Electronics and technology blog    /    Articles    /    Notes in the margins    /    Page 2

Last time, we looked at relatively compact devices for storing electricity that can help you charge your phone, laptop, or tablet. But I can already hear the obvious question: what do you do when you need to power something more demanding, or something that requires AC? So yes, today I’ll talk about uninterruptible power supplies and the finer points of using them.

Lately, I’ve been asked several times about the same thing: how to keep various devices and appliances running when the power goes out. Today I wanted to talk a little about it so I don’t have to repeat my answers in private messages and can save myself some time while giving you a more complete answer.

Today, I'm actually going to talk about a single power supply. The idea for this article came to me spontaneously while I was sorting through a pile of junk at home and came across one of the power supplies.

A few words about what's happening with the blog.

DIY battery pack assembly has become increasingly popular lately, and many beginners run into the question of how best to arrange the cells in a pack to get the maximum capacity. Today, I’ll introduce a handy calculator for working this out.

We decided to take a vacation this year, but it turned out that it’s not as simple as it seems, so I decided to ask the readers.

The Unit UT181A multimeter has a rather useful feature: a built-in real-time clock. But it turns out there’s a glitch—or, more precisely, a glitch with my particular unit. Someone else may run into the same problem, so today I’ll explain one way to fix it.

I've often come across comments along the lines of “Chinese batteries die quickly.” I generally agree, but the question caught my interest, so I decided to look into it more closely—in particular, by testing how many cycles the battery can handle. More details in the article.

A short video that could easily go in the “notes from the field” category.

Many years ago, I picked up a fan with a rather unusual design. I tried to get it running back then, but had no luck, so I ended up putting it on a shelf. Now, after all this time, it’s turned up in my hands again.

Sometimes people bring me all kinds of devices to repair. This time, someone brought in an air conditioner control board with a preliminary diagnosis: the power supply had failed due to a voltage surge caused by a lightning strike.

I once wrote a review of a cordless drill from MILWAUKEE, where I described modifying its original charger. Here, I decided to put the modification instructions in a separate, short post.

Today I’m going to tell you about a small charger that doesn’t quite live up to its advertised specs, even though it’s put together pretty well. Teardown, tests, conclusions—as always.

I've handled quite a lot of different power supplies, but every now and then I come across an epic case that I just have to tell you about.

With this short article, I’m starting a series about repairing various devices that occasionally end up on my workbench. The first article will be about repairing a 5 V, 60 A power supply. I’m also planning to publish articles for beginners, so I’d be interested to know what readers would like to learn about.