可控硅电路的基本原理

可控硅是一种开关型半导体器件,能在高电压、强电流条件下工作。常用的有单向可控硅和双向可控硅两种,在第六期已经介绍过可控整流原理。本文重点阐述可控硅电路的基础知识。任何一种可控硅电路,都可分为主电路与触发电路两大部分。从电源起经过可控硅器件直到负载的全部电路称为主电路;接在门极和阴极之间的这部分电路称为触发电路。主电路的功能是通过可控硅的特殊开关作用,在电源和负载之间进行电能变换,即触发导通作用。如:     

可控硅触发电路新探

文章较为详细地介绍了用５５６时基电路组成的可控硅触发电路的工作原理及实际应用，该触发电路与一般分立元件组成的触发电路，专用集成电路触发器相比，均有其独到之处。     

几种可控硅的触发电路

本文主要介绍了可控硅的基本原理和常用的几种触发电路。     

触发电路的性能分析及比较

可控硅触发电路是通过调整可控硅的导通角或周波占空比等技术来实现电气设备的电压电流功率调整的一种电力控制器,研究了几种可控硅触发电路的基本结构、工作原理和工作特性等,结合实验测量讨论了各种触发电路的优缺点。与此同时对实验电路进行了分析,阐明了各器件的工作环境、在电路中的作用,说明了操作方法和注意事项。最后,通过实验测得这几种触发电路的输出波形,并对实验结果进行了分析,为今后物理实验的教学提供依据。     

单片机控制的可控硅全波半控桥触发电路

介绍了用ＭＣＳ－９６系列单片机结合外围器件控制可控硅三相全波半控桥的触发电路，给出了实用的原理框图及应用程序，并详细介绍了各部分电路的特点。     

简单易制的万次电子保险丝

<正> 今介绍一种可多次使用的电子保险丝,其电原理图见附图。TV2和VT3构成一个模拟可控硅,R3的作用是在电路刚接上时触发这个模拟可控硅导通,R*的作用是设置允许通过的最大电流。一旦电流输出端B对地短路或电流过大使得R*上的压降达到0.6V,VT1导通.触发可控硅T1导通,     

某型C波段多普勒天气雷达线性脉冲调制器设计

线性脉冲调制器是整个雷达发射分系统的重要组成部分,线性脉冲调制器在放电触发脉冲作用下,形成调制脉冲并可以实现调制脉冲宽度的变化。针对某型脉冲多普勒天气雷达发射分系统的技术要求,对线性脉冲调制器中的可控硅、PFN、均压电路、反峰电路、阻尼电路等进行了相关设计。放电开关可控硅组件体积小,工作效率较高;PFN形成特定脉冲宽度、脉冲幅度和重复频率的调制脉冲;均压电路对可控硅组件进行均压,保证各个可控硅分担的电压相同,防止可控硅出现过压击穿现象;反峰电路消除PFN上的反向电压。通过在脉冲多普勒天气雷达上进行连续使用及测试,该线性脉冲调制器满足雷达发射分系统主要技术指标要求,并具有性能稳定可靠等诸多优点。     

一种简约整流电路的设计

为了降低整流电路的复杂程度,使其移相操作更简单方便,该设计运用锁相环的倍频原理和通用集成电路,只采用一套移相电路,把取自工频电源的同步移相信号输入到锁相环和6分频器构成的6倍频发生器。然后从6分频器中取出6组触发信号,并分别触发6个可控硅,从而构成三相桥式全控整流电路。实验证明该三相桥式全控整流电路与传统的6脉波整流触发电路相比,结构简单、成本低、调试简单。     

过零触发电路在热保护器自动测试系统中的应用

本文研究了热保护器自动测试系统中固态继电器(SSR)的触发电路,给出了热保护器温度控制电路的设计思路,并对电路中的过零触发电路和驱动电路进行了设计和使用。实践结果表明:该电路不但减少对电力系统的危害,电路简单,性能安全可靠,误差极小,而且还可作为各类可控硅、SSR的控制电路或需过零触发的场合。     

TCF792单、三相通用数字相位控制触发电路

TCF792是单、三相通用数字相位控制触发电路.它采用单相同步信号输入,数字分频移相120°,以适应三相触发电路.触发角2-178°,可选择矩形波或调制波输出.脉冲宽度采用电压控制,无需移相电容.在电路功能上全面兼容TC787,TC788,TC790A,TC790B,TCA785,KJ004,KJ041,KJ04等几乎所有种类的单、三相移相触发电路且价格低廉.该芯片移相角可选择传统的锯齿型线性输出或余弦函数输出两种方式.当采用余弦函数输出时,它的整流输出电压与控制电压成线形关系.该芯片可用于可控硅、双向可控硅和晶体管类控制电路.它可用于交直流转换Q电路、交流控制和三相电流控制器.它具有价廉、易用、性能优良、无需调试的优点.     

Temperature-dependence of steady-state characteristics of SCR-type ESD protection circuits

Experimental analysis of the temperature-dependent I–V characteristics of various SCR (Silicon-Controlled Rectifier) electrostatic discharges (ESD) protection circuits have been carried out. These circuits include diode-chain-triggering SCR (DCTSCR), low-voltage zener diode trigger SCR (ZDSCR), low-voltage trigger SCR (LVTSCR) and gate-coupled low-voltage trigger SCR (GCSCR) circuits. The ZDSCR uses the zener breakdown mechanism of a reverse-biased p⁺–n⁺ diode as a trigger mechanism, the DCTSCR uses the current flowing through forward-biased diode chain as a trigger mechanism, the LVTSCR uses the grounded-gate MOSFET breakdown current as the trigger mechanism and the steady-state I–V characteristics of GCSCR also uses the avalanche breakdown as a triggering mechanism. The trigger voltage can decrease or increase with increasing temperature depending upon the triggering mechanism used in the circuit, however the holding voltages of these SCRs decrease with increasing temperature.     

利用ISE-TCAD分析和设计SCR结构的静电保护电路

传统的ESD保护电路设计主要基于尝试性和破坏性的实验,这种方法不利于产品的推出[1]。文中提出使用ISE-TCAD工具对ESD保护电路进行模拟和优化,以快速地获取面积参数。并以某一典型0.6μmCMOS工艺的可控硅整流器(SCR)结构为例,进行ESD人体放电模型的模拟和面积估算,达到了缩短设计周期和增加设计成功率的目的。     

带CPLD新型通用数字触发器的设计

针对模拟触发器和基于微机控制的数字触发器存在的不足.提出了一种以复杂可编程逻辑器件(CPLD)和锁相环技术为核心的新型通用数字触发器,对其硬件电路和软件设计进行了详细分析.最后通过实验验证了该触发器的有效性和可行性.另外,由于CPLD具有在线多次编程功能,因此该触发器不必改变外围电路,只需在线修改软件程序,适用于各种晶闸管触发装置中.该触发器不仅控制精度高,调式方便,而且应用灵活,成本低廉,可以满足不同类型触发电路的要求.     

一种新型主动轮触发方法的技术研究

履带式车辆主动轮测试工况复杂且测试电路灌封于密闭壳体内,常规的触发方式无法实现触发。针对上述问题,本文提出了一种新型触发方式将信号传递到壳体内部。该触发方式在测试仪壳体内壁放置薄膜线圈,通过外部电磁铁通断电产生交变磁场,从而激励壳体内壁薄膜线圈产生感应电动势。利用Ansoft Maxwell软件,对交变磁信号在封闭壳体中传递的可行性进行了仿真研究,并通过实验进行了验证。仿真及实验结果表明,交变磁信号能够在封闭壳体中传递,实现主动轮内测试电路的触发。     

Design and Enactment of Diverse Low Power Techniques Based Schmitt Trigger

In the present-day VLSI system, low power design plays a noteworthy role. As we know that, a circuit with higher power consumption can ruin the performance of the system because in the modern world most of the systems are portable. Subsequently, they are functioned by the batteries. Therefore, it is desirable to have a system which operates at lower supply voltages along with maintaining the performance of the system. This low power system can be attained by abating the leakages of the devices up-to an enormous magnitude. In the contemporary VLSI system, a major role is being contributed by the Schmitt trigger circuit. Schmitt trigger is fundamentally a comparator. It is implemented by using a positive feedback. The Schmitt trigger circuit is used in various devices such as buffer, sub-threshold SRAM, sensors and PWM circuit. It is also used in analog to digital converter. The most significant property of the Schmitt trigger is that they provide hysteresis in their voltage transfer curve. Consequently, they provide better noise immunity as compared to their counterparts. Therefore it becomes quite important to enhance the performance of the Schmitt trigger circuit. The power dissipation of the device can be minimized by minimizing the sub-threshold current. The Schmitt trigger circuit is very imperative in producing a clean pulse from the input signal comprising of noise. There are various applications of Schmitt trigger circuit such as in scheming the oscillator circuit, analog to digital converter, function generator, signal conditioning and numerous applications. Thus, it becomes noteworthy to boost its performance by plummeting the leakages and power consumption of the Schmitt trigger circuit. We have realized the Schmitt trigger circuit by the use of FinFET. Therefore, we have got some optimum output in the parameters such as hysteresis width, power consumption and total noise of the Schmitt trigger circuit, but the leakages have been augmented. Thereafter, we have implemented several techniques on the Schmitt trigger circuit to shrink the leakage current, leakage power and other parameters further. We have applied Self Controllable Voltage Level, Adaptive voltage level and MTCMOS technique on the Schmitt trigger circuit using FinFET to further augment the presentation. All the circuits have been simulated in the virtuoso tool of the cadence in 45 nm VLSI domain. We have applied 0.7 V of the supply voltage to perform the simulation and got some tremendous outcome.     

一种用于混合电压芯片的新型ESD防护触发电路

为了降低芯片成本,通过使用低压器件串联的方式构造静电防护触发电路,使芯片在没有使用高压I/O器件的情况下实现了高压电源域的ESD防护。由于该触发电路未使用电容器件,因此有效地降低了ESD触发电路所占用的芯片面积,并且该电路为静态电压触发,其开启时间可远长于一般电容电阻耦合的触发电路。通过在HSPICE中使用类ESD(ESD-like)的方波脉冲,可以看出该电路在发生ESD时能有效地触发ESD器件,而在芯片正常工作时不易因外界干扰而产生误触发。     

基于AVR单片机的三相晶闸管触发电路的研制

介绍了一种应用于三相晶闸管整流或逆变电路的数字移相触发电路,该电路以AVR(At-mega16)单片机为核心,产生的触发脉冲稳定性好、可靠性高,并且不需同步变压器,具有相序自适应功能的双脉冲序列数字移相触发器电路。阐述了触发器的工作原理,并分析了触发器涉及的关键问题。现场实验证明,该相控数字触发电路简单可靠,产生的脉冲对称性好,抗干扰能力强。本系统在实际应用中也已显示出触发精度高、可靠性高、易于调试、操作方便等优点。     

应用于ESD防护电路的抗噪声LVTSCR组件研究

应用于ESD防护的低压触发SCR组件,当受到电路噪声干扰时,极易造成SCR组件的误导通,进而影响到电路的正常功能,严重时可以产生持续的闩锁效应,造成SCR组件烧毁。通过改进SCR的结构,提高该SCR组件的触发电流,或者提高该SCR组件的保持电压,使其抗噪声干扰能力大大增强。另外,文中对触发电流与温度的关系、保持电压与N+区宽度的关系也做了分析。     

A multibit test trigger circuit for megabit SRAMs

A multibit test (MBT) trigger circuit for megabit SRAM packages with no unused pins is discussed. The features of the MBT trigger circuit are a logic trigger mode without using any additional pins and practical use of counter circuits. The essence of trigger mode selection is that two pulses are for MBT set and three pulses are for MBT reset. In this way, a logic trigger mode that does not use NC pins is especially effective as a 4-Mb SRAM. In addition, the proposed scheme is able to act as a logic trigger for an MBT circuit. The scheme is simple and effective. The logic trigger mode is proposed for future standardization     

一种改进的晶闸管触发电路研究

晶闸管触发电路的作用是产生符合要求的门极触发脉冲,保证晶闸管在需要的时刻由阻断变为导通。为了在寒冷条件下对软起动器的晶闸管可靠触发,针对传统触发电路触发脉冲前端无强脉冲,在传统的触发电路基础上进行了改进。通过改进,使触发脉冲的电流前沿有了强触发脉冲。实验证明,该触发电路满足了实际的需要。