Hackaday links: August 29, 2010

Hotel room door lock picking

Here’s further proof that you should never leave anything of value in your hotel room. We’re not worried about someone getting in while the room is occupied. But these methods of defeating the chain lock and opening the door without a keycard (YouTube login required) do show how easy it is for the bad guys to steal your stuff.

iPhone frequency generator

Need one more way to make that iPhone a useful lab tool? Why not use it as a frequency generator. Start with a free app and mix in an audio cable with test leads and you’re in business.

Drag Soldering

[Andrei] sent us a link to a video about drag soldering. This is a method of soldering fine-pitch chips using a small bit of solder and a fat solder tip. The link he sent is dead now but we found another great example of the process. We were just using this method earlier in the week to solder a TSSOP38 package for an upcoming project and it worked like a charm.

Laser etched PCB

Here’s some art in PCB form thanks to a laser. We thought this might be interesting to share after seeing those art pieces made from old circuit boards. This example is laser etched, but not directly. As you probably guessed, the copper clad board is coated with resist and the laser etches some of it away. Whatever got zapped by the laser dissolves when the board is placed in acid, leaving [Riley Porter's] art behind.

From RepStrap to RepRap; a 3D printer is born

[Gavilan Steinman] just printed and assembled his own RepRap machine and filmed the process. This isn’t news but we found it very interesting to watch. He started with a RepStrap, a rapid-prototyping 3D printer that as built by hand instead of printed by a similar machine. This is the seminal step in the self-replicating process.

From there he prints an extruder head which improves the quality of the parts the RepStrap can produce. We then see time-lapse footage of the printing process for a Mendel unit, the second generation of RepRap machines. We’ve embedded the video after the break. It’s a great way to spend ten minutes on a Sunday afternoon.

[Read more...]

Make switched-mode power supplies do your bidding

[Ken] needed to supply 3.3 volts of regulated power. He started by using a linear voltage regulator but after a few calculations he discovered that 72% of what he put in was lost to heat. The solution to this is a switched-mode power supply. Rather than burn off energy through a voltage divider, an SMPS turns the power on and off very quickly to achieve the desired voltage.

A car charger-type USB regulator was chosen as [Ken's] donor device. He figured that making adjustments to the resistors inside would affect the output voltage and he was right. He adjusted the potential divider and ended up with a steady 3.295V.

We asked him to share the schematic that he put together from studying the board and he came through. See that and get the link to the DC-DC converter datasheet after the break. [Read more...]

Art piece from board artwork

[Theo Kamecke] is an artist who produces striking pieces using printed circuit boards. We’ve seen PCBs used as faux stained-glass before, but [Theo's] craftsmanship stands apart from everything we’ve seen. His webpage has at least one piece that sites the usage of vintage 1960’s circuit boards, but we wonder if he doesn’t design some of these to suit his work. Either way, we’d love to see him take on the finish work for that mechanized expanding round table we saw back in June. See more of his work on his photostream.

[Photo Credit]

[Thanks Mowcius]

Seaswarm: we can clean up the Gulf in a month

Want to clean up the Gulf of Mexico oil spill in one month? Seaswarm says it can be done with 5000 floating robots.

As the name implies, the project uses swarm robotics. Each unit draws power from the sun, and drags around a conveyor belt of oil absorbent nanofabric that doesn’t get wet in water. Once the fabric is saturated with crude it can be removed using heat; not a task the swarm can do by itself. But get this: after separating oil from nanofabric both can be used again. That means you get the environmental benefit of cleaning up the Gulf, not throwing away your collection medium, and the oil is once again a usable commodity. Sounds like a lot of high promises, but take a look at the video after the break and decide for yourself.

[Read more...]