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A pump assembly flows pressurized engine oil to HEUI fuel injectors in a diesel engine. The assembly includes an inlet throttle valve which controls the volume of oil flowed to the pump dependent upon the difference between the pump outlet pressure and a desired outlet pressure determined by an elec

A pump assembly flows pressurized engine oil to HEUI fuel injectors in a diesel engine. The assembly includes an inlet throttle valve which controls the volume of oil flowed to the pump dependent upon the difference between the pump outlet pressure and a desired outlet pressure determined by an electronic control module for the diesel engine.

대표청구항 ▼

A pump assembly flows pressurized engine oil to HEUI fuel injectors in a diesel engine. The assembly includes an inlet throttle valve which controls the volume of oil flowed to the pump dependent upon the difference between the pump outlet pressure and a desired outlet pressure determined by an elec

A pump assembly flows pressurized engine oil to HEUI fuel injectors in a diesel engine. The assembly includes an inlet throttle valve which controls the volume of oil flowed to the pump dependent upon the difference between the pump outlet pressure and a desired outlet pressure determined by an electronic control module for the diesel engine. de operating temperature range based on said first and third signals. 2. The method of claim 1 wherein both of the first and second predetermined currents are conducted through the one and other thermistor beads, respectively, at less than 30 milliamps. 3. The method of claim 1 wherein the first predetermined current is conducted through the one thermistor bead at an average current which renders said one thermistor bead a sense thermistor bead, and the second predetermined current is conducted through the other thermistor bead at an average current which renders said other thermistor bead a reference thermistor bead. 4. The method of claim 3 wherein the first predetermined current is conducted through the one thermistor bead at an average current of approximately 20 milliamps, and the second predetermined current is conducted through the other thermistor bead at an average current of approximately 5 milliamps. 5. The method of claim 1 including the step of combining the first and second signals to generate a fourth signal and wherein the step of detecting includes detecting the dry/wet state of the sensor over the wide operating temperature range based on the third and fourth signals. 6. The method of claim 5 wherein the step of combining includes subtracting the second signal from the first signal to generate the fourth signal. 7. The method of claim 5 wherein the step of detecting includes generating a fifth signal indicative of the dry/wet state of the sensor based on a comparison of the fourth signal to the third signal. 8. The method of claim 1 wherein the step of conducting the first predetermined current includes conducting a third predetermined current through the one thermistor bead during first duty cycle intervals of a periodic current waveform; and wherein the step of conducting the second predetermined current includes conducting said third predetermined current through the other thermistor bead during second duty cycle intervals of said periodic current waveform, said first duty cycle interval being substantially greater in time than said second duty cycle interval. 9. The method of claim 8 wherein the step of measuring the first voltage includes averaging the voltages rendered across the one thermistor bead in response to the first duty cycle third current intervals and generating the first signal representative of said average voltage; and wherein the step of measuring the second voltage includes averaging the voltages rendered across the other thermistor bead in response to the second duty cycle third current intervals and generating the second signal representative of said average voltage. 10. The method of claim 9 wherein the step of step of modifying includes modifying the second average voltage signal by an offset and gain to generate the third signal. 11. The method of claim 10 including the step of subtracting the second average voltage signal from the first average voltage signal to generate a fourth signal; and wherein the step of detecting includes detecting the dry/wet state of the sensor over the wide operating temperature range based on the third and fourth signals. 12. Apparatus for detecting a dry/wet state of a dual thermistor bead sensor over a wide operating temperature range, said apparatus comprising: a first circuit coupled to said sensor for conducting a first predetermined current through one of the thermistor beads of said sensor and for conducting a second predetermined current through the other of the thermistor beads of said sensor, said second predetermined current being substantially less tha