Year: 2010

Make Switched-mode Power Supplies Do Your Bidding

August 29, 2010 by 31 Comments

[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. Continue reading “Make Switched-mode Power Supplies Do Your Bidding” →

Art Piece From Board Artwork

August 29, 2010 by 11 Comments

[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

August 29, 2010 by 48 Comments

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.

Continue reading “Seaswarm: We Can Clean Up The Gulf In A Month” →

Beginner Concepts: Analog Circuits

August 28, 2010 by 38 Comments
We look at a lot of projects that have microcontrollers in them. That’s because microcontrollers do cool stuff, but there are still plenty of tricks you can pull off with analog circuits. [Osgeld’s] latest project explores this realm, controlling the discharge of capacitors through an LED. His setup uses just nine components and, if you’ve been collecting broken electronics from your friends and neighbors like a good hacker, you can scavenge all of these parts. Try it, you’ll like it!

Prototyping The Bulbdial Clock

August 28, 2010 by 1 Comment

Evil Mad Scientist posted a story about what went into developing the Bulbdial clock. We think the Bulbdial is one of the best pieces of kit out there for many reasons; using colored shadows for each hand is a brilliant idea, the design is clever and uses a low parts count, and the concentric rings that make it work also add to the aesthetic. But after seeing the original wood prototype it had crossed our minds that developing those circular PCBs isn’t the easiest thing to pull off. To save on board cost, the first run didn’t have the center routed out, but rather used almost-touching holes drilled during manufacture and finished by hand during assembly. They also go on to discuss the use of Charlieplexing to reduce part count and the search for a suitable diffuser for the clock face.

Gas Plasma Pinball Display

August 28, 2010 by 13 Comments

[Whoopjohn] decided to build a driver board for a display he pulled from a pinball machine. You’ve probably seen these used to scroll both score and messages using a total of sixteen 15-segment digits. We’d love to get our hands on one, and you might too but where? [Whoopjohn] notes that these were usually installed two-per machine and the driver boards were run close to their maximum ratings. That means that somewhere there’s a collection of broken machines with working displays. If you do plan to make this happen, you should be able to figure out the circuit based on this commented board layout (pdf).

Tube Preamp With A Dazzling Wood Case

August 28, 2010 by 8 Comments

It’s been a while since we’ve looked in on the world of vacuum tube audio equipment. [Bruce] just finished documenting a tube preamp he built. He actually made a couple of these with slightly different cases but they use the same circuit design. We found his discussion of common errors made when tying into ground quite interesting. It seems that many folks struggle with noise in their circuits because of ground loops. There’s some details about isolating the signal ground from a metal chassis, and also an admonition about not connecting the input or output jacks directly the chassis.
If you like this, don’t miss on of our favorite tube projects, [Bruce’s] Poddwatt.