Electronics and technology blog    /    All publication of the user kirich    /    Page 10

This review—or article, whichever you prefer—is a continuation of my write-up on modifying a power supply to turn it into a low-voltage UPS. Last time, I covered a 150 W power supply and complained that the LRS-150 turned out not to be a very good fit for this purpose. So, let’s see how its bigger brother fares.

The other day, someone brought me a power supply to repair. Well, not exactly for repair: it had already been repaired and was working, but according to the person who brought it in, it was behaving strangely. The result was a little unexpected, and that’s what I wanted to tell you about today, since I think anyone could run into this “quirk.”

As I mentioned earlier, next up is putting the PSU-UPS adapter board to use. Along the way, I'll also review the Mean Well LRS-150 series power supply today.

Not long ago, I posted an example of modifying a Mean Well UPS using my own board. That time, I used an older version of the board, which had some drawbacks due to the simplicity of the circuit design. Today, I’ll show you the new version of the board, which addresses the shortcomings of the previous design.

Today’s article is about repairing—or perhaps restoring—two power supplies from a mini PBX. These units are quite unusual and use some rather unconventional circuit designs, so this will be a long and fairly detailed article. I hope it will be useful for beginners and interesting for experienced repair technicians as well.

I hadn’t even thought about writing up this repair. Then I figured I’d just write a little and add a few photos. But I got carried away, and it ended up becoming an article about how power supplies behave when the voltage is too high, with a little extra theory about the circuitry of the chips.

As I mentioned before, along with the BL1850 and BL1860 batteries, I also received a charger for them. At first, I hadn't even planned to review it, but I tested it while checking the batteries, took it apart, and decided it was probably worth writing about after all.

So, I’ve just finished testing the second battery I received, and this one is the BL1860, rated at 6 Ah. Inspection, teardown, tests, conclusions—as usual.

Not long ago, I was asked to test and review some batteries for Makita power tools. Since this is right up my alley, and the batteries were expected to be good, I thought, why not? In short and subjectively: they’re solid. For the long, objective version, read on.

In my previous article, I wrote that repairing power supplies is usually not cost-effective, and even gave examples of cases where it really does make sense. But I just remembered a simple power supply I worked on fairly recently that’s a good example of when a repair is worthwhile.

Some time ago, I was sent several different pieces of equipment to repair, including a couple of power supplies. The repairs themselves weren’t particularly difficult, but they covered a fairly wide range of common failures. I’d like to use them as examples to show what’s what, what’s best avoided, and what you should definitely do.

The other day, one of my readers offered me some very interesting batteries to test. It turned out he lived just a couple of tram stops away, so of course I couldn't turn him down. My wife and I went for an evening walk, met up, and now I can show you the test results.

First, I should say that I know exactly how this charger works. It’s strange in its own right, but it’s probably better to look at the photos and read the short description. The real surprise comes at the end—I’m almost certain you’ve never seen anything like it.

Some time ago, I reviewed a universal trigger that was advertised as offering convenient controls and Power Delivery support, but in practice it turned out to be pretty mediocre. This time, I bought a few simple, compact models that turned out to be surprisingly good.

Thanks to one of my readers, I got my hands on some very interesting batteries. I should say right away, though, that these days the people most interested in them are precious-metal refiners. I think many radio amateurs know who they are.

These are the fourth Vapcell batteries I've received for review. They use the relatively uncommon 18500 form factor, but have a fairly high claimed capacity for their size, of course.

Today I'm reviewing Vapcell high-capacity 18650 batteries. I can say right away that there's nothing unusual about them, except that they aren't even listed on the Vapcell website.

Just before New Year, I ordered, received, and tested three different battery models. I don’t think I need to explain why I suddenly needed high-capacity batteries. Since people often asked me what their overall quality was like, I decided to put together a quick review of all three models.