CV Based Barking Dog Keeps Home Secure, Doesn’t Need Walking

Meet [Tanner]. [Tanner] is a hacker who also appreciates the security of their home while they’re out of town. After doing some research about home security, they found that it doesn’t take much to keep a house from being broken into. It’s true that truly determined burglars might be more difficult to avoid. But, for the opportunistic types who don’t like having their appendages treated like a chew toy or their face on the local news, the steaks are lowered.  All it might take is a security camera or two, or a big barking dog to send them on their way. Rather than running to the local animal shelter, [Tanner] used parts that were already sitting around to create a solution to the problem: A computer vision triggered virtual dog.

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Toddler EV Gets Big Boy Battery Upgrade

No matter the type of vehicle we drive, it has a battery. Those batteries wear out over time. Even high end EV’s have batteries with a finite life. But when your EV uses Lead Acid batteries, that life is measured on a much shorter scale. This is especially true when the EV is driven by a driver that takes up scarcely more space in their EV than a stuffed tiger toy! Thankfully, the little girl in question has a mechanic:

A 3d printed adapter sends go-juice to the DC-DC converter

Her daddy, [Brian Lough], who documented the swift conversion of his daughter’s toy truck from Lead Acid to Li-Ion in the video which you can see below the break.

Facing challenges similar to that of actual road worthy passenger vehicles, [Brian] teamed up with [bitluni] to solve them. The 12 V SLA battery was being replaced with a 20 V Li-Ion pack from a power tool. A 3d printed adapter was enlisted to break out the power pins on the pack. The excessive voltage was handled with a DC-to-DC converter that, after a bit of tweaking, was putting out a solid 12 V.

What we love about the hack is that it’s one anybody can do, and it gives an inkling of what type of engineering goes into even larger projects. And be sure to watch the video to the end for the adorable and giggly results!

Speaking of larger projects, check out the reverse engineering required in this Lead Acid to Li-Ion conversion we covered in 2016.

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Love Is A Burning Flame, And So Is This Underwater Burning Ring Of Fire

When Johnny Cash wrote “Ring of Fire”, he was talking about love. But when an unnamed follower of [TheBackyardScientist] took it literally and suggested making actual rings of fire — underwater —  they rose to the challenge as you can see in the video below the break.

Of course there are several ingredients to underwater fire rings. First you need water, and a pool clearly does the job in this video. Second, you need flammable rings of gas. [TheBackyardScientist] decided to build a machine to create the gas rings, and it’s quite interesting to see them go through several iterations before settling on a voice coil based poppet valve design. We must say that it works absolutely swimmingly.

Lastly there needs to be fire. And for fire, you need something flammable, and something shocking. Forty thousands volts light up a spark plug, even underwater. The fuel is provided by what appears to be compressed air and acetylene but we’re not 100% sure. We are sure that it goes bang! quite sufficiently, as demonstrated by its aptitude for blowing things up.

We appreciated the engineering that went into the project but also the rapid iterations of ideas, the overcoming of serious obstacles and the actual science that went into the project. Even if it is just randomly making literal burning rings of fire.

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Protecting The Hughes H4 Hercules With… Beach Balls?

Ryan in the Spruce Goose pilot seat

While visiting the Evergreen Aviation & Space Museum in McMinnville, OR, USA over the weekend, I came across a hack.

In addition to the excellent displays on site and an area where one can watch a video on repeat, the museum offers guided tours for a very reasonable price. And it was during this tour that my life as an aviation geek changed forever. Why? I got to visit the flight deck of the H4 and even sit in the pilots seat where Howard Hughes sat when he flew the plane almost 75 years ago.

It was later in the tour, after I’d had a moment to take in the enormity of sitting in the seat, that I found a wonderful hack to share with you all: and it’s all about beach balls. Continue reading “Protecting The Hughes H4 Hercules With… Beach Balls?”

Condemned Precision Capacitors Find New Home, Refuse To Become Refuse

Ah, the age old tradition of Dumpster diving! Sometimes we happen to spot something that’s not quite trash, but not quite perfect, either. And when [dzseki], an EEVblog.com forum user, spotted some high-precision capacitors being 86’d at their employer’s e-waste pile, [dzseki] did what any good hacker would do: took them home, tested them, and tore them down to understand and either repair or reuse them. They explain their escapades and teardown in this EEVblog.com forum post.

High-precision capacitors with RF connectors.

If you’re not familiar with capacitors, they are really just two or more plates of metal that are separated by an insulator, and in the case of these very large capacitors, that insulator is mostly air. Aluminum plates are attached with standard bolts, and plastic insulators are used as needed. There’s also discussion of an special alloy called Invar that lends to the thermal stability of the capacitors.

[dzseki] notes that these capacitors were on their way to the round file because they were out of spec, but only by a very, very small amount. They may not be usable for the precision devices they were originally in, but it’s clear that they are still quite useful otherwise. [dzseki]

Of course, Dumpster diving for cool parts is nothing new, and we’ve covered nifty projects such as this frankenmonitor bashed together from two bin finds.

Thank you [David] for the great tip, and don’t forget to leave your own in the Tip Line.

Reverse Engineering A Phased Array System Reveals Surprising Details

The term “phased array” has been around for a long time, but in recent years we’ve heard more and more about the beam shaping that’s possible with phased array antennae. In the video below the break, [The Signal Path] breaks down a Qualcomm 60GHz WiGig unit, and does a deep dive, even looking at the bare silicon and an x-ray of an antenna.

An X-Ray of the antenna shows the intricate design

Some fascinating highlights include how not only the data signal is sent to the antennae through a standard coaxial cable, but so are control signals and a base clock frequency. [The Signal Path] explains how the manufacturer chose to use what’s called a SuperHeterodyne (aka “superhet”) architecture, which is not all that different from those used in traditional amateur radio transceivers. In theory, anyway.

Another element that is discussed is how the PCB’s themselves are used as waveguides, inductors, and transmission line matches, among other countless little hacks to fit a rather complex system into a truly diminutive space.

If you’re not familiar the concept behind phased arrays, check out this article we published in 2019 that shows how phased arrays can steer a beam without any moving parts. It’s quite fascinating!

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Transparent Cylinder Shows You What You Otto Know About 4 Cycle Engines

When we think of a typical four stroke internal combustion engine, we think of metal. And for any type of longevity or performance, that’s certainly the right choice. But [Integza] wanted to see what happens inside a 4 stroke engine, and it wasn’t enough to see it from a transparent cylinder head. No, he wanted to see it in the cylinder itself. Thanks to advances in material sciences, he got his wish as seen in the video below the break.

While researching possible transparent materials to use as a cylinder on his model engine, he learned about resin polishing. Combining his newly learned resin polishing knowledge with his knowledge of 3D printing, [Integza] printed a new cylinder and polished the resin until it was transparent. The engine ran, but misfired terribly.

The experiment progressed into trying different fuels and learning the differences between them, as well as uncovering a new-to-him mystery: Why was the engine misfiring, and why did the different fuels act so dramatically different? Indeed, more learning and more experimenting is needed. But if you want to see the great sight of watching combustion take place in slo-mo, you have to check out the video below.

3D printing has come a long way in a short time, and may even hold the key to practical scramjets for hypersonic aircraft.

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