Mapping Out The LEDs On An Outlet Tester

August 9, 2022 by Tom Nardi 13 Comments

The concept of an outlet tester is pretty simple: plug the gadget into a suspect wall receptacle, and an array of LEDs light up in various patterns to alert the user to any wiring faults. They’re cheap, reliable, and instantaneous. Most people wouldn’t give them much more thought than that, but like any good hacker, [Yeo Kheng Meng] wanted to know how these devices worked.

After picking up a relatively advanced model that featured an LCD display capable of showing various stats such as detected voltage in addition to the standard trio of LEDs, he started by using some test leads to simulate various fault conditions to understand the basic principle behind its operation. The next step was to disassemble the unit, which is where things went briefly sideways — it wasn’t until [Yeo Kheng Meng] and a friend had nearly cut through the enclosure that they realized it wasn’t ultrasonically welded liked they assumed, and that the screws holding it together were actually hidden under a sticker. Oops.

The write-up includes some excellent PCB shots, and [Yeo Kheng Meng] was able to identify several components and ascertain their function. He was even able to find some datasheets, which isn’t always such an easy task with these low-cost devices. Unfortunately the MCU that controls the device’s more advanced features is locked away with a black epoxy blob, but he was able to come up with a schematic that explains the rather elegant logic behind the LED display.

This isn’t the first time [Yeo Kheng Meng] has taken apart an interesting piece of hardware for our viewing pleasure, and given the fine job he does of it, we hope it’s not the last either.

Smart Plugs Don’t Save You Energy, But Don’t Consume Much Either

May 29, 2018 by Bob Baddeley 60 Comments

Amazon Alexa, Google Home, and just about every electronic device manufacturer are jumping on the bandwagon of connected devices. They promise us the ability to turn on our toaster from another room, unlock our doors just by shouting at them from outside, and change the channel on our TV through perfectly enunciating a sentence instead of mashing the buttons on our remotes like chumps. And yet, despite all this new-fangled finger-less control, there is an unanswered question: does this technology save us energy in the long run?

For years we’ve been hearing about vampire power and all the devices in our home that sit in standby, waiting for their masters to turn them on, quietly burning power to listen for that signal to wake. Fortunately the One Watt Initiative and general awareness and design for energy savings has cut out a lot of this phantom load. So how does the smart home, which essentially adds a bunch of connected vampires to our base load, end up saving money in the long run? And is it better than other alternatives or just good habits? I put these questions to the test with today’s smart power strips and controllable outlets.

Continue reading “Smart Plugs Don’t Save You Energy, But Don’t Consume Much Either” →

Hackaday Links: October 1, 2017

October 1, 2017 by Brian Benchoff 37 Comments

Remember when you first saw a USB port in a standard wall outlet? It was a really great idea at the time, but how’s that 500mA charge holding up now? Fresh from a random press release, here’s a USB 3.0 wall outlet, with USB A and C ports. 5A @ 5V. Future proof for at least several years, I guess.

This is what you call ‘pucker factor’. An Air France A380 traveling from CDG to LAX suffered an uncontained engine failure somewhere over Greenland. Everyone on board is fine, except for the fact they had to spend the night in Goose Bay, Canada. Want the best Twitter/YouTube account of being a passenger? Here you go. Want to know why it landed in Goose Bay? This video is about ETOPS which really doesn’t apply in this instance but it’s a sufficient introduction to diverting airplanes after engine failures.

There are mysterious pylons going up alongside bridges and tunnels in NYC (auto-playing video). No one knows what they are, and the transportation board for New York is hiding behind a cloud of secrecy. We do know there are ‘fiber optics necessary for Homeland Security items’ inside, so place your bets. It’s facial recognition, or at the very least license plate readers. You know, exactly what New York and dozens of other cities have been doing for years.

Did somebody lose a balloon? A Raspberry Pi high-altitude balloon was found on the beach in south-west Denmark.

[Peter] is building an ultralight in his basement. We’ve covered the first part of the build, and we’ve been keeping tabs on him with semi-weekly updates. Now he’s fiberglassed the fuselage and started construction of the wings. Updates of note this week: he’s found a shop with an 8-foot CNC hot wire cutter for the wings. That really cuts down on the build time and it’s actually pretty cheap. One interesting part of this build is a ‘landing gear ejection system’, or a spring thing that allows the landing gear to fall away with the tug of a wire. Why would anyone want a landing gear ejection system? In case he needs to land in a soybean field. A flat bottom means a smoother and more survivable landing. If anyone is still concerned about [Peter]’s safety, this is a put up or shut up situation. Pitch in ten bucks for a parachute if you’re so concerned.

Hoverbike Kalashnikov! What? It’s a guy’s name. No big deal.

Open Hardware Summit is this week in Denver. What will be the highlights of the event? Well, last year, OSHWA announced the creation of an Open Hardware license. This is an all-encompassing license for Open Source Hardware that’s trying to solve some very, very hard problems. Copyright doesn’t work with hardware (except for boat hulls) like it does with software, and this Open Hardware license is the best we’ve got going for us. We’re going to get an update on how well this license is propagating. Also on deck for Summit attendees is a field trip to Sparkfun and Lulzbot. Want to see the world’s second largest 3D printer bot farm? It’ll be awesome.

Fixing Faulty But Genuine Apple Power Adapters

November 1, 2014 by Brian Benchoff 51 Comments

The standard power adapter for Apple laptops is a work of art. The Magsafe connector has saved more than one laptop owned by the Hackaday crew, and the power brick with interchangeable plugs for different countries is a work of genius. Being a miracle of modern manufacturing doesn’t mean Apple gets it right all the time; the UK adapter doesn’t use the ground plug, leading to the power supplies singing at 50 Hz when plugged in. [Gareth] had had enough of the poor design of his charger and decided to fix it.

The Apple power adapter has two obvious connections, and another shiny metal disk meant for a connection to Earth. In most of the Apple charger ‘extension cords’, this earth connection is provided by the cord. In the smaller plug adapters – even ones where space is not an issue, like the UK plug – this connection is absent.

To fix this glaring oversight, [Gareth] shoved some aluminum foil where the earth terminal on the plug should go. A hole was drilled through the plug to connect this foil to the Earth socket terminal, and everything was covered up with kneadable epoxy.

No, aluminum foil probably won’t do its actual job of preventing horribleness in the event of an insulation failure or short. It will, however, silence the 50 cycle hum emanating from the power adapter, and that’s good enough for [Gareth].