Power Resistance Isn’t Futile

May 14, 2024 by 17 Comments

As [Electronoobs] points out, everything has resistance. So, how hard can it be to make a high-power resistor? In the video below, he examines a commercial power resistor and how to make your own using nichrome wire.

Sure, in theory, you can use a long piece of wire, but normally, you want to minimize the amount of space occupied. This leads to winding the wire around some substrate. If you just wind the wire, though, you get an inductor. This can cause nasty voltage spikes when there is a change in current through the resistor. You can get “noninductive” wire wound resistors that use either two opposing windings or alternate the turn direction on each turn. This causes the magnetic fields to tend to cancel out, reducing the overall inductance.

Nichrome wire has more resistance per millimeter and can dissipate more power. Modern digital meters can measure the resistance of a wire if you account for the test leads. To make a substrate, [Electronoobs] got creative since he anticipated generating a lot of heat. The final product even uses water cooling.

Why do you want a big resistor? Maybe you need a dummy load, or you want to drain some batteries. If you want to recycle nichrome wire, it is much more common than you might expect.

Continue reading “Power Resistance Isn’t Futile” →

GitHub Hosts Ham Radio

May 13, 2024 by 23 Comments

[Alex R2AUK] has been busy creating version two of a homebrew all-band ham radio transceiver. The unit has a number of features you don’t always see in homebrew radios. It covers the 80, 40, 30, 20, 17, 15, 12, and 10 meter bands. The receiver is a single-IF design with AGC. The transmitter provides up to 10W for CW and 5W for single sideband operations. There’s a built-in keyer, too. A lot of the documentation is in Russian (including the video below, which is part of a playlist). But translation tools are everywhere, so if you don’t speak Russian, you can still probably figure it out.

The VFO for both transmit and receive is an Si5351. The transmit chain is straightforward. The receiver reuses many of the same filters.

Continue reading “GitHub Hosts Ham Radio” →

The New Extremely Large Telescopes And The US’ Waning Influence In Astronomy

May 13, 2024 by 55 Comments

For many decades, the USA has been at the forefront of astronomy, whether with ground-based telescopes or space-based observatories like Hubble and the JWST. Yet this is now at risk as US astronomers are forced to choose between funding either the Giant Magellan Telescope (GMT) or the Thirty Meter Telescope (TMT) as part of the US Extremely Large Telescope (USELT) program. This rightfully has the presidents of Carnegie Science and Caltech – [Eric D. Isaacs] and [Thomas F. Rosenbaum] respectively – upset, with their opinion piece in the Los Angeles Times going over all the reasons why this funding cut is a terrible idea.

The slow death of US astronomy is perhaps best exemplified by the slow death and eventual collapse of the Arecibo radio telescope. Originally constructed as a Cold War era ICBM detector, it found grateful use by radio astronomers, but saw constant budget cuts and decommissioning threats. After Arecibo’s collapse, it’s now China with its FAST telescope that has mostly taken the limelight. In the case of optical telescopes, the EU’s own ELT is expected to be online in 2028, sited close to the GMT in the Atacama desert. The TMT would be sited in Hawai’i.

Continue reading “The New Extremely Large Telescopes And The US’ Waning Influence In Astronomy” →

Broken Lens Provides Deep Dive Into Camera Repair

May 13, 2024 by 18 Comments

While most of us are probably willing to pick up the tools and void the warranty on just about anything, often just to see what’s inside, many of us draw the line at camera gear. The tiny screws, the complex mechanisms, and the easily destroyed optical elements are all enough to scare off the average hacker. Not so for [Anthony Kouttron], who tore into a broken eBay Sigma lens and got it working again.

Now, to be fair, modern lenses tend to have a lot more in them that’s amenable to repair than back in the old days. And it seemed from the get-go that [Anthony]’s repair was going to be more electronic than optical or mechanical. The 45-mm lens was in fantastic shape physically, but wouldn’t respond to any controls when mounted to a camera body. Removing the lens bayonet mount exposed the main controller PCB, which is tightly packed with SMD components and connectors for the flex cables that burrow further into the lens to its many sensors and actuators. By probing traces with his multimeter, [Anthony] found a DC-DC converter on the main PCB with an unknown component nearby. This turned out to be an SMD fuse, and as luck would have it, it was open. Replacing the fuse got the lens working again, and while there’s always the nagging suspicion that whatever blew the fuse the first time could happen again, the repair seems to have worked.

Despite the simplicity of the fix, [Anthony] continued the teardown and shared a lot of tips and tricks for lens repairs, including where he would have looked next if the fuse had been good. One tip we loved was the use of double-sided tape to organize parts as they’re removed; this is particularly important with camera gear where screws or different lengths can make for a really bad day on reassembly.

Feeling the need to dive deeper into lens repair? This step-by-step repair should keep you satisfied.

GPS At Any Speed

May 13, 2024 by 39 Comments

[Mellow_Labs] was asked to create a GPS speedometer. It seems simple, but of course, the devil is in the details. You can see the process and the result in the video below.

We have to admit that he does things step-by-step. The first step was to test the GPS module’s interface. Then, he tried computing the speed from it and putting the result on a display. However, testing in the field showed that the display was not suitable for outdoor use.

That prompted another version with an OLED screen. Picking the right components is critical. It struck us that you probably need a fast update rate from the GPS, too, but that doesn’t seem to be a problem. Continue reading “GPS At Any Speed” →

Sandwizz Promises To Reinvent The Breadboard

May 13, 2024 by 42 Comments

The solderless breadboard is perhaps the electronic hobbyist’s most commonly used tool, but let’s be honest, it isn’t exactly anyone’s favorite piece of gear. Even if you’ve got an infinite supply of jumpers in just the right size, any mildly complex circuit quickly becomes a nightmare to plan out and assemble. To say nothing of the annoyance of trying to track down an intermittent glitch, only to find you’ve got a loose wire someplace…

The Sandwizz Breadboard hopes to address those problems, and more, by turning the classic breadboard into a high-tech electronics prototyping platform. The Sandwizz not only includes an integrated power supply capable of providing between 1.8 and 5 volts DC, but also features an array of integrated digital and analog components. What’s more, the programmable connection system lets you virtually “wire” the internal and external components instead of wresting with jumper wires.

To configure the Sandwizz, you just need to connect to the device’s serial interface with your favorite terminal emulator and work your way through its text-based menus. You can also export a netlist file from your KiCad schematic and upload it into the board to make all the necessary connections automatically. This lets you make the leap from concept to physical prototype in literally seconds.

Continue reading “Sandwizz Promises To Reinvent The Breadboard” →

The Art Of Hackaday Hack Chat

May 13, 2024 by 15 Comments

Join us on Wednesday, May 15 at noon Pacific for the The Art of Hackaday Hack Chat with Joe Kim!

Here at Hackaday, we writers strive to bring you the freshest hacks and the best news from the world of engineering and science. When we miss the mark and make technical errors or stake out a controversial position on something, our readers will certainly let us know in the comments section. It’s a love-hate thing.

While we don’t always see eye to eye, there’s one thing that everyone seems to agree on: Hackaday’s art is amazing! Our unique look comes down to one man: art director Joe Kim. Joe’s creations have graced Hackaday’s pages for years, and his ability to come up with just the right art to illustrate subject matter that’s often complicated and abstract never ceases to amaze.

join-hack-chatA lot of you have asked about Hackaday’s art over the years, so we asked Joe to come on the Hack Chat to talk about the process of creating these mini masterpieces. If you’ve ever wondered about the art of Hackaday, or just wanted to say thanks for the visual feast, here’s your chance.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, May 15 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.