三极管

My factory is enterprise of a state-operated, produce dynatron of crystal of medium, small-power.

【摘要】我厂是一家国营企业，生产中、小功率晶体。

The phototransistor was installed through holes in the top of the case, and enclosed in a brass tube that was painted black inside and out.

该光敏是通过安装洞上方的情况下，密封一个黄铜，这是手绘的黑色内。