USB HDD Enclosure To DVD Connector

This is a “why didn’t I think of that?” idea. [Alec] needed a way to connect an IDE DVD drive using USB. Rather than order a connector he pulled the circuit board out of an old USB hard drive enclosure and connected to his DVD drive. Bang, recognized and running.

This will prove extremely handy if you have a netbook without an optical drive. We’ve used Unetbootin to move Linux ISO images to a thumb drive in the past. In addition to getting around the lack of an optical drive, this saves burning the data to a piece of plastic. But, you should be able to use this with a Leopard retail DVD instead of a 16GB thumb drive for a Hackintosh conversion. That means you could install Leopard on a netbook without needing a Mac to transfer the disk image to your thumb drive first.

120v Switching

[Kenneth] built a 5v controlled power outlet inside of a junction box. We’ve seen plenty of projects that can switch 120v outlets using 5v logic for refrigerator controllers, lighting controllers, or grow systems, but they almost always use solid state relays to facilitate the switching. This iteration uses mechanical relays along with the necessary protection circuitry. The project is housed in an extra deep single-gang box and allows for individual switching of the two outlets. You can see this connected to an Arduino switching two lamps after the break.

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Adafruit Eagle Library

We love it when a PCB comes out right the first time. We’re careful enough with our designs that if something is wrong it’s usually a footprint problem, like we picked the wrong package for the components. Adafruit is helping to make the design process easier by sharing their Eagle library. Like the Eagle library version control we saw earlier in the month, this library is housed on github making it easy to stay up-to-date. The library includes many components (switches, crystals, IC’s, etc.), and fixes some prolbem-footprints, like 0805 surface mount pads.

Servo Hacked Linear Actuator

[AntonB] has modified a servo into a powerful linear actuator (think: changing rotational motion into linear motion). The process is simple enough, modify a servo for continuous rotation and then add the custom built actuating shaft. You do of course lose the precision of the servo, but a small price to pay to be able to lift ~20 pounds straight up. Inspiration for such a cheap solution came from his Planetary Surface Exploration Rover. Check out a video of both after the break.

[Thanks Eric]

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Makita Battery Pack Repair

[Rob] grew tired of his Makita power tool battery packs dying so he figured out how to repair them himself. The video after the break walks us through the process which starts by cracking open the case. Inside there is a controller board and a battery of ten cells. [Rob] has pinpointed these battery failures to just the first cell, which is confirmed by measuring the cell voltages with a multimeter. The first cell in the demonstration battery reads zero volts and needs to be replaced. For some reason he’s got heck of a lot of these cells on hand, at the end of the video he shows off a massive block of them that provides one half of a kilowatt-hour of power.

To complete the resurrection he removed the control circuitry from the integrated PCB. It seems that the microcontroller on the battery’s PCB monitors it and bricks them when it thinks the life of the unit has ended. By hacking a charger he can now balance-charge the altered battery packs and get more use out of them before they hit the landfill.

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Don’t Put That EPROM In Your Mouth!

[Jeremy] had some chips on hand that included EPROM.  We’re not talking about EEPROM, we mean EPROM that need a UV light source to erase. Most people don’t want to drop a few hundred dollars on a dedicated EPROM eraser, there must be another way.

Boy, EPROM really suck. But so do pacifiers and he already had a solution for exposing those to UV. He pulled out his $30 UV pacifier cleaner and tossed the chip inside. Two times through the cleaning cycle and the data was gone. We’ve looked into using UV LEDs to do the job but some experimentation shows that it doesn’t work. These pacifier cleaners are cheap and easy to get a hold of. The real question is are you still using chips that require UV for erasing?

Version Control For Eagle

[Jeff] set up version control for Eagle libraries and projects. He mentions that Eagle has become the standard for open source hardware projects and he’s absolutely right. We use it for our projects, and we’ve grown to expect that the posts we feature have Eagle files available in most cases.

But Eagle falls short in its library management. There is some amazing work from SparkFun to support a usable parts library, but who hasn’t added parts themselves? [Jeff] setup libraries using github so that changes and additions to the libraries can benefit all and cut the amount of time spent making custom footprints for new components and packages.