| 摘要 |
<p>The resonator (10) comprises the resonator chamber, a tubular connection (38) having an internal passage establishing fluid communication between the duct and the resonator chamber, and a tuning member mounted to be movable across the tubular connection to vary the cross sectional area of it. A solenoid actuator (18) drives the tuning member to cause the tuning plate (22) to assume any of a series of predetermined positions, each partially blocking the tubular connection internal passage to a varying extent. A control signal source transmits signals to the actuator to cause the tuning member to be moved to a position in a range of partially blocking positions in correspondence to it. The internal passage has a shape configured to provide a linear relationship between the position of the tuning member through the range of partially blocking positions and the open cross sectional area of the internal passage.</p> |
