fig5 illustrates an electrofluidic pin transducer 64 comprising a laminate subassembly 29 which forms a fluidic circuit component of the transducer , and an electromagnetic subassembly 50 ( fig3 ). as stated above , the electromagnetic subassembly 50 comprises the magnet 52 , the first pole piece 54 , the coil 20 , the flexible member 40 , and the second pole piece 56 , the latter of which is shown seated on the laminate subassembly 29 . the pin 46 is provided as a piece of wire which is soldered to the boss 38 of the flexible member 40 and which extends across a hole formed in the boss . the pole pieces 54 , 56 are composed of a soft iron . two mounting rods 66 , 68 are tightly fitted in holes 67 , 69 , respectively , ( fig6 ) formed in the second pole piece 56 and protrude upwardly from the latter . the flexible member 40 and the first pole piece 54 are successively placed so that the rods 66 , 68 extend through holes 70 , 72 formed through a centerplate 74 of the flexible member , and into holes 76 , 78 formed through the first pole piece . thus , the first pole piece 54 is positioned atop the laminate subassembly 29 , the centerplate 74 is positioned atop the first pole piece , and the second pole piece 56 is positioned atop the centerplate 74 . the coil 20 is seated on the flange 58 , which laterally circumscribes the first pole piece 54 except over a range defined by the boss 38 . a threaded bolt 80 ( fig3 and 7 ) extends through holes 82 , 84 , 86 in the first pole piece 54 , the centerplate 74 , and the second pole piece 56 , and into a stepped bore 88 ( fig7 ) formed through the laminate subassembly 29 . the bolt 80 is threadedly engaged with a recessed nut 90 , ( fig7 ) thus securing the pole pieces 54 , 56 , and flexible member 40 to the laminate subassembly 29 . the magnet 52 is seated in recesses 92 , 94 formed in the top surface 95 of the laminate subassembly 29 . a spring washer 96 is centrally placed on the top surface 98 of the magnet 52 . an aluminum - alloy housing member 100 is laterally shaped to match the lateral shape of the laminate subassembly 29 , and has five bores ( as at 102 ) formed therethrough . these bores 102 are coaxial with bores ( as at 104 ) formed through the laminate subassembly 29 . the housing member 100 has a cavity ( not shown ) extending inwardly from its bottom surface ( indicated at 106 ) to an inner surface ( not shown ) which is parallel to the top surface 108 . the inner surface abuts the spring washer 96 when the housing member 100 is placed atop the laminate subassembly 29 . bolts ( not shown ) are extended into the coaxial holes ( as at 102 , 104 ) and threadedly engaged with recessed nuts . as the bolts are tightened , the inner surface of the housing member 100 , acting through the spring washer 96 , presses the magnet 52 against the laminate subassembly 29 so that when the entire transducer 64 is assembled , the magnet is held in place . except as stated hereinafter for purposes of completing the description of the preferred embodiment , the laminate subassembly 29 is manufactured and assembled by conventional means well - known to those skilled in the art . the subassembly 29 has a baseplate 110 atop which a plurality of laminates 112 are stacked . the laminates 112 are designed so that when stacked in proper sequence , they internally form the fluidic circuit element 28 and the required supply and vent channels ( not shown ). an uppermost plurality of laminates forms a cavity 114 into which the boss 38 extends . referring now to fig7 a stepped bore 116 is formed through the laminate subassembly 29 from the top surface 95 to the bottom surface 118 thereof . a shaft 120 having a cylindrical boss 122 protruding from its upper end 124 ( fig6 ) extends into the bore 116 so that the boss 122 protrudes above the top surface 95 . the lower end 126 of the shaft 120 is adapted by any suitable means for engagement with a torquing tool which can be used to rotate the shaft about its axis 127 ( fig6 ). as indicated , the boss 122 is displaced from the axis 127 . referring now to fig6 the second pole piece 56 has a slot 128 formed therein , the slot being located preferably near the rear end of the pole piece ( i . e . the end that is not visible in fig5 ) and extending inwardly from the bottom surface ( indicated at 130 ) of the latter . the cylindrical boss 122 extends into the slot 128 , thus engaging the electromagnetic subassembly 50 ( fig3 ). use of the preferred embodiment will now be described with reference to fig6 a - 6c and 7 . note that in fig6 a - 6c , the dashed - line circle 124 represents the end 124 of the shaft 120 and is added to aid understanding . therefore , the circle 124 should not be interpreted as a phantom view of the end 124 , since the shaft 120 extends from the boss 122 in a direction toward the viewer of fig6 a - 6c . the slot 128 and the cylindrical boss 122 function as a cam and cam follower , respectively . the null position of the pin 46 ( fig3 a ) is set with the nut 90 loosened from the bolt 80 . to set the null position , the shaft 120 is rotated as needed in directions indicated by the arcuate arrow 132 . if the shaft is rotated in one of the directions 132 , the cylindrical boss 122 exerts force on one of the sidewalls 134 defined by the slot 128 , and causes the pole pieces 54 , 56 and flexible member 40 to rotate in one of the directions 132 &# 39 ; about the axis 136 of the bolt 80 . accordingly , the boss 38 ( fig3 a ) extending from the flexible member 40 is also caused to rotate in that direction , as indicated in fig6 b . conversely , if the shaft 120 is rotated in the opposite one of the directions 132 , the cylindrical boss 122 exerts force on the opposite sidewall 138 defined by the slot 128 , and the boss 38 rotates about the axis 136 in the opposite of the directions 132 &# 39 ;, as indicated by fig6 c . once set , the null position of the pin 46 is locked - in by tightening the nut 90 onto the bolt 80 . from the above , it should be clear that the axis 136 of the bolt 80 is substantially parallel to the longitudinal axis 140 ( fig4 ) of the pin 40 . these axes extend in a direction generally indicated by the z - axis in the reference 37 of fig4 which is perpendicular to the direction of the forementioned flow path . movement of the pin 46 for control purposes occurs in the conventional manner , and is substantially rotational about an axis ( not shown ) which is substantially parallel to the x - axis and substantially perpendicular to the z - axis of the reference 37 . this unillustrated axis can be considered as nominally located along the centerplate 74 ( fig5 ) of the flexible member 40 , and extending in the longitudinal direction of a gabled cross - member 142 of the latter . the reader should understand that the foregoing portion of the specification and the accompanying drawings are not intended to restrict the scope of the invention to the preferred embodiment thereof , or to specific details which are ancillary to the teaching contained herein . accordingly , the invention should be construed as broadly as is consistent with the following claims and their equivalents .