Drone Flies 12 Cm On Wireless Power

[Sam M] wrote in with a quick proof-of-concept demo that blows our socks off: transferring enough power wirelessly to make a small quadcopter take flight. Wireless power transfer over any real distance still seems like magic to us. Check out the videos embedded below and you’ll see what we mean.

What’s noteworthy about this demo is that neither the transmitter nor the receiver are particularly difficult to make. The transmitting loop is etched into a PCB, and the receiver is made of copper foil tape. Going to a higher frequency facilitates this; [Sam M] is using 13.56 MHz instead of the kilohertz that most power-transfer projects use. This means that all the parts can be smaller and lighter, which is obviously important on a miniature quadrotor.

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Wilderness Radio Build

[AA7EE] is no stranger to building radios. His latest is a from-scratch build of a 20 meter QRP transceiver based on the popular SST design. Although the SST has been available as a kit, [AA7EE] incorporated some design changes from others and some of his own, too. He even added an onboard keyer to simplify operation. You can see videos of the radio below.

The build uses Manhattan-style PCB pads. Although the construction is very attractive, the real value of the post is the detailed explanation of not only how, but why everything is the way it is. This isn’t a simple project, and being able to see it completed step-by-step is very educational. About the only decision not adequately explained was the change of red and yellow knobs to black! You can see both versions in the videos below.

The Manhattan construction is tidy, but the radio also has an attractive case. The size is just big enough to stack a pair of paddles on top.

There may be some more enhancements for the little radio coming. We’ve covered [AA7EE’s] RF exploits before, including a physically attractive radios and details about the same construction method used in this radio.

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Hackaday Prize Entry: High End Preamps

While compact disks are seeing an uptick in popularity thanks to a convenient format that offers a lossless high-quality 44.1 KHz sample rate with 16-bit depth, some people are still riding the vinyl bandwagon of 2010. With that comes a need for the best hardware, and that means expensive cartridges and preamps designed by someone who knows what they’re doing.

For this year’s Hackaday Prize, [skrodahl] is building a really, really good preamplifier for moving coil turntable cartridges. It’s already built, it’s already tested, and the results are good: it produces between 36 and 46dB of gain, -110dB of dynamic range, and a signal to noise ratio of 79.46 relative to a 5mV input. That puts this preamplifier into the same territory as preamps sold with serial numbers, crystal lattices, and other audiophile nonsense.

The quality of this preamp comes from the design, and like any good open hardware project, [skrodahl] has made the schematic, PCB, and layout of this preamp completely open. It’s a great preamp, and a great entry for the Hackaday Prize.

High Performance Crystal Radio

When you think of a crystal radio, you probably think of something simple maybe built out of household scraps. Not if you are [Chris Wendling]. He recently posted a video (see below) of his high-performance crystal set. He doesn’t take any shortcuts: he has several hundred feet of antenna wire, and uses a cold-water pipe ground system. With no amplifier, a strong signal input is crucial.

The radio has four subsystems: an antenna tuner, a bandpass filter, a detector, and a powered audio output system. He also has a truly enormous system of speakers on the ceiling–this isn’t the crystal radio you made in the boy scouts.

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Smartphone TV Remote Courtesy Of Homekit And ESP8266

Good grief, this smartphone-to-TV remote really drives home how simple hardware projects have become in the last decade. We’re talking about a voltage regulator, IR LED, and ESP8266 to add TV control on your home network. The hardware part of the hack is a homemade two sided board that mates an ESP with a micro-USB port, a voltage regulator to step down fom 5 to 3.3 v, and an IR LED for transmitting TV codes.

Let’s sit back and recount our good fortunes that make this possible. USB is a standard and now is found on the back of most televisions — power source solved. Cheap WiFi-enabled microcontroller — check. Ubiquitous smartphones and established protocols to communicate with other devices on the network — absolutely. It’s an incredible time to be a hacker.

Television infrared remote codes are fairly well documented and easy to sniff using tools like Arduino — in fact the ESP IR firmware for this is built on [Ken Shirriff’s] Arduino IR library. The rest of the sketch makes it a barebones device on the LAN, waiting for a connection that sends “tvon” or “tvoff”. In this case it’s a Raspberry Pi acting as the Homekit server, but any number of protocols could be used for the same (MQTT anyone?).

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Waste Shark Aims To Clean Our Harbours And Oceans

Drones are adding functionality to our everyday lives, and automation is here to help humanity whether we’re ready for it or not. In a clever combination of the two, [Richard Hardiman] of RanMarine has developed small drone-boats that scoop up garbage from the ocean — he calls them ‘Waste Sharks.’

The two models — slim and fatboy — aim to collect up to 1,100 pounds of garbage apiece in the ‘mouths’ just below the water’s surface. The Waste Sharks are still restricted to remote control and are only autonomous when traveling between waypoints, but one can see how this technology could evolve into the “Wall-E of water.”

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Retrotechtacular: Railroads In The Jet Age

The front of the Soviet jet train on a monument in Tver, Russia. By Eskimozzz [PD], via Wikimedia Commons.
The front of the Soviet jet train on a monument in Tver, Russia. By Eskimozzz [PD], via Wikimedia Commons.
It started with one of those odd links that pop up from time to time on Hacker News: “The strange and now sadly abandoned Soviet Jet Train from the 1970s“. Pictures of a dilapidated railcar with a pair of jet engines in nacelles above its cab, forlorn in a rusty siding in the Russian winter. Reading a little further on the subject revealed a forgotten facet of the rivalry between Russians and Americans at the height of the Cold War, and became an engrossing trawl through Wikipedia entries, rail enthusiast websites, and YouTube videos.

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