Combined electronic pressure transducer and power switch

Claim 1

An arrangement for monitoring the pressure of a fluid in a system and providing both a switching function at a predetermined pressure and an analog signal function over a range of pressures including said predetermined pressure, said arrangement comprising: a housing having a chamber therein; a diaphragm sealing an end of said chamber; means for providing fluid communication between said system and said diaphragm outside said chamber; an actuator rod within said chamber, said actuator rod having opposed ends with a first of said ends being coupled to said diaphragm for movement in unison therewith; means for guiding said actuator rod for axial movement; means for biasing said actuator rod toward said diaphragm; a pair of switch terminal pins mounted on said housing and extending into said chamber; a Hall effect transducer mounted within said chamber; a magnet mounted on the second end of said actuator rod for movement in unison therewith, said magnet being so positioned that the distance between said magnet and said Hall effect transducer changes as said diaphragm moves; conductive means for providing a short circuit between said pair of switch terminal pins; and means for mounting said conductive means on the second end of said actuator rod so that said conductive means moves with said actuator rod as the fluid pressure increases to said predetermined pressure, whereupon said conductive means contacts said pair of switch terminal pins, said actuator rod continuing to move freely of said conductive means as the fluid pressure increases beyond said predetermined pressure.