散热风扇的内部结构

创作时间:

2025-01-22 00:42:20

作者:

@小白创作中心

散热风扇的内部结构

本文将带你深入了解一款小型散热风扇的内部结构和工作原理。通过实验测试，我们将分析风扇的工作电压与电流之间的关系，并拆解风扇以观察其驱动电路。

01散热风扇

一、前言

这是一个将要报废的散热风扇支架。其中包含有四个风扇。风扇是无刷两对极风扇。虽然它的外壳是透明的，但是从外部看不到它内部的驱动电路。原来的外壳中确实包含有一个电路板，但是这个电路板似乎只是一个电源分配器，它的内部并没有风扇旋转的驱动电路。下面拆卸一个，看一下该风扇的旋转原理。

二、风扇特性

将风扇固定在桌面，通过直流电源给风扇施加5V直流电压。棕色引线为正极。此时，风扇的工作电流为232mA，风扇在愉快地旋转。

下面测试一下风扇的工作电压与电流之间的关系。就是用DH1766本身的回读功能。它可以回读到输出电流的大小。

下面测试一下从0V到6V工作电压范围内，风扇的工作电流的变化。使用可编程直流电源DH1766提供上升的电压，同时回读输出的电流。记录一百个电压电流数据，绘制成工作电压电流曲线，可以看到，当输入电压超过2.5V之后，工作电流便开始急剧上升，之后，便随着工作电压的上升，工作电流近似线性上升了。由此可见，这个风扇的工作最低电压需要超过2.5V。

图1.2.1 电压与电流之间的关系

vdim=[0.0000,0.0606,0.1212,0.1818,0.2424,0.3030,0.3636,0.4242,0.4848,0.5455,0.6061,0.6667,0.7273,0.7879,0.8485,0.9091,0.9697,1.0303,1.0909,1.1515,1.2121,1.2727,1.3333,1.3939,1.4545,1.5152,1.5758,1.6364,1.6970,1.7576,1.8182,1.8788,1.9394,2.0000,2.0606,2.1212,2.1818,2.2424,2.3030,2.3636,2.4242,2.4848,2.5455,2.6061,2.6667,2.7273,2.7879,2.8485,2.9091,2.9697,3.0303,3.0909,3.1515,3.2121,3.2727,3.3333,3.3939,3.4545,3.5152,3.5758,3.6364,3.6970,3.7576,3.8182,3.8788,3.9394,4.0000,4.0606,4.1212,4.1818,4.2424,4.3030,4.3636,4.4242,4.4848,4.5455,4.6061,4.6667,4.7273,4.7879,4.8485,4.9091,4.9697,5.0303,5.0909,5.1515,5.2121,5.2727,5.3333,5.3939,5.4545,5.5152,5.5758,5.6364,5.6970,5.7576,5.8182,5.8788,5.9394,6.0000]
idim=[0.0000,0.0000,0.0000,0.0000,0.0000,0.0000,0.0000,0.0000,0.0000,0.0000,0.0000,0.0000,0.0000,0.0001,0.0001,0.0001,0.0002,0.0002,0.0002,0.0003,0.0003,0.0004,0.0004,0.0005,0.0005,0.0006,0.0007,0.0007,0.0007,0.0008,0.0008,0.0009,0.0009,0.0010,0.0010,0.0011,0.0011,0.0012,0.0013,0.0014,0.0357,0.0932,0.1043,0.1126,0.1138,0.1157,0.1198,0.1255,0.1277,0.1291,0.1289,0.1294,0.1307,0.1337,0.1366,0.1395,0.1425,0.1455,0.1483,0.1512,0.1539,0.1565,0.1591,0.1618,0.1643,0.1668,0.1694,0.1720,0.1743,0.1766,0.1794,0.1820,0.1842,0.1868,0.1894,0.1916,0.1941,0.1967,0.1992,0.2015,0.2038,0.2063,0.2086,0.2109,0.2131,0.2155,0.2179,0.2204,0.2226,0.2248,0.2272,0.2296,0.2317,0.2339,0.2363,0.2383,0.2406,0.2429,0.2450,0.2472]

#!/usr/local/bin/python
# -*- coding: gbk -*-
#============================================================
# TEST1.PY                     -- by Dr. ZhuoQing 2024-05-06
#
# Note:
#============================================================
from headm import *
from tsmodule.tsvisa        import *
vdim = linspace(0, 6, 100)
idim = []
for v in vdim:
    dh1766volt1(v)
    time.sleep(1)
    c = dh1766curr1()
    idim.append(c)
    printff(v, c)
    tspsave("fanvc", vdim=vdim, idim=idim)
plt.plot(vdim, idim, lw=3)
plt.xlabel("Voltage(V)")
plt.ylabel("Current(A)")
plt.grid(True)
plt.tight_layout()
plt.show()
#------------------------------------------------------------
#        END OF FILE : TEST1.PY
#============================================================

三、驱动电路

下面拆卸风扇，查看一下它的驱动电路和旋转原理。它的驱动电路在风扇背面，可以看到有两个发光二极管，一个集成芯片，以及三个定子线圈引脚。风扇电机是外转子，内部定子通过自动换向，驱动外转子上的永磁铁旋转。这需要电路板上有霍尔传感器，能够感知转子上永磁铁的位置。进而完成自动换向。转子上有两组独立的线圈，它们之间是空间垂直的。通过交替驱动两个线圈，便可以改变驱动磁场的极性。可以隐约看到，驱动芯片的型号为276。在这篇CSDN博文中，介绍了AH277风扇霍尔器件功能，估计与276对应的芯片功能是相同的。