Small, simple oscilloscope
6-02-2018, 04:16
Some time ago, I published a review of a kit for building a simple oscilloscope. It would have been fine, except that its bandwidth was very limited. I wouldn't say the little device I'm reviewing is much better, but it's rated for a bandwidth of up to 4 MHz. Let's see what it is and how it works :)
Advanced XJW01 LCR Meter DIY Kit
28-01-2018, 21:34
For quite some time now, I’ve been using a homemade meter for measuring capacitor capacitance and ESR, built from a circuit designed by GO, a member of the ProRadio forum. I also use another, equally popular meter, the FCL from the cqham website. Today’s review is of a device that claims higher accuracy and, in practice, combines the two meters mentioned above. Warning: lots of photos, little text. This may be an issue for users on expensive data plans.
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Components, Part 2: Resistors and Their Variants
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9-09-2017, 02:06
The resistor is probably the most common electronic component. I’d venture to say it’s also the oldest component still in use. So I’ll start my detailed look at different electronic components with resistors.

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Components, Part 1: X Capacitors

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1-09-2017, 21:49
With this article, I’d like to start a series about various electronic components: diodes, capacitors, resistors, varistors, and so on. There are so many different components, and I can’t shake the feeling that by the time I finish writing about them, something new will already have come out :) I’ll start with X-type capacitors, especially since this article is a follow-up to my previous article about Y capacitors.

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How to determine a transformer's power

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18-08-2017, 18:47
I've been asked more than once how to determine the power rating of an unmarked 50 Hz transformer, so I'll try to explain and show a couple of examples.

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How switched-mode power supplies with APFC work

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18-08-2017, 02:42
Some time ago, I was asked about the power factor correction circuit in switched-mode power supplies. I’ll try to briefly explain what it is and why it’s needed.

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Oscilloscope and power supply

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2-08-2017, 00:05
A short video about safety when using an oscilloscope to repair and test switch-mode power supplies.
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One example of a power supply repair
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8-07-2017, 01:01
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.
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How a Power Supply Works, Part 5
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24-06-2017, 01:49
Today's article is about the output rectifier, filter, and feedback circuit in switching power supplies. This is the final article in the general introductory series. After this, I plan to answer questions that came up while publishing the previous parts, and then take a closer look at some individual sections.

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How a Power Supply Works, Part 4

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16-06-2017, 14:40
Today we'll look at the next stage after the inverter: the power transformer. This won't be a very long article, but I think it'll be useful.

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What a switching power supply consists of, part 3

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9-06-2017, 11:09
Last time, I covered the input stage of a switching power supply, the bridge rectifier, and the filter capacitors. Now it’s time for the next stage: the inverter. This is the most complex and extensive part, but also the most useful.
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What a Switching Power Supply Is Made Of, Part 2
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31-05-2017, 02:49
I’ve already posted videos about individual parts of a power supply, but after thinking it over, I decided I hadn’t done it the right way—or, more precisely, not in a very logical order—so I’m putting that right. With this article, I’m starting a short series called "How It Works", where I’ll go through all the sections of a typical switching power supply one by one, explain what they do, and point out where components can fail.
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Q&A, attempt one
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17-05-2017, 21:29
I decided to answer a couple of questions people asked me in the comments on a video. This might be useful to other readers too.
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Output Filters for Switching Power Supplies
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20-04-2017, 19:57
A short video about power supply output filters.
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Input Filters for Switching Power Supplies
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18-04-2017, 19:42
It all started when I decided to make a video about power supply filters and what they do. I gave it a try, but realized the topic was too big to cover in a single video, so I ended up splitting it into two parts. The first part is about the input mains filter.
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How to turn a KRENka into a switching converter
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11-04-2017, 20:08
A real-world example of using a linear regulator to build a switching converter.
Another power supply, this time 24 V, 20 A, and 480 W
26-03-2017, 23:57
Not long ago, I posted a review of a 360 W power supply. I mentioned then that I was waiting for a package with a couple more power supplies, but more powerful ones. The package has arrived, and I finally got around to the first one: a 480 W model. So far, this is the most powerful power supply I’ve reviewed (apart from bench power supplies), and it also has some notable differences from the previous ones. But as usual, I’ll take a look, tear it down, and test it.
Set of 0.5–0.9 mm carbide drill bits, a quick look at
14-03-2017, 13:16
Today's brief review is about a fairly ordinary tool: drill bits. There's not much to say about them, and what could you possibly tell people about a small twist drill bit that they don't already know? Still, as usual, I'll take a look at them and try to put them through some kind of test :)


