摘要：直流恒流源主要用于微型熔断器、继电器、塑壳断路器、空气开关等检测设备中以及需要设定额定电流、动作电流、短路保护电流等生产场合，具有十分广泛的应用背景。本课题通过理论的分析和研究，对几种典型恒流源的进行比较总结，设计出一款基于三极管设计的100A直流恒流源方案。系统引入了串联负反馈的方法保证其输出的稳定性，采用高精度电压基准保证其控制的精确性，多个大功率三极管多级冗余并联来保证其大电流输出，在Multisim 12.0支持下进行系统的搭建和仿真，最终实现了恒流源电流的0-100A连续可调输出，同时就串联负反馈系统自激振荡的消除，三极管的跨导增益与离散性关系，采样电阻的选型，功耗均衡和温度均衡设计等问题进行了分析。39017
毕业论文关键词：恒流源；功率三极管；采样电阻；
The design of 100A DC current source (BJT)
Abstract：DC current source is mainly used for micro fuses, relays, molded case circuit breakers, air switches and other detection equipment and the need to set the rated current, operating current, short circuit protection current, and other production situation, with a very wide range of applications background. This paper analyzed and studied some classical constant-current source, a solution based on triode 100A DC current source programs is designed after its comparison and summary. This system introduced a series of negative feedback method to ensure the stability of its output, high-precision voltage reference is used to ensure the accuracy of control, a plurality of power transistor in parallel multiple levels of redundancy to ensure its high current output, debugging and simulation system is under the auspices of Multisim 12.0, Eventually reaching a constant current source output current 0-100A continuously adjustable, Meanwhile, the problem of a series of negative feedback system eliminates the self-excited oscillation, the transistor transconductance gain and discrete relationship, sampling resistor selection, power and temperature balance issues are analyzed.
Key word：Constant current source; power transistor; sampling resistor;
目录
摘要    I
目录    II
1 绪论    1
1.1 课题选择的目的    1
1.2 国内外研究现状与发展趋势    2
2 三极管BJT简介    4
2.1 放大状态下BJT的工作原理    4
2.1.1 内部载流子的传输过程    4
2.1.2 电流分配关系    5
2.2 BJT的V-I 特性曲线    6
2.2.1 输入特性曲线    6
2.2.2 输出特性曲线    6
2.3 BJT的主要参数    7
2.3.1 电流放大系数    7
2.3.2 极间反向电流    7
2.3.3 极限参数    8
2.4 温度对BJT参数及特性的影响    8
3 恒流源基本原理    10
4 基于三极管设计的恒流源典型电路分析    12
4.1 基本晶体管恒流源    12
4.2 改进式晶体管恒流源    12
4.3 基于集成运放恒流源    13
4.4 改进式集成运放恒流源    14
4.5 推挽功率放大电路    15
5 恒流源的系统原理和设计    16
5.1 直流电源模块的设计    16
5.2 高精度基准电压控制模块设计    17
5.3 导纳放大模块设计    18
5.3.1 三极管增益与离散性关系分析    19
5.3.2 电流串联负反馈电路设计与分析    20
5.3.3 消除自激振荡设计与分析    22 Multisim 100A直流恒流源的设计 (三极管):http://www.751com.cn/zidonghua/lunwen_38112.html