Table 24Table 25Max+125typicalMin-40Max58.395(+125 C)40.212.014.0ΩΩmHVVdegreeKPaNtypical5333.515606.28Min47.735(-40 C)26.87.53.5Max allowable number of stepper motor plug contacteach coil resistance at 25Ceach coil resistance at the operating temperature.1000Hz induction for each coil at 25CNormal operating voltagePossible operating voltageStep length of stepper motor statorTwo terminals differential pressure when the bypass channel is openMax Axial force caused by gas differential pressureoperating temperatureparameter ValueValueparameterStepper motorThrottle bypass section2.0 x 106UnitUnitConceUltimate DataPerformance DataFig.368Stepper motor actually is a micro motor. The steel stator is a multiphase coil winding and the rotor is a permanent magnet.When electrifying stator coil, the permanent magnetism stator will rotate towards corresponding direction on the impact ofthe electromagnetic power. Since stator and helix shaft are screw thread contact, stator’s angular rotation will transforminto helix shaft’s rectilinear motion. While stator rotates a fixed angle, helix shaft will move some displacement, which isone step whose step length is 15 oECU controls stepper motor move direction and steps by changing positive polarityǃnegative polarity and quantity of coilpower on phase, then changing engine throttle body bypass section area, so as to acquire the corresponding bypass airflow at idle condition.Attention for mountingIdle actuator with stepper motor is mounted on the throttle body to form bypass channel on two sides of throttle. SeeFig.368186
