This was an unadvertised gem put on in Australia as a trivial midday movie.Viewing it reminded me of the impact that “Colour Purple” had when I watched it among a large audience many years ago. That movie profoundly affected me & others around me I observed. But this movie that I’d never heard of, clearly…

The secret path, saw it today on Lifetime. Oh my goodness, what can I say except I loved it. I thought the story was so sad and yet there was hope laced throughout the story. Just when you think it can’t be any worse, the child runs towards hope and love.I was glued to the…

一、PFC 篇在电能质量和用电效率越来越重要的背景下，采用 PFC+LLC 架构的电源设计越来越普及，并已经开始在很多应用中替代传统的无 PFC 的方案或简单的反激、正激方案。今天我们从基础说起，让各位从入门到精通掌握 PFC+LLC 的先进解决方案。https://xg.zhihu.com/plugin/9a33b7d908c5528bff0100225a7c8980?BIZ=ECOMMERCE首先，为什么要用 PFC？一个没有 PFC 的电源在 AC 输入端的波形通常是长这样的：一想到这么多尖尖电流在我们的电网里流通，是不是有种如坐针毡的感觉？PFC 就是用来解决这个问题的。虽然听起来就很贵的样子，但是 PFC 可以把 AC 输入端的波形变成这样，不止可以保护电网质量，还能治好工程师的强迫症（手动狗头）。PFC 可以有很多种不同实现方式，但大部分实用电路都是在 Boost 或在 Boost 基础上的衍生变形。而从控制方式的角度来说，PFC 主要可以分为 CCM 和 CrM 两类。CCM 控制是指 Boost 电路中的电感电流处于连续导通状态，这样的好处可以用峰值比较低的电感电流实现比较大的输出功率，但同时所带来的问题是二极管反向恢复引入的开关损耗；CrM 控制是指 Boost 电路中的电感电流处于临界导通状态，这种状态下二极管电流是自然过零关断的，所以没有反向恢复问题，但在实现同等输出功率的情况下，CrM 的电感电流峰值必然大于 CCM，这不利于电感设计。基于上述特点，CCM 适合更大功率，而 CrM 适合较小的功率。二者的合理分界线通常在 300W-400W 之间。MPS 提供一系列的先进的 PFC+LLC 集合数字控制芯片HR1211 的 PFC 部分采用 CCM 控制方式，电感电流在重载情况下处于连续状态，并且开关频率可以通过数字接口进行配置。在轻载状态下 HR1211 会自动降低开关频率，并过渡到断续电流状态，以此降低开关损耗，从而达到全范围工作状态下的高效率。https://xg.zhihu.com/plugin/9da1cc990eb1923fa2e8dfc0075c79dd?BIZ=ECOMMERCEHR1275 的 PFC 部分采用 CrM…

Ever picked up a time-saving ‘life hack’ from an online video? Today might be a good day to start because a new study suggests that those little tips and tricks save people almost four hours of effort every week. That’s according to a survey of 2,002 Americans, 41% of whom have described life hacks to…

We may earn a commission from links on this page. A good productivity method can mean the difference between a disorganized, unfulfilling day and one during which you get a lot done and feel great about it. That tradeoff is why so many of these methods, techniques, and hacks exist. That said, not every productivity…

SummaryWhen it comes to working from home, being productive can be a challenge. From animals to house chores, there are a lot of distractions that can wreak havoc on your efficiency. In this article, we cover 11 tips to help you build—and stick—to a routine and increase your productivity at home.There are so many benefits…

When people first begin exploring the world of personal productivity and task management, they either don’t know where to start or can’t seem to find their footing when they do. If you’re one of these people, I’ve assembled 35 quick and simple tips for better productivity – ones you can use right away and start…

SummaryWhen it comes to working from home, being productive can be a challenge. From animals to house chores, there are a lot of distractions that can wreak havoc on your efficiency. In this article, we cover 11 tips to help you build—and stick—to a routine and increase your productivity at home.There are so many benefits…