| 摘要 |
<p>PURPOSE:To provide a heating-type air flow meter which can eliminate and suppress high frequency noise invading from a resistor installed in an air route and its supporting member and has improved resistance to electric wave troubles. CONSTITUTION:At least one unit of high band-shielding filter F composed of a capacitor Cf and an inductor Lf is installed between a temperature controlling circuit 9 and both resistors of a heating resistor Rh and a temperature sensitive resistor Rc, the middle connecting point at which one end of the capacitor Cf and one end of the inductor Lf are connected is connected to the side of both resistors Rh, Rc, and the other end of the inductor Lf is connected to the side of the temperature controlling circuit 9. Since the resistance of a heating-type air flow meter to electric wave troubles is improved from the view point of the circuit, the members of an air route can be selected optionally and also since only a few LC filters are needed to manufacture a heating-type air flow meter, the option of the designs is extended, the cost is lowered, and the meter can be made compact and light.</p> |
