of cap screws 102 passing through holes in appropriate flanges of filter housing 100 and housing 4 and engaging locking nuts 104 as seen in fig1 and 2 filter housing 100 has a hub 100a projecting into a counterbored left hand end of the housing 4 the hub 100a having an annular groove 100b therein to receive a seal 106 which cooperates between the internal counterbore of housing 4 and the hub 100a filter housing 100 also has a reduced diameter conduit 100c extending to the left the conduit having an opening therethrough communicating with the interior chamber 4c of housing 4 to define an inlet passage for the device as in the outlet passage another filter 16 is disposed in the inlet passage and held in place by a ring type nut 108 which threadably engages an internally threaded portion of the opening of conduit 100c to operate the fluid flow rate control device the brushless dc motor is controlled by a microprocessor based electronic control system wire connections for the windings and for the position sensing ring 32 are made through a connector 110 affixed to housing 4 energization of the appropriate windings 26 generates a magnetic field that interacts with permanent magnets 60 to cause rotor assembly 34 to rotate counterclockwise as viewed in fig5 through a predetermined increment of some maximum interval as physically determined by pins 112 inserted into the left hand face of rotor body 36 engaging with a stop screw 114 threadably inserted through an opening in one of the arms 80b of support tower 80 a magnet housing 116 is attached to the left hand face.