| 摘要 |
A pressure sensing switch comprises a dome member supported on a substrate such as printed circuit board 3 at an intermediate position 4. An actuator 15 displaces an actuation portion of the dome inboard of intermediate position 4, flattening the dome and causing it to transition from a first configuration where an outboard contact 53 is in contact with a connector 54 to a second configuration where contact 53 is not in contact with connector 54. The dome may have a second contact 57 to contact a second connector 55 in a third, partial configuration intermediate the first and second configurations. Contact regions 53,57 may be on opposite legs of the dome (fig 3) which can flex with a non-linear characteristic including a negative stiffness portion for hysteresis. The actuator can comprise coaxial rods 7,15 and spring 14 and transmit force from a diaphragm 10. The pressure-sensing switch is optimal for use in sensing a high pressure condition in a reaction chamber to disable a pump pumping reactant to the reaction chamber. A particular application is to fuel supply cartridges for fuel cells. |
