| 摘要 |
<p>PURPOSE:To reduce output fluctuation of an air flowmeter and stabilize detection accuracy even with the provision of activation circuit to a heater resistor type air flowmeter. CONSTITUTION:Each medium point of a bridge circuit 1 provided with a heater resistor RH for an air flowrate measurement and a temperature compensation resistor RC is connected to each input terminal of a differential amplifier 3. In between the output side of the differential amplifier 3 and the base of transistor T1 as a heat current control element 2, an activation circuit 4 consisting of R10 to R12 is connected. When the differential amplifier 3 is in negative offset input voltage characteristic at the power onset, an activation signal is input from the activation circuit 4 to the heat current element 2.</p> |
