Giving An ATX Bench Supply The Case It Deserves

July 20, 2012 by Mike Szczys 31 Comments

Your bench supply doesn’t need to look sad just because you’re using an ATX power supply instead of a commercial product. Follow [Ian Lee’s] example and you could have beautiful wooden enclosures for the tools in your own shop.

The woodworking skills used here aren’t all that advanced, but you need to have a knack for it so we suggest running some test pieces before you start the actual build. [Ian] ran a dado for the front and back panel in each piece of the wood sides. At each corner the inside of the the pieces were mitered at 45 degrees. To put it all together he laid the pieces end to end on a the work bench, then applied painters tape to the outside of the joints. This holds the joints together so that he can flip the collection over, apply glue, and then start hinging the sides into place. It’s almost like rolling up a box.

As with other ATX supply projects we’ve seen [Ian] designed this so that the PSU can be swapped out later if necessary. Instead of wiring his own cable harness he used an ATX breakout board. To get the interface layout he wanted he mounted the banana jacks separately and just ran jumper cables back to that board.

Cutting Islands Into Copper-clad PCBs With A Drill

July 20, 2012 by Mike Nathan 18 Comments

If you’re looking to build some small radio circuits, or if you are simply seeking a new look for your PCBs, you might want to check out what YouTube user [AndyDaviesByTheSea] has been working on lately. He has been building RF circuits as of late and was searching for a better way to create islands or “lands” on copper-clad PCBs.

He says that these sorts of islands are traditionally cut into the PCB with a scalpel or file – hardly an efficient process. [Andy] did a little experimenting and found a great way to quickly and precisely cut lands with a drill. Borrowing a bit of metal from an old VHS tape, he crafted a circular land cutter with a metal file. When mounted as a drill bit, his cutter produces clean, shallow cuts which create perfect lands on which to solder his components.

The only drawback to this method is that [Andy] found his bits were being dulled by the fiberglass boards pretty quickly. His solution was to carefully grind a broken heavy duty drill bit to do the task, which he says works even better than his original cutter.

Repurposing Server PSU For Your Charging Needs

July 17, 2012 by Mike Szczys 21 Comments

That grey box at the top of the photo is a modular power supply unit for a rack-mounted server system. [Sebastian] decided to repurpose it as a charging source for his RC batteries. He chose this HP DPS-600PB because of its power rating, efficiency, and you can get them at a reasonable price.

This is an active power factor corrected (APFC) PSU, which he says draws 40% less current than the non-APFC variety. Since he sometimes charges batteries in the field from a generator this is a big plus. But a bit of modification is necessary before it can be used as a source.

Since this is a rack device it has a set of connectors on the back. For power there are spade connectors which mate with a fin on the rack. He soldered positive and negative leads between the spades to interface with the battery chargers. The PSU won’t fire up if it’s not in the rack, so some jumper wires also need to be added connecting three of the interface pins.

With his modding all worked out he went on to use two PSUs for a 24V source, housing them to a nice carrying case while at it.

Dealing With The Horrors Of PDFs By Binding Your Own Books

July 16, 2012 by Brian Benchoff 66 Comments

Looking at a few PDFs of data sheets, journal articles, or even complete books can be a pain. Not only do you have to deal with the torment of a PDF reader (we’re looking at you, Adobe), but a purely electronic document misses the beautiful tactile interface available in dead tree format. [samimy] put together an amazingly professional video showing us how to turn our convenient yet unwieldy PDFs into paperback books, perfect for a very accessible off-line reference.

[samimy]’s build is basically a few pieces of wood and C clamps designed to compress the printed PDF together. After drilling a few holes along the spine, he stitches the pages together with very strong thread and applies a little glue to the spine. After removing the pages from the press, [samimy] applied a piece of tape to the spine and had a very nice looking paperback book.

While [samimy] is using his binding jig for data sheets, we see no reason why a more prodigious tome couldn’t be created with his rig. A few pages of marbled paper and a leather cover would result in a beautiful and functional work of art that will be around long after you’re gone.

Android Oscilloscope Built From Parts Just Lying Around

July 14, 2012 by Brian Benchoff 36 Comments

So you need to debug a circuit and you don’t have an oscilloscope. That’s not a problem thanks to [retronics] $0 Android oscilloscope, made with parts he just happened to have lying around.

The heart of every modern oscilloscope is the ADC – the chip that takes analog input and outputs a digital signal. Every Android device has one of these converters connected to the microphone port. All [retronics] needed to do was solder up a 3mm headphone jack, wire in a few resistors, and attach a pair of alligator clips. After installing an oscilloscope app, [retronics] had a half decent ‘scope.

Yes, this is truly a poor man’s oscilloscope, and [retronics] probably won’t be debugging high frequency RF circuits with his Android microphone jack anytime soon. Low frequency stuff such as audio is where this ‘scope really excels; even more so if a small preamp is thrown into the mix.

You can check out [retronics]’ build after the break. Sure, it’s not something for precise and calibrated measurement, but sometimes you only need a tool that will do the job.

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Hacking A Parallel Port Flash Memory Programmer

July 14, 2012 by Mike Szczys 12 Comments

[Pulko Mandy] doesn’t use his flash ROM programmer very often, but he does use it. When he tried to get support for a new chip and the manufacturer suggested he just buy a newer version he decided to hack the programmer and it’s software instead.

This device connects to the parallel port and was intended for use with MS-DOS systems (no wonder there’s no longer support from the company). The board uses logic chips to add read and write function. So the first step was to analyze how they connect together and come up with a set of commands. While at it he also made some changes to the board to bring the voltage more in spec and ensure the logic levels on the parallel port met the correct voltages.

His plan was to use the board with a Linux system so the parallel port interface can stay. He used what he learned from the hardware inspection to write his own interface in C++. It works with a chip he was able to use under the MS-DOS software, but he hasn’t gotten it to work with the chip that sparked this adventure. If you’re familiar with how the AT29C040A works please consider lending a hand.

Sorting Resistors With Speech Recognition

July 13, 2012 by Brian Benchoff 21 Comments

If you’ve ever had to organize a bunch of resistors, you’ll know why [Anthony] created EESpeak. It’s a voice-controlled component look up tool that calculates a component value by listening to you read out color code bands.

In his demo video of EESpeak, [Anthony] reads off the color bands of several resistors whilst the program dutifully calculates and displays the value. [Anthony] also included support for calculating the value of capacitors and inductors by speaking the color bands, as well as EIA-96 codes for SMD parts.

In addition to taking speech input and flashing a component value on the screen, EESpeak also has a text-to-speech function that will tell you what a component without ever having to look at your monitor.

Even though the text-to-speech function seems a little cumbersome – it takes much longer for a computer to speak a value than to display it on the screen – using voice recognition to calculate component values is an awesome idea. With an extremely limited vocabulary the computer has to understand, the error rate of EESpeak is probably very low.

You can check out [Anthony]’s demo video after the break, and of course download the app on his blog.

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