This machine is capable of shrinking coins. What you’re looking at is actually a 3D model of the Geek Groups impulse generator, which is called Project Stomper. The model is used to explain how induction shrinks a quarter to the size of a dime.
The grey chamber to the left is a reinforced containment device. It’s a safety feature to keep people in the same room as the Stomper safe from flying particles which may result from the forces this thing can put out. You see, it uses a mountain of magnetic energy to compress the edges of a coin in on itself.
As the video after the break illustrates, the main part of the machine on the right starts off by boosting mains voltage using a microwave oven transformer. This gets the AC to 2000V, which is then rectified and boosted further to get to 6000V DC. This charges three huge parallel capacitors which are then able to source 100,000A at 6 kV. When it comes time to fire, the charge is dumped into a coil which has the coin at its center. The result is the crushing magnetic field we mentioned earlier.
This isn’t a new concept, we featured a different coin crusher build in the early years of Hackaday’s existence.
Continue reading “How a quarter shrinker works”
It would be really fun to do an entire hallway of these levitating wireless lights. This a project on which [Chris Rieger] has been working for about six months. It uses magnetic levitation and wireless power transfer to create a really neat LED oddity.
Levitation is managed by a permanent magnet on the light assembly and an electromagnetic coil hidden on the other side of the top panel for the enclosure. That coil uses 300 meters of 20 AWG wire. A hall effect sensor is used to provide feedback on the location of the light unit, allowing the current going to the coil to be adjusted in order to keep the light unit stationary. When working correctly this draws about 0.25A at 12V.
Wireless power transfer is facilitated by a single large hoop of wire driven with alternating current at 1 MHz. This part of the system pulls 0.5A at 12V, bringing the whole of the consumption in at around 9 Watts. Not too bad. Check out [Chris’] demo video embedded after the break.
A similar method of coupling levitation with power transfer was used to make this floating globe rotate.
Continue reading “Levitating lightbulb does it all with no wires”
If you’re in search of a flashlight that can stand up to the elements, or simply looking for an easy way to spruce up your pool for those hot summer nights, check out these rechargeable PVC LED lights. Inspired by a post in Make: Magazine featuring Indestructible LED Lanterns, [John Duffy] decided to take the project one step further.
While he liked Make’s iteration of the waterproof lantern, he thought it would be best to permanently seal the lights for maximum durability. Not satisfied with a one-use light, he equipped the PVC lanterns with a single rechargeable AA battery, step-up circuitry to drive the LED, and an inductive charging coil.
His floating, waterproof lights sport a slightly bigger footprint than their predecessors to house the extra electronics, but we think that’s more than a fair trade off considering they can be charged wirelessly.
Place your Digikey/Mouser/Jameco orders now and check out [John’s] how-to video – you just might get some of these built in time for the weekend!
Continue reading “Mini waterproof LED lanterns charge without wires”
Despite the obvious use of a lot of wire, this project is actually a wireless charging system. [Jared] built it as a way to explore the concepts behind transferring power inductively. Alternating current on one of the white coils induces current on the other. This is then rectified, and regulated for use as a 5V charger. In this case it powers his iPod, but any USB device should work with the setup.
The transmitter uses the power supply from an old laptop as a source. Some filtering and a couple of MOSFETS are responsible for generating the AC current on the transmitting coil. The receiving coil feeds the bridge rectifier. In the writeup that voltage is fed to a 7805 regulator to provide a stable 5V output. However, in the video demo after the break [Jared] shows off the boost converter that he uses on his improved circuit. This way if the voltage drops due to poor alignment of the coils it will still be able to provide a steady output.
We’ve seen the same coil concept used to add wireless charging to cellphones too.
Continue reading “Wireless iPod charger built from scratch”
[Gadre] built his own ATtiny project without using any batteries. It’s an electronic Dice (or die if you’re being critical) which uses induction to charge a storage capacitor to act as the power source. The voltage generator is made from a tube of Perspex which houses a set of rare-earth magnets. At the enter of the tube [Gadre] machined a channel wich accepts about 1500 windings of 30 AWG magnet wire. When someone shakes the tube back and forth the magnet passes the wire, inducing a current. The product is stored in a 4700 uF capacitor, which feeds a boost converter to power the rest of the circuit.
The ATtiny13V that controls the circuit is running its internal RC oscillator at 128 kHz, the lowest setting possible in order to minimize power consumption. After a good shake the user can press a button to roll the die, which is then displayed for several seconds on a group of seven LEDs. See for yourself in the video after the break.
Continue reading “ATtiny Hacks: Look Ma, no batteries!”
Induction cook top provides power too
We’re familiar with induction cook tops but we never thought to power a microcontroller with one. [Thanks Hadez]
We’ve been big fans of the chain reaction demonstration using ping-pong balls and mouse traps ever since we saw [Mr. Wizard] do it back in the day. If you don’t know what we’re talking about, check out this demonstration that is analogous of a fission reaction. [Thanks nateL]
Phone tripod enclosure
If you’re interested in using your smart phone for some photography, [Mike] has a nice wood and elastic mount for an iPhone which you might try yourself.
Bicycle snow tires
Admittedly we’re a bit late on this one. But keep it in mind for next year: you can use some zip ties for added traction on your bike when it snows. [Thanks Rob]
Now you can BE mario
A little Kinect script lets this gentleman play Super Mario Bros. with his body. Now you can have all the fun that goes along with being a pixellated character stuck in a two-dimensional environment (plus, there are shrooms). [Thanks Das_Coach via Slashdot]
[Mirslav] built this fuidyne engine himself. This is a single piston model but you won’t find any precision milled cylinders here. That’s because fluidyne engines use columns of water as the pistons. In the rig shown above you can see one metal pipe which serves as the cold side of the loop. There’s another hot pipe underneath the insulation that completes the circuit. When that pipe is heated it causes the air inside the loop to expand, forcing the liquid on the open side of the plastic tubing (to the left) to rise. Once that air escapes to the other side of the circuit the water piston in the open tube falls back again. This results in continuous oscillation that can be used to drive a pump using a pair of check valves.
We’ve embedded a couple of videos after the break. You’ll see the system tested by heating one pipe with a hot air gun. But the example seen above uses an induction coil to bring the heat.
Continue reading “Simple fluidyne engine”