Integrated system of circuits for serial fan structure

An integrated system of circuits for serial fan structure, comprising:

• a first fan including a first frame, a first fan wheel, a first stator, a first driving unit, a first sensor unit and a first control unit;
• the first frame internally defining a first receiving space and having a first shaft base centered in the first receiving space;
• the first stator being externally fitted on around the first shaft base, and including a first silicon steel plate assembly, a first coil assembly wound around the first silicon steel plate assembly, and a first circuit board connected to the first coil assembly;
• the first circuit board being located on one side of the first shaft base facing toward the first fan wheel;
• the first sensor unit being electrically connected to one side of the first circuit board;
• and the first fan wheel being rotatably mounted on the first shaft base;
• and
• a second fan being connected to the first fan back to back, and including a second frame, a second fan wheel, a second stator, a second driving unit, a circuit unit, a second sensor unit and a second control unit;
• the second frame internally defining a second receiving space and having a second shaft base centered in the second receiving space;
• the second fan wheel being mounted on the second shaft base;
• the second stator being externally fitted on around the second shaft base, and including a second silicone steel plate assembly, a second coil assembly wound around the second silicon steel plate assembly, and a second circuit board connected to the second coil assembly;
• the second circuit board being located on one side of the second shaft base facing toward the second fan wheel;
• the first and the second driving unit, the first and the second control unit, and the circuit unit being sequentially electrically connected to one side of the second circuit board;
• and the first sensor unit and the first coil assembly also being electrically connected to one side of the second circuit board.