实测数据见下表。从数据上看出,(1)脚电压只有3.16V,低于正常值(3.25V),(2)脚电压在加热时高于正常值,其余引脚在小火力时处于不稳定状态。看来故障不是出在电压检测电路中。查D9、D10、R6、R7无异常,再沿路查控制板,经查单片机(1)脚外接抗干扰电容C103(104)严重漏电,换新后试机,故障机修到这里,终于修好值得探讨。。 单片机引脚功能R6、R7阻值增大后C103漏电后待机(V)开机(V)放锅加热各挡火力电压(V)待机(V)开机(V)放锅加热各挡火力电压V11234561234561电网电压采样2.382.39O~2.382.322302.33.163.180~3.323.093.093.092整机电流采样0.390.79O~2.443.473.83.820.38O.800~0.383.713.773.96IGBT管使能0O0~2.614.974.974.970OO~2.614.974.974.978起振、脉冲检测5.055.040~5.052.332.312.325.055.04O~5.052.332.352.9410脉宽调制信号1.421.263.152.764.24.21.421.262.533.013.012.99 说明:1.R6、R7阻值增大后,实测该机在火力1~3挡时的整机电流为0~1.42A;在火力4~6挡时的整机电流分别为8.76A、9.33A、9.35A。2.在火力1~6挡时的整机电流分别为6.6A、6.77A、6.77A、8.89A、9.63A、9.70A。 |
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