| 摘要 |
<p>In a drive processing circuit comprising a flow velocity measuring resistor (7) and a temperature compensating resistor (8) of a hot wire type air flow meter, a resistor (22) is inserted between a connecting point of two resistors (17,18) and an inverting input terminal of an operational amplifier (15). A condenser (23) is inserted between the inverting input terminal and the non-inverting input terminal of the amplifier (15). The resistance value of the inserted resistor (22) is set larger than the resistance value of the temperature compensating resistor 8). By means of the inserted resistor (22) and the inserted condenser (23) which act as a low pass filter, high frequency noises, which intrude through the temperature compensating resistor (8), are cut off.</p> |
