When the stepping motor coils ⑩ get excited in a clockwise direction,
the internally threaded rotor ⑪ will start to rotate with the
lead screw ⑫ moving leftward.
The plunger ③ directly connected with the lead screw ⑫.
will discharge the liquid inside the pump head through the outlet port
① or ②.
One or two outlet ports may be selected. When the plunger ③ comes
to the discharge completion position, the benchmark sensor ⑦
will detect the shutter ⑧, giving an electric signal.
For intake of liquid, the motor coils ⑩ will need to get excited in a counter-clockwise direction.
The rotor ⑪ will start to reverse. With the lead screw ⑫ and the plunger ③ moving rightward, the liquid will enter the inlet port ① or ②.
The discharge and suction volumes can be controlled by means of the pulse number of motor.