presence of a capacitor not shown for example composed of aluminized mylar u00ae which is located below magnet 184 and indicates the position of magnet 184 once the magnet has been driven to a desired position it is held in place by the magnetic fields surrounding ferromagnetic pins 198 and 200 because of the presence of these pins magnet 184 may be held in position with little or no current flowing in wire 188 turning now to fig7 b a side view of the rdoe of fig7 a is shown revealing the connection of the above described elements to a printed circuit board numeration from fig i is retained printed circuit board pcb 202 is seen to have ground plane 204 and voltage bus 206 fet 190 is connected in series with conductor 188 ground connector 208 and voltage connector 210 fig1 being connected to ground plane 204 and voltage bus 206 respectively similarly the capacitance sensor located on stop 194 is connected to ground plane 204 at 211 and voltage bus 206 at 212 the connection of elements to pcb 280 is intended to be illustrative and not limiting of the present invention as it will be obvious to those skilled in the.