Power outage? For the average citizen it’s very easy to take electricity for granted. Go a few hours or more without it though, and you’ll suddenly be reminded just what a luxury it is. During an emergency situation, sometimes you have to come up with alternative methods to get the job done. This human powered cell phone charger is a great example.
Using just a few ordinary around the house items, [The King of Random] turned a cordless electric drill into a human powered electrical generator. If the drill is run in reverse and cranked by hand, the generated energy can be transferred through the battery terminals to a connected device. So, he cut a USB charger cable in half and wired it up to the terminals to be able to charge his cell phone. Some yarn, a salad fork, a mixing beater, a scrap 2″x4″, some aluminum foil, and scotch tape were the only other materials he used. Using this technique, a totally dead phone battery was charged in around 3 hours.
Remember that this method is only intended to be used in an emergency, not as every day practice. Using these methods could potentially overheat or damage your gear, so be careful.
Check out the MacGyver worthy video tutorial after the break.
Continue reading “Human powered emergency cell phone charger”
We know exactly what [Dan] is going through. We also bought a cheap wireless doorbell and are plagued by the batteries running down. When that happens, the only way you know is when people start pounding on the door because you’re not answering the bell. Well no more for [Dan]. He built a backup system which monitors the voltage of the batteries on the chime unit.
You can see the small bit of protoboard he used to house the microcontroller and the UI. It’s an ATtiny13 along with a green LED and a single push button. The idea is to use the chip’s ADC to monitor the voltage level of the pair of batteries which power the chime. When it drops below 3V the green LED will come on.
First off, we wish these things would come with better power supply circuits. For instance, we just replaced the CR2032 in an Apple TV remote and measured the voltage at 2.7V. That remote and the chime both run from a 3V source. Can’t they be made to work down to 1.8V? But we digress.
In addition to monitoring voltage [Dan’s] rig also counts the number of times the chime has rung. Every eight seconds it flashes the count in binary, unless he presses the red button to clear the count. This is shown in the video after the break. We guess he wants to know how many times this thing can be used before running the batteries down.
Seriously though, for a rarely used item like this how hard would it be to use ambient light harvesting to help save the batteries? Looking at some indoor solar harvesting numbers shows it might be impossible to only power this from PV, but what if there was a super-cap which would be topped off with a trickle from the panels but would still use the batteries when that runs down?
Continue reading “Wireless doorbell battery monitor”
“I don’t understand, you don’t have the technology.” OK, so it’s not actually a futuristic tool with the same capabilities as the one off the hit TV series Dr. Who, but this homemade “sonic screwdriver” is a multifunction device that’s pretty cool nonetheless.
Created around an Arduino Pro Mini, [Gunther] really one-upped the last screwdriver we featured. Built in functions include: brown note tone generator, dog whistle, EMF meter, flashlight, IR universal remote, laser pointer, ohm meter, sound level meter, voltage detector, and a voltage meter. You can also have an electromagnet or output voltage supply if you want. If that wasn’t enough, it can even play the theme song from Star Wars! Whew. That’s a mouthful of functionality.
Although he has posted the Arduino code, you’ll have to keep an eye on his site for more details if you want to create your own. He’s mentioned that he’s working on blue prints and a full parts list… Awesome. Now where’s that lock pick function?
Check out a video showing off some of the features after the break.
Continue reading “Real multifunction “Sonic Screwdriver””
SMD components may be a little challenging for the home builder – even though the’re inordinately practical for homebrew PCBs – but if you play around with electronics and solder long enough, you’re eventually going to run into the horrors of BGA parts. Instead of convenient pins, BGA parts have tiny metallic balls on which solder is applied, a board is thrown through a reflow oven, and hopefully at the end, everything works. Sometimes these balls corrode or otherwise need to be reflowed. This isn’t an easy process, so [Edmar] came up with his own BGA rework station that costs much less than commercial offerings.
[Edmar]’s build began when he wanted to repair a graphics card. A common error on his Amilo XI2428 graphics card is having the small balls on the underside of the chip corrode, leaving the user with a non-functional graphics card. Towel trick notwithstanding, the easiest way to fix this error is to heat up the card to above the melting point of solder, removing the chip, and resoldering it with careful application of solder paste.
[Edmar]’s reflow station is made of an electric skillet for the bottom of the board, an infrared lamp for the top side of the board, and control circuitry constructed from an ATMega128, temperature sensors, and a huge power supply. The temperature is controlled via USB by a computer, allowing [Edmar] to set a temperature profile as recommended by the BGA chip’s data sheet.
Right now, removing a BGA chip works great, but [Edmar] is still working on the tech necessary to replace a BGA chip on a board.
This project most certainly has some of Trailer Park Boys rolled into it. We say that because the living room is the only place this will ever been used and this guy’s reaction to getting shocked is exactly how [Ricky] would respond.
The sword on the left has an electronic stun mechanism built into it. it works by energizing two blades which are separated by nylon bolts and spacers. Look closely at the tip and you’ll see the blue glow which indicates high voltage. To shock your victim you have to touch them with both blades at the same time. This is demonstrated in one of the videos after the break. But the real pain comes when [Jonathan] — the guy who built the stun sword — touches it on either side with this pair of blades. His body completes the connection and his NSFW language tells the tale of how it feels.
This thing seems to pack a bit more of a punch than our own stun-gun enabled quadcopter.
Continue reading “Shock sword works best on foes who fight with multiple blades”
They’re edible, yes. But they don’t light up. That’s fine with us, since the process [Becky Stern] used to make these gummy candy LEDs taps into several techniques handy to have under your belt.
The first part shown in her video (embedded after the jump) is to make a mold for the candies. You probably have a few bags of LEDs in your parts bin. Those along with a trough made of foam core come together to create the form for the silicone mold. After mixing, pouring, and hardening, [Becky] peels the silicone off of the LEDs and sends it through the oven to make it food-safe. Mixing up the candy uses simple ingredients (gelatin, water, and ascorbic acid) but you’ll need to follow the methodology closely to get the taste and clarity you’re used to. Syringes are used to fill the tiny voids in the mold before adding leads which were 3D printed using PLA.
These will be a huge hit at your next hackerspace meeting!
Continue reading “Fabricating edible LEDs”
Those of us that run Linux on a modern or nearly-modern PC know that it’s a capable operating system. It’s also (at least in my case with Ubuntu) extremely easy to install on a semi-modern computer. On a mid-90s era PowerMac 7200, things aren’t quite so simple.
In a testament to both his technical ability, and possibly even more so his tenacity, [Chris] was able to get Debian 6.07 running on a PowerMac destined for destruction. He had slated a few hours to upgrade this 56 Megabyte monster, but it turned out to be a several-day event. Those that are well-schooled in Linux may find the hairy details useful, and some more background can be found in part one. This project was a stepping-stone to something else, so we’re anxious to see what the end result is.
If you find this interesting, feel free to check out the retro edition of our site. It’s not entirely about ancient computers, but it can hopefully be displayed on one.