difference between exhaust gases communicating with said first and second exhaust gas sensors based on said first signal.
Parent Case Info
[0001] This application is a continuation-in-part of application Ser. No. 09/779,814, filed Feb. 8, 2001.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09779814 |
Feb 2001 |
US |
Child |
10661757 |
Sep 2003 |
US |