| 摘要 |
PROBLEM TO BE SOLVED: To aim for no adjustment of the heater voltage of a threshold current oxygen sensor. SOLUTION: A current limiter resistance 5 is connected between the heater, which is installed in line with the detecting element 2 of the threshold current oxygen sensor 1, and the power source line, and a power MOS-FET 6 is connected between the heater 3 and a grounding line. The resistance of the current limiter resistance 5 and the heater 3 are established so that the current I 2 is approximately √(R1/R2) times the current II, wherein II is the current flowing in the current limiter resistance 5 and the heater 3 when the resistance of the heater 3 is R1, and the I 2 is the current flowing in the current limiter resistance 5 and the heater 3 when the resistance of the heater 3 is R2. |
