Abstract: A gas sensor control apparatus (3) includes first current detection means for detecting a first pump current flowing between second electrodes (19, 20) in a state in which an object gas has become a prescribed gas supply state, the temperature of a sensor section (10f) has become a first target temperature, and the voltage between first electrodes (21, 22) has become a first target voltage; second current detection means for detecting a second pump current flowing between the second electrodes in a state in which the object gas has become the prescribed gas supply state, the temperature of the sensor section has become a second target temperature, and the voltage between the first electrodes has become a second target voltage; and H2O gas concentration detection means for detecting the H2O gas concentration of the object gas on the basis of the first and second pump currents.

Abstract: A heater control method and apparatus for a gas sensor which can quickly activate a detection element while reducing load due to heating even when a higher power supply voltage is applied. A heater element is connected to a power supply whose voltage is higher than 16 V, and power is supplied under PWM control such that a temperature rise of the heater element follows a temperature rise curve obtained when a voltage of 12 V is applied to the heater element. Even though a higher voltage is applied, the temperature rise per unit time during the ON time of the PWM control is decreased. This is because the ON time per cycle is shortened by increasing the PWM frequency to 30 Hz or higher. Thus, the temperature rise per cycle is kept low, whereby the temperature rise per 0.1 second is rendered less than 25° C.

Abstract: A gas sensor control apparatus (1) for a gas sensor (2) including an electromotive force cell (24) and a pump cell (14) includes current control means (69) for feedback-controlling the pump current Ip, voltage setting means S5, S13 for setting a target voltage Vr to either of first and second target voltage Vr1 and Vr2, and constant group setting means S4, S12 for setting a group of feedback control constants to a first group Kpid1 when the target voltage is Vr1 and to a second group Kpid2 when the target voltage is Vr2. The second group Kpid2 is determined such the pump current Ip becomes stable more quickly as compared with the case where the first group of control constants Kpid1 continues to be used.

Abstract: A gas sensor control apparatus (3) includes first current detection means for detecting a first pump current flowing between second electrodes (19, 20) in a state in which an object gas has become a prescribed gas supply state, the temperature of a sensor section (10f) has become a first target temperature, and the voltage between first electrodes (21, 22) has become a first target voltage; second current detection means for detecting a second pump current flowing between the second electrodes in a state in which the object gas has become the prescribed gas supply state, the temperature of the sensor section has become a second target temperature, and the voltage between the first electrodes has become a second target voltage; and H2O gas concentration detection means for detecting the H2O gas concentration of the object gas on the basis of the first and second pump currents.

Abstract: A heater control method and apparatus for a gas sensor which can quickly activate a detection element while reducing load due to heating even when a higher power supply voltage is applied. A heater element is connected to a power supply whose voltage is higher than 16 V, and power is supplied under PWM control such that a temperature rise of the heater element follows a temperature rise curve obtained when a voltage of 12 V is applied to the heater element. Even though a higher voltage is applied, the temperature rise per unit time during the ON time of the PWM control is decreased. This is because the ON time per cycle is shortened by increasing the PWM frequency to 30 Hz or higher. Thus, the temperature rise per cycle is kept low, whereby the temperature rise per 0.1 second is rendered less than 25° C.

Abstract: A gas sensor control apparatus (1) for a gas sensor (2) including an electromotive force cell (24) and a pump cell (14) includes current control means (69) for feedback-controlling the pump current Ip, voltage setting means S5, S13 for setting a target voltage Vr to either of first and second target voltage Vr1 and Vr2, and constant group setting means S4, S12 for setting a group of feedback control constants to a first group Kpid1 when the target voltage is Vr1 and to a second group Kpid2 when the target voltage is Vr2. The second group Kpid2 is determined such the pump current Ip becomes stable more quickly as compared with the case where the first group of control constants Kpid1 continues to be used.