Ngk Spark Plug Company, Limited

Hiroyuki Tsukada

Norikazu Ieda

Masahiro Tanaka

Yoshinori Inoue

A gas sensor control apparatus () includes a gas sensor () having an oxygen pump cell (); a sensor drive circuit () which energizes the gas sensor; terminal voltage output means () which detects and outputs a terminal voltage of the oxygen pump cell; anomaly detection means () which compares the terminal voltage and a first threshold value, and when the terminal voltage exceeds the first threshold value, outputs a short circuit anomaly signal informing of a short circuit; a controller () which compares the terminal voltage and a second threshold value less than the first threshold value, and when the terminal voltage exceeds the second threshold value, generates a cell voltage anomaly signal informing of an application of an overvoltage to the oxygen pump cell; and command means () which, when receiving the short circuit anomaly signal or cell voltage anomaly signal, outputs a de-energization command.

Gas sensor control apparatus and method

A gas concentration detection apparatus and system including a gas sensor. Voltage Vd generated across detection resistor Rd through which pump current Ip flows is differentially amplified by OPand offset voltage Vofs is superposed thereon to obtain a detection voltage Vout. The amplification factor applied to the differential amplification of the voltage Vd is changed by turning switch SWon and off. When switch SWis turned on, the input terminal potentials of the operational amplifier OPare equalized, so that voltage Vofs is output as the detection voltage Vout. The detection voltage Vout contains an error attributable to the electronic components which form the circuit. The detection voltage Vout containing the error when SWis turned on is acquired as a correction voltage for each amplification factor, and is used for correction at the time of detection of the concentration so as to cancel the error.

Growing community of inventors

Iwakura, Japan

Hiroyuki Tsukada