| 摘要 |
<p>The device measures the intake air flow rate in a combustion engine. Three temp. dependant resistors are inserted in the intake duck and form a bridge network with two other resistors. A defined current flows through the second hot wire resistor to heat it to its operating temp. The first resistor acquires a resistance determined by the intake air temp. and acts as a reference for the second resistor. The flowing air cools the second resistor which unbalances the bridge. This is detected by the control amplifier which uses the voltage controlled current source to drive more current through the bridge to balance it. The current required to balance the bridge is a measure of the air flow rate. The complete circuit is mounted directly on the intake pipe.</p> |
