| 摘要 |
<p>At a first operational state the signal is generated by the presence of a pressure in a second channel (14) coupled to the housing (10) inner chamber. In a second operational state the signal is generated in the second channel due to the lack of pressure. The signal generator contains a valve seat (18), opening a first channel (12) into the chamber. A third channel (16) couples the chamber with an outlet aperture (17) and has a second valve seat (19) with a larger dia. opening into the chamber. Between the two seats is a valve flap in the chamber for alternate stopping of the seats.</p> |
