开关电源端口浪涌抗扰度抑制措施

针对某开关电源浪涌（冲击）抗扰度试验的失败案例,结合安规要求进行分析,提出了保护电源端口的整改方案,并详细介绍了如何正确选择压敏电阻（MOV）及负温度系数（NTC）热敏电阻。整改后,该产品的浪涌抗扰度测试结果符合标准要求。     

新型复合输入滤波器及仿真

文章针对电源的浪涌保护提出了一种新型滤波器,该滤波器具有大电流浪涌保护和滤波双重功能。同时还采用matlab对电路在受到8/20μs冲击电流后的响应进行了仿真。结果表明电路具有很强的浪涌抑制能力。     

产品导购

NTC热敏电阻及温度传感器 ●高精度玻封热敏电阻 ●各种外型封装的高精度温度传感器(探头) ●抑制浪涌电流热敏电阻 ●高钻度超小型电容式NTC热敏电阻(即单端方角引线)     

产品导购

NTC热敏电阻及温度传感器 ·高精度玻封热敏电阻 ·各种外型封装的高精度温度传感器(探头) ·抑制浪涌电流热敏电阻 ·高精度超小型电容式NTC热敏电阻(即单端方角引线) ·热敏温控开关 ·半导体制冷片     

浪涌电流限制器STIL02在临界模式PFC升压变换器中的应用

以半可控整流器桥路(HCRB)为基础的STIL02浪涌电流限制器克服了NTC热敏电阻在热态重启时浪涌限流功能变差以及热态功耗较大的缺点，因而是一款优质高效的新型浪涌电流限制器。文中介绍了STIL02临界模式PFC升压预调整器中的应用，同时给出了其应用电路。     

相控阵雷达阵面电源保护电路的研制

阵面电源的保护电路关系到阵面电源的可靠性和安全性,关系到雷达的安全性和可靠性,文中提出了比较新颖的阵面电源的防浪涌电流的软启动电路、输入过欠压电路和缺相保护电路,并进行了仿真分析和试验研究,为阵面电源的设计提供了经验.     

微波站防雷技术问题的探讨

葫芦岛微波总站针对当前电子设备防雷工作存在的问题,结合目前广泛使用的浪涌保护器、压敏电阻器等防雷元器件的技术参数、选择方法进行探讨、实践,认为浪涌保护器多级保护中保护电压值应逐级递减、最后一级的保护电压值应不超过交流250伏;浪涌保护器接保护地线端应改接到零线;提出了浪涌保护器等防雷器件自身过度保护的问题;提出了利用压敏电阻器进一步限制电源过电压的原则和方法 ;在信号传输天馈系统使用压敏电阻器进行防雷保护。配合其它的综合防雷措施,取得了很好的效果,提高了电子设备的抗雷击性能。     

产品导购

●高精度玻封热敏电阻 ●各种外型封装的高精度温度传感器(探头) ●抑制浪涌电流热敏电阻 ●高精度超小型电容式NTC热敏电阻(即     

大功率机载电子设备瞬态电压保护电路设计

介绍了机载配电系统中过压浪涌与欠压浪涌两种瞬态电压干扰的信号特征及防护机理。阐述了目前常见的几种瞬态电压防护方案电路的基本原理,分析了这几种防护方案对大功率设备的限制因数。采用一体化设计思想,提出了大功率设备断电型瞬态电压保护电路,并设计了样机。最后通过试验验证了大功率设备的断电型瞬态电压保护电路可有效抵抗机载航空电源所产生的浪涌电压。     

NTC热敏电阻温度传感器高精度负温度系数

高精度NTC热敏电阻温度传感器在国内的大量应用始于80年代初期,尽管我国NTC热敏电阻温度传感器批量生产起步较早,分布全国各地,但多属中小型企业,主要产品80％以上为片状元件,多为温度补偿和抑制浪涌电流之用,即使有部分用于电子产品的测控温,也是测控温精度不高,而国内最具权威水平的中科院新疆物理研究所,生产高精度NTC热敏电阻温度传     

抑制浪涌电流用NTCR热敏电阻器的失效模型

通过对抑制浪涌电流用NTCR热敏电阻器的失效样品进行电性能和显微分析得知，其失效机理在于微观结构不均匀及银层与瓷体的接触不良。建立了表面失效、内部缺陷、外观失效三种模型。确定了影响失效的因素及对策。     

A thyristor- and thermistor-based inrush current limiter for DC-link start-up

Large inrush currents can be harmful to equipment subjected to it and can also disturb other devices through voltage dips. Traditional ways of dealing with large inrush currents include the usage of parasitic elements in the supply, negative temperature coefficient (NTC) resistances and start-up relays. These solutions have several disadvantages among which are a non-negligible standby consumption, using a relay or a compromise between inrush current and load losses using an NTC. This paper proposes a solution which solves these disadvantages. The proposed circuit uses a semi-controlled bridge rectifier requiring a very low standby power consumption and is capable of withstanding grid interruptions. Moreover, it is designed to power on only when the load is not too heavy. This is accomplished by the use of positive temperature coefficient thermistors. The presented solution can be used for DC-link start-up circuits in applications with a power range from several watts up to a few kilowatts and it is particularly suitable for on-board battery chargers designed for electrical vehicles.     

Workload- and process-variation aware voltage/frequency tuning for energy efficient performance sustainability of NTC manycores

The power-wall raised by the stagnation of supply voltage in deep-submicron technology nodes, is now the major scaling barrier for moving towards the manycore era. At the same time, the adoption of manycore architectures is considered to be crucial for satisfying the increasing computational power demands and throughput requirements imposed by the explosion in software complexity and volume. The rise of the so-called Dark Silicon, caused by the power budget violations that allow only a small portion of the available computational resources to be simultaneously exploited, points to the direction of energy efficient platforms. Near-Threshold voltage Computing (NTC) has emerged as a promising approach to overcome the manycore power-wall, at the expense of higher sensitivity to process variation and reduced performance which can be compensated with massive parallelization. Given that several application domains operate over specific performance constraints, the performance sustainability is considered a major issue for the wide adoption of NTC. In this work, assuming a feasible, low overhead Power Delivery Network (PDN) for NTC, we investigate how performance guarantees can be ensured when moving towards NTC manycores through a variability-aware voltage and frequency allocation methodology, showing that performance can be efficiently sustained at the NT region while reducing energy dramatically. Additionally, we propose an algorithm for balancing throughput under process (and workload) variation that sustains performance while providing significant energy savings.     

IGBT junction and coolant temperature estimation by thermal model

The capability of IGBT (Insulated Gate Bipolar Transistor) to handle heat is one of its main limitations of high power application. This paper aims to study an IGBT thermal model under flow cooling condition and estimate the IGBT module junction and coolant temperature. Firstly, this paper studies the IGBT module internal sandwich structure and calculates the thermal resistance and thermal capacitor for each layer using a 1D physical model. Then a Cauer electric model is built for the IGBT module to evaluate the thermal constant time of the model. The liquid cooling method is applied in this project for fast cooling and the thermal parameters are studied and measured since this cooling method involves both solid and liquid. In order to estimate the junction temperature, the sensing temperature from NTC (Negative temperature coefficient) resistor inside the module is used as reference temperature. The equivalent thermal models, also named Foster model, from both junction to NTC and NTC to coolant are built, respectively. With these thermal models, the junction and coolant temperature estimation methods are derived. For the purpose of making the estimation accurate, the thermal coupling effect is carefully studied. Finally, the thermal model is verified by inverter application with current steps sweeping; the estimated temperature is compared with thermal camera measurement result which demonstrates good accuracy of the thermal model. The estimated coolant temperature is also well matched with thermocouple measurement result.     

电源的雷电浪涌效应及加固技术研究

雷电浪涌是雷电对电子系统的一种重要的作用形式。雷电对电子系统的影响主要表现在对电源电路的浪涌破坏和干扰上。为研究雷电浪涌对电源的冲击效应,进行了雷电浪涌对直流电源的冲击实验。实验表明,雷电浪涌对直流电源有很大的干扰作用,可使电源产生大的波动或高频噪声。在雷电流涌冲击实验的基础上,对直流电源进行了加固实验,并取得了良好的效果。     

SrxPb1—xTiO3基陶瓷材料热敏特性研究

以Sr     

直流开关电源的欠压浪涌抑制技术

针对开关电源在欠压浪涌中存在的诸多问题,分析了瞬态欠压浪涌的工作机理、抑制方法,以及由此引起的负载端启动电流或浪涌电压的处理思路,给出了处理直流开关电源欠压浪涌的合理解决方案。     

薄膜封装型NTC热敏电阻器的研制

为适应电子整机产品狭窄空间安装的需要,NTC热敏电阻器(NTCR)要进行超薄设计。采用固相反应法制粉,压锭烧结制作NTCR芯片,焊接引线和薄膜封装等工艺方法实现产品的薄形化封装,研制出了一种阻值R25为10k?,材料常数B为3435K,产品最大厚度仅0.5mm的新型薄膜封装型NTC热敏电阻器,为家电产品和生产设备的轻薄化推出了一种新型NTC热敏电阻器。     

利用“软启动电路”消除开关电源浪涌电流

详细论述了软启动电路的电气工作原理,包含两条设计原则：即在加电瞬间除去负载、同时限制有用的电流。实践证明利用＂软启动电路＂消除开关电源浪涌电流的方法大大优于传统的输入浪涌电流限制方法,而且该电路可以改制成适合于各种开关电源所用的电路中,具有不错的市场推广价值。