| 摘要 |
PROBLEM TO BE SOLVED: To provide a heater control device for gas sensors that makes possible acquisition of element resistance values less affected by noise without having to alter the timing of element resistance values or the on/off timing of PWM control, and control of power supply to the heater based on the element resistance values.SOLUTION: A CPU figures out an upper limit and a lower limit by adding or subtracting a prescribed value to or from the last figured-out Rpvs average (the acquired Rpvs value at the first time) and sets a window W1. During the first PWM control period, the CPU acquires multiple Rpvs values [P2] to [P11], and excludes Rpvs values [P5], [P6] and [P9], which cannot be accommodated in the window W1 (neither below the lower limit nor above the upper limit) to obtain the average Rpvs value A1. The CPU figures out the upper limit and the lower limit by adding or subtracting a prescribed value to or from the average Rpvs A1 and sets the next window W2. |
