新颖的电路保护器件——聚合体开关

１．概述过流、过热保护元件—聚合体开关是一种聚合体ＰＴＣ（ｐｏｓｉｔｉｖｅＴｅｍｐｅｒａｔｕｒｅＣｏｅｆｉｃｉｅｎｔ）器件。当温度升高时，它的电阻值急剧增加。常态时，聚合体开关的阻值非常低，当流过它的电流达到一定数值时，它的温度急剧升高，当温度达到...     

等离子体中频电源的驱动与保护电路设计

讨论了150 kHz等离子体中频电源的驱动与保护电路设计方案。该电路采用脉冲变压器耦合MOSFET管驱动电路,具有输出变压器原边平均电流和副边峰值电流的过流保护功能。结果表明:驱动波形的上升和下降时间都不超过80 ns,并能在检测到过流信号时封锁驱动信号,关断变换器中的开关器件,切断过流故障,有效进行电路保护。     

用自恢复PPTC器件提高电子设备的可靠性

保护电子电路免于电流过大或温度过高而损坏是众多电路保护技术的一个主要功能。在过去，电路保护一般是采用保险丝或可熔断的导线，但在当前的应用中，可恢复型的器件，例如聚合正温度系数(PPTC)器件、陶瓷正温度系数器件、双金属断路器和恒温开关已经成为首选的解决方案。这些器件在     

PWM开关稳压电源保护及告警电路浅析

本文浅析了PWM开关稳压电源的过流保护，过压保护，欠压保护，过热保护等电路有并联运行的告警方案。     

对一种由555定时电路组成的过电流保护电路的评析与改进

对一种由５５５定时电路组成的过电流保护电路的评析与改进顾水方（苏州新华机床厂，２１５００５）《电子与自动化》１９９４年第１期刊登的韩有望同志的文章《一种由５５５定时电路组成的过电流保护电路》（以下简称“原文”），具有一定的新意，然而所介绍的电路有多处...     

EMI对策元件和电路保护元件的发展与应用

简要介绍EMI对策元件和过电压，过电流，过热电路保护元件的一些最新进展及其应用状况。     

一种高精度的开关稳压电源设计

本文利用PWM芯片TL494,来控制开关电源管IRFP460的导通和截止,利用单片机为控制核心的开关稳压电源,可以输出可调电压在30V-36V之间,最大输出电流为2A;通过键盘能对输出电压进行键盘设定和一伏的步进调整,并通过液晶显示器件显示电流和电压值,同时开关稳压电源具有过流与过压保护功能.     

下一代电子装置使用的过电流和过电压保护元件

防静电、防过电流和过电压冲击是目前工程师设计电子产品时必须考虑的一个问题，否则这些产品的市场销路一定会大打折扣。本文集中探讨了目前市场上所有的电路保护技术，并展望了未来电路保护器件的发展方向。     

松下M15L机心彩电保护电路故障检修(上)

<正> 松下公司设计的M15L型机心彩电共设有两套保护电路,即电源系统过流过压及负载短路保护电路与扫描系统包括束电流保护电路。 上述第一套电源系统保护电路是由Q834、Q851、Q812、Q813等完成+B(113V)过压保护、+12V负载短路与开路无输出保护及待命电源输出过压过流保护的,保护电路动作时控制电源厚膜集成块IC801(STR50213)停止输出电压,因此该套保护电路动作的故障特征是整机无光无图无声,“待机”指示灯常亮或闪烁后常亮。 第二套保护电路是由Q503、Q504、Q451、D502、D520、D522等完成场输出IC401工作电流过大和场偏转线圈电流过大保护、超高压电子束电流过大保护、显像管灯丝电压过高保     

某型天气雷达发射系统控制保护电路的改进

简要介绍了某型天气雷达发射系统高压电源和控制保护电路的工作原理，分析了高压电源在瞬间大电流过荷时电路大面积损坏的原因，指出了控制保护电路存在的问题，并提出了改进措施。     

开关电源过流保护电路设计研究

本文研究了电源过流电路设计方案和特点以及一些常见的开关电源过流保护方式,寻找到良好的保护电路设计。     

一种数控用开关电源保护电路的分析与设计

开关电源的可靠性直接影响到电子产品系统的可靠性。文中从相关数控系统开关电源的各种保护电路着手,分析设计了数控开关电源的软启动电路,过压保护、过流保护、欠压保护等电路的工作原理和具体设计方法,解决了数控开关电源的工作可靠性问题,为数控系统的批量生产提供了保障。     

High-efficiency dual transistor base drive circuit based on the Cukconverter topology

A dual transistor base drive circuit that unifies all important functions (on-state base current power supply for two power transistors, off-state negative U_be =-5 V base-emitter voltage, overcurrent and short-circuit protection scheme based on saturation voltage, and on- and off-state monitoring circuits) is described. The unit provides two base drive outputs using a single switching converter. It can be used to control two individual power transistors in different inverter configurations, e.g. common emitter or bridge configuration. The concept of a dual transistor base drive circuit using the Cuk switching regulator topology enables the low volume construction of a high-efficiency base drive unit for a high-power transistor inverter bridge leg. The circuit is powered from a common DC rail. The base current waveforms are characterized by steep slopes and an overcurrent peak at turn on     

Digital Current Control of a Voltage Source Converter With Active Damping of LCL Resonance

Inductance–capacitor–inductance (LCL)-filters installed at converter outputs offer higher harmonic attenuation than L-filters, but careful design is required to damp LCL resonance, which can cause poorly damped oscillations and even instability. A new topology is presented for a discrete-time current controller which damps this resonance, combining deadbeat current control with optimal state-feedback pole assignment. By separating the state feedback gains into deadbeat and damping feedback loops, transient overcurrent protection is realizable while preserving the desired pole locations. Moreover, the controller is shown to be robust to parameter uncertainty in the grid inductance. Experimental tests verify that fast well-damped transient response and overcurrent protection is possible at low switching frequencies relative to the resonant frequency.     

串联谐振型激光器用开关电源的研制

介绍了采用功率ＩＧＢＴ模块研制成功的大功率串联谐振型激光器用开关电源的工作原理及ＩＧＢＴ的过压、过流保护方法,给出了访原主回路、驱动电路结构及电源系统的相关波形,该电源已成功地应用地双光路激光焊接机上,与传统激光电源比较,有明显优越性。     

基于UCC2897有源正激多路输出电源

随着电力电子技术的飞速发展,各类软开关技术应运而生。文章基于电流控制型芯片UCC2897应用有源箝位技术设计出了一种多路输出的同步整流开关电源。该电源具有过流保护,过压和欠压保护。文中详细介绍了UCC2897的功能和电路设计过程,并采用变压器堆叠绕法和输出比例取样来提高调整率。     

Design of LIGBT protection circuit for smart power integration

Development of a monolithic power integrated circuit by making the lateral insulated gate bipolar transistor (IGBT) the main switching device is a current topic. The overcurrent protection scheme is usually necessary to be built as part of the function in such a power integrated circuit. The protection circuit requires distinguishing various fault conditions and reacting differently based on the device safe operating area (SOA) limitation. At the same time, the protection circuit should also be relatively concise and suitable for integration. In this paper, a concise circuit suitable for integration and with gate drive capability is proposed to provide the complete function of overcurrent SOA protection for the LIGBT. The operational principle was described in detail and the circuit performance was verified with experimental results from both the discrete circuit and the fabricated LIGBT integrated circuit     

Comparison of temperature limits for Trench silicon IGBT technologies for medium power applications

This work focuses on determining the switching limits in temperature for Reverse Conducting IGBTs and compares them to “conventional” IGBTs based on Trench technologies, all them belonging to 600 V–50 A application scenario. After, their leakage current under blocking state is tested at several working temperatures, in order to study the leakage current that limits the blocking safe operating area with temperature. Next, overcurrent tests have been performed. This investigation deals with understanding the overcurrent induced failures due to thermal effects using short circuit tests adapted to our needs. As a result, we observe that RC-IGBTs integrating a free-wheeling diode show the highest leakage losses in blocking state, whereas it presents the best ruggedness under short circuit tests.     

一种新型智能功率模块（IPM）

介绍一种新型智能功率模块的功能、工艺及应用。该功率模块将多块IGBT芯片与其栅极驱动电路、短路保护、过流（OC）保护、过温（0T）保护、欠压（UV）锁定电路等集成封装于一体,具有供电简单、开关速度高、死区时间小、驱动效率高的特点。在技术方面,对IGBT芯片、续流二极管芯片（FWD）、控制驱动电路及封装结构等方面采取了多种优化处理措施,从而使其具有很高的性能价格比。     

Engineering design of lossless passive soft switching methods for PWM converters. II. With nonminimum voltage stress circuit cells

This paper proposes the analysis and design methodology of lossless, passive soft switching methods for PWM converters. The emphasis of the design and analysis is for PWM converters that use nonminimum voltage stress (non-MVS) circuit cells to provide soft switching. PWM converters with non-MVS circuit cells have several distinct advantages over converters that use minimum voltage stress (MVS) cells. With the same relative size of the inductor and capacitor added for soft switching, the non-MVS cells have a substantially larger duty ratio range where soft switching is guaranteed. In addition, the overcurrent stress of the main switch, under most conditions, will be lower and an optimum value of inductor and capacitor added for soft switching can be used. Therefore, with proper design, the non-MVS cells provide higher efficiency. These advantages are obtained with the price of higher switching voltage stress and one additional inductor. The loss model for a MOSFET and optimum capacitor and inductor values are utilized in the design procedure. Examples of the design procedure are given for PFC and DC-DC applications. Experimental results backup the claim of higher efficiency.