At present, the length of UL plug on the projector on the market is usually 2 meters. The power supply is not enough for the classroom. Some are not strong enough to deal with the use, often off line or plug in, very inconvenient, unsafe. Therefore, the teacher on audio-visual courses, but also with a multi-purpose socket and UL plug manufacturers, the length of ordinary wire should be in 3M. Only in this way, the power line runs through the ground from the socket on the classroom wall, avoiding the behavior area of teachers and students, which is more convenient and safe. Once there is a riot, it can be broken in time.

However, quite a number of schools have projectors without power cord. It is wrong to simply use the power cord on the projector to deal with applications. The thought of safety first should be set up and the equipment accessories should be matched as soon as possible. Some schools therefore extend the power cord on the projector, and the skills of the new device are also desirable. In addition, as for the hand plug, the ordinary projector has a three pin plug, while the classroom wall is a fixed two pin socket. If it is not matched, it can not be used, or it is wrong and unsafe to use it. There is another sign that some female teachers are afraid of electricity and dare not grasp the plug installation with their hands, but pull the UL plug manufacturer by hand, which often causes the wire to be pulled off or the plug is loose, which affects the application.

Other teachers don't pay attention to check the plug and socket before application. When they are applied, they are caught in trouble, which affects the progress of audio-visual teaching. Therefore, schools should be equipped with audio-visual equipment accessories to create a good application premise. At the same time, we should improve the operation skills of teachers through training.