Reciprocating fluid pump having Hall switch - has reciprocating closing magnetic at end of pumping stroke to increase value produced by Hall effect switch

摘要

The fluid pump has a magnetic circuit responsive to a predetermined position of a reciprocating magnetically permeable piston. The reciprocating piston closes the magnetic circuit at the end of its pumping stroke increasing the value of the signal produced by a Hall effect switch. The increased value of the generated signal energizes a solenoid coil returning the piston to a cocked position against the force of a resilient member which urges the piston forward on its pumping stroke. One input of the Hall effect switch is connected to the positive pole of the battery, the collector of a transistor and one end of the solenoid coil. The negative pole of the battery is connected to a common ground, as is a second electrode of the switch. The output of the Hall effect switch is connected to the base of the transistor and to the ground through a Zener diode.