| 摘要 |
<p>PURPOSE:To improve engine control precision by inputting the reference potential signal of a hot wire flowmeter to the A/D converter in a controller and correcting the output voltage, and calculating the accurate quantity of sucked air on the basis of the information after correction. CONSTITUTION:An operational amplifier 9 is incorporated in the hot wire flowmeter 1 and operated at a reference potential 4, but this potential 4 is VG=IR higher because of a current I which flows from the resistance 7 in wiring and the meter 1 to the earth potential 8 of a battery 10 through a potential 4. Therefore, the output voltage 5 of the meter 1 becomes Vout which is the sum of a voltage VQ based upon the quantity of sucked air and said VG and the earth potential of the A/D converter 3 in the controller is not equal to the potential 8 because the current in the wiring 11 is small. Therefore, it is considered that the quantity of sucked area which is the voltage VG larger than the actual voltage VQ, so the potential 4 of the meter 1 is inputted to the converter 3 by using the wiring 6 to obtain the voltage VQ corresponding to the actual quantity of sucked area as information for engine control.</p> |
