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我根据投影放大的原理,设计了一个灯光投影放大器,材料简单,价钱便宜,经试用,投影清晰、图可大可小、效果很好。能帮助解决中学,特别是山区中学因绘图仪器不足而存在的困难。其制作方法如下: 准备容纳三节电池的手电筒一个,25×20cm的薄玻璃一块(玻璃越薄越好),15×15cm透明的玻璃纸一张。用墨水在玻璃纸上模印好书上的图(大致轮廓),再用浆糊将它的四个角贴在玻璃中央的上半部(直接用描图笔把图轮廓画在玻璃上也可以)。把玻璃插进竖立四条木棍的缝隙里,手电简固定在木架的一
According to the projection enlargement principle, I designed a light projection amplifier, the material is simple, the price is cheap, the trial, the projection is clear, the picture can be large and small, the effect is very good. Can help to solve the difficulties of middle school, especially mountain middle school due to lack of drawing instruments. The production method is as follows: prepare to accommodate three batteries of a flashlight, 25 × 20cm thin glass piece (the thinner the glass the better), 15 × 15cm transparent cellophane one. Ink on the cellophane on a good book on the map (general outline), then paste the four corners of the glass in the center of the upper half (directly with a drawing pen on the outline of the drawing on the glass) . Put the glass into the crevice of the erection of four sticks, flashlight Jane fixed in the wooden one