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直流电流放大系数 H_(FE)是晶体三极管的重要参数,它定义为H_(FE)=((I_C)/(I_B)|_(V_(CE)(?)常数)为使测量的数据接近实用状态,必须在一定的 V_(CE)和I_C 的条件下,测量 I_B 的数值,得出 H_(FE)的值。此时被测的量 I_B 和 H_(FE)成反比,当被测管的 H_(FE)较大时,对应的 I_B 值很小。以往测试 I_B 都采用指针式电表,由于此时指针的偏转角很小,难以准确地读出 I_B 的数值,给数据测量带来很大的误差。本文介绍一种简便的方法,可用数字直接显示 H_(FE)值,从而大大提高测量精度。由上述讨论可知,被测量 I_B 和显示量 H_(FE)成反比关系,而一般 A/D 转换器的输入电压和输出数字量成正比关系,所以无法用普通的方法来完成这种反比关系的 A/D 转换工作。通过反复试验发现,只要改变A/D 转换器的常规使用方法,将 V_(IN)(常规接法中的
The DC current amplification factor, H_ (FE), is an important parameter of the transistor and is defined as H FE = (I_C) / (I_B) | _ (V_ (CE)) constant) To make the measured data nearly practical State, we must measure the value of I_B under the condition of certain V_ (CE) and I_C to get the value of H_ (FE) .The measured quantity I_B is inversely proportional to H_ (FE) H_ (FE) is larger, the corresponding I_B value is very small.Past test I_B are used pointer meter, because the pointer deflection angle is very small, it is difficult to accurately read the value of I_B, to bring a large data measurement Of the error.This article describes a simple method that can be used directly digital H_ (FE) value, thereby greatly improving the measurement accuracy.It can be seen from the above discussion, the measured I_B and display the amount of H_ (FE) is inversely proportional relationship, while the general A / D converter input voltage and the output digital is proportional to the relationship, so can not use the normal method to complete the inverse relationship between the A / D conversion work.Through repeated tests found that as long as the conventional A / D converter to change the method, Will V_ (IN) (conventional connection method