| 摘要 |
A contactless pressure switch 10 sensitive to fluid pressure rates of change includes a housing 36 and a diaphragm 42 secured in the housing defining first and second chambers. Ports 48, 50 are included in the first and second chambers to vent the chambers. A magnet 52 is secured to the diaphragm and a switching module 54 is secured to the housing within one of the first or second chambers at a position spaced from the diaphragm. A biasing magnet 53 is mounted with the module to provide symmetrical switching by the module. The other of the first or second chambers is coupled to a sensing tube 28 such that upon a pulse or rate change of pressure being introduced in the other of first and second chambers, the diaphragm is deflected. This moves the magnet 52 toward the module actuating it to switch the module and actuate a desired circuit. In an alternative embodiment, the position of the module may be varied relative to the diaphragm to vary the sensitivity of the switch. |
