试灯法与电压测试法的正确选用

在汽车电器电路检修中,当需要对部分电路的短路、断路或虚接进行在线确认时,试灯法和电压测试法是常用的两种方法。二者有相同功效又有不同之处,正确选用试灯法或电压测试法是汽车电器维修工必须掌握的基本技能。

交流发动机故障的检查方法

个别驾驶维修人员，在维护修理交流发电机时，不知用什么方法来检修，下面介绍几种实用检查方法：

农用运输车电路故障的检查

照明电路故障一般是由于接线或插头松动引起的接触不良，或导线的短、断路等引起，常用电源法、试灯法、划火法配合电流表加以排除。把车灯总开关置于二挡，脚踏变光开关，远、近光均不亮，则可能是车灯总开关至变光开关电路有断路或变光开关有故障。检查时，用导线在变光开关火线接线柱与机体之间划火，若无火花，表明从车灯总开关至变光开关之间有断路处；若有火花，应进一步检查变光开关。检查时，可用螺丝刀或导线将变光开关火线分别触及远、近光接线柱，若远、近光均亮，表明变光开关有故障。

怎样在车上查找电路的断路和搭铁部位

当汽车电路中发生断路或短路(即搭铁)故障时,会造成相关电气设备不能正常工作及电气系统的损坏,以致严重影响了机车的正常工作和安全生产。现介绍几种在车上查找电路中断路和搭铁部位的简便易行的方法。 一、查找断路部位 1.试灯法。用本车的灯泡做一个小试灯。检查时,先将试灯一端的引出线接在车架上。

Thermal simulation and optimization design on a high-power LED spot lamp

In this paper, thermal characteristics of the high-power LED spot lamp are reported. The emphasis is placed upon optimizing design of the heat sink of LED spot lamp using the optimization module and the orthogonal-experiment method. Results demonstrate that the weight of the heat sink is decreased to 46.1% of that for the initial structure, and the influence of each factor on junction temperature and weight of the heat sink is acquired by range analysis. Finally, the influence of ambient temperature and natural convection coefficient on the LED maximum temperature is analyzed. The results and the optimizing methodology are of great importance to the thermal design of LED lamps.