Author: Al Williams

4504 Articles

Antenna Analyzer Is A Lab In A Box

March 3, 2017 by 6 Comments

There was a time when the measure of a transmitting radio antenna was having it light an incandescent bulb. A step up was a classic SWR/Power meter that showed you forward and reflected power. Over the years, a few other instruments have tried to provide a deeper look into antenna performance. However, the modern champion is the antenna analyzer which is a way of measuring vector impedance.

[Captain Science] did a review of an inexpensive N1201SA analyzer. This device is well under $200 from the usual Chinese sellers. The only thing a bit odd is the frequency range which is 140 MHz to 2700 MHz. For some extra money (about $80 or $100 more) you can drop the low-end frequency to just under 35 MHz.

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Making Laser Cutter Designs Work In A 3D Printer

March 3, 2017 by 18 Comments

The main mechanical tools in a hacker’s shop used to be a drill press and a lathe. Maybe a CNC mill, if you were lucky. Laser cutters are still a rare tool to find in a personal shop, but today’s hackers increasingly have access to 3D printers. What happens when you have a design for a laser cutter (2D parts) but only have access to a 3D printer? You punt.

[DIY3DTECH] has a two-part video on taking a 2D design (in an SVG file) and bringing it into TinkerCad. At that point, he assembles the part in software and creates a printable object. You can see the videos below.

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Speech To Sign Language

March 2, 2017 by 20 Comments

According to the World Federation of the Deaf, there are around 70 million people worldwide whose first language is some kind of sign language. In the US, ASL (American Sign Language) speakers number from five hundred thousand to two million. If you go to Google translate, though, there’s no option for sign language.

[Alex Foley] and friends decided to do something about that. They were attending McHack (a hackathon at McGill University) and decided to convert speech into sign language. They thought they were prepared, but it turns out they had to work a few things out on the fly. (Isn’t that always the case?) But in the end, they prevailed, as you can see in the video below.

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The Best Of Both Worlds: Arduino + 555 Should Confuse Commenters

March 2, 2017 by 110 Comments

Hardly a week goes by that some Hackaday post doesn’t elicit one of the following comments:

That’s stupid! Why use an Arduino when you could do the same thing with a 555?

And:

That’s stupid! Why use a bunch of parts when you can use an Arduino?

However, we rarely see those two comments on the same post. Until now. [ZHut] managed to bring these two worlds together by presenting how to make an Arduino blink an LED in conjunction with a 555 timer. We know, we know. It is hard to decide how to comment about this. You can consider it while you watch the video, below.

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ESP32 Tutorials

March 1, 2017 by 24 Comments

The ESP8266 has become one of those ubiquitous parts that everyone knows. However, the new ESP32 has a lot of great new features, too. If you want to take the ESP32 for a spin, you should check out [Neil Kolban’s] video series about the device. When we say series, we aren’t kidding. At last count, there were nineteen videos. Some are only a few minutes long, but some weigh in at nearly twenty minutes and the average is somewhere in between.

The topics range from setting up tools and using Eclipse and GDB. There are also tutorials on specific tasks like PWM, analog conversion, real-time operating systems, and more.

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DIY 3D Slicer Is A Dynamo

March 1, 2017 by 15 Comments

We all know that hacker that won’t use a regular compiler. If he’s not using assembly language, he uses a compiler he wrote. If you don’t know him, maybe it is you! If you really don’t know one, then meet these two. [Nathan Fuller] and [Andy Baldwin] want to encourage you to write your own 3D slicer.

Their post is very detailed and uses Autodesk Dynamo as a graphical programming language. However, the details aren’t really specific to Dynamo. It is like a compiler. You sort of know what it must be doing, but until you’ve seen one taken apart, there are a lot of subtleties you probably wouldn’t think of right away if you were building one from scratch.

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Beefy 100 Amp Electronic Load Uses Two MOSFETs

February 28, 2017 by 31 Comments

[Kerry Wong] had some extreme MOSFETs (IXTK90N25L2) and decided to create a high current electronic load. The result was a two-channel beast that can handle 50 A per channel. Together, they can sink 400 W and can handle a peak of 1 kW for brief periods. You can see a demo in the video below.

An electronic load is essentially a load resistor you can connect to a source and the resistance is set by an input voltage. So if the load is set to 10 A and you connect it to a 12 V source, the MOSFET should look like a 1.2 ohm resistor. Keep in mind that’s 120 watts–more power than a common incandescent light bulb. So you are going to need to carry some heat away.

The circuit is pretty simple. The FETs accept a voltage on their gates that sets them to look effectively like a resistor that varies with the voltage. A very small source resistor develops a voltage based on current (only 75 mV for a 50 A draw). That voltage feeds a comparator which generates the gate voltage after looking at the input control voltage. Each millivolt into the comparator translates to an additional 1.33 A through the load.

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