Here’s a classic project for the weekend. This KT88 based tube amplifier is surprisingly simple. The parts count is low, but the sound produced by the amplifier is considered quite pleasing. For the budget conscious, there are several optional tubes that can be used in place of the primary KT88.
classic hacks2768 Articles
How-To: Make An RGB Combination Door Lock (Part 2)
In part 1 we showed you how to build your own prototype RGB keypad. Today we’ll show off some new ideas we worked on to create the project and turn it from prototype to fully functional battle station er door lock.
Continue reading “How-To: Make An RGB Combination Door Lock (Part 2)”
Waterproof USB For Underwater Cameras
Underwater camera housings work great – but they are prone to humidity, dirt and dust problems if you open them more often than needed. In order to download the images off of his digital camera between dives, [Matt] decided to add a waterproof external USB port to his housing. He had an extra 5 pin strobe bulkhead installed by Ikelite (makers of excellent housings). Then he spliced on a mini-usb cable for the camera and spliced a standard USB end onto a strobe cable. During dives, the port is closed with an o-ring sealed cap.
Check Washing Vulnerabilities
[vector] sent in some of his other work, but I found his posts(part 1, part 2, part 3 and final thoughts) on check washing experiments pretty interesting. His results should be enough to make you think twice about writing checks. He tested a few different pens and tested them on real check using Acetone and Alcohol as solvents.
PIC Controller Cable Tracer
[Kevin Gorga] submitted this PIC controller based wire tracer to a project contest last year over at circuit cellar.A 125Khz signal is injected to the target cable and a pickup coil is used to detect the field and identify the wires location. You can grab the full project schematics and code here. The rest of the entries are pretty sweet, so be sure to check them out.
Servo Focus And Aim Your Telescope
The idea of using servos to aim a telescope isn’t new, but [John]’s build looks so much like a prop from Johnny Mnemomic that we can’t resist posting it. The goal isn’t so much remote control as it is usability. He added a webcam and a pair of servos to help him fine focus and adjust the elevation of the scope to minimize vibration during those sensitive operations.
Laser Insect Photography Rig
[Marc] sent in this awesome insect photography rig. The camera is manually pre-focused and set for a 30 second exposure at ISO100. The aluminum cylinder in front of the lens is an external shutter mounted with a custom turned lens adapter. It’s used because the built in shutter is too slow for insect capture. The camera/shutter is triggered by a pair of lasers with photo detectors. When both beams are broken, the insect should be in front of the lens. A Garmin GPS provides position information that’s tagged on the image by the Nikon D200. A large photo of the rig is here, while a more detailed writeup on building it is here.
Update: It looks like we covered a previous version of this rig, but the old links are down and we didn’t have a shot of the setup. Oh, and I forgot to mention [Marc] new control box for running this rig.
