| 摘要 |
<p>A hot wire air flowmeter comprising a bridge circuit means constituting a constant temperature drive circuit by a heating resistor and a temperature compensation resistor, a means for detecting a heating condition of the heating resistor and a circuit means for controlling a heating time according to a heating condition, whereas a conventional hot wire air flowmeter for measuring an intake air volume of an internal combustion engine for an automobile or the like requires a heating resistor with a small heat capacity, for example, a thin film heater formed on a silicon substrate, to improve responsiveness, but a heating absorbing substance such as dirt and water deposited on the heating resistor will provide a continued maximum heating condition in excess of the original heat capacity of the heating resistor to deteriorate a thin film resistor.</p> |
